| Cotton is not only a cardinal economic crop in the word, but also a largest natural fiber crop. With the improvement of living standard and the development of textile industry, it is urgent to improve the fiber quality characters.In this study, using the molecular maker SSR as technology support, together with two correlation analysis methods: one-way ANOVA and regression analysis, QTL analysis was carried out based on synthetic population contructed from 16 parents hybridization. The purpose of this study was to find the genetic loci associated with fiber quality, so as to realize preliminary mapping of fiber quality traits. The main research results were listed as follows:1. The broad sense heritability of fiber uniformity index was 35.84%, but The broad sense heritability of upper half mean length(63.46%),micronaire value(56.01%),fiber elongation(55.90%),fiber strength(53.45%) were much higher.2. The genetic correlation analysis of the fiber quality traits indicated that fiber uniformity index and fiber strength were very significantly and positively correlated with upper half mean length respectively, the same with fiber uniformity index and fiber strength; micronaire value and fiber elongation have highly significant negative correlation with upper half mean length respectively. Nagative correlation coeffient of fiber uniformity index-fiber elongation was significant at 0.01 level, and the negative correlation of micronaire value-fiber strength, fiber elongation-fiber strength were also very significantly. Fiber uniformity index and micronaire value, micronaire value and elongation did not reach significant levels.3. The one-way ANOVA analysis of the data collected from 2006 and 2007 showed that the molecular markers (SSR) related to 5 phenotypes were repeatly detected in the two years, respectively, and the repeated numbers of the molecular markers range from 2 to 17. Among the markers related to upper half mean length, BNL3400-c had the highest positive effect to the trait both in 2006 and 2007, whose relative effect were 10.16%, 7.84%, respectively. Among the markers related to fiber uniformity index, the maker with the highest positive effect to the trait is JESPR-215-b in 2006, whose relative effect was 2.53%, while it is BNL3976-a in 2007 with the relative effect of 0.81%. Among the markers related to micronaire value, the marker with the highest positive effect to the trait is BNL3400-b in 2006, whose relative effect was 9.43%, while both BNL1655-a and MUSS281-d had the highest positive effect to the trait in 2007, whose relative effects were both 20.70%. Among the markers related to fiber elongation, BNL3400-b had the highest positive effect to the trait in 2006 with the relative effect of 6.72%, while it is BNL3649-d in 2007, whose relative effect was 3.14%. Among the markers related to fiber strength, BNL3400-c had the highest positive effect to the trait both in 2006 and 2007, whose relative effect were 15.41%, 10.87%, respectively.4. Based on regression analysis of the data collected from 2006 and 2007, we found that the numbers of repeat molecular marker detected in the two different years were less than those by one-way ANOVA method, among which the largest number was only 6 that is associated with upper half mean length. Among the markers related to upper half mean length, BNL3400-c had the highest positive effect to the trait both in 2006 and 2007, whose relative effect were 10.16%, 7.84% , respectively. The marker with the highest positive effect to the fiber uniformity index was NAU2162-b in 2006, whose relative effect was 2.18%, while it was JESPR-236-b in 2007, with the relative effect of 0.99%. Among the markers related to micronaire value, BNL3400-b had the highest positive effect to the trait in 2006, whose relative effect was 9.43%, while the marker with the highest positive effect to the trait was MUSS281-d in 2007, whose relative effect was 20.70%. NAU934-a had the highest positive effect to fiber elongation in 2006, whose relative effect was 5.50%, while it was BNL2835-a in 2007 with the relative effect of 1.86%. Among the markers related to fiber strength, NAU2162-b had the highest positive effect to the trait in 2006 with the relative effect of 12.72%, while it was MUSS006-a in 2007, whose relative effect was 4.31%.5. The analysis of interaction effect among molecular markers correlated to the fiber quality character of cotton indicated that the QTL accosiated with markers had significant interactions. Upper half mean length of the group where each sample was simultaneously marked BNL3400-c and BNL3400-a SSR molecular markers was significantly different from the group where each sample was only marked BNL3400-a or BNL3400-a of SSR molecular or neihter of them. The phenomenon suggested that the OTL accosiated with BNL3400-c and BNL3400-a may existed some interactions. The marker pairs of MUSS006-a and BNL3267-a, MUSS006-a and BNL2441-a, BNL4082-a and BNL3400-a, BNL4082-a and BNL3267-a, BNL4082-a and BNL2441-a, BNL3400-a and BNL3267-a associated with fiber strength appeared the similar phenomenon metioned above. |
