关键词: 海岛棉, 种质资源, 表型性状, 遗传多样性, 综合评价

Abstract:

【Objective】The study is an attempt to the genetic diversity relationship of phenotypic traits of Sea-island cotton germplasm and screen Sea-island cotton germplasm with excellent traits, which provides a theoretical basis for in depth research on quality traits of Sea-island cotton.【Method】Genetic diversity analysis and comprehensive evaluation were carried out with 12 phenotypic traits of 175 Sea-island cotton. Principal component analysis, weights and the use of membership function to generate comprehensive evaluation value D for comprehensive evaluation of Sea-island cotton germplasm resources.【Result】The results (showed that) Sea-island cotton have rich types and consistent with the range of phenotypic traits was 6.40%-28.10%,which the resource genetic diversity index is 1.97 to 2.05, the diversity analysis significant differences in genetic diversity of Sea-island cotton resources between Xinjiang and outside Xinjiang (P＜0.05); 3 comprehensive factors were converted from principal component analysis 12 traits, which the contribution rates are: 49.34%, 18.03% and 10.63%, with a total contribution rate of 78%; The larger load of the first principal component is the number of envoys, the height of envoys, the number of effective branches, the number of bolls, the number of effective bolls, the weight of seed cotton per plant and the weight of lint per plant, representing growth and effective yield factors; The larger load of the second component is lint, single boll seed cotton weight and single boll lint weight, which represents the single boll yield factor; The third component load is the plant height and the number of boll shedding, representing plant height and boll shedding factor; The statistical analysis of Sea-island cotton resources evident that the difference was not significant in extreme germplasm at domestic , and there are more materials with medium-performing Sea-island cotton resources in China. In China, the proportion of extreme germplasm outside Xinjiang is relatively high, and the difference was not significant between Xinjiang and foreign intermediate germplasm; Cluster analysis 175 Sea-island cotton resources then divided into 4 groups. Group I has discrepancy germplasm with short stalk of gravity, low yield; Group II has high lint percent and extensive yield of lint yield per plant, and has higher potential yielding germplasm; Group III has perferable comprehensive traits and excellent germplasm; group IV is short-stalked, high-lint, and extremely particular germplasm; comprehensive evaluation screens out 2 excellent comprehensive traits varieties XH30 and 270; By stepwise regression screening Sea-island cotton germplasm screening phenotype of five key indicators (plant height first node height, number of fruit branches, lint weight per boll and cotton weight per seed). 【Conclusion】The genetic diversity of the tested Sea-island cotton germplasm resources is relatively high, but the genetic diversity is low. The plant height, fruit branch number and lint yield per plant are normally distributed among the genotypes, those left traits are skewed. The tested germplasm divided into 4 categories; Plant height, height of the first node, fruit branch number, yield of single boll Lint yield, seed cotton yield per plant, the research provides a theoretical reference to selection of excellent germplasm for sea-island cotton germplasm resources that 5 indicators can be used as comprehensive indicators for the evaluation of core germplasm.

Key words: Gossypium barbadense, germplasm resources, phenotypic traits, genetic diversity, comprehensive evaluation