Abstract:A genetic map composed of 14 linkage groups including A genome and B genome was constructed with 241 SSR(Simple Sequence Repeat) markers by using a population consisted of 99 F10 recombinant inbred lines(RILs) derived from a cross of Triticum polonicum L.line ‘XN555’ and Triticum aestivum L.line ‘Zhong 13’.With growth curve fitting of Logistic equation,conditional and unconditional QTLs for thousand-grain weight in the period of slow growth,rapid growth and plateau phase were detected.(1)5 unconditional QTLs and 5 conditional QTLs for thousand-grain weight were detected on A genome and B genome in total.(2)Of unconditional QTLs,two QTLs were found in the period of slow growth and rapid growth each and one QTL was found in the plateau phase,associating with chromosomes 2B,3A,3B and 7A.The phenotypic contribution of individual unconditional QTL was in the range of 9.66%~15.18%.(3)Of conditional QTLs,one QTL was detected in the period of rapid growth and four were detected in the plateau phase,involving chromosomes 1A,2B,5B and 7B,respectively.The phenotypic contribution of individual conditional QTL ranged from 13.01% to 29.27%.(4)One unconditional QTL and one conditional QTL in the period of rapid growth,as along with one unconditional QTL in the plateau phase,were detected between markers Xbarc361 and Xwmc422 with a distance of 0.05 cM away from marker Xbarc361 on chromosome 2B.For dry matter accumulation of wheat kernels,numbers of QTLs and the genetic effects of the same QTL were different in differing grain filling periods,which indicated time-dependent and sequenced expression of QTLs.
