Page 121 - 《渔业研究》2025年第6期

812 渔 业 研 究 第 47 卷

Genetic diversity analysis of cultured and wild populations of
Ruditapes philippinarum based on COⅠ gene

GUO Xiang，NING Yue，WU Qisheng，QI Jianfei，YE Jun，WU Liyun，GE Hui *
(Key Laboratory of Cultivation and High-value Utilization of Marine Organisms in Fujian Province, Fujian Collaborative Innovation
Center for Exploitation and Utilization of Marine Biological Resources, Fisheries Research Institute of Fujian, Xiamen 361013, China)

Abstract: [Background] The Manila clam (Ruditapes philippinarum) is one of the important naturally distrib-
uted bivalve species in East Asia and is widely cultured in China. [Objective] This study aims to comparat-
ively analyze the genetic diversity between cultured and wild populations of R. philippinarum. [Methods] A
total of 162 samples from two cultured populations (Fujian, China) and three wild populations (Laizhou, China;
Nampo and Haeju, the Democratic People’s Republic of Korea) were analyzed by amplifying and sequencing a
partial segment of the mitochondrial cytochrome c oxidase subunit Ⅰ(COⅠ) gene. [Results] Within the 646
bp COⅠ gene fragment, a total of 63 polymorphic sites were detected across five populations, defining 59 hap-
lotypes. The haplotype diversity indices (Hd) ranged from 0.880 to 0.938, and nucleotide diversity indices (π)
varied between 0.001 and 0.010 among the five populations. Wild populations exhibited haplotype diversity in-
dices of 0.905~0.938 and nucleotide diversity values of 0.005~0.010, with 41 haplotypes identified, accounting
for 69.5% of the total haplotypes. Cultured populations showed haplotype diversity of 0.880~0.902 and nucle-
otide diversity of 0.001~0.006, defining 22 haplotypes, which represented 37.3% of the total haplotypes.
AMOVA analysis revealed a low genetic differentiation index (0.081) between cultured and wild populations,
contribution rate of variation was only 8.13%, which was not statistically significant (P>0.01). Most genetic
variation (80.34%, P<0.001) originated from differences among individuals within populations. Genetic dis-
tance (F ) analyses indicated significant divergence (P<0.01) between the Democratoc People’s Republic of
st
Korea’s and China’s populations, while no significant differentiation was observed among other populations
(P>0.01). Phylogenetic trees and network analysis showed that the five populations formed two distinct genetic
clusters, primarily influenced by geographic isolation. [Conclusion] The findings suggest that aquaculture
practices have not significantly affected the genetic diversity of R. philippinarum. However, wild populations
exhibited higher genetic diversity and more unique haplotypes compared to cultured populations. This implies
that the reduced genetic diversity in cultured populations may result from smaller effective population sizes and
inbreeding within closed-cycle farming systems. The study provides valuable insights for the sustainable man-
agement and genetic breeding of R. philippinarum in future aquaculture.
Key words: Ruditapes philippinarum; cytochrome c oxidase subunit Ⅰ(COⅠ) gene; genetic diversity; cultured
and wild populations