Identification Of QTL For Cottonseed Oil、protein And Gossypol Content In Upland Cotton(Gossypium Hirsutum L.)RIL Population

In order to identify more major QTLs which express stably in multiple environments, the population of196recombinant inbred lines (F6:8) of upland cotton derived from the cross of0-153and SGK9708was used to analyze heredity and identify quantitative trait loci (QTLs) for cottonseed oil contents、protein contents and gossypol contents in a multi-environments condition including4environments based experiments in two locations and three years. The results were analyzed by the software WinQTLcart2.5in the study. The main results acquired in this study are as following:1. The Phenotype data of oil、protein and gossypol contents in cottonseed indicate that the absolute value of skewness of the three traits was less than one in all the four environments, which showed a feature of normal distribution and could be considered,to identify QTLs of the said three traits.2. The analysis of oil, protein and gossypol contents in cottonseed in4environments indicates that oil, protein and gossypol contents in cottonseed are typical quantitative traits, among which oil and gossypol contents in cottonseed existed transgressive segregations lower than the low parent, while cottonseed protein content showed transgressive segregations higher than the high parent.3. The line of MBR004has the highest oil content of45.45%among all the RILs and expressed stably in four environments and the line of MBR080has the highest protein content of56.39%among all the RILs and only expressed in one environment.4. The correlation analysis in the four environments displayed that oil content was negatively correlated with protein content in great significance and partially positively correlated with gossypol content. The protein content was positively correlated with oil content in significance.5. Based on a genetic map of186SSR markers and a total genetic distance of827.84cM with an average interval of4.45cM between two markers and covering about18.6%of cotton genome,8QTLs were detected for oil content and contributed to the phenotypic variation(PV) by5.42%-13.15%, in which1QTL was identified stably expressed;4QTLs were detected for protein content and contributed to the phenotypic variation(PV) by 4.35%-14.93%;2QTLs were detected for gossypol content and contributed to the phenotypic variation(PV) by0.08%-0.22%.