加勒比松种源苗期DNA甲基化多样性分析

Analysis of DNA Methylation Diversity among Provenances of Piuns caribaea Morelet Seedlings

摘要:

为了解加勒比松（Pinus caribaea）种源的遗传多样性，利用甲基化敏感扩增多态性技术对加勒比松3个变种17个种源的DNA甲基化多样性进行了研究。结果表明，56对引物组合共扩增出425条谱带，其中多态性谱带422条，多态性百分率为99.25%。加勒比松种源幼苗半甲基化比率比全甲基化比率稍高，洪都拉斯加勒比松、古巴加勒比松和巴哈马加勒比松的DNA甲基化率分别为22.39%、22.29%和22.35%，差异不显著。加勒比松的DNA序列遗传多样性（H=0.4376）高于DNA甲基化多样性（H=0.3274），Mantel检验表明，基因组遗传变异与表观遗传变异不存在相关性（r=-0.171，P=0.16）。表观聚类与遗传聚类间存在较大差异，两种聚类分析结果均未将3个加勒比松变种分开。这表明加勒比松变种间的表观遗传变异极为丰富，能为加勒比松遗传改良提供优良种质资源。

Abstract:

In order to understand the genetic diversity of Piuns caribaea Morelet, the methylation diversity among 17 provenances to 3 varieties of P. caribaea was studied by using methylation sensitive amplification polymorphism (MSAP) technique. The results showed that a total of 425 bands were amplified by 56 pairs of primer combinations, 422 of them were polymorphic with a polymorphism rate of 99.25%. The major DNA methylation type in P. caribaea was hemi-methylation. The average methylation rate of P. caribaea var. caribaea, var. hondurensis and var. bahmaensis was 22.39%, 22.29% and 22.35%, respectively, which had no significant difference. The genetic diversity of DNA sequences (H=0.4376) was significantly higher than that of DNA methylation (H=0.3274). The Mantel test showed that there was no relation between genome genetic variation and methylation epigenetic variation (r=-0.171, P=0.16). The genetic cluster result was very different from that of methylation, although the two clustering results could not divided the three varieties of P. caribaea. So, it was suggested that P. caribaea had a high epigenetic diversity, which could provide excellent germplasm resources for genetic improvement of P. caribaea.