ISSN e:2007-4034 / ISSN print: 2007-4034

English | Español

     

 
 
 
 
 
 
 
 

     Vol. 28, issue 3 September - December 2022   Creative Commons License

      
 

     Vol. 28, issue 3 September - December 2022  

 
  

Relationships between stomatal and gas exchange characteristics of the leaf blade in ‘Colín V-33’ avocado seedlings

Relaciones entre características estomáticas y de intercambio de gases de la lámina foliar en plántulas de semilla de aguacate ‘Colín V-33’

Keywords: Persea americana Mill., intercambio gaseoso, índice estomático, densidad estomática, conductancia estomática, transpiración

10.5154/r.rchsh.2021.05.008

Received: 2021-05-07
Accepted: 2022-07-06
Available online: 2022-08-24
Pages:133-144

El uso de portainjertos de aguacate es muy común, pero éstos han sido poco estudiados desde el punto de vista anatómico y fisiológico de la hoja, variables que pueden ser útiles para entender su papel al ser injertados, como las relacionadas con los estomas y el intercambio de gases. El objetivo de esta investigación fue estudiar las características de los estomas e intercambio de gases de la lámina foliar en plántulas derivadas de semilla de aguacate ‘Colín V-33’ para determinar posibles relaciones entre estas. Se utilizaron 93 plantas derivadas de semilla de ‘Colín V-33’ de seis meses de edad. Se evaluaron cuatro variables de estomas y cinco de intercambio de gases en la hoja once de cada planta. Los estomas se clasificaron como anomocíticos, y su longitud fue de 13.11 a 19.65 µm, su densidad varió de 317.65 a 105.88 estomas·mm-2 y su índice estomático fue de 11.78 a 26.16 %. Se encontró correlación positiva significativa entre las variables fisiológicas conductancia estomática y tasa de transpiración (r = 0.96**), mientras que en la tasa de asimilación de CO2 y la concentración interna de CO2 existió una correlación negativa (r = -0.64**). No se encontró asociación entre las características de intercambio de gases y las variables relacionadas con estomas. Debido a la variación encontrada en la densidad y el índice estomático, es posible seleccionar genotipos contrastantes que podrían tener impacto en el injerto cuando sean utilizados como portainjertos, dada la evidencia de otros estudios donde hay modificaciones en dichas variables.

El uso de portainjertos de aguacate es muy común, pero éstos han sido poco estudiados desde el punto de vista anatómico y fisiológico de la hoja, variables que pueden ser útiles para entender su papel al ser injertados, como las relacionadas con los estomas y el intercambio de gases. El objetivo de esta investigación fue estudiar las características de los estomas e intercambio de gases de la lámina foliar en plántulas derivadas de semilla de aguacate ‘Colín V-33’ para determinar posibles relaciones entre estas. Se utilizaron 93 plantas derivadas de semilla de ‘Colín V-33’ de seis meses de edad. Se evaluaron cuatro variables de estomas y cinco de intercambio de gases en la hoja once de cada planta. Los estomas se clasificaron como anomocíticos, y su longitud fue de 13.11 a 19.65 µm, su densidad varió de 317.65 a 105.88 estomas·mm-2 y su índice estomático fue de 11.78 a 26.16 %. Se encontró correlación positiva significativa entre las variables fisiológicas conductancia estomática y tasa de transpiración (r = 0.96**), mientras que en la tasa de asimilación de CO2 y la concentración interna de CO2 existió una correlación negativa (r = -0.64**). No se encontró asociación entre las características de intercambio de gases y las variables relacionadas con estomas. Debido a la variación encontrada en la densidad y el índice estomático, es posible seleccionar genotipos contrastantes que podrían tener impacto en el injerto cuando sean utilizados como portainjertos, dada la evidencia de otros estudios donde hay modificaciones en dichas variables.

 

Chelated zinc and beneficial microorganisms: a sustainable fertilization option for pecan production

Zinc quelado y microorganismos benéficos: una opción de fertilización sostenible en la producción de nueces

Keywords: Carya illinoinensis, Pisolithus tinctorius, mycorrhizal fungi, soil zinc.

