a Genetic analysis of non-restorer lines in Sorghum (Sorghum Bicolor (L) Moench)

Abstract

A genetic analysis of malntainers of sterility in the milo-kafir cytoplasmic genetic system was undertaken at the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru, Andhra Pradesh, India during 1981-83, to study divergence, combining ability, heterosis and variance components of important characters through a 15xl5 dialle and lIne x tester cross analyses in sorghum .

Results indicated high variabilIity in the non-restorer collection. Additive genetic varieance component was predominant In controlling important agronomic characters. Heritability estimates for all characters were high. High heteros is was observed for grain yield, panicle yield, biomass production, plant height and grain number. The expression of heteros is in yield was attributed to cumulative effects of yield components. Heteros is was not related to genetic, geographic or taxonomic diversity. All the high yielding crosses involved at least one parent with a high gca effect.

Based on results, good prospect of Improving female parents for hybridization programme were envisaged, primarily due to the contribution of new variability from the population derived lines developed at ICRISAT. It was suggested to Initially screen parents on the basis of their perse performance and then evaluate their combining ability for optimal use of resources in a breeding program. A mass selection scheme subsequently followed by reciprocal recurrent selection for gca was recommended for the improvement of parental populations.

A line, Rs/R-Z0768Z-5-1 recessive for the two genes (b1b1b2b2) determining. testa in sorghum grain, was discovered. The line would produce white grained sorghum hybrids with any poll inator parent and would be useful in breeding programmes on a global basis.