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

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     Vol. 26, issue 1 January - April 2020   Creative Commons License

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     Vol. 26, issue 1 January - April 2020  

 
  

Doses and number of applications of ethephon in sex reversal of zucchini squash flowers

Dosis y número de aplicaciones de etefón en la reversión sexual de flores de calabacita

Edgard Henrique Costa-Silva; Aline Torquato-Tavares; Tiago Alves-Ferreira; Irais Dolores Pascual-Reyes; Francielly Quitéria Guimarães-Alves; Ildon Rodrigues-do Nascimento

Keywords: Cucurbita pepo, ethylene, phytohormones, sex expression in Cucurbits

10.5154/r.rchsh.2019.06.011

Received: 2019/06/05
Accepted: 2019/09/12
Available online: 2019-12-31
Pages:05-14

Ethylene can change the flowering pattern of some cucurbits, favoring the emergence of female flowers. The objective was to determine the influence of doses and number of ethephon applications in sex reversal of zucchini (Cucurbita pepo L.). The experiment was conducted in a 4 x 4 factorial arrangement, plus a control (natural flowering), the first factor being the ethephon doses (125, 250, 375 and 500 mg∙L-1) and the second the number of applications (1, 2, 3 and 4). Ethephon influenced the sexual expression of zucchini, but not enough to achieve complete sex reversal. The 500 mg∙L-1 dose provided the largest feminization for all applications. Ethephon might be a useful tool for zucchini breeding programs.

....

Ethylene can change the flowering pattern of some cucurbits, favoring the emergence of female flowers. The objective was to determine the influence of doses and number of ethephon applications in sex reversal of zucchini (Cucurbita pepo L.). The experiment was conducted in a 4 x 4 factorial arrangement, plus a control (natural flowering), the first factor being the ethephon doses (125, 250, 375 and 500 mg∙L-1) and the second the number of applications (1, 2, 3 and 4). Ethephon influenced the sexual expression of zucchini, but not enough to achieve complete sex reversal. The 500 mg∙L-1 dose provided the largest feminization for all applications. Ethephon might be a useful tool for zucchini breeding programs.

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A cauliflower-sweet corn intercropping system in high-temperature conditions

Sistema de cultivo intercalado de coliflor y maíz dulce en condiciones de temperatura elevada

Susi Kresnatita; Ariffin -; Didik Hariyono; Sitawati -

Keywords: Brassica oleracea, Central Kalimantan, leaf area growth, plant spacing, planting time

10.5154/r.rchsh.2019.09.014

Received: 2019/08/30
Accepted: 2019/10/26
Available online: 2019-12-31
Pages:15-27

The cauliflower (Brassica oleracea var botrytis L.) has received increased interest due to its high price and high demand. The study aimed to assess the effect of planting time and plant spacing on the growth and yield of cauliflower plants intercropped with sweet corn under high-temperature conditions in Central Kalimantan, Indonesia. The main plot consisted of three different sweet corn planting times: four weeks before cauliflower planting, two weeks before cauliflower planting and simultaneous planting with cauliflower. In the sub-plots three different plant spacing distances were used for sweet corn: J1 = 60 cm, J2 = 30 cm and J3 = 20 cm. Variables analyzed in this study were air temperature, leaf area, plant dry weight, curd weight, curd diameter and curd yield. Results showed that planting sweet corn two weeks before transplanting the cauliflower and the J1 distance gave an air temperature, in the cauliflower plant canopy, suitable for leaf area growth and an increase in both plant dry weight and caul flower curd yield (4.18 and 5.07 t∙ha-1).

....

The cauliflower (Brassica oleracea var botrytis L.) has received increased interest due to its high price and high demand. The study aimed to assess the effect of planting time and plant spacing on the growth and yield of cauliflower plants intercropped with sweet corn under high-temperature conditions in Central Kalimantan, Indonesia. The main plot consisted of three different sweet corn planting times: four weeks before cauliflower planting, two weeks before cauliflower planting and simultaneous planting with cauliflower. In the sub-plots three different plant spacing distances were used for sweet corn: J1 = 60 cm, J2 = 30 cm and J3 = 20 cm. Variables analyzed in this study were air temperature, leaf area, plant dry weight, curd weight, curd diameter and curd yield. Results showed that planting sweet corn two weeks before transplanting the cauliflower and the J1 distance gave an air temperature, in the cauliflower plant canopy, suitable for leaf area growth and an increase in both plant dry weight and caul flower curd yield (4.18 and 5.07 t∙ha-1).

....
 

