Comprehensive Evaluation And Analysis Of Excellent Germplasm Resources Of Upland Cotton

In order to broaden the genetic breeding base of upland cotton,select excellent germplasm resources as parents,and use 185 domestically collected upland cotton germplasm resources as test materials,a two-year single-point experimental planting was carried out at the Yunyuan Base of Hunan Agricultural University in Changsha,Hunan Province,and the botanical traits,agronomic traits,fiber quality and yield traits were comprehensively evaluated and analyzed.Genetic diversity analysis,principal component analysis,correlation analysis and cluster analysis of the main traits were carried out to screen out the germplasm resources of upland cotton with excellent agronomic traits,fiber quality and yield traits.Among the quantitative traits of agronomic traits,the nodal variability coefficient of the first fruit branch was the highest,at 24.39%,and the genetic diversity index of the first fruit branch height was the highest,at 2.94;the coefficient of variation of the short and medium fiber index of the fiber quality trait was the highest,which was23.08%,and the genetic diversity index of the maturity index was the highest at 2.08;the coefficient of variation of lint cotton was the highest at 29%,and the genetic diversity of seed finger was the highest at 2.05.The results of principal component analysis showed that the cumulative contribution rate of the three main components of agronomic traits was69.245%,the cumulative contribution rate of the two main components of fiber quality was59.59%,and the cumulative contribution rate of the two main components of yield traits was62.762%.;The correlation analysis results showed that there was a significant positive correlation between the number of fruit branches and plant height,and there was a significant negative correlation between the number of fruit branches and the nodules of the first fruit branch;there was a significant positive correlation between the height of the first fruit branch and the nodality of the first fruit branch;there was a significant negative correlation between the maturity index and the short fiber index and the elongation at break,and there was a significant positive correlation between the average length and the strength of the upper half;there was a significant negative correlation between the short fiber index and the length neatness index,the average length of the upper half,and the strength of the fracture ratio;The specific strength of the fracture was significantly positively correlated;the average length of the upper half was significantly positively correlated with the specific strength of the fracture and the elongation at break;the strength of the specific break was significantly negatively correlated with the elongation at break;the weight of seed cotton was significantly positively correlated with the weight of lint cotton and the clothing,and the lint was significantly positively correlated with the clothing.Cluster analysis shows that the forth group in agronomic traits belongs to high-quality materials,the fiber quality class I.belongs to high-quality materials,and the third group in the yield shape belongs to high-yield materials,through comprehensive evaluation and analysis,8 excellent high-yield germplasms are finally screened out,which can be used as parental materials for fine seed breeding,providing high-quality materials for future cotton variety breeding,as well as improving the economic benefits of cotton planting and increasing the practical value of upland cotton planting.