Quantitative trait loci analysis of economically important traits inSorghum bicolor×S. sudanensehybrid

Abstract

Lu, X-p., Yun, J-f., Gao, C-p. and Acharya, S. 2011. Quantitative trait loci analysis of economically important traits in Sorghum bicolor×S. sudanense hybrid. Can. J. Plant Sci. 91: 81–90. Many agronomic traits of Sorghum bicolor×S. sudanense hybrid are quantitatively inherited, and the gene mapping of these traits has important research and practical consequences. In this study, genetic mapping and quantitative trait loci (QTL) analyses were conducted using 248 F2:3plants of a cross between sorghum 314A (female parent) and Sudan grass 2002GZ-1 (male parent). A total of 178 markers (170 amplified fragment length polymorphism and 8 random amplified polymorphic DNA) were employed to construct a linkage map with 10 linkage groups covering 836 cM of the genome. The two parents expressed polymorphism for 10 agronomic characters (plant height, stem diameter, leaf number, leaf length, leaf width, spike length, tiller number, ratio of stem and leaf weight, fresh plant weight and dry plant weight). When analyzed for possible QTLs a total of 98 QTLs were identified in two test sites, out of which 26 QTLs overlapped in both sites. The average number of QTLs per character was found to be 2.6 and the distributions of these QTLs were found to be uneven across linkage groups. This, and the fact that molecular marker densities were not proportional with QTL frequencies, indicates that the detectable QTLs correlated with the agronomic traits and the genetic map can be useful for improvement in relevant characters in Sorghum bicolor×S. sudanense hybrids.