猪配套系生长性状基因效应与杂种优势的分析

Heterosis and genetic effect of growth traits in multi-line hybrid breeding system of pigs

测定杜长大三元杂交体系和斯格配套系各杂交组合的生长性能,计算出生长性状的杂种优势率;选用5个与生长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生长性状各位点的基因效应。结果显示:斯格配套系父母代与商品代各时期的平均日增重的差异均达到极显著水平(P<0.01),杜长大杂交体系父母代与商品代各时期的平均日增重的差异均达到显著水平(P<0.05),斯格配套系父母代和商品代与杜长大杂交体系的父母代和商品代的差异达到极显著水平(P<0.01),前期的的杂优率处于较高水平,后期及全程的杂优率不高。基因效应分析显示早期日增重的基因效应既有加性效应又有显性效应,后期日增重和全程日增重的加性效应明显,因而加性效应是日增重杂种优势的主要遗传学基础。

Heterosis of crossing combinations of DurocxLandracexYorkshire in the three-breed cross breeding system and Seghers S-linecrossbreed commercial hybrid line were calculated through growth performance measurement. Animals were genotyped for 5 microsatellites which were correlated with growth traits and gentic effects were calculated by using least square method. The results showed that highly significant differences existed between Segbers grand parent herds and parent herds of average daily gain all periods （ P〈0. 01 ） and significant difference existed between Duroe×Landrace maternal herd and commercial hybrid herd （ P〈0. 05 ） , and highly significant difference existed between Duroc×Landrace×Yorkshire of the three-breed cross breeding System and Seghers 5-line-crossbreed commercial hybrid line （P〈 0. 01 ）. Not only dominant effect, but also additive effect were observed at First period daily gain and additive effect was widely functioning of latter period daily gain and whole period daily gain. The main genetic effect was additive effect at average daily gain.