不同系统梨种质遗传多样性与分类关系的SSR分析

Genetic diversity and polygentic relationship among pears reveled by SSR analysis

利用SSR分子标记技术深入探讨了梨主要栽培种白梨(Pyrus bretschneideri Rehd.)、砂梨(Pyrus pyrifolia(Burm.f.)Na-kai)、秋子梨(Pyrus ussuriensis Maxim.)、西洋梨(Pyrus communis L.)、新疆梨(Pyrus sinkiangensis Yü)和野生种以及种间杂交新选育品种共150份资源的遗传多样性、亲缘关系以及系统分类地位。通过筛选出的25对SSR引物共检测到407个位点,不同引物检测位点数5～25个,其中多态性位点数390个,占检测位点的95.82%,检测位点杂合度为0.4～0.7,不同品种间的遗传多样性指数为0.67～1.00。应用NTSYS-pc2.01软件,以非加权数据分析法(UPGMA)对获得的多态性位点进行聚类分析,系统聚类结果将150份梨种质分为2大类群,即西洋梨和东方梨类群。西洋梨类群包括了西洋梨品种及具西洋梨亲缘的种间杂交品种。东方梨类群包括了中国白梨、砂梨、秋子梨、新疆梨、野生资源以及日韩梨品种,在相似系数0.708处又分为2大组,并可细分为7个亚组。其中,中国的白梨、砂梨和秋子梨相互交错在一起,没有独自成组。中国砂梨表现出最丰富的遗传多样性;其次是中国白梨。日本梨与中国砂梨表现了高度的亲缘关系,并且没有独立成组。多数新选育品种的遗传关系表现出趋母本聚类型或趋父本聚类型。

Genetic diversity and polygentic relationship of 150 cultivars of pear,which belong to Pyrus bretschneideri Rehd.,Pyrus pyrifolia（Burm.f.）Nakai,Pyrus ussuriensis Maxim.,Pyrus communis L.,Pyrus sinkiangensis Yü.,wild species and inter-specific hybridization cultivars,were analyzed by SSR markers in this paper.25 primer-pairs produced a total of 407 alleles,of which 390 were polymorphic with a polymorphism percentage of 95.82%.Prime conbination were 5-25,Heterozygosity ratio was 0.4-0.7,and the similarity coefficient between cultivars ranged from 0.67 to 1.00.The dendrogram generated from all the 150 accessions by unweighted pair-group method of arithmetic analysis（UPGMA）cluster analysis clearly distinguished Occidental pears from accessions of East Asia.Cultivars of P.communis and inter-specific hybridization with P.communis are clustered into the Occidental clade.The clade of oriental pear formed two main groups,seven subgroups,at the coefficient of 0.708.P.bretschneideri,P.ussuriensis and P.pyrifolia originating in China interveined each other,and did not group independently.Chinese P.pyrifolia showed the most abundant genetic diversity,followed by P.bretschneideri.The cultivars from Japan and the Chinese P.pyrifolia demonstrated a high degree of genetic relationship,and there is no separate group.The genetic relationship of most new cultivar selections show increasingly female parent type or increasingly male parent poly-poly-type.