Abstract
Plant height is vital for crop yield by influencing plant architecture and resistance to lodging. Although lots of quantitative trait loci (QTLs) controlling plant height had been mapped in foxtail millet, their contributions to phenotypic variation were generally small and mapping regions were relatively large, indicating the difficult application in molecular breeding using marker-assisted selection. In the present paper, a total of 23 QTLs involving in 15 traits were identified via a high-density Bin map containing 3024 Bin markers with an average distance of 0.48 cM from an F2 population. Among them, qPH9 with a large phenotypic variation explained (51.6%) related to plant height, was one of the major QTLs. Furthermore, qPH9 was repeatedly detected in multi-environments under field conditions using two new F2 population from the same F1 plant, and was narrowed down to a smaller interval of 281 kb using 1024 recessive individuals of F2 population. Finally, we found that there was an extremely significant correlation between marker MRI1016 and plant height, and speculated that Seita.9G088900 and Seita.9G089700 could be key candidates of qPH9. This study laid an important foundation for the cloning of qPH9 and molecular breeding of dwarf varieties via marker-assisted selection.
Fine mapping of qPH9, a major quantitative trait locus, responsible for plant height in foxtail millet [Setaria italica (L.) P. Beauv.]
