ISSN e:2007-4034 / ISSN print: 1027-152X

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     Vol. 11, issue 2 July - December 2005   Creative Commons License

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     Vol. 11, issue 2 July - December 2005  

 
  

BIOTECHNOLOGY OF TREHALOSE IN PLANTS

BIOTECNOLOGIA DE LA TREHALOSA EN LAS PLANTAS

José Oscar Mascorro-Gallardo; N. Avonce; G. Iturriaga

Keywords: Arabidopsis, abiotic stress, yeast, Selaginella.

10.5154/r.rchsh.2005.04.020

Received: 0000-00-00
Accepted: 0000-00-00
Available online: 2016-07-01
Pages:193-202

Trehalose (a-D-glucopyranosil-(1,1)-a-D-glucopyranoside) is a non-reducing disaccharide, formed by two molecules of glucose. It is present in a broad spectrum of different organisms playing roles as reserve carbohydrate and conferring tolerance to abiotic stress. It posses broad biotechnological applications, since it is able to protect proteins and biological membranes, which allows its use for preserving foods, enzymes, vaccines, cells, tissues and organs, and can also substitute sucrose in confitery and bakery. The presence of this disaccharide in plants, has several functions, where besides of being an osmoprotectant it plays an essential role in several developmental stages, such as embryo maturation and flowering. Trehalose also is involved in regulating carbon metabolism and photosynthesis, and its accumulation is related with tolerance to abiotic stresses. Finally, this sugar seems to perform an essential role in the plant-microorganism interaction.

....

Trehalose (a-D-glucopyranosil-(1,1)-a-D-glucopyranoside) is a non-reducing disaccharide, formed by two molecules of glucose. It is present in a broad spectrum of different organisms playing roles as reserve carbohydrate and conferring tolerance to abiotic stress. It posses broad biotechnological applications, since it is able to protect proteins and biological membranes, which allows its use for preserving foods, enzymes, vaccines, cells, tissues and organs, and can also substitute sucrose in confitery and bakery. The presence of this disaccharide in plants, has several functions, where besides of being an osmoprotectant it plays an essential role in several developmental stages, such as embryo maturation and flowering. Trehalose also is involved in regulating carbon metabolism and photosynthesis, and its accumulation is related with tolerance to abiotic stresses. Finally, this sugar seems to perform an essential role in the plant-microorganism interaction.

....
 

THE EFFECT OF TWO ORGANIC AMENDMENTS AND Trichoderma spp. TO CONTROL Sclerotinia spp. IN LETTUCE

EFECTO DE DOS ENMIENDAS ORGÁNICAS Y Trichoderma spp. PARA CONTROLAR Sclerotinia spp. EN LECHUGA

Keywords: Lactuca sativa L., Organic admendments, biocontrol agent, Trichoderma lignorum, Trichoderma harzianum.

10.5154/r.rchsh.2004.08.040

Received: 0000-00-00
Accepted: 0000-00-00
Available online: 2016-07-01
Pages:203-208

The effect of organic matter contained in a biosolid and chicken manure on the establishment and performance of Trichoderma spp. used as biocontrol agents against Sclerotinia spp. in lettuce (Lactuca sativa L. cv. Buba) was evaluated. Population dynamics of Trichoderma spp. was evaluated by the method of counting colony forming units on plaques of Potato-Dextrose-Agar (PDA), and its efficiency to control the disease was measured by visual assessment of the degree of crop damage by Sclerotinia spp. Statistically significant differences observed in population dynamics of Trichoderma spp. were attributed to the influence of the source of the organic matter. The biocontrol agent Trichoderma lignorum was able to use the organic matter of the biosolid and in situ organic matter. Poultry manure and the biosolid were not efficient enough to promote population growth of native Trichoderma species. The damage caused by Sclerotinia spp. was statistically similar in all treatments and less than 25 %, so that the efficiency of T. lignorum and T. harzianum to control the pathogen was proven.

....

The effect of organic matter contained in a biosolid and chicken manure on the establishment and performance of Trichoderma spp. used as biocontrol agents against Sclerotinia spp. in lettuce (Lactuca sativa L. cv. Buba) was evaluated. Population dynamics of Trichoderma spp. was evaluated by the method of counting colony forming units on plaques of Potato-Dextrose-Agar (PDA), and its efficiency to control the disease was measured by visual assessment of the degree of crop damage by Sclerotinia spp. Statistically significant differences observed in population dynamics of Trichoderma spp. were attributed to the influence of the source of the organic matter. The biocontrol agent Trichoderma lignorum was able to use the organic matter of the biosolid and in situ organic matter. Poultry manure and the biosolid were not efficient enough to promote population growth of native Trichoderma species. The damage caused by Sclerotinia spp. was statistically similar in all treatments and less than 25 %, so that the efficiency of T. lignorum and T. harzianum to control the pathogen was proven.

....
 

GROWTH, NUTRITION AND YIELD OF ‘ATAULFO’ MANGO WITH DWARF ‘ESMERALDA’ INTERSTOCK

CRECIMIENTO, NUTRICIÓN Y RENDIMIENTO DEL MANGO ‘ATAULFO’ CON INTERINJERTO DE PORTE BAJO ‘ESMERALDA’

Victor Vázquez-Valdivia; María Hilda Pérez-Barraza; Samuel Salazar-García; E. Becerra-Bernal

Keywords: Mangifera indica L., nutrimental content, tree size.

10.5154/r.rchsh.2004.07.035

Received: 0000-00-00
Accepted: 0000-00-00
Available online: 2016-07-01
Pages:209-213

The effect of ‘Esmeralda’, a dwarf genotype, as interstock on the behavior of ‘Ataulfo’ mango was evaluated. A mango orchard was established using seedling rootstocks; ‘Esmeralda’ genotype was grafted on these rootstocks in lengths of 0, 21 to 30, 31 to 40 and 41 to 50 cm; afterwards ‘Ataulfo’ was grafted. ‘Esmeralda’ interstock affected the size of the trees when compared to the controls. Interstock trees showed a reduction in height, canopy diameter, trunk perimeter and canopy volume. No significant differences were detected in the yield of four harvesting seasons (1996 to 1999); however significant differences were detected in the 2000 season. Trees with interstock of 21 to 30 cm yielded 226 kg while the control trees yielded only 191 kg. Nutritional content was not affected by the interstock. Nitrogen, phosphorus and potassium were found within the normal content range, while a calcium deficiency was found.

....

The effect of ‘Esmeralda’, a dwarf genotype, as interstock on the behavior of ‘Ataulfo’ mango was evaluated. A mango orchard was established using seedling rootstocks; ‘Esmeralda’ genotype was grafted on these rootstocks in lengths of 0, 21 to 30, 31 to 40 and 41 to 50 cm; afterwards ‘Ataulfo’ was grafted. ‘Esmeralda’ interstock affected the size of the trees when compared to the controls. Interstock trees showed a reduction in height, canopy diameter, trunk perimeter and canopy volume. No significant differences were detected in the yield of four harvesting seasons (1996 to 1999); however significant differences were detected in the 2000 season. Trees with interstock of 21 to 30 cm yielded 226 kg while the control trees yielded only 191 kg. Nutritional content was not affected by the interstock. Nitrogen, phosphorus and potassium were found within the normal content range, while a calcium deficiency was found.

....
 

CONTENT OF CAROTENOIDS AND EXTRACTABLE COLORS IN SIX NEW CULTIVARS OF PIMIENTO PEPPERS

CONTENIDO DE CAROTENOIDES Y COLOR EXTRACTABLE DE NUEVOS CULTIVARES EN CHILE PIMIENTO

Vianey Mendez-Trujillo; D. Mendoza-González; Federico Gutierrez-Miceli

Keywords: Capsicum annum sp. carotenoids, pigments

10.5154/r.rchsh.2003.03.023

Received: 0000-00-00
Accepted: 0000-00-00
Available online: 2016-07-01
Pages:215-218

Six cultivars of sweet peppers (‘CHR 9802’; ‘CHR MURZUCH’; ‘CHR 9002’; ‘CHR 9801’; ‘CHR 9803’ and ‘CHR INV’) were evaluated. These cultivars were submitted to 75 ºC for 8 hours to quantify extractable colors in ASTA units, and the spectrophotometric variation in the concentration of red (R) and yellow (A) carotenoids. The results indicated that the cultivar CHR-MURZUCH showed the highest value (190 units ASTA); and the highest carotenoid content of the group (A) (40.2 U·g-1 per dry sample), followed by the cultivate CHR-9802, which had the highest carotenoid content of the group (R) (8.7 U·g-1 per dry sample) compared with the other varieties. The use of drying temperature of 75 ºC probably generated a decrease in the total content of carotenoids and extractable colors.

....

Six cultivars of sweet peppers (‘CHR 9802’; ‘CHR MURZUCH’; ‘CHR 9002’; ‘CHR 9801’; ‘CHR 9803’ and ‘CHR INV’) were evaluated. These cultivars were submitted to 75 ºC for 8 hours to quantify extractable colors in ASTA units, and the spectrophotometric variation in the concentration of red (R) and yellow (A) carotenoids. The results indicated that the cultivar CHR-MURZUCH showed the highest value (190 units ASTA); and the highest carotenoid content of the group (A) (40.2 U·g-1 per dry sample), followed by the cultivate CHR-9802, which had the highest carotenoid content of the group (R) (8.7 U·g-1 per dry sample) compared with the other varieties. The use of drying temperature of 75 ºC probably generated a decrease in the total content of carotenoids and extractable colors.

....
 

