马氏珠母贝生长性状QTL鉴定及基因型选择效应分析

Verification of QTL and genotype selection effect of QTL for growth-related traits in the Pearl Oyster,Pinctada fucata

对马氏珠母贝生长性状QTL411871进行初步验证,然后建立两种基因型组配:♀AT×♂AT(30号)和♀TT×♂AT(31号),对其实际的基因型效应进行分析。结果显示,QTL411871在验证群体中与闭壳肌重显著相关(P<0.05),优势基因型为AT。在30和31号基因型组配中,QTL411871与生长性状关联不显著(P>0.05),AT基因型的遗传效应小,但仍是个体生长性状均值最大的基因型。QTL423886标记在30号组配中与壳高、壳长和总重显著相关(P<0.05),其AG基因型个体的壳高、壳长和总重显著大于GG基因型;而在31号组配中与生长性状关联不显著(P>0.05)。基于这2个QTL标记在30和31号组配中分别构建二倍型,发现在30号组配中二倍型C1(ATAG)和31号组配中D1(ATAA)型对马氏珠母贝的生长最为有利,可作为优先的基因型组合。该结果为开展马氏珠母贝的分子标记辅助选择育种提供了指导。

QTL411871 was identified in the verifying population of Pinctada fucata, and two genotype matings♀AT×♂AT(Group No.30 ) and ♀TT×♂AT(Group No.31) were established to analyze genotype selection effect of QTL. The results showed that QTL411871 was significantly associated with muscle mass in the verifying population (P<0.05), and AT was the superior genotype. QTL411871 was not significantly associated with growth traits in Groups No. 30 and No. 31 (P>0.05);the genetic effect of AT genotype was small, but it was still the genotype with the maximal average of growth traits.QTL423886 was significantly associated with shell height, shell length and total weight in Group No. 30 (P<0.05), and the oysters with genotype AG were bigger than those with the genotype GG in terms of shell height, shell length and total weight,but it was not significantly associated with growth traits in Group No.31 (P>0.05). Diplotypes were constructed based on the two QTLs, and association analyses revealed that C1 (ATAG) in Group No.30 and D1 (ATAA) in Group No.31 might be the most advantageous diplotypes for growth traits. These results are useful for developing molecular marker assisted breeding of Pinctada fucata.