Can genetic diversity be maintained during mass selection of the Chinese mitten crab,Eriocheir sinensis? |
| |
| Authors: | Jie He Qing Liu Yongxu Cheng |
| |
| Affiliation: | 1. Key Laboratory of Freshwater Aquatic Genetic Resources, Ministry of Agriculture, Shanghai Ocean University, Shanghai, China;2. Shanghai Collaborative Innovation Center for Aquatic Animal Genetics and Breeding, Shanghai Ocean University, Shanghai, China;3. National Demonstration Center for Experimental Fisheries Science Education, Shanghai Ocean University, Shanghai, China |
| |
| Abstract: | The Chinese mitten crab (Eriocheir sinensis) is an important aquaculture species and food source in Eastern Asia. This study assesses the changes in genetic diversity in successive generations of early‐ and late‐maturing strains of E. sinensis using 30 microsatellite markers with high polymorphism. The mean average number of alleles (N) in the founder population (G0), first generation (G1), second generation (G2) and third generation (G3) of the early‐maturing strain were 18.367, 14.800, 16.400 and 16.533, respectively; while in late‐maturing strain the values were 18.500, 16.267, 14.367 and 16.533 respectively. Likewise, there was a slight decline in average allelic richness (Rs) in the three successive generations. In both strains, the mean observed heterozygosity (Ho) remained relatively constant for the early‐maturing strain and the values were 0.655, 0.667, 0.685 and 0.705, respectively; and for the late‐maturing strain these were 0.665, 0.672, 0.688 and 0.702 respectively. Similarly, the expected heterozygosity (He) remained constant, ranging from 0.823 to 0.854. There was a decrease in effective population sizes (Ne) of the early‐maturing strain with successive generations: values were 492.2, 35.0, 134.7 and 193.2, respectively; while the values in the late‐maturing strain were 1268.5, 75.6, 111.5 and 97.2 respectively. All pairwise population distances were very close in both strains. In conclusion, these results suggest that mass selection of E. sinensis did not significantly diminish genetic diversity although there was a decline for the Ne. Therefore, it is important to maintain sufficient broodstock numbers and a large effective population when following a selective breeding programme. |
| |
| Keywords: | Chinese mitten crab effective population size genetic diversity microsatellites selective breeding |
|
|