Selection of native yeasts for the production of sparkling ciders from apple varieties established in Querétaro, Mexico

Selección de levaduras nativas para la elaboración de sidras espumosas a partir de variedades de manzana establecidas en Querétaro, México

Alma Karina León-Teutli; Monserrat Hernández-Iturriaga; Dalia Elizabeth Miranda-Castilleja; Jesús Alejandro Aldrete-Tapia; Lourdes Soto-Muñoz; Ramón Álvar Martínez-Peniche

Keywords: Malus domestica Borkh, killer effect, β-glucosidase, Saccharomyces, champenoise method

10.5154/r.rchsh.2019.06.010

Received: 2019/06/17
Accepted: 2019/11/02
Available online: 2019-12-31
Pages:29-47

The low quality of the apple produced in Querétaro, Mexico, impedes its efficient fresh marketing. One possible solution to this problem is to produce champagne-type sparkling cider. Therefore, the objective of this work was to select strains of Saccharomyces yeasts isolated from apple varieties of the region, based on desirable traits to make sparkling ciders. To select the yeasts, we induced the spontaneous fermentation of the must of 14 varieties, from which 135 strains (102 Saccharomyces spp.) were isolated and three (MM7, 436.4 and RY5) were selected, all with killer phenotype, β-glucosidase activity, tolerance to 8 % ethanol and 50 mg∙L-1 of SO2, a different degree of flocculation and with the ability to produce more than 3 atm of pressure in the bottle. With MM7, a base cider of good quality was obtained (glucose < 2 g∙L-1, pH 3.57, total titratable acidity of 4.03 g∙L-1 and volatile acidity of 0.27 g∙L-1). For the second fermentation, the base ciders made with MM7 were bottled, 15 g∙L-1 of sucrose were added and then they were inoculated separately with MM7, 436.4, RY5 or K1-V1116. By day 21, they all reached about 6 atm of pressure. Sensorially, ciders made with MM7 stood out in effervescence speed, and those made with RY5 in taste acceptability. The amplification and sequencing of the ITS1/ITS4 domain identified MM7 and 436.4 as S. cerevisiae, and RY5 as S. paradoxus. The selected yeasts showed desirable traits for the production of quality sparkling ciders typical of the region.

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The low quality of the apple produced in Querétaro, Mexico, impedes its efficient fresh marketing. One possible solution to this problem is to produce champagne-type sparkling cider. Therefore, the objective of this work was to select strains of Saccharomyces yeasts isolated from apple varieties of the region, based on desirable traits to make sparkling ciders. To select the yeasts, we induced the spontaneous fermentation of the must of 14 varieties, from which 135 strains (102 Saccharomyces spp.) were isolated and three (MM7, 436.4 and RY5) were selected, all with killer phenotype, β-glucosidase activity, tolerance to 8 % ethanol and 50 mg∙L-1 of SO2, a different degree of flocculation and with the ability to produce more than 3 atm of pressure in the bottle. With MM7, a base cider of good quality was obtained (glucose < 2 g∙L-1, pH 3.57, total titratable acidity of 4.03 g∙L-1 and volatile acidity of 0.27 g∙L-1). For the second fermentation, the base ciders made with MM7 were bottled, 15 g∙L-1 of sucrose were added and then they were inoculated separately with MM7, 436.4, RY5 or K1-V1116. By day 21, they all reached about 6 atm of pressure. Sensorially, ciders made with MM7 stood out in effervescence speed, and those made with RY5 in taste acceptability. The amplification and sequencing of the ITS1/ITS4 domain identified MM7 and 436.4 as S. cerevisiae, and RY5 as S. paradoxus. The selected yeasts showed desirable traits for the production of quality sparkling ciders typical of the region.

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Salinity response of Kentucky bluegrass (Poa pratensis L.) as influenced by salicylic acid and progesterone

Respuesta a la salinidad del pasto azul de Kentucky (Poa pratensis L.) tratado con ácido salicílico y progesterona

Keywords: Poa pratensis, chlorophyll, malondialdehyde, environmental stress

10.5154/r.rchsh.2019.08.012

Received: 2019/07/11
Accepted: 2019/12/07
Available online: 2019-12-31
Pages:49-63

The effect of salicylic acid (SA) and progesterone (P4) on physiological and biochemical parameters of Kentucky bluegrass under salinity stress was assessed. A factorial experiment was established based on a randomized complete block design with four replications, under greenhouse conditions. The experimental treatments included four levels of salinity (0, 2, 4 and 6 dS∙m-1) and two plant growth regulators (P4 and SA) at six levels including the control (1 and 10 mg∙L-1 P4, 1 and 3 mM SA, and 1 mg∙L-1 P4 + 1 mM SA). The increase in salinity impaired the quality of grass, but SA and P4 application alleviated the impacts of salinity and ameliorated the quality of grasses under salinity. The highest electrolyte leakage was observed under 6 dS.m-1 salinity and 3 mM SA. The application of SA and P4 improved the carotenoid content in bluegrass subjected to saline stress compared to plants not treated with growth regulators. The highest total chlorophyll content was obtained from 2 dS∙m-1 salinity and 10 mg∙L-1 P4. Leaf proline content was increased with salinity level. However, slight differences existed between different levels of growth regulators. The SA and P4 increased proline content. Salinity increased the concentration of malondialdehyde (MDA) in the grass from 12 to 50 %, and growth regulators helped to reduce this concentration. Also, an increase in peroxidase activity with 6 dS∙m-1 salinity was observed when SA and P4 were applied simultaneously. Overall, it was observed that SA and P4 increased salinity tolerance through enhancing grass quality, chlorophyll, and carotenoid content and scavenging free oxygen radicals through influencing antioxidant enzymes.

