香港巨牡蛎与近江牡蛎杂交及回交子代早期生长发育比较

Comparisons of growth and development of hybrid and backcrossing progenies between Crassostrea hongkongensis and Crassostrea ariakensis

为评估香港巨牡蛎与近江牡蛎杂交及回交育种的可行性,以香港巨牡蛎与近江牡蛎为实验对象,比较了两种牡蛎杂交与回交子代的受精率、孵化率、幼虫及稚贝的生长和存活率。结果表明,香港巨牡蛎卵子可以与近江牡蛎精子受精,受精率为47.33%±2.52%,但近江牡蛎卵子与香港巨牡蛎精子不受精。在回交实验中,香港巨牡蛎(H♀)与近江牡蛎(A♂)的杂交牡蛎(HA)与香港巨牡蛎(HH)或近江牡蛎(AA)都可以正常交配,但各回交组受精率明显低于两牡蛎自交组。幼虫期,HA幼虫存活率明显低于两牡蛎自交组HH和AA;HA幼虫生长快于AA,但慢于HH;A♀×HA♂回交组和HA自繁组的幼虫存活率为0。稚贝期,HA稚贝存活率与HH、AA自交组存活率差异不显著。HA稚贝生长快于HH,但慢于AA。另外,研究发现H♀×HA♂回交组幼虫和稚贝的生长与HA差异不显著,优于其它回交组。

Hybridization and backcrossing between Crassostrea hongkongensis and Crassostrea ariakensis were conducted in this study, and consequently, the experimental groups HH （ C. hongkongensis）, AA （ C. ariakensis） ,HA（ C. hongkongensis ♀ × C. ariakensis ♂ ）, AH（ C. hongkongensis ♂ × C. ariakensis ♀ ）, HAHA（HA♀ ×HA ♂ ）,HHA（HH ♀ ×HA ♂ ）,HAH（HA ♀ ×HH ♂ ）,HAA（HA ♀ ×AA ♂ ）,AHA （ AH ♀ × AA × ） were produced using the method of diallel cross. The results showed that C. hongkongensis eggs can be fertilized by C. ariakensis sperm （47.33 % ±2.52% ）, but not vice versa. The fertilization can occur between HA and HH or AA. The fertilization rates of backcrossing groups were lower than those of inbred groups HH and AA. The hatching rates of the backcrossing between HA and AA were lower than those of the other groups, which were 20.33% ±2.08% （AHA） ,55.67% ±2.52% （HAA） respectively. The larval survival rate of the AHA and HAHA was 0 ;The survival of HA larvae was lower than HH and AA. The hybrid larvae grew faster than C. ariakensis larvae, but grew slower than C. hongkongensis. The survival rates of HA, HH, and AA juveniles were not significantly different（P 〉 0.05 ）. The hybrid juveniles grew faster than C. hongkongensis larvae, but grew slower than C. ariakensis. In addition, the larval and juvenile growth of HHA and HA was not significantly different（P 〉 0.05 ）. The larval survival rate was not significantly different in HHA and HA. The juvenile survival rate of HHA was lower than HA, but was higher than that of the other backcrossing groups. The results provide a basis for study on the hybridization and backcrossing between C. hongkongensis and C. ariakenis.