繁殖性状的杂种优势与基因效应分析

Heterosis and Genetic Effect of Reproductive Traits in Multi-line Hybrid Breeding System

测定杜长大三元杂交体系和斯格配套系各杂交组合的繁殖性能,计算出繁殖性状的杂种优势率;选用5个与繁殖性状紧密连锁的微卫星标记对测定个体进行基因型检测,利用混合效应线性模型计算出繁殖性状各位点的基因效应。结果表明:斯格祖代猪与父母代猪产仔数、产活仔数、断奶仔数、断奶窝重的差异均达到极显著水平(P<0.01),父母代猪与祖代猪的初生窝重差异显著(P<0.05),斯格父母代猪的产仔数、产活仔数、断奶仔数和断奶窝重与长大母猪的差异均达到极显著水平(P<0.01),斯格父母代猪与长大母猪的初生窝重差异显著(P<0.05),初生重、断奶重杂优率低,其余各性状的杂种优势率处于较高水平。显性效应在初生窝重、断奶窝重的杂种优势中起着很重要作用,加性效应是初生重和断奶重杂种优势的主要遗传学基础,产仔数、产活仔数、断奶仔数的杂种优势的产生存在上位效应。

Heterosis rate of crossing combinations of DurocxLandracexYorkshire of the three-breed cross breeding system and Seghers 5-line-crossbreed commercial hybrid line were calculated through reproductive performances measure. Animals were genotyped for 5 microsatellites which were correlated with reproductive traits and reproductive gentic effects were calculated by using least square method. The results showed that highly significant difference existed between Seghers grand parent herds and parent herds of litter size, living litter size, ablactation size, ablactation litter weight（P 〈 0.01 ）and the same results observed between Seghers parent herds and Durocx Landrace maternal herds（P 〈 0.01 ）; Born weights were significant difference among Seghers parent herds, grand parent herds and DurocxLandrace maternal herds（P 〈 0.05）. Heterosis rate of born weight and ablactation weight were in lowlevel, but otherreproductive traitswere in higherlevel. The main genetic effect was dominant effect at litter weight, ablactation litter weight. Additive effect was widely functioning of born weight, ablactation weight and epistatic effect is exited in litter size, alive litter size, ablactation size.