Abstract：Abstract: The clams of the genus Corbicula are the dominant shellfish in Lake Dongting Basin, but their ploidy has not been investigated yet. Flow cytometry, as an efficient method for ploidy identification based on DNA content, has not been applied to Corbicula. In this study, besides the traditional karyotype analysis, flow cytometry was also used to identify the ploidy of Corbicula clams in Yuan River of Lake Dongting Basin. The relationship of the ploidy with clam morphology and gonad was further analyzed to provide a theo-retical basis for the evaluation and management of Corbicula germplasm resources. The results showed that there were 30 diploids and 15 triploids in 45 collected samples, and their karyotype formulas were 2n=36=2M+2SM+32ST and 3n=54=3M+15SM+36ST, respectively. Using diploid Crassostrea gigas and diploid Misgurnus anguillicaudatus as references, the DNA content ratios of these clams with two different ploidies were measured to be 2︰3. Among the 30 diploids, the proportions of hermaphrodite, male and female were 53.4%, 23.3% and 23.3%, respectively. The proportions of hermaphrodite, male and female in the 15 triploids were 46.7%, 40.0% and 13.3%, respectively. One-way ANCOVA, with shell weight as the covaria-te, showed that there was no significant difference in shell length, width and height between the two ploidies, but the ratio of shell width to length of diploid Corbicula was significantly greater than that of triploid (P<0.05). The above results indicated that compared with the karyotype analysis, flow cytometry was a more simplified method to identify Corbicula polyploidy. Co-existence of diploid and triploid as well as hermaphrodite and dioecism in Yuan River was confirmed using this method. The study on the effects of large-scale environ-mental factors on ploidy and gonadal characteristics of Corbicula is helpful to comprehensively understand mechanisms of ploidy and reproductive evolution of Corbicula clams.
引用本文:
裴宏谦, 占江凡, 秦 玲, 李科静, 皮 杰, 曾 聪, 李德亮. 洞庭湖流域沅江蚬属贝类的倍性研究[J]. 生命科学研究, 2020, 24(6): 452-458. PEI Hong-qian, ZHAN Jiang-fan, QIN Ling, LI Ke-jing, PI Jie, ZENG Cong, LI De-liang. Ploidy Investigation of Corbicula from the Yuan River, Lake Dongting Basin. Life Science Research, 2020, 24(6): 452-458.
