Hunger and malnutrition still affecting part of the Mexican population, for whom the tortilla is a staple food. However, maize tortillas are high in calories but deficient in proteins; therefore, studies have been conducted to fortify tortillas, with protein-rich nonconventional sources. This study examines the physicochemical and rheological characteristics of dough and maize tortillas fortified with nontoxic Jatropha curcas flour. Fortified maize doughs were prepared with 0%, 5%, 10%, 15% and 20% J. curcas nontoxic flour, which contains 55% protein. Tortillas were made and their chemical profile and tortilla quality were quantified and subjected to sensorial analysis. Rheological characteristics of dough were slightly modified but the protein in the tortillas increased 10.8% with treatment T20. They did not change in color, were soft, and consumer acceptance was not affected. It is concluded that nontoxic J. curcas flour is an excellent option for increasing the protein value of tortillas.

Las accesiones de la raza de maíz Palomero Toluqueño no cuentan con información de su capacidad de expansión y las propiedades fisicoquímicas del grano relacionadas con esta característica. Por lo anterior, el objetivo del presente fue determinar la relación que existe entre la capacidad de expansión del grano y variables físicas (dureza, densidad, peso hectolítrico y espesor de pericarpio) y químicas (contenido de almidón total, amilosa y amilopectina) en accesiones de la raza de maíz Palomero Toluqueño. Se evaluaron 18 accesiones de esta raza y siete materiales premejorados. Los materiales se cultivaron en el ciclo agrícola primavera-verano 2014 en Montecillo, Estado de México y Santa María Zacatepec, Puebla. Como testigo, se utilizó un palomero comercial de la marca ‘Valle Verde’. Los datos de las variables evaluadas se analizaron en un diseño completamente al azar, comparación de medias y de correlación entre las variables estudiadas. La media del peso hectolitrico de los materiales premejorados superó por 3.9 kg hL-1 a la de las accesiones de Palomero Toluqueño. Con respecto a la dureza, los materiales premejorados fueron estadísticamente similares al testigo. La raza Palomero Toluqueño y los materiales premejorados presentaron el grosor de pericarpio menor a 0.6 µm mientras que el testigo mostró 0.9 µm del testigo. No se observó diferencia estadística en las variables químicas evaluadas. El peso hectolítrico y el grosor de pericarpio tuvieron correlación positiva con el volumen de expansión, lo que permitirá su uso como pruebas indirectas en el mejoramiento genético para la capacidad de expansión de la raza Palomero Toluqueño.

Drought is a major constraint for common bean (Phaseolus vulgaris L.) production in México. Dehydrins are constitutive or stress-induced proteins related with a protective role of membranes and macromolecules against denaturation, thus preventing loss of their function. In this work, seed production and patterns of dehydrins accumulation in leaves and pods were evaluated in common bean cv. ‘Otomí’ subjected to drought, as compared with well-irrigated plants. Drought applied at pod formation and seed filling (SF) reduced yield up to 57 %. An antibody against a consensus sequence present in most dehydrins allowed for dehydrin identification. Two dehydrins of 82 and 73 kDA turned up both in leaves and pods throughout all the evaluated conditions. Presumably, both dehydrins are constitutive in the ‘Otomí’ cultivar. These dehydrins showed higher expression than controls in leaves after 6 d of drought at seedling and SF stages, and in pods 6 d after drought had started at SF. Increased expression might provide better protection during early stages of seedling and seed development. Increments on 63, 36 and 22 kDa dehydrin expression in pods at late SF might coincide with plant developmental programs, which prepare seed for desiccation. Dehydrins of 158, 54, 46, and 41 kDa were detected in pods 10 d after floral opening as a transient response to drought stress in SF. These results indicate dehydrins are relevant during plant development, as well as during drought stress.

Characterizing the genetic diversity of maize (Zea mays L.) populations by their morphological and molecular attributes makes it possible to place populations into specific groups; thus, facilitating the design of procedures for their optimum and sustainable use. In this study, data from two lines of evidence were analyzed simultaneously to robustly classify maize populations and to determine their genetic relationships. Seven maize races of the central high plateau of Mexico were characterized using a combined analysis of 13 morphological traits and 31 microsatellite loci. The germplasm assessed included samples of 119 accessions held at Mexican germplasm banks. Cluster and principal component analyses were performed. Also, genetic and geographic relationships among the accessions were determined. Principal component analysis separated the different accessions into well-defined groups using first three principal components. The accessions of Arrocillo Amarillo and Elotes Cónicos races did not exhibit a grouping pattern, indicating greater genetic complexity. Better grounded grouping and phylogenetic relationships were obtained when traits of both lines of evidence were used simultaneously.

In Mexico there are wild and domesticated populations of Carica papaya; however, studies related to its variation in situ have been limited in number of both individuals and geographic areas. The objective of this study was to characterize in situ the morphological variation of C. papaya specimens native to Mexico. Twelve morphological characteristics (six quantitative and six qualitative) of fruits collected from 222 specimens of C. papaya from 10 states of the slopes of the Pacific and the Gulf of Mexico were evaluated. Analysis of variance, principal component (PCA) and hierarchical grouping with euclidean distances were performed. According to the analysis of variance, all the morphological characteristics between accessions showed significant differences (P ≤ 0.01). The PCA revealed that the characteristics of greater contribution to the variation among the evaluated specimens were edible volume, diameter of the central cavity, length, diameter, thickness of pulp, shape of the peduncular end and fruit shape. The cluster analysis formed three statistically different phenotypic groups (P ≤ 0.01) and detected continuity based on the dimensions and shape of the fruit. Both multivariate analyses showed differences between the wild and domesticated types collected in homegardens. The high morphological variability among C. papaya is appropriate to establish a national germplasm conservation program of genotypes with genetic dissimilarity to be used in breeding programs. En México existen poblaciones silvestres y domesticadas de Carica papaya; sin embargo, los estudios relacionados con su variación in situ han sido limitados en número tanto de ejemplares como de zonas geográficas. El objetivo del presente estudio fue caracterizar in situ la variación morfológica de ejemplares de C. papaya nativos de México. Se evaluaron 12 características morfológicas (seis cuantitativas y seis cualitativas) de frutos recolectados de 222 ejemplares de papayos nativos provenientes de 10 estados de las vertientes del Pacífico y Golfo de México. Se realizaron análisis de varianza, de componentes principales (ACP) y de agrupamiento jerárquico con distancias euclidianas. De acuerdo con el análisis de varianza, todas las características morfológicas entre recolectas presentaron diferencias significativas (P ≤ 0.01). El ACP reveló que las características de mayor contribución a la variación entre los ejemplares analizados fueron volumen comestible, diámetro de cavidad central, longitud, diámetro, grosor de pulpa, forma del extremo peduncular y forma del fruto. El análisis de conglomerados formó tres grupos fenotípicos estadísticamente diferentes (P ≤ 0.01) y detectó continuidad con base en dimensiones y forma del fruto. Ambos análisis multivariados diferenciaron entre tipos silvestres y domesticados recolectados en huertos familiares. La alta variabilidad morfológica entre C. papaya es apropiada para establecer un programa nacional de conservación de germoplasma de genotipos con disimilitud genética para usarse en programas de mejoramiento genético.