基于单拷贝核基因PAL研究贵州金花茶遗传多样性

A Study on Genetic Diversity of Camellia huana by Single-copy Nuclear Gene PAL

贵州金花茶是一濒危物种,分布在广西北部与贵州南部交界的石灰岩山的常绿阔叶林内。本文对贵州金花茶12个居群共120个个体的单拷贝核基因苯丙氨酸解氨酶(phenylalanine ammonia-lyase,PAL)进行扩增与测序,利用相关软件计算相应的遗传多样性和遗传分化系数。结果表明:1)序列总长为660 bp,包括7个多态位点,共检测到8个单倍型,总的核苷酸多样性指数Pi和单倍型多样性指数Hd分别为0.00131和0.631。2)AMOVA分析结果显示91.47%的遗传变异存在于居群内,8.53%的遗传变异存在于居群间,遗传分化系数FST值为0.08531。3)Mantel test结果显示,遗传距离和地理距离之间没有显著的相关性。鉴于贵州金花茶具有低水平的遗传多样性和中等水平的居群间遗传分化,建议在加强其自然居群保护的同时,从多个栽培居群取样进行迁地保护,以最大程度地保护其遗传多样性。

Camellia huana is an endangered species which distributed in the evergreen,broad-leaved forests in the limestone hills bordering the northern Guangxi and southern Guizhou province.A single-copy nuclear gene PAL(phenylalanine ammonia-lyase,PAL)was employed to amplify and sequence 120 individuals in 12 populations of C.huana plant,and relevant softwares were used to calculate the corresponding genetic diversity and genetic differentiation coefficients.The results were as follows.The aligned nDNA(PAL)with a consensus length of 660 bp contained seven polymorphic sites.A total of eight haplotypes were identified,and genetic diversity indices of total nucleotide(Pi)and haplotype(Hd)diversity were 0.00131 and 0.631,respectively.Analysis of molecular variance(AMOVA)further revealed that the majority of genetic variation(91.47%)was examined among populations,while only small amount(8.53%)was partioned within populations.The value of FST was 0.08531.No significant correlation was detected between genetic and geographic distance which was supported by the result of Mantel test.Low level of genetic diversity and moderate level of genetic differential were detected for C.huana.It is suggested that while strengthening the protection of its natural populations,sampling from multiple cultivated populations for ex-situ conservation to maximize the protection of its genetic diversity.