结缕草属植物种间关系和遗传多样性的SSR标记分析

利用SSR分子标记技术对结缕草属(Zoysia Willd.)5种、1变种共96份种质材料进行遗传多样性分析,结果表明:(1)结缕草属种质间存在丰富的遗传多样性,29对SSR引物共扩增出282条清晰谱带,其中多态性条带272条,多态性比率(PPB)为96.45%,Nei’s基因多样性指数(H)为0.2203,Shannon信息指数(I)为0.3504。(2)应用Nei—Li相似系数法估算了96份材料间的遗传相似系数(GS),范围在0.5922~0.9362,平均为0.7811,在不同种之间,结缕草(Z.japonica Steud.)与中华结缕草(Z.sinica Hance.)、沟叶结缕草(Z.matrella(L.)Merr.)与细叶结缕草(Z.tenuifloia Willd.ex Trin.)中的遗传相似系数较高,大穗结缕草(Z.macrostachya Franch.)Z010、长花结缕草(Z.sinica var.nipponica)Z122与其它结缕草的遗传相似系数均相对较低。结缕草、中华结缕草和沟叶结缕草的种内遗传变异较大,GS分别为0.5922~0.9362,0.6879~0.9078和0.6738~0.8582。(3)通过分子系统聚类法,将96份种源分为6个大类群,其中第一大类主要包括结缕草、中华结缕草和少量沟叶结缕草,占所有材料的90.6%。沟叶结缕草和细叶结缕草聚成一小类,大穗结缕草Z010、长花结缕草Z122、沟叶结缕草(Z.matrella)Z095和结缕草(Z.japonica)Z115聚为一类。从亚群来看,基本上结缕草与中华结缕草交叉相聚,沟叶结缕草与细叶结缕草交叉相聚,沟叶结缕草与结缕草、中华结缕草也有交叉聚类现象。本研究明确了结缕草属植物不同种质间亲缘关系及遗传多样性、部分种质的种类归属,还为其进一步研究与利用提供了分子水平的依据。

Interspecific Relationship and Genetic Diversity of Zoysiagrass Revealed by SSR Markers

The genetic diversity and interspecific relationship of 96 germplasms of Zoysia Willd.belonging to 5 species and 1 mutation were analyzed using SSR(Simple Sequence Repeat) markers.The results showed that:(1)Total 282 bands were detected by 29 pairs of SSR primers,and 272 of 282 were polymorphic with PPB(Percentage of Polymorphic Bands) at 96.45%,the Nei's gene diversity index(H) was 0.2203,and the Shannon diversity index(I) was 0.3504,indicating a high level of genetic diversity in zoysiagrass.(2) The GS(genetic similarity) among 96 Zoysia germplasms ranged from 0.5922 to 0.9362 with the average of 0.7811.GS between Z.japonica and Z.sinica and between Z.matrella and Z.tenuifolia were relatively high,both Z.machrostachya(Z010) and Z.sinica.var.nipponica(Z122) had a relatively lower GS than other species.The range of GS within species of Z.japonica,Z.sinica,and Z.matrella were 0.5922~0.9362,0.6879~0.9078,and 0.6738~0.8582,respectively.(3) Genetic distance and relationship among 96 Zoysia germplasms were showed clearly in the cluster dendrogram.The 96 Zoysia germplasms were classified into 6 major groups by cluster analysis.Group I included Z.Japonica,Z.sinica,and some accessions of Z.matrella,accounted for 90.6% of all germplasms.Some accessions of Z.matrella and Z.tenuifolia form one group.Z.machrostachya(Z010),Z.sinic var.nipponica(Z122),Z. matrella(Z095),and Z.sinica(Z115) form one group by itself,respectively.The cluster results of some secondary groups showed that most accessions of Z.japonica and Z.Sinica were clustered to one group,whereas,Z.matrella and Z.tenuifolia were one group,and some accessions of Z.japonica,Z.Sinica and Z.matrella were one group.In this research,the diversity and relationship among 96 germplasms were displayed;meanwhile,a preliminary discussion was made on the ownership of part accessions.We consider the findings could provide a scientific basis at the molecular level for future study and application of zoysiagrass germplasms.