年龄结构对群体近交遗传漂变的作用

Effect of Age Structure of Inbreeding and genetic Drift in animal Populations

将Leslie年龄结构矩阵加上控制项(人工淘汰)引入家畜保种群,创建了世代重叠群体的计算机模拟保种模型,并用该模型模拟了年龄结构对秦川牛群近交及基因丢失概率的影响。研究发现,各种家系后代供量方差及世代间隔因群体年龄结构的改变而变化;母牛年龄结构对群体近交及遗传漂变有极显著影响,延长母牛使用年限既可增大世代间隔,又可降低公牛女儿供量方差,从而增强了保种效果。相较而言,公牛年龄结构的影响不明显。

Using the Leslie matrix plus and artifical control vdtor (culling) in the domestic animal population, a computer simulation model of conservation in populations with overlapping generations was developed, and it was utilized to simulate the effect of age structure of the inbreeding and gene less probabilities in Qinchuan cattle conservation population. Results showed that in populations with overlapping generations, even mating and selection were purely at random, family sizes were still not in Poisson distribution, and the varance of family sizes changed with different age structures. Age structure of cow population had a significant effect on both inbreeding and genetic drift. Prolonging cow in-herdtime could increase generation interval and decrease the varance of father-daughter family sizes so that the conservation results could increase. The effect of sire age structure was relatively low.