....

The effect of salicylic acid (SA) and progesterone (P4) on physiological and biochemical parameters of Kentucky bluegrass under salinity stress was assessed. A factorial experiment was established based on a randomized complete block design with four replications, under greenhouse conditions. The experimental treatments included four levels of salinity (0, 2, 4 and 6 dS∙m-1) and two plant growth regulators (P4 and SA) at six levels including the control (1 and 10 mg∙L-1 P4, 1 and 3 mM SA, and 1 mg∙L-1 P4 + 1 mM SA). The increase in salinity impaired the quality of grass, but SA and P4 application alleviated the impacts of salinity and ameliorated the quality of grasses under salinity. The highest electrolyte leakage was observed under 6 dS.m-1 salinity and 3 mM SA. The application of SA and P4 improved the carotenoid content in bluegrass subjected to saline stress compared to plants not treated with growth regulators. The highest total chlorophyll content was obtained from 2 dS∙m-1 salinity and 10 mg∙L-1 P4. Leaf proline content was increased with salinity level. However, slight differences existed between different levels of growth regulators. The SA and P4 increased proline content. Salinity increased the concentration of malondialdehyde (MDA) in the grass from 12 to 50 %, and growth regulators helped to reduce this concentration. Also, an increase in peroxidase activity with 6 dS∙m-1 salinity was observed when SA and P4 were applied simultaneously. Overall, it was observed that SA and P4 increased salinity tolerance through enhancing grass quality, chlorophyll, and carotenoid content and scavenging free oxygen radicals through influencing antioxidant enzymes.

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White smut (Entyloma australe Speg.) resistance in tomatillo (Physalis spp.) germplasm

Resistencia al carbón blanco (Entyloma australe Speg.) en germoplasma de tomate de cáscara (Physalis spp.)

Cristhyan David Moncayo-Pérez; Natanael Magaña-Lira; Aureliano Peña-Lomelí; Santos Gerardo Leyva-Mir; Jaime Sahagún-Castellanos; Mario Pérez-Grajales

Keywords: Pathogenic fungi, occurrence, severity, genetic resistance, tomatillo

10.5154/r.rchsh.2019.09.016

Received: 2019-09-17
Accepted: 2019-12-12
Available online: 2019-12-19
Pages:65-77

Tomatillo (Physalis ixocarpa Brot. ex Horm.) is attacked by a great variety of pathogens,  which result in high yield losses, such is the case of white smug (Entyloma australe Speg.). Therefore, the objective was to evaluate the damage caused by white smug in 24 tomatillo materials to determine their resistance and susceptibility, as well as the pathogen’s impact  on yield. Two production cycles were established: spring-summer and summer-fall in 2017. In the former, yield per plant (kg) was evaluated in two harvest periods carried out 72 and 83 days after transplanting (YP1 and YP2). The size of the fruit was also evaluated in weight (g) of 10 fruits from each harvest (FW1, FW2), volume (mL), total yield per plant (TYP; kg), average weight of the fruits (AFW;g), plant height (PH; cm) and the area under the disease progress curve (AUDPC). The last two variables were also evaluated in the second cycle. Accession 12 (JAL 103) had the highest yield, but it was the most susceptible to being   attacked by the pathogen, while 26 (48 BNGEN) and 64 (147 BNGEN) were more resistant to this fungus. The varieties with the highest yield and size were Tecozautla 04, Gema, Manzano T and Puebla SM3. However, Tecozutla 04, Manzano T and Gema were the most susceptible to the disease, while Zafiro MSM and Diamante were the least susceptible.

....

Tomatillo (Physalis ixocarpa Brot. ex Horm.) is attacked by a great variety of pathogens,  which result in high yield losses, such is the case of white smug (Entyloma australe Speg.). Therefore, the objective was to evaluate the damage caused by white smug in 24 tomatillo materials to determine their resistance and susceptibility, as well as the pathogen’s impact  on yield. Two production cycles were established: spring-summer and summer-fall in 2017. In the former, yield per plant (kg) was evaluated in two harvest periods carried out 72 and 83 days after transplanting (YP1 and YP2). The size of the fruit was also evaluated in weight (g) of 10 fruits from each harvest (FW1, FW2), volume (mL), total yield per plant (TYP; kg), average weight of the fruits (AFW;g), plant height (PH; cm) and the area under the disease progress curve (AUDPC). The last two variables were also evaluated in the second cycle. Accession 12 (JAL 103) had the highest yield, but it was the most susceptible to being   attacked by the pathogen, while 26 (48 BNGEN) and 64 (147 BNGEN) were more resistant to this fungus. The varieties with the highest yield and size were Tecozautla 04, Gema, Manzano T and Puebla SM3. However, Tecozutla 04, Manzano T and Gema were the most susceptible to the disease, while Zafiro MSM and Diamante were the least susceptible.

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