10.5154/r.rchsh.2022.01.001

Received: 2021-10-29
Accepted: 2022-07-06
Available online: 2022-08-24
Pages:145-159

Zinc (Zn) fertilization of pecan trees is carried out by foliar spraying, since the nutrient in the soil is bound to carbonates, which hinders its absorption by the tree. This practice has environmental repercussions because it is an aerosol. Therefore, the objective of this study was to generate an alternative to foliar Zn application with soil-applied chelated Zn combined with beneficial microorganisms to maintain or improve pecan production. Fifteen homogeneous trees were selected based on trunk cross-sectional area and crown volume in a pecan orchard in Chihuahua, Mexico. During four years (2015-2018), three treatments with five replications were evaluated under a completely randomized design. The treatments were: 1) foliar Zn (36 % ZnSO4), 2) soil Zn (14 % Zn chelated with carboxylic acids) and 3) soil Zn + mycorrhizal fungus (Pisolithus tinctorius + Azospirillum brasilense). The orchard studied had native communities of P. tinctorius, which was found in 83.7 % of the roots analyzed. Pecan production, in the four years, with the different treatments was 27 kg with foliar Zn, 25.4 kg with chelated Zn and 26.9 kg with chelated Zn plus microorganisms. The results indicate that soil-applied Zn is a viable and environmentally friendly option.

Zinc (Zn) fertilization of pecan trees is carried out by foliar spraying, since the nutrient in the soil is bound to carbonates, which hinders its absorption by the tree. This practice has environmental repercussions because it is an aerosol. Therefore, the objective of this study was to generate an alternative to foliar Zn application with soil-applied chelated Zn combined with beneficial microorganisms to maintain or improve pecan production. Fifteen homogeneous trees were selected based on trunk cross-sectional area and crown volume in a pecan orchard in Chihuahua, Mexico. During four years (2015-2018), three treatments with five replications were evaluated under a completely randomized design. The treatments were: 1) foliar Zn (36 % ZnSO4), 2) soil Zn (14 % Zn chelated with carboxylic acids) and 3) soil Zn + mycorrhizal fungus (Pisolithus tinctorius + Azospirillum brasilense). The orchard studied had native communities of P. tinctorius, which was found in 83.7 % of the roots analyzed. Pecan production, in the four years, with the different treatments was 27 kg with foliar Zn, 25.4 kg with chelated Zn and 26.9 kg with chelated Zn plus microorganisms. The results indicate that soil-applied Zn is a viable and environmentally friendly option.

 

Phenolic profile and nutritional value of Dahlia x hortorum flowers

Perfil fenólico y valor nutricional de flores de Dahlia x hortorum

Keywords: ácidos fenólicos, flavonoides, composición proximal, florifagia, recursos fitogenéticos.

10.5154/r.rchsh.2022.03.004

Received: 2022-02-22
Accepted: 2022-07-06
Available online: 2022-08-24
Pages:161-174

The consumption of edible flowers has increased the search for new species to improve their nutritional impact. Therefore, the aim of this study was to determine the phenolic profile and nutritional value of the flowers of some Dahlia x hortorum clones (C1Var – variegated, C2Gui – cherry, C3Roj – red, C4Nar – orange, C5Ama – yellow, C6Fuc – fuchsia) and C7Ros – pink). The experiment was conducted at the Department of Plant Science, Universidad Autónoma Chapingo, Mexico, under a completely randomized experimental design with three replications. Phenolic acids (gallic, caffeic and chlorogenic) and flavonoids (quercetin and hesperidin) were detected. Similar contents of gallic acid (between 1.91 and 3.19 μg·g) were found in C7Ros, C1Var, C5Ama and C4Nar, where C1Var also stood out for the presence of quercetin (81.46 μg·g-1). The highest incidence of caffeic acid and hesperidin was found in C2Gui and C6Fuc. In general, C1Var showed a high percentage of crude fiber, crude fat and protein, although the last one was similar to C7Ros and C5Ama (13.68 and 13.72 μg·g-1, respectively). Likewise, C2Gui, C4Nar and C3Roj showed variation with respect to total carbohydrates (64.09, 61.64 and 62.37 %, respectively). According to the results, dahlia ligulate flowers have a significant content of phenolic acids, flavonoids, fiber and protein, as well as a variable caloric level, so they can be considered as a functional food and be integrated into daily intake.

