Raúl Rodríguez

Comparison of isogenic sorghums for two types of cytoplasm and general and specific combining aptitude.

espanolEl objetivo de este estudio fue comparar las estimaciones de aptitud combinatoria en un grupo de hibridos isogenicos para tipo de citoplasma (A1 y A2), estudiando la posibilidad de utilizar el sistema A2 a nivel comercial. Los genotipos se evaluaron en diez ambientes y se tomaron datos de rendimiento de grano, dias a floracion, porcentaje de humedad del grano, altura de planta, longitud de panicula y longitud de excercion. Los calculos para estimar aptitud combinatoria general (ACG) y especifica (ACE) se hicieron de acuerdo al modelo propuesto por Beil y Atkins en 1967. Los resultados indicaron que aunque en general los mejores valores de ACG y ACE correspondieron a genotipos con el citoplasma A2, no se encontro relacion con el tipo de citoplasma. Tambien sugiere que el citoplasma A2 puede ser usado para la produc-cion comercial de hibridos de sorgo como una alternativa al citoplasma A1. EnglishThe purpose of this study was to compare estimates of relati ve general and specific combining ability effects on isogenic hybrids in two different cytoplasm types (A1 and A2), and observe the possibility of use the A2 system for the commercialproduction of sorghum hybrids. Genotypes were evaluated in ten environments located in northern Mexico. Grain yield, days to flowering, grain moisture content at harvest, plant height, panicle lenght and panicle excertion were recorded from the experiments. Combining ability was estimated ac-cording to the model suggested by Beil and Atkins in 1967. Although in all studied, the characteristics generally, the best SCA and GCA were for A2 cytoplasm, there was no relation between cytoplasm type and combining ability. These results indicate that A2 cytoplasm can be used for commercial hybrid sorghum seed production, as an alternative to Al cytoplasm.