Genetic diversity and variability in Foxtail millet [Setaria italica (L.)] germplasm based on morphological traits

Abstract

Fifty one accessions of foxtail millet (Setaria italica (L.) P. Beauv.), constituting a national elite germplasm collection were evaluated for morphological diversity based on nine quantitative traits viz., plant height, number of basal tillers, days to flowering, flag leaf length, flag leaf width, petiole length, inflorescence length, thousand seed weight and single plant yield. The traits showed a continuous distribution, however number of basal tillers, and single plant yield exhibited skewness in positive directions. Considerable variability was observed among the genotypes for all the traits. Among these, grain yield per plant exhibited the maximum variation with a CV of 22.5%, while days to fifty per cent flowering and plant height exhibited the least variation with a CV 7.2% and 9.3% respectively. PCA analysis revealed that the first four components in the PCA results contributed to a maximum of 70 per cent of the variability, the contributions from PC1, PC2, PC3 and PC4 being 30.1%, 14.2%, 13.8%, and 11.4%, respectively. The first two components were a measure of vegetative and inflorescence characters, while the third component was a measure of thousand seed weight. Cluster analysis based on the nine morphological traits assorted the 51 genotypes into four main clusters. Dendrogram based on hierarchal clustering grouped the genotypes based on their morphological traits, however the grouping of genotypes did not correspond with their geographic origin. Plant height, number of tillers, days to fifty per cent flowering, grain yield per plant, and 1000 seed weight were found to be the most important traits in distinguishing the major clusters of foxtail millet genotypes at the morphological level.