SOMATIC EMBRYOGENESIS IN POTATO CVS. ATLANTIC AND FRITOLAY-1867

EMBRIOGÉNESIS SOMÁTICA EN PAPA CVS. ATLANTIC Y FRITOLAY-1867

M.C. Sánchez-Enciso; José Luis Rodríguez-de la O; G.P. Zárate-de Lara; Agustín de Jesús López-Herrera; J. S. Barrales-Domínguez; G. González-de la Cruz

Keywords: Solanum tuberosum L., thidiazuron, 2,4-dichlorophenoxy acetic, in vitro cultures.

10.5154/r.rchsh.2003.12.086

Received: 2003-12-16
Accepted: 2004-09-03
Available online: 2016-07-01
Pages:219-224

The use of in vitro cultivation of vegetable cells and tissue to obtain somatic embryos is considered to be an efficient propagation method for a number of important agronomical and horticulture species. Among these is Solanum tuberosum L. The main objective of this study was to obtain embryogenetic cells from explants from potato leaf mesophyll, cultivars Fritolay-1867 and Atlantic. Formation of somatic embryos of Fritolay-1867 was promoted when, in the culture medium, thidiazuron was used at a concentration of 1.0 mg·liter-1 was used as a growth regulator. The embryos were cultivated in a Murashige and Skoog medium complemented with vitamins, carbohydrates, and antioxidants, and initially incubated during eight weeks of darkness and later with photoperiods of 16 h using 44 mmol·s-1·m-2 light intensity at a temperature of 26±1 °C for 60 days. At nine weeks, the first indication of embryonic germination was obtained with 5 % and development of complete plants.

....

The use of in vitro cultivation of vegetable cells and tissue to obtain somatic embryos is considered to be an efficient propagation method for a number of important agronomical and horticulture species. Among these is Solanum tuberosum L. The main objective of this study was to obtain embryogenetic cells from explants from potato leaf mesophyll, cultivars Fritolay-1867 and Atlantic. Formation of somatic embryos of Fritolay-1867 was promoted when, in the culture medium, thidiazuron was used at a concentration of 1.0 mg·liter-1 was used as a growth regulator. The embryos were cultivated in a Murashige and Skoog medium complemented with vitamins, carbohydrates, and antioxidants, and initially incubated during eight weeks of darkness and later with photoperiods of 16 h using 44 mmol·s-1·m-2 light intensity at a temperature of 26±1 °C for 60 days. At nine weeks, the first indication of embryonic germination was obtained with 5 % and development of complete plants.

....
 

PRELIMINARY ANALYSIS OF CAROTENOIDS AND PHENOLIC COMPOUNDS IN SAPOTE MAMEY [Pouteria sapota (Jacq.) H.E. Moore & Stearn] FRUIT

ANÁLISIS PREELIMINAR DE CAROTENOIDES Y COMPUESTOS FENÓLICOS EN FRUTOS DE ZAPOTE MAMEY [Pouteria sapota (Jacq.) H.E. Moore & Stearn]

Irán Alia-Tejacal; Ramón M. Soto-Hernández; Ma. Teresa Colinas-León; Ma. Teresa Martínez-Damián

Keywords: chromatography, spectrophotometry, quercetin

10.5154/r.rchsh.2004.04.025

Received: 2004-04-12
Accepted: 2004-10-10
Available online: 2016-07-01
Pages:225-231

Sapote mamey fruit has high concentrations of carotenoids and phenolic compounds, metabolites, whose consumption has recently been associated with a low incidence of cardiovascular and cancer diseases. On the other hand, phenols are related to flesh browning in this fruit, thus reducing postharvest life. The objective of this research was an analysis of carotenoids and phenolic compounds present in the pulp of sapote mamey fruit. Five carotenoids were separated by thin layer chromatography; the first band was the most intense and had the maximum absorption values (424, 452, 470 nm), which in turn were similar to those obtained by the b-carotene standard. Bands 2-3 and 4-5 showed very similar absorption characteristics (423 449 474 - 420 446 474 nm and 399 423 446 - 400 424 446 nm, respectively). They were therefore considered to be isomers of a - carotene and z- carotene, respectively. Quercetin glucosides (flavonols) were detected under ultraviolet light developed with ammonia vapors and diphenylboric acid 2- amino ethyl ester; their maximum absorption coincided with the literature (253, 367 nm). The main components in the bands were identified as derivatives of cinnamic acid, and catequins. Results indicate the presence of metabolites with high antioxidant activity in the pulp of sapote mamey fruit.

....

Sapote mamey fruit has high concentrations of carotenoids and phenolic compounds, metabolites, whose consumption has recently been associated with a low incidence of cardiovascular and cancer diseases. On the other hand, phenols are related to flesh browning in this fruit, thus reducing postharvest life. The objective of this research was an analysis of carotenoids and phenolic compounds present in the pulp of sapote mamey fruit. Five carotenoids were separated by thin layer chromatography; the first band was the most intense and had the maximum absorption values (424, 452, 470 nm), which in turn were similar to those obtained by the b-carotene standard. Bands 2-3 and 4-5 showed very similar absorption characteristics (423 449 474 - 420 446 474 nm and 399 423 446 - 400 424 446 nm, respectively). They were therefore considered to be isomers of a - carotene and z- carotene, respectively. Quercetin glucosides (flavonols) were detected under ultraviolet light developed with ammonia vapors and diphenylboric acid 2- amino ethyl ester; their maximum absorption coincided with the literature (253, 367 nm). The main components in the bands were identified as derivatives of cinnamic acid, and catequins. Results indicate the presence of metabolites with high antioxidant activity in the pulp of sapote mamey fruit.

....
 

GARLIC YIELD AND QUALITY WITH DIFFERENT MANAGEMENT TECHNIQUES OF DRIP IRRIGATION

RENDIMIENTO Y CALIDAD DE AJO CON DIFERENTE MANEJO DEL RIEGO POR GOTEO

J.M. Barrios-Díaz; M.C. Larios-García; J.Z. Castellanos; G. Alcántar-González; María de las Nieves Rodríguez-Mendoza; L. Tijerina-Chávez; W. Cruz-Romero

Keywords: Allium sativum L., fertirrigation, localized irrigation, tensiometer, pungency.

10.5154/r.rchsh.2003.06.043

Received: 2003-06-24
Accepted: 2004-10-15
Available online: 2016-07-01
Pages:233-239

Faced with the problem of overexploitation of underground water resources in Guanajuato, Mexico, horticultural growers are changing their traditional irrigation methods to other more efficient ones, for example, drip irrigation. The effect of different strategies of water management with this system on yield and quality is not well known. For this reason, an experiment was conducted during the fall-winter period of 2001-02 with garlic cv. Tacatzcuaro, to evaluate its response to Soil Water Tension (SWT). The treatments were: T1 (9, 7 and 8 kPa), T2 (9, 7 and 19 kPa), T3 (9, 11 and 28 kPa), and T4 (19, 11 and 8 kPa). Every SWT corresponded to the periods: 0 to 90, 91 to 130 and 131 to 185 days after sowing. The yield was 29.3, 27.9, 26.0 and 22.3 t·ha-1 of bulb; water use efficiency was 3.0, 3.1, 3.2 and 2.5 kg·m-3; respectively for T1, T2, T3 and T4. The bulb caliber with the highest yield proportion was Super Colossal (70 to 75 mm diameter). The maximum number of whole bulb skins was 5.6 in T3 and the minimum was 4.3 in T2. Clove pungency (alliin and total thiosulfinates) decreased when SWT increased at the end of analyzed period (T2 and T3). The gradual increase of SWT during growth cycle (T3) was found to be the best strategy of water management with drip irrigation.

....

Faced with the problem of overexploitation of underground water resources in Guanajuato, Mexico, horticultural growers are changing their traditional irrigation methods to other more efficient ones, for example, drip irrigation. The effect of different strategies of water management with this system on yield and quality is not well known. For this reason, an experiment was conducted during the fall-winter period of 2001-02 with garlic cv. Tacatzcuaro, to evaluate its response to Soil Water Tension (SWT). The treatments were: T1 (9, 7 and 8 kPa), T2 (9, 7 and 19 kPa), T3 (9, 11 and 28 kPa), and T4 (19, 11 and 8 kPa). Every SWT corresponded to the periods: 0 to 90, 91 to 130 and 131 to 185 days after sowing. The yield was 29.3, 27.9, 26.0 and 22.3 t·ha-1 of bulb; water use efficiency was 3.0, 3.1, 3.2 and 2.5 kg·m-3; respectively for T1, T2, T3 and T4. The bulb caliber with the highest yield proportion was Super Colossal (70 to 75 mm diameter). The maximum number of whole bulb skins was 5.6 in T3 and the minimum was 4.3 in T2. Clove pungency (alliin and total thiosulfinates) decreased when SWT increased at the end of analyzed period (T2 and T3). The gradual increase of SWT during growth cycle (T3) was found to be the best strategy of water management with drip irrigation.

....
 

VEGETATIVE AND FLORAL GROWTH OF CHRYSANTHEMUM [Dendranthema x grandiflorum (Ramat) Kitamura] IN RESPONSE TO THE OSMOTIC PRESSURE OF NUTRITIVE SOLUTION

CRECIMIENTO VEGETATIVO Y FLORAL DEL CRISANTEMO [Dendranthema x grandiflorum (Ramat) Kitamura] EN RESPUESTA A LA PRESIÓN OSMÓTICA DE LA SOLUCIÓN NUTRITIVA

J.S. Flores-Ruvalcaba; A.E. Becerril-Román; Víctor A. González-Hernández; L. Tijerina-Chávez; T. Vásquez-Rojas

Keywords: salts concentration, flowers, subirrigation, quality.

