福建东张水库陆封型香鱼的遗传变异

测定了福建东张水库18尾陆封型香鱼的ND4-tRNA^Ser基因533 bp序列,发现2个可变位点和2个简约信息位点,共检测到4种单倍型。基于Kimura 2-parameter模型的遗传距离在0.001 9～0.003 9之间,在NJ系统树上无明显谱系结构;单倍型多样性(Hd)和核苷酸多样性(Pi)分别为0.627和0.001 37,平均核苷酸差异数为0.732,远低于两侧洄游型日本香鱼指名亚种(Hd为0.793,Pi为0.002 94),与被列为IUCN濒危物种名录的日本琉球香鱼亚种(Hd=0.519,Pi=0.001 11)相当。东张水库香鱼遗传多样性如此贫乏到底是历史原因还是近期陆封的结果,仍需进一步研究。目前亟待采取有效措施保护东张水库陆封香鱼。

Genetic variation of lacustrine Plecoglossus altivelis population in Dongzhang Reservoir, Fujiang Province

Five hundred and thirty three bp sequence of partial mitochondrial ND4-tRNA~(Ser) gene of 18 individuals of lacustrine Plecoglossus altivelis population from Dongzhang Reservoir, Fujiang Province was determined, and 4 haplotypes, 2 variable sites and 2 parsimony-informative sites were detected. Genetic distance based on Kimura 2-parameter model among 4 haplotypes ranged from 0.001 9 to 0.003 9. No obvious genealogical clusters were found in neighbor-joining tree. Haplotype diversity(Hd) and nucleotide diversity(Pi) were 0.627 and 0.001 37 respectively with average nucleotide difference 0.732 in the population, which were much lower than in Plecoglossus altivelis altivelis in Japan(Hd=0.793, Pi=0.002 94), but similar as compared with Plecoglossus altivelis ryukyuensis, an endangered subspecies listed in IUCN(Hd=0.519, Pi=0.001 11). Further studies are still needed to make clear the reasons responsible for such poor genetic diversities in Dongzhang reservoir populations; meanwhile urgent measures should be taken to conserve the valuable fishes.