QTL Analysis Of Important Quality Related Traits Using Recombinant Inbred Lines Derived From The Cross Of Triticum Polonicum L. Line "XN555"×Triticum Aestivun L. Line "Zhong13"

Wheat is one of the most important food crops in the world, and more than40%of thepopulations live on wheat. With the improvement of living standards, people have becomeincreasingly demanding on the quality of wheat especially the nutritional and processingquality. Therefore, the wheat quality breeding is an important breeding objective at presentand in the future. Important quality traits of wheat and other crops is generally controlled bymultiple genes of quantitative trait loci, which is the inheritance of quantitative characters inthe most effective analysis method. Compared with the traditional quantitative geneticsanalysis, QTL positioning can analyze the effects of genes controlling traits loci, single geneloci and genetic mode of action, and can be obtained with the loci closely linked molecularmarkers for marker assisted selection. Poland wheat (Triticum polonicum L.2n=4x=28=AABB) is relatives of common wheat, which have many prominent agronomictraits, such as big spike, big grain, and good quality traits. To investigate the genetic basis ofTriticum aestivum L. quality traits, the QTLs for grain hardness (GH), grain protein content(GPC), flour protein content (FPC), wet gluten content (WGC) and starch pasting properties(RVA) were analyzed in a population which consisted of ninety-nine F10recombinant inbredlines (RILs) derived from the cross Triticum polonicum L. line “XN555” and Triticumaestivum L. line “Zhong13”. The results were as the following:1. Based on the linkage map constructed by our laboratory, Two hundred and forty onemarkers were located to the14linkage groups including genome A and B. This map spanned1338.92cM with the average distance of5.56cM between any two markers. The longestlinkage map is chromosome7B which up to183.67cM and7A chromosome was the shortest,reaching37.48cM. The average of each chromosome contains17.21markers, linkages tochromosome7B most, achieve25,6A chromosome contains at least, for11.2. The QTLs for quality related traits, i.e. GH, GPC, FPC, WGC and RVA, were detected based on the phenotypic in2012and2013. Based on the linkage map constructedwith single sequence repeat (SSR) makers, the software Icimapping v3.2and the inclusivecomposite interval mapping were used to identify QTL for quality related traits. A total of54additive QTLs with the genetic distance from0.00cM to5.70cM away from the nearestmarker were detected on12chromosomes, including1A、2A、3A、4A、5A、6A、7A、1B、2B、3B、5B and6B. Among them, GPC and FPC are7QTLs, WGC and GH are both5QTLs,RVA is30(5peak viscosity,5trough viscosity,4breakdown,5final viscosity,4setback,6pasting time,1pasting temperature). Single QTL for5quality traits could account forphenotypic variations from8.30%to29.69%,6.90%~29.50%，10.10%~18.43%，7.93%~30.49%and7.79%~35.18%respectively.3. The QTLs on1A and1B for GH were identified both in2012and2013. The QTLs in1B were all main effect QTL whose contribution rate was up to a maximum of29.59%. Twoof seven QTLs for GPC were detected in the interval of Xbarc104~Xcfa2114on chromosome6A based on the phenotypic of two years, which showed that the wheat6A chromosome maybe related to protein content. Stable expressions of QTLs for FPC were detected in5Bbetween two years. In the interval of Xbarc104~Xcfa2114on chromosome6A, with geneticdistances of1.2cM from the nearest marker Xbarc104, two QTLs for WGC were detectedboth in2012and2013. Meanwhile, one QTL for FPC in2012and one QTL for GPC in2013were detected in the same interval as well. In this study, in the interval of Xwmc161～Xwmc501on chromosome4A, with genetic distances of0.05cM from the nearest markerXwmc501,5main effect QTLs for peak viscosity, trough viscosity, final viscosity and pastingtime were detected. And pasting time was detected both in2012and2013. This study showsthat the4A chromosome plays an important role on RVA, consistented with the results ofprevious studies.The results of this study provide theoretical basis and technical support for the use ofPoland wheat in wheat quality breeding and application of molecular assisted selection inwheat quality breeding.