10.5154/r.rchsh.2003.11.077

Received: 2003-11-24
Accepted: 2004-10-12
Available online: 2016-07-01
Pages:241-249

The chrysanthemum [Dendranthema x grandiflorum (Ramat) Kitamura cv. Polaris White] is one of most widely cultivated ornamental crops in Mexico. Its nutrient requirements in hydroponics are nevertheless unknown. This lack of knowledge limits the use of high plant density. Therefore, the effect of the osmotic pressure of the nutrient solution (0.018, 0.027, 0.036 and 0.045 MPa) on the growth and flowering of chrysanthemum was evaluated in Texcoco, in the state of Mexico using a hydroponics system of subirrigation in pots containing eight plants, which is equivalent to a density of 156.6 plants m-2, managed at one stem per plant and one flower per stem. The most notable growth and flower quality was obtained with 0.036 and 0.045 MPa osmotic pressure of the nutrient solution (plant height: 110 to 115 cm; stem diameter: 0.6 to 0.63 cm; internodes per plant: 33; leaf area: 730 to 790 cm2; inflorescence diameter: 11.4 cm; diameter of the central yellow coloration of inflorescence: 6.5 cm with 0.036 MPa; intensity of coloration and vase life period: 7.3 and 17 days, respectively, both with 0.045 MPa). Transplant to cutting time was diminished as the osmotic pressure of the nutrient solution increased (90 and 84 days with 0.036 and 0.045 MPa, respectively).

....

The chrysanthemum [Dendranthema x grandiflorum (Ramat) Kitamura cv. Polaris White] is one of most widely cultivated ornamental crops in Mexico. Its nutrient requirements in hydroponics are nevertheless unknown. This lack of knowledge limits the use of high plant density. Therefore, the effect of the osmotic pressure of the nutrient solution (0.018, 0.027, 0.036 and 0.045 MPa) on the growth and flowering of chrysanthemum was evaluated in Texcoco, in the state of Mexico using a hydroponics system of subirrigation in pots containing eight plants, which is equivalent to a density of 156.6 plants m-2, managed at one stem per plant and one flower per stem. The most notable growth and flower quality was obtained with 0.036 and 0.045 MPa osmotic pressure of the nutrient solution (plant height: 110 to 115 cm; stem diameter: 0.6 to 0.63 cm; internodes per plant: 33; leaf area: 730 to 790 cm2; inflorescence diameter: 11.4 cm; diameter of the central yellow coloration of inflorescence: 6.5 cm with 0.036 MPa; intensity of coloration and vase life period: 7.3 and 17 days, respectively, both with 0.045 MPa). Transplant to cutting time was diminished as the osmotic pressure of the nutrient solution increased (90 and 84 days with 0.036 and 0.045 MPa, respectively).

....
 

POSTHARVEST CONTROL OF ANTHRACNOSE IN PAPAYA AND THE SENSITIVITY OF Colletotrichum gloeosporioides (Penz.) Sacc TO ORGAN SYNTHETIC FUNGICIDES

CONTROL POSTCOSECHA DE LA ANTRACNOSIS EN PAPAYA Y SENSIBILIDAD DE Colletotrichum gloeosporioides (Penz.) Sacc. A FUNGICIDAS ORGANOSINTÉTICOS

M.J. Zavala-León; J.M. Tún-Suárez; E. Ruíz-Sánchez; J. Cristóbal-Alejo; O. Gutiérrez-Alonso; M. Vázquez-Calderón; R. Méndez-González

Keywords: Carica papaya L., benzimidazole, strobilurin, imidazole, CE50, CE95

10.5154/r.rchsh.2004.03.019

Received: 2004-03-03
Accepted: 2004-10-12
Available online: 2016-07-01
Pages:251-255

Colletotrichum gloeosporioides, the causal agent of anthracnose, is the main postharvest pathogen in papaya. This study, therefore, evaluates the effect of five fungicides to control this disease in papaya cv. Maradol. The experiment comprised two stages: in vivo and in vitro, in which the fungicides benomyl, imazalil, prochloraz, azoxystrobin, kresoxim methyl were evaluated. The results of the first stage indicated that prochloraz was the fungicide that offered greater perspectives in the control of anthracnose with an average effectiveness of 96.5%, while benomyl was the least efficient, (15.71%). In the second stage, the fungicide prochloraz had the smallest CE95 with 7.91 µg·ml-1 during conidial germination and the smallest CE50 and CE95 for the mycelia growth with 0.0002 µg·ml-1 and 1.46-µg·ml-1, respectively. However, azoxystrobin obtained greater CE50 and CE95 for the mycelia growth, with 258.25 µg·ml-1 , and 365.25 µg·ml-1, respectively. It is concluded that prochloraz was the fungicide that best controlled both anthracnose and C. gloeosporioides germination and mycelia growth.

....

Colletotrichum gloeosporioides, the causal agent of anthracnose, is the main postharvest pathogen in papaya. This study, therefore, evaluates the effect of five fungicides to control this disease in papaya cv. Maradol. The experiment comprised two stages: in vivo and in vitro, in which the fungicides benomyl, imazalil, prochloraz, azoxystrobin, kresoxim methyl were evaluated. The results of the first stage indicated that prochloraz was the fungicide that offered greater perspectives in the control of anthracnose with an average effectiveness of 96.5%, while benomyl was the least efficient, (15.71%). In the second stage, the fungicide prochloraz had the smallest CE95 with 7.91 µg·ml-1 during conidial germination and the smallest CE50 and CE95 for the mycelia growth with 0.0002 µg·ml-1 and 1.46-µg·ml-1, respectively. However, azoxystrobin obtained greater CE50 and CE95 for the mycelia growth, with 258.25 µg·ml-1 , and 365.25 µg·ml-1, respectively. It is concluded that prochloraz was the fungicide that best controlled both anthracnose and C. gloeosporioides germination and mycelia growth.

....
 

MATHEMATICAL MODELS OF VEGETABLES IN GREENHOUSES: BEYOND A CONTEMPLATIVE VIEW OF CROP DYNAMICS

MODELOS MATEMÁTICOS DE HORTALIZAS EN INVERNADERO: TRASCENDIENDO LA CONTEMPLACIÓN DE LA DINÁMICA DE CULTIVOS

Irineo Lorenzo López-Cruz; José Armando Ramírez-Arias; Abraham Rojano-Aguilar

Keywords: explanatory models, differential equations,

10.5154/r.rchsh.2003.08.050

Received: 2003-08-22
Accepted: 2004-11-11
Available online: 2016-07-01
Pages:257-267

The purpose of this paper is to describe state of the art of mathematical models (explanatory or mechanistic models) for vegetable greenhouse crops. An overview of the main characteristics of some models proposed in the scientific literature for tomato, cucumber and lettuce crops is presented. Furthermore, the most important applications of the greenhouse crops models are discussed. Finally, some issues which have not yet been considered by modelers of greenhouse horticultural crops around the world are described and analyzed.

....

The purpose of this paper is to describe state of the art of mathematical models (explanatory or mechanistic models) for vegetable greenhouse crops. An overview of the main characteristics of some models proposed in the scientific literature for tomato, cucumber and lettuce crops is presented. Furthermore, the most important applications of the greenhouse crops models are discussed. Finally, some issues which have not yet been considered by modelers of greenhouse horticultural crops around the world are described and analyzed.

....
 

EFFECT OF BRASINOESTEROID AND PLANT DENSITY IN BIOMASS ACCUMULATION AND YIELD OF AYOCOTE (Phaseolus coccineus L.)

EFECTO DEL BRASINOESTEROIDE Y DENSIDAD DE POBLACIÓN EN LA ACUMULACIÓN DE BIOMASA Y RENDIMIENTO DE AYOCOTE (Phaseolus coccineus L.)

M.L.P. Vargas-Vázquez; M.B.G. Irizar-Garza

Keywords: Ayocote bean, growth regulator, dry matter.

10.5154/r.rchsh.2003.12.082

Received: 2003-12-09
Accepted: 2004-12-24
Available online: 2016-07-01
Pages:269-272

The effect of the brasinoesteroid growth regulator on total dry matter production and seed yield of the “ayocote” bean (Phaseolus coccineus L.) Blanco Tlaxcala variety was studied in Tetelco, Tlahuac, in D. F., Mexico. The sowing date was May 3, 2000, during the rainy season. Plant densities of the populations studied were: 60, 75, 90, 105 and 120 thousand plants per hectare. Brasinoesteroid (solution concentration 1 mg·ml-1) was applied 40 mg·ha-1 in three parts: 10 mg·ha-1 30 days after planting (dap); 10 mg·ha-1 60 dap; and 20 mg·ha-1 90 dap. Brasinoesteroid increased total and organ biomass production in most of the plant population densities studied. In the case of the densities of 105 and 120 thousand plants per hectare, the total biomass production tripled when compared to the other plant population densities. Brasinoesteroid increased seed yield by 68 % in the plant density of 90 thousand plants per hectare.

....

