基于ISSR和SRAP标记的栀子种质遗传多样性研究

目的对栀子遗传多样性进行研究,为栀子资源保护和新品种培育提供依据。方法采用12条ISSR和9对SRAP分子标记,以3个居群21份栀子种质资源为材料,通过多态性检测水平、遗传多样性比较和聚类分析,揭示栀子种质资源遗传多样性。结果 ISSR引物和SRAP引物分别扩增出125和80条带数,多态性条带数分别为100和74,多态性比率(PPB)分别为80.00%和92.50%,栀子居群的总体物种水平的等位基因观察数(Na)分别为1.461 3和1.579 2,有效等位基因数(Ne)分别为1.307 7和1.342 1,Nei's基因多样性指数(H)分别为0.173 1和0.197 4,Shannon's指数(I)分别为0.254 5和0.295 9;遗传多样性分析结果表明,ISSR和SRAP标记中3个居群之间的遗传多样性(Ht)分别为0.239 1和0.289 9,种间遗传多样性(Hs)分别为0.173 1和0.197 4,基因分化系数(Gst)分别为0.276 2和0.318 9,即72.38%和68.11%的遗传变异在种群内进行,居群间基因流(Nm)分别为1.310 3和1.068 0,证明居群间存在一定的基因流动(Nm1);UPGMA聚类分析表明,ISSR和SRAP标记将栀子资源分为2个类群,且以SRAP分析的聚类结果更符合实际居群。结论取样栀子种质有丰富的遗传多样性,遗传分化主要发生在居群内,SRAP标记更适合用于栀子遗传多样性分析,对栀子资源的保护和育种提供了参考。

Genetic diversity analysis of Gardenia jasminoides based on ISSR and SRAP molecular markers

Objective To analyze of genetic diversity of Gardenia jasminoides and provide the information for the conservation and new variety breeding of G. jasminoides. Methods 12 ISSR primers and 9 primer combinations of SRAP were used to assess the polymorphisms, genetic diversity, and cluster analysis within 21 G. jasminoides materials from three populations. Results The results showed that 100 (80.00%) of 125 and 74 (92.50%) of 80 bands were polymorphic by ISSR and SRAP primers amplification, respectively. In ISSR results, the populations of species level of observed number of alleles (N_a), effective number of alleles (N_e), Nei''s gene diversity (H), Shannon''s information index (I), total genetic diversity for species (H_t), and the mean heterozygosity with populations (H_s) were 1.461 3, 1.307 7, 0.173 1, 0.254 5, 0.239 1, and 0.173 1, respectively. Comparatively, for SRAP primers, the N_a, N_e, H, I, H_t, and H_s value was 1.579 2, 1.342 1, 0.197 4, 0.295 9, 0.289 9, and 0.197 4, respectively. The coefficient of gene differentiation (G_st) for population was 0.276 2 and 0.318 9, which indicated that the within-population component accounted for 73.38% and 68.11%, respectively. The average mean of gene flow (N_m > 1) suggested that there certainly gene flow among the populations. UPGMA analysis showed that 21 samples were clustered into 2 branches, and a hierarchical dendrogram based on SRAP was more consistent with actual populations. Conclusion The gene diversity of G. jasminoides populations was high. The characteristics of genetic structure included genetic differentiation that occurs mainly within populations, which provided a reference for conservation and breeding of G. jasminoides germplasm.