Nei氏标准遗传距离的估测精度

ACCURACY OF THE ESTIMATION OF NEI'S STANDARD GENETIC DISTANCE

以实际基因频率为基础，用计算机模拟和实例分析等方法研究了Ｎｅｉ氏标准遗传距离估测精度的影响因素。指出：（１）稀有等位基因和在品种间低变异度的基因对聚类分析贡献极小，实验设计中可不予考虑；（２）相似品种间具有较低的遗传距离期望值，此时遗传距离的估测精度较低，实验设计中应多考虑位点数和个体数；（３）位点数较少时遗传距离估测精度较低，可靠性不高，使用很少位点进行聚类分析的工作以后不应再度进行；（４）随个体数增加，遗传距离估测精度增高。

おeal allele frequencies are used in computer simulation and case study to analyse the accuracy of the estimation of Nei's standard genetic distance.The results indicate that:(1)The contributions of rare alleles and lowinterpopulationvariation alleles to cluster analysis are negligible.(2)The coefficient of variance of genetic distance estimations among closely related populations which have low distance expectations are high and therefore special considerations should be paid when trying to establish genetic relationships among these populations.(3)The reliability of the estimations of genetic distances are low when few loci are used,and therefore studies in the context of establishing genetic relationships using few loci should not be done in the future.(4)The accuracy of genetic distance estimations increases with the increase of sample size.These results are in agreement with those of other studies using different approaches.