The effect of the brasinoesteroid growth regulator on total dry matter production and seed yield of the “ayocote” bean (Phaseolus coccineus L.) Blanco Tlaxcala variety was studied in Tetelco, Tlahuac, in D. F., Mexico. The sowing date was May 3, 2000, during the rainy season. Plant densities of the populations studied were: 60, 75, 90, 105 and 120 thousand plants per hectare. Brasinoesteroid (solution concentration 1 mg·ml-1) was applied 40 mg·ha-1 in three parts: 10 mg·ha-1 30 days after planting (dap); 10 mg·ha-1 60 dap; and 20 mg·ha-1 90 dap. Brasinoesteroid increased total and organ biomass production in most of the plant population densities studied. In the case of the densities of 105 and 120 thousand plants per hectare, the total biomass production tripled when compared to the other plant population densities. Brasinoesteroid increased seed yield by 68 % in the plant density of 90 thousand plants per hectare.

....
 

PRODUCTION AND ANTAGONISTIC EFFECT OF CHITINASES AND GLUCANASES BY Trichoderma spp., IN THE INHIBITION OF Fusarium subglutinans AND Fusarium oxysporum IN VITRO

PRODUCCIÓN Y EFECTO ANTAGÓNICO DE QUITINASAS Y GLUCANASAS POR Trichoderma spp., EN LA INHIBICIÓN DE Fusarium subglutinans y Fusarium oxysporum IN VITRO

Alejandro Casimiro Michel-Aceves; M. A. Otero-Sánchez; O. Rebolledo-Domínguez; R. Lezama-Gutiérrez; M.E. Ochoa-Moreno

Keywords: antibiosis, Trichoderma harzianum, T. longibrachiatum, T. virens, T. koningii, T. minutisporum.

10.5154/r.rchsh.2003.12.085

Received: 2003-12-15
Accepted: 2004-11-30
Available online: 2016-07-01
Pages:273-278

Hydrolytic enzymes, chitinases and glucanases, produced by Trichoderma spp strains were quantified, and their in vitro antibiotic effect on the growth of the mycelium and on the reproductive potential of Fusarium subglutinans and F. oxysporum was assessed. The production of chitinases oscillated between 0.33 and 2.29 mmol of N-acetilglucosamine, and that of glucanases oscillated between 14.4 to 60.6 mmol of glucose. The T. harzianum (Thzcf-9 and Thzcf-6) chitinases inhibited the growth of the mycelium of F. oxysporum in 34 and 27 % and of F. subglutinans 35 and 21%, respectively. The reproductive potential in the production of conidia decreased from 95 and 86 %, while their viability varied 66 and 73 % in F. oxysporum and F. subglutinans, respectively. The T. koningii (Tkcf-2) and T. harzianum (Thzcf-6) glucanases inhibited the growth of the mycelium of F. oxysporum 44 and 32 % and in the case of F. subglutinans 38 and 34 %, respectively. It was also possible to reduce conidia production of both species of Fusarium by 95 % and viability in F. oxysporum and F. subglutinans by 74 and 64 %, respectively. The results obtained under laboratory conditions suggest that T. harzianum (Thzcf-9 and Thzcf-6) for quitinase activity, as well as T. koningii (Tkcf-2) and T. harzianum (Thzcf-6) for glucanases activity have potential as biocontrol agents on the two species of Fusarium involved in the etiology of mango malformation.

....

Hydrolytic enzymes, chitinases and glucanases, produced by Trichoderma spp strains were quantified, and their in vitro antibiotic effect on the growth of the mycelium and on the reproductive potential of Fusarium subglutinans and F. oxysporum was assessed. The production of chitinases oscillated between 0.33 and 2.29 mmol of N-acetilglucosamine, and that of glucanases oscillated between 14.4 to 60.6 mmol of glucose. The T. harzianum (Thzcf-9 and Thzcf-6) chitinases inhibited the growth of the mycelium of F. oxysporum in 34 and 27 % and of F. subglutinans 35 and 21%, respectively. The reproductive potential in the production of conidia decreased from 95 and 86 %, while their viability varied 66 and 73 % in F. oxysporum and F. subglutinans, respectively. The T. koningii (Tkcf-2) and T. harzianum (Thzcf-6) glucanases inhibited the growth of the mycelium of F. oxysporum 44 and 32 % and in the case of F. subglutinans 38 and 34 %, respectively. It was also possible to reduce conidia production of both species of Fusarium by 95 % and viability in F. oxysporum and F. subglutinans by 74 and 64 %, respectively. The results obtained under laboratory conditions suggest that T. harzianum (Thzcf-9 and Thzcf-6) for quitinase activity, as well as T. koningii (Tkcf-2) and T. harzianum (Thzcf-6) for glucanases activity have potential as biocontrol agents on the two species of Fusarium involved in the etiology of mango malformation.

....
 

CONSUMER PREFERENCE FOR PIQUIN PEPPER COMPARED TO OTHER HOT PEPPERS IN NORTHEASTERN MEXICO

PREFERENCIA DEL CONSUMIDOR POR EL CHILE PIQUÍN EN COMPARACIÓN CON OTROS CHILES EN EL NORESTE DE MÉXICO

L.A. Rodríguez-del Bosque

Keywords: Capsicum annuum L., marketing, preference, opinion, survey

10.5154/r.rchsh.2004.06.029

Received: 2004-06-28
Accepted: 2004-12-03
Available online:
Pages:279-281

A total of 1,000 adult male consumers from nine cities in northeastern Mexico were asked for their preferences in hot peppers, with special reference to piquin. Although consumer preferences varied with the locality, overall, piquin was highly preferred by consumers (30-37 %), at a level similar to jalapeno (33-37 %), even when the latter is available on the market all-year round at a lower price. Other peppers that were less preferred (<25 %) included: serrano, habanero, arbol, chipotle, cambray, japones, cascabel, guajillo, morron, puya, poblano, and chilaca. Overall, 93 % of the people said that they had tried piquin sometime. This study showed an important potential market for piquin peppers in northeastern Mexico.

....

A total of 1,000 adult male consumers from nine cities in northeastern Mexico were asked for their preferences in hot peppers, with special reference to piquin. Although consumer preferences varied with the locality, overall, piquin was highly preferred by consumers (30-37 %), at a level similar to jalapeno (33-37 %), even when the latter is available on the market all-year round at a lower price. Other peppers that were less preferred (<25 %) included: serrano, habanero, arbol, chipotle, cambray, japones, cascabel, guajillo, morron, puya, poblano, and chilaca. Overall, 93 % of the people said that they had tried piquin sometime. This study showed an important potential market for piquin peppers in northeastern Mexico.

....
 

EFFECTS OF PROHEXADIONE – Ca ON TOMATOS AS RELATED TO THE VARIATION IN THE CONCENTRATION OF GIBBERELLINS AND CYTOKININS

EFECTOS DE PROHEXADIONA – Ca EN TOMATE Y SU RELACIÓN CON LA VARIACIÓN DE LA CONCENTRACIÓN DE GIBERELINAS Y CITOCININAS

Homero Ramírez; R.M. Peralta-Manjarrez; Adalberto Benavides-Mendoza; A. Sánchez-López; Valentín Robledo-Torres; J. Hernández-Davila

Keywords: Lycopersicon esculentum Mill., growth regulators, tomato, endogenous hormones.

10.5154/r.rchsh.2003.06.044

Received: 2003-06-24
Accepted: 2004-10-15
Available online: 2016-07-01
Pages:283-290

The present study was conducted for purpose of determining the effects of prohexadione – Ca (P-Ca) on the vegetative and reproductive growth related to endogenous gibberellins and cytokinins in two experimental saladette tomato hybrids (Lycopersicon esculentum Mill.) with determinate and indeterminate growth habit. The P-Ca was sprayed when plants reached 12 true leaves at a concentration of 0 (control), 175 and 250 mg·liter-1. The results showed that both P-Ca concentrations reduced plant height at six days after treatment in both hybrids. This effect was reverted 8 days after P-Ca treatment. Internodal number, leaf number and shoot diameter were increased with P-Ca treatments in both tomato cultivars. Fruit and raquis number, fruit weight, fruit firmness, total soluble solids and total plant yield also increased with P-Ca, whereas fruit radius was not affected. Both concentrations of P-Ca reduced the levels of gibberellins in apical meristems and increased the cytokinin content. Gibberellins A12, A20 and zeatin were identified in these tissues. In control sample apexes gibberellins A1, A4, A7 and zeatin were found.

....

The present study was conducted for purpose of determining the effects of prohexadione – Ca (P-Ca) on the vegetative and reproductive growth related to endogenous gibberellins and cytokinins in two experimental saladette tomato hybrids (Lycopersicon esculentum Mill.) with determinate and indeterminate growth habit. The P-Ca was sprayed when plants reached 12 true leaves at a concentration of 0 (control), 175 and 250 mg·liter-1. The results showed that both P-Ca concentrations reduced plant height at six days after treatment in both hybrids. This effect was reverted 8 days after P-Ca treatment. Internodal number, leaf number and shoot diameter were increased with P-Ca treatments in both tomato cultivars. Fruit and raquis number, fruit weight, fruit firmness, total soluble solids and total plant yield also increased with P-Ca, whereas fruit radius was not affected. Both concentrations of P-Ca reduced the levels of gibberellins in apical meristems and increased the cytokinin content. Gibberellins A12, A20 and zeatin were identified in these tissues. In control sample apexes gibberellins A1, A4, A7 and zeatin were found.

....
 

GROWTH DINAMICS AND PHYSIOLOGICAL EFFICIENCY OF ZUCCHINI PLANTS

DINÁMICA DEL CRECIMIENTO Y EFICIENCIA FISIOLÓGICA DE LA PLANTA DE CALABACITA

G. Sedano-Castro; Víctor A. González-Hernández; E.M. Engleman; Clemente Villanueva-Verduzco

Keywords: Cucurbita pepo L., Growth analysis, source-sink relations, biomass distribution.

