Quantitative genetic avenues of improving productivity in sorghum - an appraisal

Abstract

Sorghum classified as an often-cross-pollinated crop has the dual advantage of parental maintenance by selfing without undue inbreeding depression and yielding high heterosis in identified cross combinations. Of the several component traits that have a direct bearing on seed yield, earliness plant height and maturity were recognized crucial and have been exploited in the past through conscientious selection. Phenotypic and genetic diversity between tropical and temperate genotypes have been judiciously exploited to produce high yielding hybrids which helped to tone up productivity to a great extent. The yield levels of hybrids remained always higher than those of pure lines and populations. With biotic and abiotic constraints gaining ground, sorghum productivity has started plateauing and it is time to contemplate conducive alternatives or modifications to the breeding procedures presently in vogue. Basic research into identifying a 'key' component character set that is dynbamic and relevant to the material targeted for improvement will provide vital clues in those areas. Results of fundamental genetic value generated in other self-pollinated crops may quality for test verification. With this view, the current status of sorghum breeding is reviewed and basic results from groundnut are examined in the light of achievements and requirements for improving productivity in sorghum.