比较了长牡蛎(Crassostrea gigas)不同外套膜色家系的受精率与孵化率,不同生长阶段的生长与存活及外套膜色在子代个体中的分布规律。结果表明,不同家系的卵径、受精率和孵化率无显著差异(P〉0.05);壳高在60和150日龄稚贝阶段略有差异(P〈0.05),在350和450日龄成体阶段差异不显著(P〉0.05);不同生长阶段的存活率差异不显著(P〉0.05)。外套膜纯黑BB家系的子代外套膜基本全部为4级着色;外套膜纯黄YY1家系子代的外套膜基本全部为1级着色,YY2家系子代的外套膜黄色与黑色比例约为3∶1,符合孟德尔分离定律。由此推测长牡蛎外套膜色可能由一个主效基因控制,且黄色对黑色具有显性上位效应。研究结果可以为长牡蛎外套膜色的人工选育提供理论依据。
In the interest of increasing the value of the Pacific oyster(Crassostrea gigas) sold as "singles" for the half-shell market, we explored the feasibility of modifying mantle pigmentation through selective breeding. The experimental 12 full-sib families of pedigreed oysters were investigated for growth, survival and mantle pigmentation. Initial investigations showed the trait was complex and best described as 1-4 degrees. At 350 and 450 days old, no significant survival and shell height difference were found among different families(P0.05) which showed that the performance traits of growth and survival were not correlated with mantle pigmentation. The distributions of pigmentation levels among individuals within full-sib families were further examined. High within-family variation in mantle pigmentation that in the hybrid and control families was normally and continuously distributed. However, offspring within three BB families, the 4 degree mantle was dominant absolutely. Furthermore, offspring within YY2 family segregated into phenotypically distinct "lighter" and "darker" mantle groups in a 3∶1 ratio supporting the hypothesis that a single major gene is segregating in these families with the "light" allele being dominant over the "dark" allele. These findings will facilitate the selection of desired mantle coloration lines for oyster aquaculture.