The consumption of edible flowers has increased the search for new species to improve their nutritional impact. Therefore, the aim of this study was to determine the phenolic profile and nutritional value of the flowers of some Dahlia x hortorum clones (C1Var – variegated, C2Gui – cherry, C3Roj – red, C4Nar – orange, C5Ama – yellow, C6Fuc – fuchsia) and C7Ros – pink). The experiment was conducted at the Department of Plant Science, Universidad Autónoma Chapingo, Mexico, under a completely randomized experimental design with three replications. Phenolic acids (gallic, caffeic and chlorogenic) and flavonoids (quercetin and hesperidin) were detected. Similar contents of gallic acid (between 1.91 and 3.19 μg·g) were found in C7Ros, C1Var, C5Ama and C4Nar, where C1Var also stood out for the presence of quercetin (81.46 μg·g-1). The highest incidence of caffeic acid and hesperidin was found in C2Gui and C6Fuc. In general, C1Var showed a high percentage of crude fiber, crude fat and protein, although the last one was similar to C7Ros and C5Ama (13.68 and 13.72 μg·g-1, respectively). Likewise, C2Gui, C4Nar and C3Roj showed variation with respect to total carbohydrates (64.09, 61.64 and 62.37 %, respectively). According to the results, dahlia ligulate flowers have a significant content of phenolic acids, flavonoids, fiber and protein, as well as a variable caloric level, so they can be considered as a functional food and be integrated into daily intake.

 

Alternaria alternata, Fusarium oxysporum and Fusarium verticillioides identified as causal agents of broccoli head rot in Mexico

Alternaria alternata, Fusarium oxysporum y Fusarium verticillioides agentes causales de la pudrición de brócoli en México

Keywords: Brassica oleracea

10.5154/r.rchsh.2022.03.003

Received: 2022-02-05
Accepted: 2022-08-12
Available online: 2022-08-26
Pages:175-188

El brócoli es una de las hortalizas de mayor importancia económica en México, y una de las enfermedades que reduce su rendimiento y calidad es la pudrición del florete, la cual se ha asociado a diferentes fitopatógenos. El objetivo del presente trabajo fue identificar morfológica y molecularmente a los agentes causales de la pudrición del florete en el cultivo de brócoli en México. Se colectaron floretes con síntomas de pudrición en diferentes municipios del estado de Guanajuato (León, San Francisco del Rincón, Valle de Santiago, Abasolo, Juventino Rosas y Dolores Hidalgo). Los aislados obtenidos se identificaron con base en sus características culturales, morfológicas y molecularmente (mediante PCR-ITS) como Alternaria alternata (AA), Fusarium oxysporum (FO) y Fusarium verticillioides (FV). La patogenicidad de estas especies fúngicas se corroboró mediante los postulados de Koch. La frecuencia de aislamiento de los hongos fue de 55, 26 y 19 % para AA, FV y FO, respectivamente, del total de muestras analizadas. La secuencia obtenida de un aislado representativo de cada hongo se comparó con las reportadas en el banco de genes del NCBI, donde los mayores porcentajes de similitud fueron 99.6, 98.9 y 98.2 % para FO, FV y AA, respectivamente, con lo cual se confirmaron los resultados de la identificación morfológica. Este es el segundo reporte de la presencia de AA y FO asociados a la pudrición del florete de brócoli en México, y el primer reporte de FV como parte del complejo de agentes causales de esta enfermedad.

  • Losses caused by head rot of broccoli are over 40 % in Guanajuato, Mexico.
  • Alternaria alternata, Fusarium oxysporum and Fusarium verticillioides are the causal agents of head rot of broccoli in Mexico.
  • 83 isolates of Fusarium spp. were identified in head rot of broccoli.
  • 102 isolates of Alternaria alternata were identified in head rot of broccoli.
  • El brócoli es una de las hortalizas de mayor importancia económica en México, y una de las enfermedades que reduce su rendimiento y calidad es la pudrición del florete, la cual se ha asociado a diferentes fitopatógenos. El objetivo del presente trabajo fue identificar morfológica y molecularmente a los agentes causales de la pudrición del florete en el cultivo de brócoli en México. Se colectaron floretes con síntomas de pudrición en diferentes municipios del estado de Guanajuato (León, San Francisco del Rincón, Valle de Santiago, Abasolo, Juventino Rosas y Dolores Hidalgo). Los aislados obtenidos se identificaron con base en sus características culturales, morfológicas y molecularmente (mediante PCR-ITS) como Alternaria alternata (AA), Fusarium oxysporum (FO) y Fusarium verticillioides (FV). La patogenicidad de estas especies fúngicas se corroboró mediante los postulados de Koch. La frecuencia de aislamiento de los hongos fue de 55, 26 y 19 % para AA, FV y FO, respectivamente, del total de muestras analizadas. La secuencia obtenida de un aislado representativo de cada hongo se comparó con las reportadas en el banco de genes del NCBI, donde los mayores porcentajes de similitud fueron 99.6, 98.9 y 98.2 % para FO, FV y AA, respectivamente, con lo cual se confirmaron los resultados de la identificación morfológica. Este es el segundo reporte de la presencia de AA y FO asociados a la pudrición del florete de brócoli en México, y el primer reporte de FV como parte del complejo de agentes causales de esta enfermedad.

