OPTIMIZATION OF SELECTION RESPONSE UNDER RESTRICTED INBREEDING
OPTIMIZATION OF SELECTION RESPONSE UNDER RESTRICTED INBREEDING
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DOI：
10.1051/gse:19900107
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发表时间：
1990-01-01
影响因子：
4.1
通讯作者：
PEREZENCISO, M
中科院分区：
文献类型：
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作者：
TORO, M;PEREZENCISO, M
在小群体中选择程序的合理目标是响应最大化，并限制近亲繁殖的增加。在利用亲属信息对候选人进行甄选评估时，这一限制尤其重要。为了实现这一目标，已经提出了不同的策略：（i）降低选择的强度;（ii）降低指数中家庭信息的权重，使其低于最佳值;（iii）限制家庭规模的变化;（iv）在所选动物之间进行交配，以使平均共祖系数最小化;以及（v）使用线性规划找到一般解决方案。这些策略已通过遗传模拟的一个简单的例子来说明。该群体包括从每种性别评价的32只动物中选择的8只雄性和8只雌性。候选人进行了评估的指数使用的个人及其7个同胞的信息。经过五代的选择。得出的结论是，有几种替代策略，确保近亲繁殖低于固定水平（每代5%），而没有显着的损失的响应，与经典的策略，近亲繁殖不受限制。大量减少近亲繁殖被发现与使用的交配具有最小的共同祖先。然而，这种减少主要是由于延迟1代的外观近亲繁殖。线性规划在实现这些目标方面也很有效。原则上，它比其他策略更灵活，但其计算成本高是一个缺点，并且在实践中，使用更简单的策略可能会获得类似的结果。
A reasonable objective for selection programs in small populations is the maximization of response, with a restriction on the increase of inbreeding. This restriction will be especially important when information on relatives is used for evaluation of candidates for selection. To achieve this objective, different strategies have been proposed: (i) to reduce the intensity of selection; (ii) to lower the weight given to family information in an index below the optimal value; (iii) to restrict the variation of family size, (iv) to make matings between the selected animals, so as to minimize the average coancestry coefficient; and (v) to find a general solution using linear programming. These strategies have been illustrated by genetic simulation of a simple example. The population consisted of 8 males and 8 females selected from 32 animals evaluated in each sex. The candidates were evaluated by an index using information on the individual and its 7 sibs. Five generations of selection were practised. It was concluded that there are several alternative strategies which ensure that inbreeding is below the fixed level (5% per generation) without a significant loss of response, in comparison with classical strategies, where inbreeding is not restricted. A substantial reduction of inbreeding was found with the use of matings having minimal coancestry. However, this reduction was due principally to a delay of 1 generation in the appearance of inbreeding. Linear programming was also efficient in achieving these aims. It is, in principle, more flexible than the other strategies, but its heavy cost of computation is a disadvantage, and, in practice, comparable results can probably be obtained using much simpler strategies.