凡纳滨对虾多代选育群体生长和耐综合胁迫性状的配合力及杂种优势分析

Analysis of combining ability and heterosis of growth and comprehensive stress tolerance traits of Litopenaeus vannamei multi-generation breeding population

为筛选凡纳滨对虾(Litopenaeus vannamei)最佳的交配组合方式,以5个不同遗传背景的凡纳滨对虾群体为亲本,经交配构建12个组合F_(1)代。利用ASReml4软件估计凡纳滨对虾12个组合105日龄的生长和耐综合胁迫(高盐(35)、低pH(6±0.1)与高氨氮(70 mg/L)共同胁迫)性状的一般配合力(GCA)及特殊配合力(SCA)。结果显示:亲本的SCA对子代性状的表现起主导作用,组合K♀×K♂(0.35±0.25)、GX♀×W♂(0.31±0.22)和GX♀×M♂(0.29±0.29)体质量的SCA排名靠前;组合GX♀×GX♂(3.65±1.79)、L♀×L♂(2.19±2.33)和W♀×GX♂(1.30±2.03)耐综合胁迫的SCA排名靠前。杂种优势分析表明,杂交组合的生长(体质量、体长、头胸甲长与腹节全长)和耐综合胁迫性状均表现出一定的杂种优势,6个杂交组合GX♀×W♂、GX♀×K♂、GX♀×M♂、W♀×GX♂、K♀×GX♂与K♀×M♂生长及耐综合胁迫性状的杂种优势率除组合GX♀×K♂为负外(-5.95%~1.00%和-8.03%),其余均为正(0.10%~80.79%和6.87%~42.86%),其中,组合GX♀×W♂体质量的杂种优势最高(25.52%);组合W♀×GX♂耐综合胁迫的杂种优势较高(41.72%)。研究表明,杂交组合GX♀×W♂体质量的SCA和杂种优势均最高;杂交组合W♀×GX♂耐综合胁迫的SCA最高且杂种优势较高,可考虑分别加强该两组合在生长和耐综合胁迫性状方面的配套杂交应用。

This research aimed to screen the best mating combinations of Litopenaeus vannamei.Five populations of L.vannamei with different genetic backgrounds were used as parents,and 12 combinations of the F_(1) generation were constructed by mating.The ASReml 4 software was used to estimate the general fitness(GCA) and specific fitness(SCA) for growth and tolerance to combined stress(high salt(35),low pH(6±0.1),and high ammonia nitrogen(70 mg/L) co-stress) traits of the 12 combinations of P105 in L.vannamei.The results showed that the SCA of the parents played a dominant role in the performance of offspring traits,with combinations K♀×K♂(0.35±0.25),GX♀×W♂(0.31±0.22) and GX♀×M♂(0.29±0.29) ranking high in SCA for body mass;combinations GX♀×GX♂(3.65±1.79),L♀×L♂(2.19±2.33) and W♀×GX♂(1.30±2.03) ranking high in SCA for tolerance to combined stress.The analysis of heterozygous dominance H showed that the crosses showed some heterozygous dominance for growth(body mass,body length,cephalothorax length,and full length of ventral segments) and stress tolerance traits,and the H for growth and stress tolerance traits of the six crosses GX♀×W♂,GX♀×K♂,GX♀×M♂,W♀×GX♂,K♀×GX♂ and K♀×M♂ were negative except for the combination GX♀×K♂(0.10%-80.79% and 6.87%-42.86%),with the highest H for the combination GX♀×W♂ body mass(25.52%) and the higher H for the combination W♀×GX♂ tolerance to combined stress(41.72%).The study showed that the hybrid combination GX♀×W♂ had the highest SCA and H for body mass;the hybrid combination W♀×GX♂ had the highest SCA and higher H for tolerance to combined stress,which can be considered to enhance the application of the two combinations in matching crosses for growth and combined stress tolerance traits respectively.