    • Losses caused by head rot of broccoli are over 40 % in Guanajuato, Mexico.
    • Alternaria alternata, Fusarium oxysporum and Fusarium verticillioides are the causal agents of head rot of broccoli in Mexico.
    • 83 isolates of Fusarium spp. were identified in head rot of broccoli.
    • 102 isolates of Alternaria alternata were identified in head rot of broccoli.
     

    Relationship between chlorophyll and nitrogen content, and fresh matter production in basil ‘Nufar’ (Ocimum basilicum) with three handheld chlorophyll meter readings: SPAD, atLEAF and MC-100

    Relationship between chlorophyll and nitrogen content, and fresh matter production in basil ‘Nufar’ (Ocimum basilicum) with three handheld chlorophyll meter readings: SPAD, atLEAF and MC-100

    Keywords: non-destructive analysis; aromatic plant, soilless culture.

    10.5154/r.rchsh.2021.09.018

    Received: 2021-08-07
    Accepted: 2022-07-06
    Available online: 2022-08-24
    Pages:189

    Determinations of nitrogen (N) and chlorophyll (Chl) by destructive methods are precise but time-consuming and frequently expensive. The objective of this study was to determine the relationship between SPAD, atLEAF, and MC-100 readings with the concentrations of Chl, N, and fresh matter (FM) in basil 'Nufar'. In addition, we determined the relationship of the N concentration with fresh matter (FM). The plants were irrigated with five levels of N (0, 4, 8, 12, and 16 mEq·L-1 of NO3) based on a modified Steiner solution for 42 days after transplant. Plants were evaluated weekly with SPAD, atLEAF and MC-100 portable chlorophyll meters in the greenhouse, while fresh matter and the concentration of chlorophyll and N were determined in the laboratory using conventional techniques. The relationship between SPAD readings, Chl, N, and FM was strong, positive, linear, and significant, with correlation coefficients (R2) between 0.94 and 0.98. For atLEAF and MC-100 readings, R2 values were 0.96 to 0.99 and 0.96 to 0.99, respectively. The relationships between SPAD, atLEAF and MC-100 readings were strong, positive, and significant, with R2 values of 0.98. Similar behavior was shown by the relationship of N concentration and FM with R2 of 0.88. With these results, we conclude that SPAD, atLEAF, and MC-100 can be used to estimate the nutrient status of N in a non-destructive, rapid and reliable manner during basil production.

    Determinations of nitrogen (N) and chlorophyll (Chl) by destructive methods are precise but time-consuming and frequently expensive. The objective of this study was to determine the relationship between SPAD, atLEAF, and MC-100 readings with the concentrations of Chl, N, and fresh matter (FM) in basil 'Nufar'. In addition, we determined the relationship of the N concentration with fresh matter (FM). The plants were irrigated with five levels of N (0, 4, 8, 12, and 16 mEq·L-1 of NO3) based on a modified Steiner solution for 42 days after transplant. Plants were evaluated weekly with SPAD, atLEAF and MC-100 portable chlorophyll meters in the greenhouse, while fresh matter and the concentration of chlorophyll and N were determined in the laboratory using conventional techniques. The relationship between SPAD readings, Chl, N, and FM was strong, positive, linear, and significant, with correlation coefficients (R2) between 0.94 and 0.98. For atLEAF and MC-100 readings, R2 values were 0.96 to 0.99 and 0.96 to 0.99, respectively. The relationships between SPAD, atLEAF and MC-100 readings were strong, positive, and significant, with R2 values of 0.98. Similar behavior was shown by the relationship of N concentration and FM with R2 of 0.88. With these results, we conclude that SPAD, atLEAF, and MC-100 can be used to estimate the nutrient status of N in a non-destructive, rapid and reliable manner during basil production.