Allotriploid Abalone Induction by Cytochalasin B

Fertilized eggs crossing between H.diversicolor aquatilis(♀) and H.discus discus(♂) were treated with Cytochalasin B to induce allotriploid by inhibiting the release of second polarbody.Different treatments of CB,including initial treating time(5 ～ 25 mins after fertilization),concentration(0.2 ～ 1.0 mg/L) and duration(5 ～15 min),were tested at 24 ℃ water temperature,and the trochophora survival rate and ploidy rate were calculated.The optimal initial time was 10 ～15 min after fertilization,which resul-ted in 52.07 % survival rate of trochophora and 55.81 % allotriploid percentage.The best combination of concentration and duration was 0.4 mg/L CB with 10 mins treatment,which resulted in 21.43 % rate of trochophora and 50.96 % allotriploid percentage.The diploid percentage and survival trochophora rate of the group(H.diversicolor aquatilis♀ × H.diversicolor aquatilis♂) were 95.42 % and 85.38 % respectively.The diploid percentage and survival trochophora rate of the group(H.diversicolor aquatilis♀ × H.discus discus(♂) were 95.42 % and 85.38 %.Overall,the most effective procedure for inducing allotriploid of H.diversicolor aquatilis(♀) × H.discus discus(♂) was to treat fertilized eggs for 10 mins by 0.4 mg/L CB the moment(13 mins after fertilization) when 40 % ～50 % fertilized eggs released the first polar body.