长牡蛎3种壳色家系间杂交子代生长和存活比较

为了利用杂种优势培育长牡蛎优良新品种,实验以3种不同壳色长牡蛎家系(白色/W、黑色/B、紫色/P)为材料,采用3×3完全双列杂交法,建立了3个自交组合和6个正反杂交组合,分析了各实验组幼虫期和养成期的生长、存活以及杂交子代的杂种优势。结果表明,浮游幼虫期,杂交组PB表现出显著的生长优势;与自交组相比,各杂交组均有着较高的幼虫存活率;在幼虫存活率方面,所有杂交组均有较高的杂种优势率。在养成期,紫壳色自交组的壳高显著大于白壳色和黑壳色自交组;6个杂交组中,PB的壳高生长最快,BP次之,PW、WP的生长最慢;各杂交组与自交组的成活率差异均不显著;杂交组BP及其反交组PB的壳高、壳长、总重和存活率的杂种优势率分别介于3.71%~15.27%、-2.00%~13.10%、11.23%~41.56%、-2.77%~9.83%,其他4个杂交组在整个养成阶段没有表现出杂种优势。

Comparison of growth and survival among the hybrid offspring of three different shell color families of Pacific oyster(Crassostrea gigas)

A 3×3 diallel crosses of three different shell color families of Pacific oyster(Crassostrea gigas)(white/W, black/B, purple/P)were conducted.Three parental groups and six reciprocal hybrid crosses were established.The growth, survival rate and heterosis of hybrid crosses at larval and grow-out stages were compared among all experimental groups.The results showed that at the larval stage, hybrid cross PB presented significant growth superiority than other experimental groups.The larval survival rates of all the hybrid crosses were higher than that of parental crosses.All the hybrid crosses showed obvious larval survival heterosis.At the grow-out stage, the shell height of parental group PP was significantly greater than that of WW and BB.The grow of hybrid PB was the fastest among the six hybrid crosses, followed by hybrid BP, then hybrid WP and PW were the slowest.The survival rates were not different significantly among all the hybrid crosses and parental crosses during the grow-out stage.The heterosis of shell height, shell length, total weight and survival rate of hybrid cross BP and its reciprocal cross PB were between 3.71%-15.27%, -2.00%-13.10%, 11.23%-41.56% and -2.77%-9.83%, respectively.The other four hybrid groups had no heterosis during the grow-out stage.