10.5154/r.rchsh.2002.08.047

Received: 2002-08-14
Accepted: 2004-12-06
Available online: 2016-07-01
Pages:291-297

Physiological aspects of Cucurbita pepo L., hybrid Tala, such as dinamics and aerial biomass distribution were studied at the Experimental Station of the Colegio de Postgraduados, Montecillo Texcoco, México, during the 1999 and 2000 growing seasons. Four plants were sampled every two weeks during the first season, and used to measure leaf area, fresh and dry weight of leaf, stem and fruit. In the second season fruits of 18 development stages (from flowering to immature fruit) were measured every twelve hours, regarding fresh and dry weight; additionally, every seven days, fruits ranging from immature stage to physiologically mature stage, were sampled to measure fresh and dry weight. Instantaneous CO2 assimilation and transpiration rates were measured on mature leaves. The plant assigned biomass among their organs as follows, 59.4 % to leaves, 34.1 % to immature fruits and 6.38 % to stems. Plant growth showed sigmoid kinetics. Maximum leaf area occurred at 69 days after planting (dap), and immediately afterwards followed rapid defoliation. Biomass increase on reproductive organs was slow during the floral bud stage, with 0.062 g·d-1; the rate was much faster from anthesis to young fruit (“vegetable” stage), reaching 1.257 g·d-1. Maximum CO2 assimilation and minimum transpiration were registered 47 dap, 22 days before maximum leaf area (69 dap). Seed weight barely reached 2.9 % with respect to fresh fruit weight, while in dry weight it represented 32 %.

....

Physiological aspects of Cucurbita pepo L., hybrid Tala, such as dinamics and aerial biomass distribution were studied at the Experimental Station of the Colegio de Postgraduados, Montecillo Texcoco, México, during the 1999 and 2000 growing seasons. Four plants were sampled every two weeks during the first season, and used to measure leaf area, fresh and dry weight of leaf, stem and fruit. In the second season fruits of 18 development stages (from flowering to immature fruit) were measured every twelve hours, regarding fresh and dry weight; additionally, every seven days, fruits ranging from immature stage to physiologically mature stage, were sampled to measure fresh and dry weight. Instantaneous CO2 assimilation and transpiration rates were measured on mature leaves. The plant assigned biomass among their organs as follows, 59.4 % to leaves, 34.1 % to immature fruits and 6.38 % to stems. Plant growth showed sigmoid kinetics. Maximum leaf area occurred at 69 days after planting (dap), and immediately afterwards followed rapid defoliation. Biomass increase on reproductive organs was slow during the floral bud stage, with 0.062 g·d-1; the rate was much faster from anthesis to young fruit (“vegetable” stage), reaching 1.257 g·d-1. Maximum CO2 assimilation and minimum transpiration were registered 47 dap, 22 days before maximum leaf area (69 dap). Seed weight barely reached 2.9 % with respect to fresh fruit weight, while in dry weight it represented 32 %.

....
 

YIELD PERFORMANCE OF TOMATO HYBRIDS AND THEIR F2 GENERATIONS

COMPORTAMIENTO PRODUCTIVO EN HÍBRIDOS DE JITOMATE Y SUS RESPECTIVAS POBLACIONES F2

Juan Martínez-Solís; Aureliano Peña-Lomelí; Juan Enrique Rodríguez-Pérez; Clemente Villanueva-Verduzco; Jaime Sahagún-Castellanos; Margarita Gisela Peña-Ortega

Keywords: Lycopersicon esculentum Mill. plant breeding, seeds, heterosis, transgressive segregation.

10.5154/r.rchsh.2004.04.028

Received: 2004-04-26
Accepted: 2005-03-16
Available online: 2016-07-01
Pages:299-307

Since the price of tomato hybrid seed is expensive, many farmers are using F2 in commercial plots. As a result in order to evaluate the performance between F1 and F2 tomato genotypes, 37 hybrids and their F2’s generations were grown under greenhouse conditions. Most of the F2 generations had lower values for total fruit weight per plant and fruit number per plant, compared to their F1 hybrids. However, these differences were statistically significant only in two ball fruit bush type as well as four ball fruit indeterminate genotypes, which F2´s showed fruit production reductions over 20 %.

....

Since the price of tomato hybrid seed is expensive, many farmers are using F2 in commercial plots. As a result in order to evaluate the performance between F1 and F2 tomato genotypes, 37 hybrids and their F2’s generations were grown under greenhouse conditions. Most of the F2 generations had lower values for total fruit weight per plant and fruit number per plant, compared to their F1 hybrids. However, these differences were statistically significant only in two ball fruit bush type as well as four ball fruit indeterminate genotypes, which F2´s showed fruit production reductions over 20 %.

....
 

SYMPTOMATOLOGY ASSOCIATED WITH THE LOSS OF COLOR IN CHAYOTE

ESTUDIO DE LOS SÍNTOMAS ASOCIADOS A LA PÉRDIDA DE COLOR DEL CHAYOTE

Jorge Cadena-Iñiguez; Lucero del Mar Ruiz-Posadas; Juan Francisco Aguirre-Medina; Pastor Sánchez-García

Keywords: Sechium edule (Jacq.) Sw., calcareous, chlorosis, mycorriza.

10.5154/r.rchsh.2004.11.058

Received: 2004-11-04
Accepted: 2005-04-14
Available online: 2016-07-01
Pages:309-316

The initial nutrimental deficiency symptoms associated to the loss of the plant vigor and fruit color of Sechium edule (Jacq.) Sw., locally called White Chayote, were reproduced under greenhouse conditions to evaluate response to nutriment addition and microsymbiont inoculation. The soil used was from Actopan, Veracruz, Mexico, and was subdivided into layers at 0-30, 30-60, 60-90 cm and mixture of total profile to determine fertility. For every 30 liters of soil layer, 8.29 g (NH4)2SO4, 1.0 g of Ca3(PO4)2, 4.4 g of K2SO4, 1.15 g of FeSO4, MnSO4 and ZnSO4, and 0.75 g of sulfur, 40 g of Glomus intraradices (MA) and Azospirillum brasilense were applied. Plant height, chlorophyll, total biomass, and CO2 assimilation were evaluated; in addition, X-ray analyses were performed in cuttings from the fourth internode below the apical bud of the main stem. The soil showed Cl-, SO42-, HCO3-, Na+ soluble compounds and pH of up to 7.9. In addition, values of P, Ca2+ and Mg2+ of 5.6, 50.3 and 4.7 times, respectively, above the consigned values for the species were found. Plants sown in the soil of the 0-30 layer showed the highest growth compared with the 30-60, 60-90 levels and total profile mixture. The nutrients mixed with MA, as well as with MA and A. brasilense, was statistically significant. The control plant showed crystals made of P, Ca, S, Si, Na, Mg obstructing the stem xylem bundles. The experimental evidence showed that the initial symptoms associated to White Chayote, were due mainly to nutrimental deficiencies, which was more evident in the levels of soil below 0-30 cm.

....

The initial nutrimental deficiency symptoms associated to the loss of the plant vigor and fruit color of Sechium edule (Jacq.) Sw., locally called White Chayote, were reproduced under greenhouse conditions to evaluate response to nutriment addition and microsymbiont inoculation. The soil used was from Actopan, Veracruz, Mexico, and was subdivided into layers at 0-30, 30-60, 60-90 cm and mixture of total profile to determine fertility. For every 30 liters of soil layer, 8.29 g (NH4)2SO4, 1.0 g of Ca3(PO4)2, 4.4 g of K2SO4, 1.15 g of FeSO4, MnSO4 and ZnSO4, and 0.75 g of sulfur, 40 g of Glomus intraradices (MA) and Azospirillum brasilense were applied. Plant height, chlorophyll, total biomass, and CO2 assimilation were evaluated; in addition, X-ray analyses were performed in cuttings from the fourth internode below the apical bud of the main stem. The soil showed Cl-, SO42-, HCO3-, Na+ soluble compounds and pH of up to 7.9. In addition, values of P, Ca2+ and Mg2+ of 5.6, 50.3 and 4.7 times, respectively, above the consigned values for the species were found. Plants sown in the soil of the 0-30 layer showed the highest growth compared with the 30-60, 60-90 levels and total profile mixture. The nutrients mixed with MA, as well as with MA and A. brasilense, was statistically significant. The control plant showed crystals made of P, Ca, S, Si, Na, Mg obstructing the stem xylem bundles. The experimental evidence showed that the initial symptoms associated to White Chayote, were due mainly to nutrimental deficiencies, which was more evident in the levels of soil below 0-30 cm.

....
 

GENOTYPES OR VARIETIES EVALUATED ACROSS YEARS AND SITES. CROSSED vs NESTED FACTORS

EVALUACIÓN DE GENOTIPOS O VARIEDADES A TRAVÉS DE AÑOS Y LOCALIDADES. FACTORES CRUZADOS vs ANIDADOS

Jaime Sahagún-Castellanos; Juan Enrique Rodríguez-Pérez; Aureliano Peña-Lomelí

Keywords: Variance component estimation, annual crops, heritability, response to selection, environmental interaction

10.5154/r.rchsh.2005.11.056

Received: 2005-11-12
Accepted: 2004-04-14
Available online: 2016-07-01
Pages:317-321

In series of experiments conducted in several locations (L) during a years (A) to evaluate genotypes (G) associated with annual crops in several levels of the main plot factor B the definition of the model should consider the true relationship between A and L. Considering that choice of the wrong model affects quality of analysis, the objective of this paper was to study the effect on the estimators of variance components, heritability, and response to selection, of the use of a model based on the common consideration that A and L are crossed factors (model AxL) when in reality A is nested in L (model A/L). Two cases were studied: a) all factors were random, and b) only B was a fixed effects factor. In both cases the estimators of the variance components for G and GB from the model AxL showed a bias which was the negative value of the variance of GA and GAB divided by a, respectively; and their variances were larger than the ones of the corresponding estimators generated in model A/L, the excess being the variance of the unbiased estimator of their respective bias divided by a2. The underestimation of the variance of G in turn must produce an underestimation of the heritability and response to selection because the phenotypic variance would be equally estimated in both models.

