Variation in inflorescence architecture associated with yield components in a sorghum germplasm

Abstract

This study was undertaken to analyse the variation in panicle-related traits of 206 sorghum accessions collected from 27 Asian and African countries. Significant differences among the accessions were observed for 18 measured traits. First, we found that the patterns of the observed panicle-related traits reflected the distribution of the accessions of different origins. Second, the distribution of several components of inflorescence architecture in sorghum accessions influenced their yield components. Principal component analysis of the data showed a wide range of variations across the 206 sorghum accessions. Despite their geographical isolation, no distinct separation between the Asian and African accessions was observed. Correlation coefficient and path coefficient analysis indicated that panicle length (PanL), the total number of branches, rachis length (Rac) and panicle width had a positive direct effect on grain yield. Finally, we showed that the variation in the inflorescence architecture of sorghum accessions was dependent not only on the PanL, but also on the total number of branches, the maximum length of primary branches, Rac, panicle diameter and panicle width. Thus, there are major panicle determinants that are strongly associated with grain yield which should be considered in breeding programmes. These results will serve as a starting point for further evaluation of sorghum germplasm via quantitative trait loci analysis and may be useful for improving yield based on careful consideration of trait selection and inflorescence morphology.