Genetic variability among Ethiopian sorghum landrace accessions for major agro-morphological traits and anthracnose resistance

Abstract

Sorghum [Sorghum bicolor (L.) Moench] is one of the major food crops serving millions of people in the semi-arid regions of the world but its production is curtailed by anthracnose, among other challenges. Breeding high yielding and anthracnose resistant sorghum cultivars is an overriding goal for water-limited environments that experience high humid conditions, including Ethiopia. The objective of this study was to assess genetic variation among Ethiopian sorghum landrace accessions based on agro-morphological traits and anthracnose resistance, aiming to select promising genotypes for breeding. Three hundred and sixty six sorghum landrace accessions and three check cultivars were evaluated at the Bako Agricultural Research Center in western Ethiopia for 2 years. Data on 11 agro-morphological traits and anthracnose reaction were collected. The analysis of variance indicated that the genotype main effects were highly significant (P ≤ 0.01) for all the assessed traits. Hierarchical clustering using the phenotypic trait data grouped the accessions into five major clusters. The five clusters contained genotypes sourced from different geographical origins, and two accessions that did not belong to any particular cluster. The phenotypic coefficient of variation was higher than the corresponding genotypic coefficient of variation for all traits, reflecting the confounding effect of environment and genotype interactions in the observed variation. Panicle length, anthracnose reaction and fresh biomass yield had relatively higher heritability and high expected genetic advance, suggesting that these traits could be improved by direct selection. Path coefficient analysis indicated that harvest index and fresh biomass had the strongest direct effects on grain yield. Accessions 71559, 71571, 71425, 71644, 243645, 71524, 70161, 204622, 71653 and 71551 were the best performers in grain yield, yield components and anthracnose resistance. These accessions are selected for yield and anthracnose improvement in sorghum breeding programs.