Genetic variability, heritability and genetic gain for quantitative traits in South African sorghum genotypes

摘要

Sorghum is one of the most important cereal crops grown in the world for human consumption, animal feed and bio-energy. Theobjective of the study was to estimate the genetic variability, heritability and genetic gain of some agro-physiological traits of 98sorghum accessions in South Africa. The studies were conducted at Makhathini in KwaZulu-Natal and Burgershall in Mpumalangaprovinces. The experiments were laid out in an alpha lattice design replicated twice. The plant height, panicle length, panicle widthand panicle exsertion, rachis number, panicle weight, thousand seed weight, and grain yield per panicle were recorded. The datawere subjected to analysis of variance using generalised linear model and means were separated using Duncan Multiple RangeTest. Coefficients of variation were also determined. There were significant differences among the traits measured. Plant heightwas significant and positively associated with panicle length (r =0.139), panicle width (r = 0.127) and panicle weight (r = 0.1457).Panicle exsertion was highly significant and negatively correlated with all other traits except with plant height. The PrincipalComponent analysis revealed three most important PCs contributing a total variation of 92.36%. The PC1, PC2, and PC3 contributed42.53, 34.65 and 15.18%, respectively. Low, medium and high estimates of broad sense heritability were found in different plantcharacters under study. Highest heritability estimates were found in plant height, thousand seed weight, panicle length and rachisnumber. Values of genetic advance ranged between 0.39 to 17655.04 and the genetic gain (of the mean percent) ranged from 3.27to 372.52. Greater magnitude of broad sense heritability coupled with higher genetic advance in traits studied provided theevidence that these were under the control of additive genetic effects indicating that selection in the germplasm should lead to afast improvement of the traits.