....

In series of experiments conducted in several locations (L) during a years (A) to evaluate genotypes (G) associated with annual crops in several levels of the main plot factor B the definition of the model should consider the true relationship between A and L. Considering that choice of the wrong model affects quality of analysis, the objective of this paper was to study the effect on the estimators of variance components, heritability, and response to selection, of the use of a model based on the common consideration that A and L are crossed factors (model AxL) when in reality A is nested in L (model A/L). Two cases were studied: a) all factors were random, and b) only B was a fixed effects factor. In both cases the estimators of the variance components for G and GB from the model AxL showed a bias which was the negative value of the variance of GA and GAB divided by a, respectively; and their variances were larger than the ones of the corresponding estimators generated in model A/L, the excess being the variance of the unbiased estimator of their respective bias divided by a2. The underestimation of the variance of G in turn must produce an underestimation of the heritability and response to selection because the phenotypic variance would be equally estimated in both models.

....
 

CUT FLOWERS AND FOLIAGE IN FLOWER SHOPS AND MARKETS OF PUEBLA, MÉXICO

FLORES DE CORTE Y FOLLAJE EN FLORERÍAS Y MERCADOS DE PUEBLA, MÉXICO

C. Tlahuextl-Tlaxcalteca; J.M. Ávila-Sanchez; H. Leszczyñska-Borys

Keywords: commerce, flower color, price, floral arrangement.

10.5154/r.rchsh.2004.04.026

Received: 2004-04-21
Accepted: 2005-04-20
Available online: 2016-07-01
Pages:323-327

Puebla, México, the capital of the state, is an important consumer of cut flower and foliage species. A questionnaire was applied by interviews to owners or sales managers of 40 flower shops and six flower markets. Puebla´s flower shops offer a wider variety of flower species than those offered by Puebla´s markets. Flower species at the markets are cheaper but their quality is lower. Also, markets offer more cut flower species from open-air production (Celosia cristata, Centaurea cyanus, Gladiolus sp., Matthiola incana, Tagetes erecta). It is interesting to note that both flower shops and markets offer a wide assortment of good quality of cut foliage. The objective of this investigation was to receive information on offer and demand of species and varieties of cut flowers and foliage in Puebla, as well as preferences of men and women for these products.

....

Puebla, México, the capital of the state, is an important consumer of cut flower and foliage species. A questionnaire was applied by interviews to owners or sales managers of 40 flower shops and six flower markets. Puebla´s flower shops offer a wider variety of flower species than those offered by Puebla´s markets. Flower species at the markets are cheaper but their quality is lower. Also, markets offer more cut flower species from open-air production (Celosia cristata, Centaurea cyanus, Gladiolus sp., Matthiola incana, Tagetes erecta). It is interesting to note that both flower shops and markets offer a wide assortment of good quality of cut foliage. The objective of this investigation was to receive information on offer and demand of species and varieties of cut flowers and foliage in Puebla, as well as preferences of men and women for these products.

....
 

GENETIC VARIABILITY ACCORDING TO RAPD’s OF GUAVA ‘MEDIA CHINA’ TREES FROM FOUR PLANTATIONS AND MORPHOLOGICAL RESPONSE TO LOW AVAILABILITY OF NUTRIMENTS

VARIABILIDAD GENÉTICA SEGÚN RAPD’s DE ÁRBOLES DE GUAYABO ‘MEDIA CHINA’ PROCEDENTES DE CUATRO PLANTACIONES Y SU RESPUESTA MORFOLÓGICA A BAJA DISPONIBILIDAD DE NUTRIMENTOS

Juan Porfirio Legaria-Solano; J.L. Domínguez Álvarez; Raúl Nieto-Ángel; Alejandro Facundo Barrientos-Priego; Joel Pineda-Pineda

Keywords: Psidium guajava L., phenotype variability, evaluate morphological, RAPD’s analysis.

10.5154/r.rchsh.2004.11.061

Received: 2004-11-12
Accepted: 2005-04-14
Available online: 2016-07-01
Pages:329-343

In this study, molecular and morphological variability of guava plants (Psidium guajava L.) ‘Media China’ derived from seeds and subjected to low availability of Fe and Zn was evaluated by RAPD’s markers (Random Amplified Polymorphisms in the DNA). Associations among seventeen morphological characters and 49 RAPD’s loci and response of the plants to the nutrimental stress were established by cluster analysis using the NTSYS, DARwin and c2. The analysis of RAPD’s patterns obtained from a sample of 82 plants showed the existence of genetic variability. From a total of 49 loci evaluated, 96 % were polymorphous, with an average diversity rate of 0.744. The comparative analysis of the efficiency of RAPD’s markers derived from 82 plants versus morphological markers obtained from 72 plants to define and differentiate groups of genotypes with and without symptoms of deficiency of Fe and Zn, showed that the RAPD’s markers are more efficient for that purpose. The groups of plants without symptoms were associated with the presence of RAPD’s loci A20-4, A20-2 and A20-1, with a molecular weight of 0.85, 1.4 and 1.6 kb and a frequency of 86.5, 78 and 89 %, respectively, while the common characteristic for the plants with symptoms was the presence of a band A03-3, of 1.3 kb and a frequency of 74 %. Due to the association of more than one locus with the characteristic absence of symptoms, it can be inferred that this characteristic is polygenic and the combination of the three mentioned loci is necessary to define the groups without symptoms of Fe and Zn deficiency. When calculating the correlation, a non-significant association, r = 0.05743, was found. When the analysis was performed integrating the two types of markers in one single matrix and using the coefficient c2, no separation between the groups with and without symptoms of deficiency was found, and the average distance for RAPD’s was 8.09, with a range of 3.8, while for morphological traits the average distance was 0.15 and the range was 0.4. This confirms that efficiency of RAPD’s markers to detect genetic variability is greater than morphological markers. It also suggests that changes that occur at genome level are not always related to changes in the plant phenotype, and it is possible to establish that even when the correlation detected between the two types of markers is low, simultaneous evaluation is advisable because they are complementary: RAPD’s markers are good describers of the variability at genome level, while morphological variability permits a better explanation of the selection process of the material and has the advantage of better accessibility.

....

In this study, molecular and morphological variability of guava plants (Psidium guajava L.) ‘Media China’ derived from seeds and subjected to low availability of Fe and Zn was evaluated by RAPD’s markers (Random Amplified Polymorphisms in the DNA). Associations among seventeen morphological characters and 49 RAPD’s loci and response of the plants to the nutrimental stress were established by cluster analysis using the NTSYS, DARwin and c2. The analysis of RAPD’s patterns obtained from a sample of 82 plants showed the existence of genetic variability. From a total of 49 loci evaluated, 96 % were polymorphous, with an average diversity rate of 0.744. The comparative analysis of the efficiency of RAPD’s markers derived from 82 plants versus morphological markers obtained from 72 plants to define and differentiate groups of genotypes with and without symptoms of deficiency of Fe and Zn, showed that the RAPD’s markers are more efficient for that purpose. The groups of plants without symptoms were associated with the presence of RAPD’s loci A20-4, A20-2 and A20-1, with a molecular weight of 0.85, 1.4 and 1.6 kb and a frequency of 86.5, 78 and 89 %, respectively, while the common characteristic for the plants with symptoms was the presence of a band A03-3, of 1.3 kb and a frequency of 74 %. Due to the association of more than one locus with the characteristic absence of symptoms, it can be inferred that this characteristic is polygenic and the combination of the three mentioned loci is necessary to define the groups without symptoms of Fe and Zn deficiency. When calculating the correlation, a non-significant association, r = 0.05743, was found. When the analysis was performed integrating the two types of markers in one single matrix and using the coefficient c2, no separation between the groups with and without symptoms of deficiency was found, and the average distance for RAPD’s was 8.09, with a range of 3.8, while for morphological traits the average distance was 0.15 and the range was 0.4. This confirms that efficiency of RAPD’s markers to detect genetic variability is greater than morphological markers. It also suggests that changes that occur at genome level are not always related to changes in the plant phenotype, and it is possible to establish that even when the correlation detected between the two types of markers is low, simultaneous evaluation is advisable because they are complementary: RAPD’s markers are good describers of the variability at genome level, while morphological variability permits a better explanation of the selection process of the material and has the advantage of better accessibility.

....
 

POTENTIAL TO DEVELOP TOLERANCE TO DELTAENDOTOXINS OF Bacillus thuringiensis subsp. Kurstaki IN Plutella xylostella (Lepidoptera: Plutellidae)

POTENCIAL PARA DESARROLLAR TOLERANCIA A LAS DELTAENDOTOXINAS DE Bacillus thuringiensis subsp. kurstaki EN Plutella xylostella (Lepidoptera: Plutellidae)

M.A. Silva-Flores; O. Díaz-Gómez; N. Bautista-Martínez; J. Concepción Rodríguez-Maciel

Keywords: diamond back, resistance to insecticides, toxins, bioessay.

