Abstract:To decipher the genetic interaction of the fiber yield with quality-related traits in high-quality cotton varieties and screen elite lines with higher fiber quality, several traits have been measured in F2 and F2:3 populations, derived from variety CCRI127 with elite fiber quality crossing with sGK line Zhong 156 with high yield. Statistical analysis showed a normal distribution in traits including boll weight, lint percentage, upper half mean fiber length, fiber strength, micronaire, elongation and fiber uniformity. The transgression separation in populations if compared to both parents suggested abundant genetic variations. The ratios over the super high parent were 61.38% and 69.5% for average length of upper part of fiber in F2 and F2:3, 42.12% and 61.00% for fiber strength, and 41.75% and 28.43% for boll weight. A significant positive correlation between the average length of the upper half and fiber strength, and a significant negative correlation between lint percentage and fiber quality traits, including the average length of the upper half and fiber strength were observed, implying antagonistic on fiber yield and fiber quality. Ten individuals with fiber strength higher than 38.0 cN?tex-1 in F2 and F2:3 generations were selected, showing more than 31.0 mm on the average length of the upper half. Collectively, this study provided elite materials for the quantitative trait locus (QTL) mapping for fiber yield and fiber quality, and molecular breeding by stacking multiple elite genes.

Abstract:A total of 290 inbred lines with rich genetic diversity were used in this study. We investigated the relationship between Stalk pushing resistance and fiber quality related traits with at different densities. Stalk pushing resistance and fiber quality related traits excellent performance lines were screened by multiple comparisons among different heterosis. The results shows that different lines had highly significant difference at different densities, furthermore , significantly positive correlation was studied between stalk pushing resistance and content of cellulose. The results of multiple comparison shows that content of cellulose among different heterosis no significant difference at high density. Pushing resistance exist significant difference under two density and content of cellulose under low density among different heterosis. In different heterosis, the number of lines of screened out with excellent performance about pushing resistance and content of cellulose under two density, and there are 4 and 3 lines in the Reid group, 1 and 5 lines in the Lancaster group, 2 and 2 lines in the P group, 2 and 1 lines in the LRC group, 2 and 1 lines in the TangSPT group.

Abstract:In this research, 2 generations of CSSLs( Chromosome Segment Substitution Lines) which derived from combination of upland cotton (Gossypium hirsutum L.) CCRI36 (Chinese Cotton Research Institute 36) as the recipient parent and island cotton (Gossypium barbadense L.) hai1 as the donor parent were used to evaluate the phenotype traits related to yield and fiber quality. Compared with recurrent parent in the same year, the variance ranges and genetic variation coefficients of all traits in populations were very large. In 1942 BC5F3 individuals, the largest lint percentage was up to 49.57%, and the lint percentage was 71.78% higher than recurrent parent, the peak value of fiber strength reached 36.5cN/tex. In 658 BC5F3：4, the maximum value of fiber length and fiber strength reached 32.25mm and 32.2cN/tex respectively, the transgressive rates were 47.57% and 40.27% for fiber length and fiber strength. The correlation analysis showed that it was positive correlation for yield and fiber quality traits between the two generations, but the negative correlation between fiber quality and lint percentage still existed. These results indicated that there were abundant genetic variations and individuals with good yield and fiber quality in CSSLs, the materials were stable and consistent in two generations. However, it was still difficult to improve fiber quality and lint percentage simultaneously. In this study, many materials were provided, which could be further used for QTL fine mapping, gene cloning and molecular assistant pyramid breeding.