Evaluation of advantages in the growth, survival and reproductive aspects of triploid hybrids derived from Crassostrea gigas tetraploids and C. ariakensis diploids in northern China

Crossbreeding and polyploid breeding are two important tools for the genetic improvement of oysters, and their cross-application is expected to provide new benefits to oyster breeding. To evaluate the aquaculture traits of allotriploids between Crassostrea gigas and Crassostrea ariakensis, two triploid hybrids (TAG (diploid C. ariakensis ♀ × tetraploid C. gigas ♂) and TGA (tetraploid C. gigas ♀ × diploid C. ariakensis ♂)) were established. Phenotypic traits including growth, survival and reproduction were analyzed in two diploid hybrids (AG (diploid C. ariakensis ♀ × diploid C. gigas ♂) and GA (diploid C. gigas ♂ × diploid C. ariakensis ♀)) as controls. The results showed that TAG presented triploid advantage in fertilization rates and hatching rates, up to 11.34% and 26.50% respectively, while TGA did not. The survival rate of TAG and the shell height of TGA exhibited triploid advantage throughout the larval stage and were significantly higher (P