10.5154/r.rchsh.2003.01.010

Received: 2003-01-29
Accepted: 2005-04-30
Available online: 2016-07-01
Pages:345-349

This study demonstrates the potential of Plutella xylostella L. to develop tolerance to entomotoxins from Bacillus thuringiensis Subs. kurstaki (Btk.) One susceptible population and one subjected to selection pressure were studied. The first was reared for eight generations without insecticide treatment; for the ninth generation a medium lethal concentration was estimated at 65. Selection of the second population began with Btk treatment. Four continuous generations of the resistant population were exposed to the LC65 concentration estimated for the susceptible population of P. xylostella. The entomotoxin used in the experiment was a 6.4 % formula of Btk (Javelin® WG, Novartis México). In the bioassays, 90 mm diameter discs of cabbage (Brassica oleracea L.) leaves were cut, submerged for 10 seconds in different concentrations of entomotoxins, and placed in Petri dishes where they were infested with third instar larvae, ten larvae per concentration with three replications. The percentage of mortality was quantified 48 hours later. Data analysis was performed using the Probit model. With linear regression in the PcProbit software LC50, LC65, and LC95 were estimated, and relative resistance was calculated. The results indicate that the percentage of mortality of P. xylostella decreases more than 50 % after being subjected to selection pressure and the tolerance factor obtained was approximately 14 times greater.

....

This study demonstrates the potential of Plutella xylostella L. to develop tolerance to entomotoxins from Bacillus thuringiensis Subs. kurstaki (Btk.) One susceptible population and one subjected to selection pressure were studied. The first was reared for eight generations without insecticide treatment; for the ninth generation a medium lethal concentration was estimated at 65. Selection of the second population began with Btk treatment. Four continuous generations of the resistant population were exposed to the LC65 concentration estimated for the susceptible population of P. xylostella. The entomotoxin used in the experiment was a 6.4 % formula of Btk (Javelin® WG, Novartis México). In the bioassays, 90 mm diameter discs of cabbage (Brassica oleracea L.) leaves were cut, submerged for 10 seconds in different concentrations of entomotoxins, and placed in Petri dishes where they were infested with third instar larvae, ten larvae per concentration with three replications. The percentage of mortality was quantified 48 hours later. Data analysis was performed using the Probit model. With linear regression in the PcProbit software LC50, LC65, and LC95 were estimated, and relative resistance was calculated. The results indicate that the percentage of mortality of P. xylostella decreases more than 50 % after being subjected to selection pressure and the tolerance factor obtained was approximately 14 times greater.

....
 

OPTIMIZATION OF DNA FINGERPRINTS OBTAINED WITH RAPD’s AND MP-PCR BY THE RAMPNR TECHNIQUE

OPTIMIZACIÓN DE LAS HUELLAS DE DNA OBTENIDAS CON RAPDS Y MP-PCR MEDIANTE LA TÉCNICA RAMPnr

Ernestina Valadez-Moctezuma; G. Kahl; A. Rubluo-Islas†; R. Arreguín-de los Monteros

Keywords: molecular markers, PCR, genotyping.

10.5154/r.rchsh.2004.02.016

Received: 2004-02-17
Accepted: 2005-06-23
Available online: 2016-07-01
Pages:351-356

PCR-based analysis of DNA has been a routine strategy since the 1990s; it has been widely used for several purposes, among these characterization, differentiation and identification of organisms. The RAPD technique is the most common; however its reproducibility has been questioned among laboratories. In this study, the potential of a non-radioactive technique for genotypification that uses both random and microsatellite primers in the same PCR reaction, called RAMPnr-PCR (non-radioactive RAMP-PCR), is reported. This technique was evaluated with different species of legumes (Cicer arietinum L., Phaseolus vulgaris L., Arachis hypogaea L., Medicago sativa L., Lens esculenta Moench, Vicia faba L., Glycine max L., Pisum sativum L. y Tamarindus indica L.). DNA profiles exhibited were more informative than those obtained independently with RAPDs and MP-PCR. RAMPnr-PCR has several advantages: it is more stability and produces a higher number of DNA fingerprints, marking is not required and cost is equivalent to that of RAPDs or MP-PCR techniques. For those reasons, RAMPnr-PCR can be of great use in typification of genomes as well as in the search for molecular markers related to specific traits.

....

PCR-based analysis of DNA has been a routine strategy since the 1990s; it has been widely used for several purposes, among these characterization, differentiation and identification of organisms. The RAPD technique is the most common; however its reproducibility has been questioned among laboratories. In this study, the potential of a non-radioactive technique for genotypification that uses both random and microsatellite primers in the same PCR reaction, called RAMPnr-PCR (non-radioactive RAMP-PCR), is reported. This technique was evaluated with different species of legumes (Cicer arietinum L., Phaseolus vulgaris L., Arachis hypogaea L., Medicago sativa L., Lens esculenta Moench, Vicia faba L., Glycine max L., Pisum sativum L. y Tamarindus indica L.). DNA profiles exhibited were more informative than those obtained independently with RAPDs and MP-PCR. RAMPnr-PCR has several advantages: it is more stability and produces a higher number of DNA fingerprints, marking is not required and cost is equivalent to that of RAPDs or MP-PCR techniques. For those reasons, RAMPnr-PCR can be of great use in typification of genomes as well as in the search for molecular markers related to specific traits.

....
 

EFECTO DE LA LUZ SOLAR SOBRE EL DESARROLLO Y RENDIMIENTO DEL CHILE PIQUIN (Capsicumannuum L. var. aviculare)

SUNLIGHT EFFECT ON DEVELOPMENT AND YIELD OF PEQUIN PEPPER (Capsicumannuum L. var. aviculare)

L.A. Rodríguez-del Bosque; R. Sánchez-de la Cruz; M.M. Silva-Serna

Keywords: chiltepin, flamboyant, light regimes, shading

10.5154/r.rchsh.2004.06.025

Received: 2004-06-14
Accepted: 2005-06-25
Available online: 2016-07-01
Pages:357-359

Effect of four light regimes of exposition (all-day, only morning, only afternoon, and all-day shaded) on piquin pepper (Capsicum annuum L. var. aviculare) growth and yield was studied in Río Bravo, Tamaulipas, in northeastern Mexico during 2001-2002. Sunlight-shading conditions were created by placing potted piquin plants under or next to flamboyant trees. Direct sunlight and subsequent higher temperatures, particularly during afternoon, reduced piquin growth and yield, probably related to evolution of piquin growing under shade of trees and shrubs in its natural habitat. Growth and yield was higher with none and morning sunlight. This information is important for piquin potential exploitation in intercropping systems with perennial crops.

....

Effect of four light regimes of exposition (all-day, only morning, only afternoon, and all-day shaded) on piquin pepper (Capsicum annuum L. var. aviculare) growth and yield was studied in Río Bravo, Tamaulipas, in northeastern Mexico during 2001-2002. Sunlight-shading conditions were created by placing potted piquin plants under or next to flamboyant trees. Direct sunlight and subsequent higher temperatures, particularly during afternoon, reduced piquin growth and yield, probably related to evolution of piquin growing under shade of trees and shrubs in its natural habitat. Growth and yield was higher with none and morning sunlight. This information is important for piquin potential exploitation in intercropping systems with perennial crops.

....
 

DAMINOZIDE INCREASES INFLORESCENCE DIAMETER OF CHRYSANTHEMUM (Dendranthema grandiflora Tzelev.), CV. POLARIS WHITE

EL DAMINOZIDE AUMENTA EL DIÁMETRO DE INFLORESCENCIA DEL CRISANTEMO (Dendranthema grandiflora Tzelev.), CULTIVAR POLARIS WHITE

A.G. Esquivel-Pool; E. Villanueva-Couoh; A. Pérez-Gutiérrez; L.A. Sánchez-Cach; C.F.J. Fuentes-Cerda

Keywords: growth inhibitor, B-nine, B-9, flower, ornamental plant.

10.5154/r.rchsh.2005.03.021

Received: 2005-03-18
Accepted: 2005-06-24
Available online: 2016-07-01
Pages:361-364

Several daminozide concentrations (1,000, 2,000, 3,000, 4,000 y 5,000 mg·liter-1) were tested on potted chrysanthemum cv. Polaris White plants; data included stem diameter, plant height, nodes, internode length, inflorescence diameter, biomass and leaf area, to compare plants treated with daminozide versus untreated control. The concentration 1,000 mg·liter-1 increased stem diameter 10.08 % compared with the control, while with 4,000 mg·liter-1 it decreased 8 %. Internode length decreased up to 76 % with 4,000 mg·liter-1 compared with the control. Concentrations equal to or greater than 2,000 mg·liter-1 reduced height plant by 34.3 %. Daminozide increased inflorescence diameter by 31.22%.

....

Several daminozide concentrations (1,000, 2,000, 3,000, 4,000 y 5,000 mg·liter-1) were tested on potted chrysanthemum cv. Polaris White plants; data included stem diameter, plant height, nodes, internode length, inflorescence diameter, biomass and leaf area, to compare plants treated with daminozide versus untreated control. The concentration 1,000 mg·liter-1 increased stem diameter 10.08 % compared with the control, while with 4,000 mg·liter-1 it decreased 8 %. Internode length decreased up to 76 % with 4,000 mg·liter-1 compared with the control. Concentrations equal to or greater than 2,000 mg·liter-1 reduced height plant by 34.3 %. Daminozide increased inflorescence diameter by 31.22%.

