Analysis of QTLs for Yield Traits of Wheat

The yield traits of wheat were very important for breeding and wheat production,but most of them were quantitatively inherited parameters.The objectives of this study were to find more QTLs for yield traits of wheat and to apply them in the variety improvement and marker-assisted breeding.Tiller number per plant(TPP),kernel number of major spike(KPMS),kernel number per spike(KPS) and 1000-kernel weight(TKWT) of 104 recombinant inbred lines (RILs) from a cross between Wangshuibai(a Jiangsu landrace) and Alondra(a Mexico variety) were assessed in the field trails at two locations in 1998,2000 and 2003.With the methods of interval mapping and MQM mapping,a QTL located on chromosome 5A for TPP was detected and able to explain 10.3%~18.8% of phenotypic variation.8 QTLs on chromosome 1B,1D,3B,4A,5D,6B(2)and linkage group 4(the exact chromosome unknown) and 11 QTLs on chromosome 1B,1D,2A,2B,3B(2),4A,5D,6B(2)and 7A were found for KPMS and KPS,explaining 9.9%~19.9% and 7.5%~43.4%of phenotypic variation,respectively.Among these QTLs,5 QTLs on chromosome 3B,4A,5D and 6B(2) were the same between KPMS and KPS.5 QTLs associated with TKWT were detected on chromosome 2A,2B,3B,4D and 7A,each QTL was able to explain 9.6%~25.7% of phenotypic variation respectively.These QTLs detected in this study could be useful in future marker-assisted-selection programs.