利用RAD-seq（Restriction site Associated DNA sequencing）技术开发了10对新的多态性微卫星引物, 对9个野生缢蛏群体进行了遗传多样性分析, 在270个缢蛏个体中共检测到了352个等位基因。平均等位基因数(Na, number of alleles)在3.2000-4.3000之间, 平均有效等位基因数(Ne, effective number of alleles)在1.8789-2.5433之间; 观测杂合度(Ho, observed heterozygosity)范围为0.0000-0.9667, 平均观测杂合度在0.3088-0.5533之间; 期望杂合度(He, expected heterozygosity)范围为0.0000-0.7945, 平均期望杂合度在0.3456-0.5715之间; 平均多态信息含量(PIC, polymorphic information content)在0.3373-0.5989之间。遗传多样性评估显示, 9个缢蛏群体的遗传多样性水平属于中等。群体间的遗传分化系数Fst(genetic differentiation coefficient)在0.0547-0.3511之间, 其中河北秦皇岛和大连庄河群体之间的Fst值最低为0.0547, 而江苏连云港和广西北海群体之间的Fst值最高为0.3511; 基因流Nm(gene flow)在0.4620至4.3204之间, 河北秦皇岛和大连庄河群体之间的Nm值最高为4.3204, 而江苏连云港和广西北海群体之间的Nm值最低为0.4620。AMOVA分析结果显示, 群体间的遗传变异占总变异的33.04%(P<0.01), 而群体内的遗传变异占总变异的66.96%(P<0.01), 表明遗传变异不仅存在于个体间, 也存在于群体间, 但个体间的遗传变异大于群体间的遗传变异。UPGMA聚类、Structure聚类以及主坐标分析(PCoA, Principal Coordinate Analysis)结果一致。研究结果显示, 9个缢蛏群体可分为三大支: 河北秦皇岛与大连庄河亲缘关系最近, 再与青岛沙子口汇聚, 最后与辽宁丹东汇成第一支; 第二支由江苏连云港和宁波象山、福建厦门和广东惠州组成; 第三支由广西北海独立成支。这些研究结果丰富了缢蛏群体的遗传背景资料, 为提高缢蛏种质资源的管理水平和避免种群退化提供了重要的基础资料。

RAD-seq technology was utilized to develop 10 pairs of novel polymorphic microsatellite primers for assessing genetic diversity in nine wild populations of Sinonovacula constricta. In 270 individuals of S. constricta, a total of 352 alleles were detected. The average number of alleles (Na) ranged from 3.2000 to 4.3000, with the average effective number of alleles (Ne) falling between 1.8789 and 2.5433. Observed heterozygosity (Ho) varied from 0.0000 to 0.9667, with an average ranging from 0.3088 to 0.5533. Expected heterozygosity (He) spanned from 0.0000 to 0.7945, with an average of 0.3456 to 0.5715. The average polymorphic information content (PIC) ranged from 0.3373 to 0.5989. Genetic diversity analysis indicated a moderate level of genetic diversity across the nine populations of S. constricta. The genetic differentiation coefficient (Fst) among populations ranged from 0.0547 to 0.3511, with the lowest Fst value observed between Qinhuangdao in Hebei and Zhuanghe in Dalian (0.0547) and the highest between Lianyungang in Jiangsu and Beihai in Guangxi (0.3511). Gene flow (Nm) values ranged from 0.4620 to 4.3204, with the highest Nm value recorded between Qinhuangdao and Zhuanghe (4.3204) and the lowest between Lianyungang and Beihai (0.4620). AMOVA analysis revealed that 33.04% of the total genetic variation existed among populations (P<0.01), while 66.96% was within populations (P<0.01), underscoring significant genetic variation both within and among populations, with greater diversity observed among individuals. Consistent results were obtained from UPGMA clustering, Structure clustering, and Principal Coordinate Analysis (PCoA). The study delineated three main groups among the nine populations: the first group comprised Qinhuangdao in Hebei and Zhuanghe in Dalian, which were closely related and later merged with Shazikou in Qingdao and Dandong in Liaoning; the second group included Lianyungang in Jiangsu, Xiangshan in Ningbo, Xiamen in Fujian, and Huizhou in Guangdong; and the third group was independently represented by Beihai in Guangxi. These findings enhance the genetic background knowledge of S. constricta, offering crucial foundational data for enhancing germplasm resource management and preventing population degradation in this species.