The QTL Mapping And Effects Analysis Of Wheat Grain Yield And Quality Traits Based On SRAP And SSR Markers

Wheat is one of the most important crops in the world, and its yield and quality directly affects the life of peoples. Therefore, development of the high yielding and good quality wheat varieties are main target of wheat breeder’s. Yield and quality are quantitative traits which are controlled by polygene, the genetic basis are complex and easily affected by environment. The molecular markers and QTL mapping technique provides an effective method for quantitative traits detection. In this study F2 population of two different varieties Xinong981 and Shanmai159 were used to construct a genetic map on the basis of SRAP and SSR molecular markers. The phenotypic data of F2:3 linesin two locations(Yangling and Sanyuan) were used to analyse the agronomic characters and QTL positioning. The major results were as follows:1) Fifteen linkage groups containing 115 molecular markers involved in A, B and D genomes were established by using 169 F2 population and 612 pairs of SRAP and 1550 pairs of SSR primers. The whole genetic linkage covered 3203.67 cM of the genome and most of the markers located in A and B genomes. The 2B chromosome contained most of the markers and had 21 markers, while 1D chromosome were the one with least, 3markers.2) Thirty-three QTLs for quality related traits were identified including 11 QTLs for protein content which were distributed in the 1A, 3A, 5A, 6A, 2B and 4B chromosome; 7QTLs for starch content distributed in the 1A, 6A, 4B and 2D chromosome; 12 QTLs for gluten content distributed in the 1A, 3A, 5A, 6A, 2B, 3B and 4B chromosome; 3 QTLs for Zeleny sedimentation value distributed in the 3A, 1B and 3B chromosome, They could explain 0.69- 2.48%, 2.94- 6.99%, 0.58- 2.37% and 2.72- 11.31% phenotypic effects; This study could not detected quality related QTL stable in two environments but revealed some QTLs control protein,wet gluten,starch traits stable in the same region of chromosome.3) One hundred and two agronomic and yield traits related QTL were found, 7 QTLs for wheat kernel length, only 1 kernel length QTL was detected in Yangling interval and locatedon 3B chromosome, whereas, 6 kernel length QTLs were detected in Sanyuan interval which distributed on 5A, 6A, 7A, 2B, 3B and 4B chromosome and can explain 4.36%~14.80%phenotypic variance, one kernel length QTL in 3B chromosome can express stable in two environment; 42 plant height QTLs, distributed on chromosome of 1A, 2A, 3A, 4A, 5A, 6A,7A, 1B, 2B, 3B, 4B, 5B and 7B and could explain 0.14~1.08% phenotypic effects; there were 7 for plant height QTLs which can express stable in two environment; 6 plant height QTLs were discovered on 2B chromosome, and thousand kernel weight QTLs and spike grain number QTL were also detected in this chromosome,so more concerns can be paid to2 B chromosome for the further research. 3 spike length QTLs were detected on the chromosome of 2A, 6A and 2B, explaining 4.72~8.35% phenotypic effects. We could not detected grain numbers per spike QTLs in Yangling interval, but there were 26 numbers per spike QTLs in Sanyuan interval. However, the phenotypic variation rate that can explain were low, only 0.45~0.98%;24 QTLs for thousand grain weight, distributed on 2A, 3A, 5A, 6A,7A, 1B, 2B, 3B, 4B, 5B and 7B chromosome and can explain 0.25 ~ 8.23% phenotypic variance. 5 QTLs for thousand grain weight were detected on 2B chromosome, suggest that2 B chromosome might contribute greatly to thousand grain weight trait in this population.