Cruzas intervarietales de maíz para la región semicálida de Guerrero, México

The topography and agro-ecology of the Guerrero State is diverse and in agricultural areas of intermediate elevation (1 200 to 1 700 m), almost no improved varieties are planted, due to unfavorable climatic and soil conditions, so it is difficult to establish a maize breeding program for every ecological niche. In these regions, the stability of 25 maize varieties was examined, during five summer-autumn crop seasons from 2005 to 2009; aiming to identify an intervarietal cross that was stable, consistent and with good yield potential through the environments. The data was analyzed in 20 varieties, using a randomized complete block design with three replications by location and combining locations. Using this information, the stability parameters proposed by Eberhart and Russell, and described by Molina were estimated, also the additive main effects and multiplicative interaction model (AMMI) was applied. The V15 and V16 male parents showed stability and consistency through the environments, a similar behavior was shown by V3, V7 and V9 intervarietal crosses, they were also outstanding in grain yield, V11 was consistent and showed greater production potential in unfavorable environments. Intervarietal crosses V1, V4, V6, V10, farmer's local variety V13 and female parents V17, V18 and V20, showed good response infavorable environments but were also inconsistent. The two methods used, showed similar results, so, it was possible to select three varieties by its grain yield potential, stability, and consistency in environments. La orografía y agroecología del estado de Guerrero es muy diversa y en las áreas agrícolas de altitud intermedia (1 200 a 1 700 m), prácticamente no se siembran variedades mejoradas, debido a condiciones climáticas y edáficas poco favorables, por lo que dificulta establecer un programa de mejoramiento genético de maíz para cada nicho ecológico. En estas regiones se examinó la estabilidad de 25 variedades de maíz, durante cinco ciclos agrícolas verano-otoño de 2005 a 2009; con el propósito de identificar una cruza intervarietal estable, consistente y con buen potencial de rendimiento a través de ambientes. La información se analizó en 20 variedades, usando un diseño de bloques completos al azar con tres repeticiones por localidad y combinando localidades. Con esta información se estimó los parámetros de estabilidad propuestos por Eberhart y Russell y descritos por Molina; además se aplicó el modelo de efectos principales aditivos e interac