基于表型数据的辣椒核心种质构建研究

以收集保存的603份辣椒种质为材料,根据果形指数大小将其分成5组。基于28个性状的表型数据,采用简单比例、平方根比例、对数比例及遗传多样性指数比例法计算各组内取样份数,比较4种组内取样比例法、6种总体取样规模和2种取样方法在构建辣椒核心种质中的作用和效果。结果表明:(1)简单比例、平方根比例、对数比例、遗传多样性指数比例法入选的材料份数占预选核心种质份数依次为24.2%、22.2%、21.1%、17.8%,说明遗传多样性指数比例法对各组取样数量的修正能力最强,使取样更加均衡。(2)当总体取样规模为15%时,遗传多样性指数比例法构建的预选核心种质遗传多样性指数(I)达到最大,表型保留比例(RPR)超过98%;当总体取样规模超过20%时,RPR值、变异系数(CV)和极差符合率(CR)虽然平缓增加,但I值反而减小;说明15%为合适的总体取样规模。(3)利用对数比例法和多样性比例法,在15%的总体取样规模下,聚类取样构建的核心种质I值、RPR值、CV值及CR值均高于随机取样。(4)该研究根据所获得的优化方案最终在表型水平建立了包含91份种质的辣椒核心种质。

Studies on the Constructing of Pepper Core Collection Based on Phenotypic Data

The method to construct pepper core germplasm based on phenotypic data was studied with 603 accessions which were divided into 5 groups by the fruit shape index.Four types of sampling proportion methods in group,six overall sampling scales and two sampling methods were compared by the phenotypic data of 28 characters.The main results were as follows:(1) The proportions of materials selected by proportional ratio,square root ratio,logarithm ratio and diversity ratio in primary core germplasm were 24.2%, 22.2%, 21.1% and 17.8%, respectively,which illustrated that the best proper sampling proportion within group was based on index of genetic diversity which enabled the sampled number or proportion from different groups tend to balance.(2) The index of genetic diversity (I) of the core germplasm established according to the method of genetic diversity index proportion reached maximum and the ratio of phenotypic retained (RPR) reached 98% when the over all sampling scale increased to 15%.Although the proportion of phenotypes retained,coefficient of variation (CV) and the coincidence rate of range (CR) all increased gently,the genetic diversity index of the preconcentrated core germplasm decreased accordingly when the overall sampling scale increased to over 20%.So 15% of the overall sampling sizes were more appropriate.(3) Using logarithmic ratio method and diversity ratio,under 15% of the total sample size,the I,RPR,CV and CR of the core germplasm constructed by cluster sampling were much higher than that by random sampling.(4) Based on the optimized sampling scheme,the core germplasm of 91 accessions of pepper germplasm were established.