两个地理群体香港牡蛎(Crassostrea hongkongensis)杂交子代早期生长发育的杂种优势研究

HETEROSIS IN EARLY GROWTH STAGE OF HONG KONG OYSTER CRASSOSTREA HONGKONGENSIS HYBRIDIDS FROM TWO GEOGRAPHICAL POPULATIONS

为探讨不同地理群体香港牡蛎的杂种优势,于2014年5月开展了广东珠海(Z,生长快)和广西茅尾海(M,抗逆性强)群体间的2×2双列杂交,比较了各实验组早期生长、存活优势,并计算了各阶段的杂种优势,实验由2个杂交组MZ(M♀×Z♂)、ZM(Z♀×M♂)和2个自交组MM(M♀×M♂)、ZZ(Z♀×Z♂)组成。结果表明:浮游期间,正交组(MZ)幼虫在9日龄前未表现出生长优势,但表现出一定的存活优势,幼虫大小存在显著的母本效应;12日龄时正交杂种优势5.34。反交组(ZM)幼虫生长和存活都表现出了正杂种优势,但生长优势值逐渐减小,到了12日龄时壳高与自繁组(ZZ)幼虫间差异不显著(P>0.05)。室内苗种培育阶段,杂交稚贝表现出明显的生长、存活优势,正交组(MZ)和反交组(ZM)子代的生长优势分别为7.86±3.12、17.47±13.14;存活优势分别为8.33±1.41、2.86±1.08。以上结果说明两个群体香港牡蛎杂交可以产生杂种优势,可为牡蛎杂种优势开发利用提供参考。

To evaluate heterosis in early growth stage of Hong Kong oyster Crassostrea hongkongensis hybrids between two geographical populations （Zhuhai： Z, Maowei Sea： M）, a 2×2 diallel crossing was conducted in May 2014, including two self-fertilized groups （MM, ZZ） and two reciprocal crosses （MZ, ZM）. Results show that there was no growth heterosis before Day 9, but positive heterosis was observed on day 12 for MZ group with survival heterosis. However, positive heterosis in growth and survival appeared in ZM group during plantonic stage. At spat stage, positive growth and survival heterosis were 7.86±3.12 and 17.47±13.14 for MZ group, and 8.33±1.41 and 2.86±1.08 for ZM group, respectively. The above results indicate that heterosis can be produced from different populations, which offered a theory to use the heterosis for Hong Kong oyster culture.