【摘要】 以226个建兰品种为材料,应用16对SSR荧光引物进行扩增,基于等位基因最大法,按照93.36%、83.19%、71.68%、64.16%、54.42%、47.35%、32.30%、23.45%、17.26%、12.39%和8.41%等11个压缩比例逐步聚类,形成备选种质。结果表明,16对SSR荧光引物共检测到135个等位基因,平均观测等位基因数(Na)、有效等位基因数(Ne)、Nei’s基因多样性指数(H)、Shannon’s指数(I)、观测杂合度(Ho)、期望杂合度(He)和多态信息量(PIC)分别为8.5、3.218、0.584、1.228、0.617、0.384、0.539,表明建兰品种的遗传多样性丰富。各品种间的遗传多样性系数在0.64～1.0之间,在0.75处可分为4类,聚类结果客观反映出品种间的亲缘关系。经过对11个压缩比例形成的备选种质的对比,压缩比例32.30%为构建核心种质的最佳比例。t检验结果表明,构建的包含73个品种的核心种质与原始种质的遗传参数无显著差异,能充分代表原始种质的多样性。更多还原

【Abstract】 In this study,226 Cymbidium ensifolium cultivars were used as materials,and 16 pairs of SSR fluorescent primers were used for amplification. Based on the maximum allele method,stepwise clustering according to 11 compression ratios(93.36%,83.19%,71.68%,64.16%,54.42%,47.35%,32.30%,23.45%,17.26%,12.39%,8.41%)were performed to form alternative germplasm. The results showed that a total of 135 alleles were detected in 16 pairs of SSR fluorescent primers,the number of observed alleles(Na),the number of effective alleles(Ne),the Nei’s genetic diversity index(H)and the Shannon’s index(I),the observational heterozygosity(Ho),the expected heterozygosity(He)and the polymorphic information(PIC)were 8.5,3.218,0.584,1.228,0.617,0.384 and 0.539,respectively,indicating that the genetic diversity of C. ensifolium cultivars is abundant. The genetic diversity coefficients among the cultivars ranged from 0.64 to 1.0,and were classified into four categories at 0.75. The clustering results objectively reflect the genetic relationship between the cultivars. After comparing 11 candidate core collection,the 32.30% compression ratio was considered to be the optimal ratio for constructing core collections. The t-test results showed that there were no significant differences in the genetic parameters of the core collections containing 73 cultivars and the original germplasm,which could fully represent the diversity of the original germplasm.更多还原