Identifying The QTLs For Chlorophyll Content, Grain Weight And Density And The Effects Of Variations In TaCRE1on Secondary Root Of Wheat

Photosynthesis is an important factor in determining the potential of wheat yield,chlorophyll is the main organ of wheat photosynthesis, which affects grain filling andweight, grain quality and yield of wheat. Therefore, it’s very necessary to researchchlorophyll dynamic changes during wheat grain filling. In this research, The recombinantinbred line population (RILs) from the cross between Jing411and Hongmangchun21wasinvestigated which included177lines, and the QTLs for chlorophyll content of flag leaf,grain weight and grain density were also identified based on the population. At the sametime, the relationship of the allelic variation in TaCRE1with secondary root of wheat hasbeen studied using the collection and original genotypes (in total40). The main resultswere as follows:1. The chlorophyll content of flag leaf at early and middle stages of grain filling andthe total content had a significant correlation with1000-grain-weight of wheat, however, atlater stage of filling, the chlorophyll content didn’t show a close relationship with grainweight. These results indicated the chlorophyll content from the early to middle stage hadmore significant effects on the grain weight than that of other stages during wheat filling.2. In our research, grain density of wheat showed a significant correlation only withthe chlorophyll content of flag leaf at the later grain filling stage in2011crop season, andonly with the total content of chlorophyll in2012crop season. The results showed that therelationship between chlorophyll content of flag leaf at different filling stages and graindensity was easily affected by in the different environments.3. Two QTLs (2AS1and2AS2)for chlorophyll content of flag leaf at I and II fillingstages were located on the short arm of2A, which were linked to the SSR marker intervalsof Barc1138~Barc212and Barc5~Gwm448respectively in2011crop season. However, in2012crop season, only2AS2was detected. The two QTLs also associated with1000-grainweight of wheat and were all found in2011and2012crop season. In this research, no QTLwas found for grain density of wheat.4. A significant correlation was found between the allelic variations of TaCRE1andsecondary root number of wheat at the developing stage before winter and jointing stagerespectively, but not significant at spring developing stage. The allelic variations ofTaCRE1showed more effect on the secondary root at jointing stage than the stage beforewinter, but has the smallest effect at spring developing stage.