九孔鲍养殖群体与野生群体杂交一代生长比较

Growth and Survival Studies on Hybridization Between Cultured Stock and Wild Stock of Haliotis diversicolor supertexta

利用九孔鲍(Haliotis diversicolor supertexta)汕尾养殖群体(BD)和深圳野生群体(YS)进行群体间杂交及群体内自繁,获得YS♀×BD♂、BD♀×YS♂、BD♀×BD♂和YS♀×YS♂4个组合的F1代,对其卵径、受精率、幼体附着率、幼体变态率,以及40、70、100、160、220、280日龄幼鲍的存活率及壳长、壳宽等进行比较。结果表明:野生群体卵径比养殖群体大12.14%,差异极显著(p值<0.01);受精率、附着率、变态率,杂交组显著大于自繁组(p值<0.05);杂交组在幼体存活率、稚贝主要生长性状与自繁组相比均表现出不同程度的杂种优势,幼鲍存活率平均杂种优势变化范围为(14.89±3.60)%～(43.00±2.15)%,壳长平均杂种优势变化范围为(5.18±1.46)%～(18.52±2.12)%,壳宽平均杂种优势变化范围为(6.17±1.09)%～(16.72±1.26)%,体质量平均杂种优势变化范围为(9.86±1.25)%～(12.55±1.26)%;通过野生群体与养殖群体的杂交育苗能提高九孔鲍的经济性状。

Haliotis diversicolor supertexta is an economically important shellfish species in southern China. However, genetic degradation, such as inbreeding depression, becomes more and more serious. In addition, massive mortality of the H.diversicolor supertexta occurred at post-larval and grow-out stages and production of H.diversicolor supertexta dramatically reduced in recent year. Genetic improvement plays an important role in sustainable development for H.diversicolor supertexta aquaculture industry. F1 generation of four groups, Shanwei （ BD ）♀×Shenzheng （ YS ）♂, YS♀×BD♂, BD♀×BD♂ and YS♀×YS♂ were obtained from mating and crossing within and between Cultured stock and Wild stock of H. diversicolor supertexta. We comparison of egg size, fertilization rate, larval settlement rate, larval metamorphosis rate, larval survival rate and postlarval growth among four groups in 40-280 days. The results revealed that the egg size of wild populations were 12.14% bigger than cultured populations. （p〈0.01） . The hybridization groups also bigger than self-fertilized groups on fertilization rate, larval settlement rate, larval metamorphosis rate （p〈0.05）. The hybridization groups showed heterosis of various degrees on larval settlement rate, larval metamorphosis rate, larval survival rate and postlarval growth compared to self-fertilized groups. Heterosis of the survival rate in juvenile abalone ranged from （ 14.89 ± 3.60 ）% to （ 43.00±2.15 ）%. Heterosis of shell length in juvenile abalone ranged from （ 5.18± 1.46 ） % to （ 18.52±2.12 ） %, Heterosis of shell width in juvenile abalone ranged from （ 6.17 ± 1.09 ） % to （ 16.72±1.26 ） %, Heterosis of body weight in juvenile abalone ranged from （ 9.86 ± 1.25 ） % to （ 12.55 ± 1.26 ） %, It is indicated that the cross between geographically different stocks may be an effective way for genetic improvement of H. diverscolor supertexta.