QTL Analyses Of Some Agronomic Traits In Synthetic Wheat

Common wheat (Triticum aestivum L.) is one of the most important crops worldwide. The grain kernel traits and growth stage traits of wheat are very important for the yield, which are generally controlled by multiple genes, and inherited as QTL. QTL analysis has become an important and essential work in crop improvement. In this study, we developed a new genetic linkage map using 171 recombinant inbred lines (RILs), which was generated from the cross between SHW-L1 and Chuanmai 32. QTL analyses were performed using the software of QTL Cartographer v.2.5 based on the CIM model. QTL for seven traits, including kernel wedth, kernel length-wedth rate, thousand kernel weight, emerge date, tillering date, heading date, flowering time. The results were described as following:1 The genetic map consisted of 299 loci and 3959.4 cM with 1006.1 cM for the A genome,1257.1 cM for the B genome and 1696.2 cM for the D genome.2 QTL for kernel wedth, kernel length-wedth rate, thousand-kernel weight, emerge date, tillering date, heading date and flowering time were mapped via Composition interval mapping. And presence of a QTL was declared at a significant threshold a=0.005. For each trait, one to nine additive QTL were identified with individual contribution ranging from 5.73% to 63.39% of the total phenotypic variation. For heading time (HD), two QTL were located on chromosome 2D, one was located between the markers gpw4473 and gpw332a, explained 63.39% of the phenotypic variation. Another QTL was located between the markers gpw4085 and gpw4473 with a strong additive effect contribution (36.45%). For kernel width (KW), one QTL was located on chromosome 2D between the markers gpw4085 and gpw4473, which explained 13.86% of the total phenotypic variation. Another QTL for kernel width was located on chromosome 7B, which explained 10.11% of the total phenotypic variation. For flowering time (FT),3 QTL were detected on chromosomes 1A,2D and 3B. For the date of emergence (ED),2 QTL were detected on chromosomes 2D and 7D. For length-width ratio (LW), three OTL were detected, among which one was located on chromosome 1B, two QTL were located on chromosome 2D. For date of tillering (TD), only one QTL was detected on chromosome 5A. For thousand kernel weight (TKW), nine QTL were detected, among which 1,1,2,2 and 3 QTL were located on chromosomes 2D,3B,1A, 1D and 2A, respectively.