| Sorghum [Sorghum bicolor (L.) Moench] is one of the most important cereal crops globally after wheat, maize, rice, barley, and has a predominant role in the food, fodder and energy resources. It has "C4" photosynthetic system with high photosynthetic efficiency and has multiple abiotic stress resistance like drought, lodging, barren land and salkine-alkaline. Using F6individuals from a cross of sorghum line T70and P607, a molecular genetic linkage map was constructed with SSR markers, and important traits including number of primary branches, number of basal tillers, and growth period were QTL mapped in order to provide foundation for marker assisted selection in sorghum breeding and precise mapping of major effect QTL. Following main research results were obtained:1. A linkage map for sorghum spanned a distance of318.8cM with an average distance between markers of3.84cM was developed with83SSR markers, the218F6recombinant inbred lines from the cross of sorghum lines T70and P607.2. Based on the constructed linkage map, QTL mapping was conducted for six traits of number of primary branches (PBRNB), number of basal tillers (TINB), days to booting (DTBO), days to earring (DTEA), days to flowering (DTFL) and days to fruiting (DTFR). Eleven QTLs controlling PBRNB were mapped on chrl, chr2, chr3, chr5, chr6, chr8, chr9and chr10, which explained1.25%-21.70%; Nine QTLs controlling TINB were mapped on chrl, chr2, chr4, chr5and chr6, which explained1.37%-13.45%; Six QTLs controlling DTBO were mapped on chrl, chr2, chr5, chr6, chr7and chr8, which explained3.09%-16.20%; Five QTLs controlling DTEA were mapped on chr2, chr3, chr7, chr8and chr9, which explained2.61%-15.36%; Five QTLs controlling DTFL were mapped on chr2, chr3, chr7, chr8and chr9, which explained2.73%-15.09%; Three QTLs controlling DTFR were mapped on chrl, chr2, and chr8, which explained6.71%-12.27%.3. Lots of QTL clusters for traits collective expression were identified on chrl, chr2, chr7, chr8and chr9. QTLs hot expression region on chr8control four texted growth period traits, which further verified the pleiotropism of growth period loci. |
