关键词: 福寿螺, 小管福寿螺, 隐秘福寿螺, 斑点福寿螺, 系统发育分析, 遗传多样性, 分子变异分析, 大理白族自治州

Abstract: Objective　To conduct molecular identification and population genetic analysis of Pomacea based on mitochondrial cytochrome c oxidase subunit Ⅰ (COI) gene sequence in Dali Bai Autonomous Prefecture, so as to provide the theoretical evidence for the scientific management of the invasive Pomacea.  Methods　Pomacea samples were collected during field surveys of Pomace spp. in Dali Bai Autonomous Prefecture from March 2023 to December 2024. Genomic DNA was extracted from the foot muscle tissue of Pomacea samples for PCR amplification and sequencing. The sequences were subjected to haplotype analysis, sequence similarity, and phylogenetic analysis using the software MEGA 11, DnaSP 5.1, and Geneious Prime 2024, respectively. The haplotype network relationship diagram was plotted with the software PopART to unravel the population genetic structure of Pomacea spp., and genetic diversity parameters and molecular variance analyses were conducted using the software DnaSP 5.1 and Arlequin 3.5. The population genetic differentiation index (Fst) and inter⁃population gene flow (Nm) were calculated, and the historical population dynamics of the Pomacea spp. were inferred in Dali Bai Autonomous Prefecture based on neutrality tests and mismatch analysis.  Results　A total of 379 gene sequences from nine geographical populations of Pomacea spp. were obtained in this study. Haplotype analysis revealed nine haplotypes, including hap1, hap4, hap11, hap18, hap20, hap21, hap22, hap 23 and hap24, and both sequence similarity and phylogenetic analyses indicated that these nine haplotypes were clustered into three distinct groups, and were identified as P. canaliculate (hap1, hap4 and hap11), P. occulta (hap18, hap20, hap21, hap22, and hap23), and P. maculata (hap24). P. canaliculata was detected across all nine geographical populations in Dali Bai Autonomous Prefecture, with a high overall genetic diversity, and the inter⁃population genetic variation (71.20%) was much higher than intra⁃population genetic variation (19.50%), with Fst of 0.712, and Nm of 0.351. P. occulta had unique haplotypes (hap20 to hap23), which contained few gene sequences and had a relatively low overall genetic diversity, and the intra⁃population genetic variation (80.50%) was much higher than inter⁃population genetic variation (16.45%), with Fst of 0.165, and Nm of 1.515. Neutrality tests and mismatch analysis showed that the overall Tajima's D value (4.564), Fu and Li's F* value (3.866), and Fu and Li's D* value (2.163) of P. canaliculata populations were all positive and exhibited significant differences in Dali Bai Autonomous Prefecture (all P values < 0.05), with two distinct peaks generated by mismatch distributions. In contrast, the overall Tajima's D value (-1.574), Fu and Li's F* value (-0.889), and Fu and Li's D* value (-0.328) of P. occulta populations were all negative, with no significant differences detected (all P values > 0.05), and the mismatch distribution produced only a single main peak. Conclusions　This is the first report to unravel P. canaliculata, P. occulta, and P. maculata in Pomacea spp. populations in Dali Bai Autonomous Prefecture, and P. canaliculata is the dominant species in the majority of geographical Pomacea spp. populations, with a high genetic diversity and high inter⁃population genetic differentiations. The P. canaliculata population conforms to the neutral evolution theory and the population size may be in an equilibrium or contraction state. In contrast, P. occulta has a relatively low genetic diversity and a low inter⁃population genetic differentiation, which may have recently experienced a population expansion event.  

Key words: Pomacea spp., Pomacea canaliculata, Pomacea occulta, Pomacea maculata, Phylogenetic analysis, Genetic diversity, Molecular variance, Dali Bai Autonomous Prefecture