Quantitative Genetic Analysis And QTL Mapping For Developmental Behavior Of Swelling Index Of Glutenin(SIG) In Wheat

A set of recombinant inbred lines (RIL) population (F2:8) derived from Jing771×Pm9703 was used for analysis of the relationship between swelling index of glutenin(SIG) and other eight quality traits, for studing on dynamic changes of SIG value in common wheat and mapping QTLs related to SIG value at five measured stages of wheat kernel's development .Major results are described below:1. The method of measuring SIG value in wheat was studed, when used 0.24g flour weight the result was best.2. The results showed that the frequency of SIG value and other 8 quality traits in RIL population was approximately normally distributed and the tremendous transgressive segregation for all traits was observed. The results of correlations analysis showed that the relation between SIG value and Zeleny sedimentation, glutenin index, wet gluten content, glutenin macropolymer (GMP)content were extreme significant positive correlation except swelling power and protein content , and the relativity between Zeleny sedimentation value and SIG value was the highest。While, extreme significant and significant negative correlation were observed between SIG value and alkaline water retentiveness capacity(AWRC),kernel hardness. The results of multiple linear regression analysis showed that the better linear relationship between SIG value and wet gluten content, Zeleny sedimentation value, swelling power, AWRC, kernel hardness, protein content were observed, the regression equation were set up at same time. Path analysis showed that Zeleny sedimentation value was the most important index. It affected SIG value directly, while, wet gluten content and swelling power affected SIG value indirectly.3. The dynamic changes and the net genetic variation of SIG were investigated. The results indicated that the dynamic change of SIG value in most RILs was the similar to their parents Jing 771 and Pm97034. The peak values of SIG value were reached on the 17 and 27 days after anthesis, and droped to the lowest on the 22 days after anthesis. However, SIG value was lower than the peak value at maturity generally. The results of conditional genetic variance components showed that the dynamic changes of the SIG value net genetic variation were similar to SIG value phenotypic value.4. 129 Simple Sequence Repeat (SSR) makers were assigned on a linkage map which contained 21 chromosomes, the total length of the linkage map equals to 2106.3 cM, with an average interval of 16.3 cM.5. Two main-effect additive QTLs located on 4A and 5B were associated with SIG value were detected in stage of grain maturation, and explained 12.49% of genotypic variation..Seven interaction QTLs were detected, which located on 2A,2B,5B,6A,6B,6D,7A,7B chromosomes .6. Eight unconditonal QTLs and five conditional QTLs were detected affecting SIG value at five measured stages of kernel's development by using conditional composite interval mapping method,but no one QTL was found in all five stages.It meant that the genes espress controlled SIG value was different in different time and different location.