科研之友
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摘要
Gracilariopsis lemaneiformis is an economically important alga as it produces agar. Establishing a genetic breeding system for this species is crucial. Simple sequence repeat (SSR) markers have been used to establish such breeding systems in other species. In this study, abundant SSR loci were identified from the genome survey sequences of Gp. lemaneiformis, and their repeat numbers and lengths were determined. The repeat numbers of these SSRs ranged from 4 to 31, with 4 repeats being the most abundant number, representing 48.69%, while repeat numbers from 15 to 31 represented less than 1%. The total SSRs contained 120,873 bp, accounting for 0.12% of the genome, and the length of each SSR ranged from 12 to 62 bp, with an average of 15.62 bp. In 12 individuals, 120 SSRs were detected, 115 (95.83%) were successfully amplified, and 31 (25.83%) were developed into polymorphic primers. Subsequently, the polymorphic primers were used to screen 82 individuals from three geographical populations: Qingdao Sculpture Garden, Qingdao Zhanshan Bay, and Weihai Stone Island. Parameters, such as the observed number of alleles, effective number of alleles, Nei's gene diversity index, Shannon's diversity index, and polymorphism information content, indicated a low level of genetic diversity in the overall wild population. Genetic diversity was highest in the Weihai Stone Island population and lowest in the Qingdao Zhanshan Bay population. Based on Nei's and Shannon's diversity indices, the genetic variation within populations contributed the most to the total genetic variation, as indicated by the analysis of molecular variance. In addition, the genetic differentiation coefficient among populations was below 0.05, revealing that the degree of differentiation among the populations was low. A cluster analysis showed no obvious regional features, further indicating the non-significant differentiation among the three populations. These results suggest a scarcity of idioplasmic resources in Gp. lemaneiformis, which is related to its specialized living environment and reproductive mode. The over-exploitation of coastal areas is also an important factor affecting the low genetic diversity of the wild Gp. lemaneiformis population.
- 出版日期2018-2
- 单位中国海洋大学
