Mapping QTLs For Part Of Traits Associated With Harvest Index In Wheat

To definite genetic basis of traits related to harvest index in wheat, a population of236RIL(F7and F8generation) derived from two elite Chinese wheat cultivars Xiao yan81and Xinong1376were cultivated in Yangling of Shaanxi Province, Zhumadian of Henan Provinceand Jinan of Shandong Province for two consecutive years. An genetic linkage map wasconstructed with181SSR markers and the additive QTLs for traits related to harvest index inwheat were analyzed through the software QTL lciMapping V3.2which is based on theinclusive composite interval mapping. The results have showed that:1.1909pairs of SSR primers derived from different origins were filtered using parents.223pairs of SSR core primers were obtained together and the polymorphism frequency is11.68%. And181markers were mapped on21linkage groups.2. The QTLs were analyzed through the inclusive composite interval mapping（LI et al.2007）using the software QTL lciMapping V3.2which is based on stepwise regression linearmodel.53QTLs were detected and respectively distributed on chromosomes1A,3A,4A,5A,6A,7A,3B,4B,5B,6B,1D,3D,5D and7D explaining3.52%~26.15％of the phenotypicvariances.3. The QTLs for flag leaf length, width and area were analyzed.8QTLs for flag leaflength located on chromosomes1A,4A,3B,5D and7D were found explaining5.10％~16.44％of the phenotypic variances.6QTLs were situated on chromosomes1A,3A,5A,7A and5D, detected for flag leaf width, explaining the phenotypic variations from4.63％~14.24％.9QTLs for flag leaf area were mapped on1A,3A,4A,7A,3B and5D chromosomes,accounting for4.25％~21.18％of the phenotypic variation.4. QTL analysis on plant height in wheat were conducted.11QTLs for plant height werechecked out located on3A,6A,7A,3B,4B,6B,1D,3D and5D chromosomes explaining3.84％~21.47％of the phenotypic variances.5. QTL analysis on spikelets per spike and Grains per spike were conducted.8QTLs forspikelets per spike were detected and able to explain3.95％-19.74%phenotypic variation.11QTLs for Grains per spike mapped on1A,4A,7A,3B,4B,5B,1D,3D and7D chromosomeswere found, accounting for3.52%~26.15％of the phenotypic variation. 6. QTLs for flag leaf length, width and area were different and the genetic contribution ofthe same QTL were also variant in different phenotypic traits. Among the QTLs for the sametrait in the same year in different locations and those in different years in the same location,some were the same but the others different.7. Some QTLs for different trait were located at the same marker interval of achromosome and they perform pleiotropisms. The results have suggested that1QTL detectedon chromosomes1A control the flag leaf length, width and area in wheat together and thephenotypic variation is significant,1QTL detected on chromosomes3B control the flag leaflength, area and plant height in wheat together so that they could be used in marker-assistedselection breeding and Polymerization breeding.