Improvement of polyploidy induction in Eriocheir sinensis

An incubating temperature of 15℃ is used to induce triploidy in Eriocheir sinensis through inhibition of the release of polar body Ⅱ,and that of 18℃ to induce tetraploidy through inhibition of the first cleavage.Flow cytometry is used to identify the ploidy in different developmental stages.For induction of triploidy in fertilized eggs in vitro,the highest induction rate observed in blastula by cytochalasin B,6-DMAP and KC1 is 49.1%,51.7% and 77.5%,respectively.In the KCl treatment of pregnant crabs with the fertilized eggs,the highest triploid induction rate observed in the zoea is 85.3%.For induction of tetraploidy,the highest induction rate observed in the blastula by cytochaslasin B,6-DMAP and KCl is 50.3%,54.9% and 79.8% respectively.In the KC1 treatment of pregnant crabs with the fertilized eggs,the highest induction rate in zoea is 27.3%.Through this study such difficulty as in vitro culture is overcome.Triploid zoea Eriocheir sinensis has been developed for the first time.The induction rate of tetraploid zoea has also been greatly improved.