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PLANT HEAT ZONES OF MEXICO

ZONAS DE CALOR DE PLANTAS DE MÉXICO

L.E. Giddings; M. Soto-Esparza

Keywords: ornamental plants, distribution of plants, databases

10.5154/r.rchsh.2004.02.017

Received: 2004-02-17
Accepted: 2005-06-23
Available online: 2016-07-01
Pages:365-369

A Plant-Heat Zone Map of Mexico is presented, equivalent to the “Plant Heat-Zone Map” of the United States of America (USA). It presents the average number of days per year with maximum temperature over 30 °C (86 °F). Its principal use is to evaluate the potential for cultivating an ornamental plant in a given locality, as does the corresponding USA map, prepared by the American Horticultural Society. In an electronic form it may also be used for calculating potential distributions of wild plants. It was derived from data in the Eric II CD-ROM, which contains daily and monthly records for a large majority of Mexican meteorological stations. Data for individual stations were analyzed for the number of days over 30 °C per year, and average values were compiled. Stations with fewer than 20 years were eliminated, as were years with fewer than 360 days of data in a year. A comprehensive effort eliminated errors of various kinds. The corrected data were used to form a heat-zone map of all of Mexico using kriging (an interpolation technique). Large format maps and electronic data are available from the authors.

....

A Plant-Heat Zone Map of Mexico is presented, equivalent to the “Plant Heat-Zone Map” of the United States of America (USA). It presents the average number of days per year with maximum temperature over 30 °C (86 °F). Its principal use is to evaluate the potential for cultivating an ornamental plant in a given locality, as does the corresponding USA map, prepared by the American Horticultural Society. In an electronic form it may also be used for calculating potential distributions of wild plants. It was derived from data in the Eric II CD-ROM, which contains daily and monthly records for a large majority of Mexican meteorological stations. Data for individual stations were analyzed for the number of days over 30 °C per year, and average values were compiled. Stations with fewer than 20 years were eliminated, as were years with fewer than 360 days of data in a year. A comprehensive effort eliminated errors of various kinds. The corrected data were used to form a heat-zone map of all of Mexico using kriging (an interpolation technique). Large format maps and electronic data are available from the authors.

....
 

FOLIAR FERTILIZATION AS A TOOL IN THE DEVELOPMENT OF THE LILIUM CROP CV. STARGAZER

FERTILIZACIÓN FOLIAR UNA HERRAMIENTA EN EL DESARROLLO DEL CULTIVO DE LILIUM CV. STARGAZER

M. Betancourt-Olvera; María de las Nieves Rodríguez-Mendoza; Manuel Sandoval-Villa; E. A. Gaytán-Acuña

Keywords: honey of bee, nutrition, diagnosis, postharvest.

10.5154/r.rchsh.2004.08.038

Received: 2004-08-04
Accepted: 2005-07-23
Available online: 2016-07-01
Pages:371-378

The present was conducted to evaluate foliar fertilization efficiency on growth, development and quality of the flower of lilium cv Stargazer. The treatments were five, including the control, (with 186-102-174 fertilizer to soil): fertilization based on the diagnosis with 100 % fertilizer to soil, foliar application of honey with 100 % fertilization to soil, and use of the fertilizer NV3 with two levels of fertilization to the soil (100 % and 50 %). For the distribution of the treatments in the greenhouse a completely random design with nine replications was used. Variables measured at the end of the crop cycle were plant height, basal and apical diameter of stem, number of leaves, SPAD readings, fresh and dry weight of the plant, chemical analysis of nutriments in plant tissue (N, P, K, Ca, Mg, Fe, Zn, Mn, Cu and B ). In the treatment where foliear application of honey was performed, response increased for the plant height, number of leaves, basal and apical diameter of the plant; while treatment NV3 affected SPAD readings, fresh and dry weight of the plant, days to floral differentiation and flowering. There were no significant differences for macronutriments, iron and boron. Treatment NV3+100 % had the greatest number of days of vase life.

....

The present was conducted to evaluate foliar fertilization efficiency on growth, development and quality of the flower of lilium cv Stargazer. The treatments were five, including the control, (with 186-102-174 fertilizer to soil): fertilization based on the diagnosis with 100 % fertilizer to soil, foliar application of honey with 100 % fertilization to soil, and use of the fertilizer NV3 with two levels of fertilization to the soil (100 % and 50 %). For the distribution of the treatments in the greenhouse a completely random design with nine replications was used. Variables measured at the end of the crop cycle were plant height, basal and apical diameter of stem, number of leaves, SPAD readings, fresh and dry weight of the plant, chemical analysis of nutriments in plant tissue (N, P, K, Ca, Mg, Fe, Zn, Mn, Cu and B ). In the treatment where foliear application of honey was performed, response increased for the plant height, number of leaves, basal and apical diameter of the plant; while treatment NV3 affected SPAD readings, fresh and dry weight of the plant, days to floral differentiation and flowering. There were no significant differences for macronutriments, iron and boron. Treatment NV3+100 % had the greatest number of days of vase life.

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CITRUS LEAFMINER Phyllocnistis citrella Stainton (Lepidoptera: Gracillaridae) DAMAGE ON MEXICAN LIME TREES

DAÑO DE MINADOR DE LA HOJA DE LOS CÍTRICOS Phyllocnistis citrella Stainton (Lepidoptera: Gracillaridae) EN LIMÓN MEXICANO

Manuel Marciano Robles-González; Víctor Manuel Medina-Urrutia; A. Morfín-Valencia

Keywords: Citrus aurantifolia (Christm) Swingle, mined leaves, curled leaves, dynamics of larvae damage, percentage of infected leaves.

10.5154/r.rchsh.2004.12.095

Received: 0000-00-00
Accepted: 0000-00-00
Available online: 2016-07-01
Pages:379-386

Dynamics of leaf damage by larvae of Phyllocnistis citrella Stainton on Mexican lime trees were studied. Similar damage was observed in three orchards established at different altitudes in the state of Colima. Damage on lime leaves was observed all year around but a high intensity was recorded from October to December and a second important peak was recorded from May to July when up to 90 % of leaves were affected. There was a high correlation between the variables percentage of infested leaves, percentage of curled leaves, mined leaves and number of mines per leaf at the three sites. Low temperature (below 15 °C) were associated to a decrease in damage in winter (Late January, February and March). A notorious decrease in CLM damage was observed also during rainy season (August-September). An increase in anthracnose disease in leaves and the presence of natural predators of CLM were related with low damage during the rainy season. Significant impact on fruit yield of leaf damage caused by CLM was not observed.

....

Dynamics of leaf damage by larvae of Phyllocnistis citrella Stainton on Mexican lime trees were studied. Similar damage was observed in three orchards established at different altitudes in the state of Colima. Damage on lime leaves was observed all year around but a high intensity was recorded from October to December and a second important peak was recorded from May to July when up to 90 % of leaves were affected. There was a high correlation between the variables percentage of infested leaves, percentage of curled leaves, mined leaves and number of mines per leaf at the three sites. Low temperature (below 15 °C) were associated to a decrease in damage in winter (Late January, February and March). A notorious decrease in CLM damage was observed also during rainy season (August-September). An increase in anthracnose disease in leaves and the presence of natural predators of CLM were related with low damage during the rainy season. Significant impact on fruit yield of leaf damage caused by CLM was not observed.

....
 

RIPENING PROCESS OF SAPODILLA FRUITS Manilkara sapota (L.) P. Royen FINO TYPE

PROCESO DE MADURACIÓN DE FRUTOS DE CHICOZAPOTE [Manilkara sapota (L.) P. Royen] TIPO FINO

Benjamín Bautista-Reyes; Ma. de Lourdes Catalina Arévalo-Galarza; Crescenciano Saucedo-Veloz; Ma. Teresa Martínez-Damián

Keywords: Postharvest, softening, pectinesterase, respiration, ethylene.

10.5154/r.rchsh.2004.04.023

Received: 0000-00-00
Accepted: 0000-00-00
Available online: 2016-07-01
Pages:387-391

Sapodilla [Manilkara sapota (L.) P. Royen] is an exotic fruit with great market potential, but it is highly perishable. This study was conducted to evaluate the physiological and biochemical changes during ripening of sapodilla fruit, Fino type, at 21±2 °C and 60 to 65 % , relative humidity. The sapodilla fruits showed a climacteric pattern of respiration, with a maximum level of 21.3 ml·kg-1·h-1 of CO2 and high maximum production of 6.4 ml·kg-1·h-1 of ethylene, during the eight and seven days, respectively; reaching eating ripeness nine days after harvest, associated with an increase in the pectinesterase activity, diminishing firmness, an increase in the sugar content and with diminishing phenols. Acetaldehyde and ethanol production was maintained at low levels during ripening, during senescence production of these volatiles increased.

....

Sapodilla [Manilkara sapota (L.) P. Royen] is an exotic fruit with great market potential, but it is highly perishable. This study was conducted to evaluate the physiological and biochemical changes during ripening of sapodilla fruit, Fino type, at 21±2 °C and 60 to 65 % , relative humidity. The sapodilla fruits showed a climacteric pattern of respiration, with a maximum level of 21.3 ml·kg-1·h-1 of CO2 and high maximum production of 6.4 ml·kg-1·h-1 of ethylene, during the eight and seven days, respectively; reaching eating ripeness nine days after harvest, associated with an increase in the pectinesterase activity, diminishing firmness, an increase in the sugar content and with diminishing phenols. Acetaldehyde and ethanol production was maintained at low levels during ripening, during senescence production of these volatiles increased.

....