大叶黑桫椤及桫椤SSR标记的开发（英文）

Novel nuclear SSR markers in the large frond tree fern Alsophila gigantea and its congeneric species Alsophila spinulosa

大叶黑桫椤是桫椤科的大型树蕨,多分布在亚热带山地,为渐危种。迄今为止,鲜有大叶黑桫椤种群遗传变异的报道。采用FIASCO法开发了大叶黑桫椤15个SSR标记,用来自海南岛的4个种群检测标记的多态性。其中,7个标记具多态性,每个标记的实际等位基因数为1~9,观察杂合度和期望杂合度范围分别为0~0.769和0~0.805。位点AG-12和AG-23分别在HNjfl和HNbwl种群显著地偏离哈代温伯格平衡。鉴定出4个哑等位基因。发现3对标记存在连锁不平衡现象。此外,4个SSR标记能成功地用于桫椤种群的遗传分析。这些新的多态性SSR标记将用于大叶黑桫椤的群体遗传变异、局部适应性的研究以及建立有效的保护策略。

Alsophila gigantea is a large frond tree fern in family Cyatheaceae.The plant is a vulnerable species that prefers specific subtropical montane climate.Little work has been done so far to access the population genetic variation in A.gigantea.In this study,we developed 1 5 SSR markers using FIASCO protocol and evaluated these markers in four natural populations from Hainan Island,China.Seven loci proved to be polymorphic.The actual number of alleles ranged from one to nine,and the observed and expected heterozygosity varied from 0 to 0.769, and from 0 to 0.805 ,respectively.Loci AG-1 2 and AG-23 were found to significantly deviate from the Hardy-Wein-berg equilibrium in populations HNjfl and HNbwl,respectively.Four null alleles were identified.Linkage disequi-librium was further detected at three pairs of loci.Moreover,four SSR markers were verified to be successfully transferred in Alsophila spinulosa.The novel polymorphic SSR markers characterized here will be used to survey population genetic variation and local adaptation in A.gigantea,which helps design effective conservation strate-gies.