摘要
以黑桫椤分布在海南和广东 9个种群为材料 ,通过 PCR产物直接测序和克隆后再测序的方法测定了叶绿体 DNA(cp DNA) trn L- F非编码区序列。序列长度介于 10 17bp至 10 2 1bp;碱基组成 A+T含量较高 ,百分比值为 6 0 .4 3%～ 6 2 .2 6 %。根据序列的核苷酸变异共鉴定出 15个单倍型。黑桫椤具高水平单倍型多样性 (h=0 .880 )和较高水平核苷酸多样性 (Dij=0 .0 0 342 ) ,其悠长的进化历史可能增加了遗传变异在谱系内的积累。单倍型最小生成网图和邻接树、种群间分化度 (FST=0 .12 6 4 5 )和基因流 (N m=3.4 9)、AMOVA分析 (地区间遗传变异占 11.91% ,p>0 .0 5 )以及 DNA歧义度结果一致显示 ,黑桫椤分布在海南和广东的种群彼此间不存在遗传分化。黑桫椤单倍型的系统发育地理式样具“星状”特征 ,提示种群在历史上曾经发生过扩张 。
Alsophila podophylla Hook is a large perennial herbaceous fern species belonging to family Cyatheaceae in taxonomy. In this research, population genetic structure and phylogeographical pattern of the species were inferred from variations of chloroplast DNA (cpDNA) trnL-F noncoding sequences. 9 natural populations were sampled, locating at Jian Feng Ling (HNJFL), Wu Zhi Shan (HNWZS), and Diao Luo Shan (HNDLS) in Hainan Province, as well as Gui Keng (ZQDHG), Ji Feng Lin (ZQDHJ), Da Chong (FKHDC), Du Tian (FKHDT), Xue Si Shang You (FKHXU), and Xue Si Xia You (FKHXD) in Guangdong Province of southern China. cpDNA trnL-F noncoding regions were determined by cycle sequencing or sequencing cloned PCR products. Sequence length varied from 1017 bp to 1021bp. Base composition was with high A+T content of 60.43%~62.26%. 15 haplotypes were identified based on nucleotide variation. Relatively high level of haplotype diversity (h=0.880) and nucleotide diversity (Dij=0.00342) were detected in A. podophylla. This is probably associated with its long evolutionary history which allowed the accumulation of genetic variation within lineages. Minimum spanning network constructed from trnL-F haplotypes showed that haplotypes identified in Hainan populations rapidly coalesced to those in Guangdong populations with short branch length of one or two mutations. In neighbor-joining tree, haplotypes of Hainan and Guangdong populations were exhibited as highly mixed branches, neither forming as a monophyletic group. Gene genealogies of trnL-F haplotypes suggested a close genetic relationship between populations of A. podophylla distributed in Hainan and Guangdong. Investigations of population differentiation (F_(ST)=0.12645), gene flow (Nm=3.49), AMOVA (11.91% genetic variation was partitioned among regions, p>0.05), and DNA divergence also demonstrated that no genetic differentiation occurred bewteen populations of Hainan and Guangdong. A “star like” pattern of phylogeography of haplotypes was uncovered in A. podophylla, which meant an outcome of population expansion during its evolutionary history, and since then there will have been insufficient time to form a more complicated population structure.
出处
《生态学报》
CAS
CSCD
北大核心
2004年第5期914-919,共6页
Acta Ecologica Sinica
基金
国家自然科学基金资助项目 ( 3 0 170 10 1)
国家自然科学基金重点资助项目 ( 3 983 0 3 10 )
广东省自然科学基金资助项目 ( 0 1112 5 )~~
关键词
黑桫椤
CPDNA
trnL—F非编码区
单倍型
遗传结构
地理分化
Alsophila podophylla
cpDNA trnL-F noncoding sequence
haplotype
genetic structure
geographical differentiation
