QTL Mapping For Some Important Agronomic Traits In Upland Cotton (Gossypium Hirsutum L.)

The Acala 1517 and DeZhou 047 were used to establish the recombined inbred line, which was used to construct the linkage maps. Based on the maps, some QTLs controlling the important agronomic characters were located, which may be helpful in improving the quality of cotton. The objective of our research was finding QTLs with good agronomic characters, which will generate some materials used in pyramiding or transferring some elite genes. The major methods adopted and conclusions in our study were summarized below.1.In our study, Acala 1517 with elite fiber quality and early maturated DeZhou 047 were used to generate the RIL CRIG6. The two parents were crossed by individual to individual, and then the F₁ was self-crossed, which generated 146 F₂ individuals. From the F₂ generation, the single seed descent method was introduced to reproduce the next generations. To the summer of 2006, 126 F₁₁ families have been acquired.2.The agronomic characters at its different stages of development, the fiber quality, and the yield were tested or observed systematically. Data of observation was analysised by SPSS.The results showed that: the difference of every characters between the two parents was significant or extremely significant; and most of the individuals was distributed in normal distribution with two good shoulders, which match to the phenotypes conditioned by multiple micro-effect genes. Skewness and kurtosis located in the normal range, so it is adequate to QTLs location.3.The correlation analysis of each character detailed that: DFS, DFF, BOS, three stages of the maturation performance significantly positive correlation each other. The FFBN against DFS, DFF, BOS performed significant negative correlation. The fiber quality traits, yield traits correlation was very close. This result was in accord with the ancestors. It was valuable to the marker assistant breeding about cotton different traits synchronous improvement.4.From the screening of the polymorphism, it was showed that the relative rate was 1.76%, which made it difficult to construct the high density genetic map. But in the nearer genetic background, the QTL location was more efficient and the relationship between the QTL and the character was more convictive.5.The composed interval mapping method and the mixed linear modal analysis were used to locate QTLs controlled concerned characters. 18 QTLs were acquired including 3 concerned with development stages, 7 with fiber quality and 8 with yield .In addition; some epistatic QTLs were found when we adopted the mixed linear modal analysis.6.Overviewing the linkage maps, stage of QTLs conditioned the cotton development fiber quality, yield showed clustered in some locus which indicated that among the different characters there existed the one gene-multiple effect and interaction of genes. From the information above, our study was helpful to the molecular marker assistant breeding...