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【目的】分析陆地棉核心种质的遗传多样性和表型性状遗传变异规律,并探讨核心种质的综合评价方法。【方法】利用17个表型性状数据分析419份陆地棉核心种质的遗传多样性。用Shannon-weaver信息多样性指数计算表型性状的遗传多样性,用Nei’s 1973法计算表型性状遗传距离,并使用NTSYS-pc 2.20q软件对核心种质进行聚类分析;用SAS9.2对表型性状数据进行最佳线性无偏估计(BLUE),然后根据最佳线性无偏估计值计算出表型性状的最佳值。同时,结合主成分、回归和相关分析,研究核心种质的综合评价指标和方法。【结果】核心种质表型性状分析发现,单株铃数、单铃重、衣分、子指等性状的变异系数均较大,变异系数超过10%。而断裂比强度、马克隆值以及上半部平均长度的变异程度较小,变异系数均在10%以下。方差分析发现,各表型性状地点间、年份间、地点和年份间、品种间均有极显著差异;不同地理来源的种质表型性状差异较大,长江流域地理来源的种质生育期、伸长率、上半部平均长度、衣分等性状均高于其他的地理来源,西北内陆地理来源的种质纤维强度,单铃重、整齐度指数、株高、纺纱均匀性指数等综合性状最好,美国种质的产量和纤维品质的性状优于其他国家的总和。表型性状的遗传多样性指数范围为0.351—3.796,平均为1.715。分析不同地理来源种质的遗传多样性,发现黄河流域的遗传多样性和遗传丰富度最高,中国南部区域最低。类群聚类结果发现陆地棉整体分散,没有比较明显的类群关系,部分具有相似特点的种质聚类13个组群。核心种质综合评价表明在累计贡献百分比高于85%时,共发现7个主成分,陆地棉核心种质的表型性状综合值(F值)平均为1.740,来自澳大利亚的N74-250F值最高(2.302),辽阳绿绒棉的F值最低(0.624)。对17个表型性状与F值的相关分析,发现除马克隆值、子指和黄度外,单铃重、衣分、断裂比强度、上半部纤维长度等14个表型性状与F值间的相关性具有极显著差异,最后构建了以吐絮期、单铃重、伸长率、花期、马克隆值、株高、果枝数、纺纱均匀性指数8个表型性状为自变量的回归方程,综合评价核心种质资源。【结论】中国保存的陆地棉核心种质具有较为丰富的遗传多样性,不同地理来源遗传变异有较大的差异,不同生态区的核心种质具有独特的性状特性。
【Objective】 The genetic diversity of Gossypium hirsutum (G. hirsutum L.) germplasm and genetic variation of phenotypic traits were analyzed, and the comprehensive evaluation method of core collection was discussed. 【Method】 The genetic diversity of 419 accessions of upland cotton accessions was analyzed using 17 phenotypic traits. The Shannon-weaver information diversity index was used to calculate the genetic diversity of phenotypic traits. Nei’s 1973 method was used to calculate the genetic distance of phenotypic traits. Cluster analysis of core collection was performed using NTSYS-pc 2.20q software. The best linear unbiased estimate (BLUE) of phenotypic trait data was then used to calculate the best phenotypic trait based on the best linear unbiased estimate. At the same time, combined with the principal components, regression and correlation analysis, the comprehensive evaluation of core collection of indicators and methods. 【Result】 The results showed that the coefficient of variation of boll number per boll, boll weight, lint percentage and sub-index were all larger with the coefficient of variation exceeding 10%. The variation of breaking strength, micronaire and the average length of the upper part of the model were less, and the coefficients of variation were below 10%. Variance analysis showed that there were significant differences among the locations, years, locations and years among all the phenotypic traits. The germplasm traits varied greatly from different geographical origins. Germplasm growth period, Elongation, average length of the upper half, and lint percentage were all higher than those of other geographic sources. Germplasm intensity, single boll weight, uniformity index, plant height, spinning uniformity index, etc. of inland geographic origin of Northwest China The best combination of traits, the yield of American germplasm and the quality of fiber quality better than the sum of other countries. The genetic diversity index of phenotypic traits ranged from 0.351 to 3.796 with an average of 1.715. By analyzing the genetic diversity of germplasm from different geographical origins, we found that the genetic diversity and genetic richness of the Yellow River valley is the highest, while the lowest in southern China. Cluster analysis showed that Upland cotton was dispersed as a whole, there was no obvious group relationship, and some of the 13 groups with similar characteristics were clustered. The comprehensive evaluation of core collection showed that seven principal components were found when the accumulated contribution percentage was higher than 85%, the average value of phenotypic trait (F value) of upland cotton core collection was 1.740, and the highest N74-250F value from Australia (2.302), Liaoyang green velvet cotton F value of the lowest (0.624). Correlation analysis of 17 phenotypic traits and F values showed that 14 phenotypic traits such as boll weight, lint percentage, breaking strength, upper half fiber length, and F The results showed that there were significant differences in the correlations between them. Finally, eight phenotypic traits, including boll opening, boll weight, elongation, florescence, micronaire, plant height, fruit branch number and evenness index Regression equation, a comprehensive evaluation of the core germplasm resources. 【Conclusion】 The core collections of Gossypium hirsutum cultivars in China are rich in genetic diversity. Genetic variations among different geographical sources are quite different. Core collections in different ecological regions have unique traits.