The Comparative Analysis Of The Genetic Effects Of Main Characters Of Medium-early Upland Cotton×Island Cotton

The land and sea cotton hybrid has a strong heterosis, especially in fiber quality, the heterosis research and utilization of F1hybrid between Island Cotton and Upland Cotton is one major way to effectively improve and enhance cotton fiber quality. Using7Upland Cottons(4middle maturity,3early maturity) and4Island Cottons as parents, the NC Ⅱ design was adopted to prepare28crosses to investigate the heterosis performance of mid-early maturity Island Cottons and Upland Cottons. All traits were conducted by Variance Analysis according to single factor experiment with randomized block design, and further implemented correlative analysis. The major traits of Island Cotton and Upland Cotton hybrid were studied by Combining ability analysis and Heritability Estimation. Using the comparisons of single degree of freedom method from Mo huidong Using the comparisons of single degree of freedom method from Mo huidong. The performance of the parents and hybrids between Island Cotton and Upland Cotton were also studied at growth stage. The results were:1Heterosis Comparison Boll number per plant and fiber length had an obvious heterosis. Lint yield and specific strength had a high mid-parent heterosis. The lint yield of cross A5B3and A6B2was higher than the control cross.2Analyses of Genetic Effects Joint position.plant height and uniformity were fully controlled by additive effect. The boll number per plant was mainly controlled by dominant effect. Single boll weight, lint yield, mic value and specific strength were mainly governed by additive effect. The results of heritability Evaluation showed that the narrow heritabilities of boll number per plant and the first boll number were the highest of the Agronomic Characters. Of the quality characters, the narrow heritabilities of mic value and fiber length were the highest. The results of genetic variation coefficient showed that among the agronomic characters the variation coefficient of the lower of thefrist fruit branch of the first fruit branch of the length of a knot was high. The variation coefficient of mic value was high among the quality traits.3Correlation analysis The Correlation Coefficient between boll number per plant and lint yield, lint percentage and lint yield reached a positively very significant level. Single boll weight and lint yield were positively significantly correlated. There was a negatively very significant correlation between plant height and lint yield. The correlation coefficient between fiber length and elongation was negatively significant. The correlation coefficient between plant height and fiber quality, plant height and specific strength was positively very significant, while that of plant height and mic value was negatively very significant. There was a negatively very significant correlation between fiber length with specific strength and boll number. There was a positively very significant correlation between single boll weight and mic value. between lint yield and mic value.4Combining Ability Analysis The GCA effects among each parent of the same trait or among each trait of the same parent existed obvious differences. The GCA of agronomic characters in Baimian2, Zhongmiansuo50and Xinhai27was high. In the whole, the GCA of quality traits in Island Cotton (performed better than that of upland cotton. The differences of SCA among traits in the same cross, among crosses from the same parent were high. The SCA effects of agronomic and quality characters from the crosses taking the Baimian2as female parents were high. In particular.the cross A5B5showed high positively significant SCA effects both in fiber quality and specific strength.5Single degrees of freedom analysis The difference of various female parents with earliness mainly contributed to the difference among plant height, lint percentage and mic value in F1hybrid from Island Cotton and Upland Cotton. The difference between boll number per plant and single boll weight was due to the difference among various types of male parents. The difference of lint yield was mainly affected by various female parents of earliness, interactions between female parents with earliness and different types of male parents. The difference of female parents with various maturities led to the difference of fiber quality and specific strength.6Growth periods The results showed that offspring crosses were able to stably inherit earliness from Baimian2. This was also true of Zhongmiansuo50. The average growth period of crosses taking the Baimian2as the female parents was the shortest. In particular, cross A5B4had the shortest growth period, and121.5days.