针茅水孔蛋白基因多态性分析及其地理分布

Gene polymorphism and its geographical distribution of aquaporin in Stipa

以分布于内蒙古的草甸草原(森林草原)、典型草原、荒漠草原上的7种针茅属植物为材料,利用聚合酶链反应-单链构象多态性(PCR-SSCP)方法,分析了水孔蛋白基因的外显子1和内含子1的遗传多态性。结果表明:外显子1有AA、BB和CC3种基因型,内含子1有DD、EE、FF和GG4种基因型;种间存在基因多态性,种内没有多态性,所有种均表现出遗传的单态性和100%的纯合度。从基因型地理分布看,AA基因型在草甸草原、森林草原、典型草原及荒漠草原区的针茅种上均有分布,BB、CC基因型只分布在荒漠草原区的针茅中;DD基因型分布于草甸草原、森林草原及典型草原区的针茅属植物中,荒漠草原区分布有EE、FF、GG等3种基因型。荒漠草原区的植物是旱生程度最强的一类草原群落,该区的3种针茅具有丰富的遗传多态性。

By the method of polymerase chain reaction-single strand conformation polymorphism （PCR-SSCP） , this paper studied the genetic polymorphism of exon 1 and intron 1 in the aquaporin gene of seven species of Stipa in the meadow steppe （ forest steppe） , typical steppe, and desert steppe of Inner Mongolia. The results showed that exon 1 had the genotypes of AA, BB and CC, while intron 1 had the genotypes of DD, EE, FF and GG. There existed gene polymor- phism in inter-species but not in intra-species. All the test species displayed genetic monomorphism and 100% of purity. From the viewpoint of genotype＇s geographical distribution, AA existed in the Stipa species on meadow steppe （forest steppe）, typical steppe and desert steppe, BB and CC only existed in the species on desert steppe, DD was found in the species on meadow steppe （forest steppe） and typical steppe, and genotypes EE, FF and GG were detected in the species on desert steppe. The plants on desert steppe exhibited the strongest xeromorphic characteristics, and 3 species of Stipa on the desert steppe had abundant genetic polymorphism.