CALCULATION OF SELECTION COEFFICIENTS AGAINST UNNECESSARY GENES FOR VIRULENCE FROM FIELD DATA
CALCULATION OF SELECTION COEFFICIENTS AGAINST UNNECESSARY GENES FOR VIRULENCE FROM FIELD DATA
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DOI：
10.1094/phyto-73-547
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发表时间：
1983-01-01
期刊：
影响因子：
3.2
通讯作者：
ARCHER, SA
中科院分区：
文献类型：
--
作者：
GRANT, MW;ARCHER, SA
一个模型的频率下降的一个不必要的毒力基因在病原体种群的大规模删除的品种与相应的抗性基因在农业的情况下。该模型是基于正向和反向突变和选择的毒力和无毒力的存在和不存在，分别在宿主种群中的抗性等位基因。该模型是用来估计无毒和有毒的比赛，从现场数据显示，随着时间的推移，毒力基因频率下降之间的适应性差异。一组数据是1948年至1955年澳大利亚小麦（Triticum aestivum）中Sr 6抗性基因引起的小麦柄锈菌（Puccinia graminis triumphus）毒力下降。第二个是1969-1975年英国大麦白粉菌（白粉病的原因）对大麦（大麦）Mla 6抗性基因的毒力下降。在这两种情况下，估计的适合度差异约为4- 6%，无毒小种更适合。这些值是相当小的比经常被假定，并意味着使用多系品种是更有可能提供有利于复杂的，而不是简单的小种病原体的定向选择。
A model of the decline in frequency of an unnecessary virulence gene in a pathogen population following the mass removal of cultivars with the corresponding resistance gene in an agricultural situation is presented. The model is based on both forward and backward mutation and on selection for virulence and for avirulence in the presence and absence, respectively, of the allele for resistance in the host population. The model is used to estimate the fitness difference between avirulent and virulent races from field data that show declining virulence gene frequencies with time. One set of data was the decline of virulence in Puccinia graminis tritici (the cause of stem rust) to the Sr6 resistance gene in wheat (Triticum aestivum) in Australia between 1948 and 1955. The second was the decline of virulence in Erysiphe graminis hordei (the cause of powdery mildew) to the Mla6 resistance gene in barley (Hordeum vulgare) in the UK in 1969-1975. In both cases the estimated fitness differences were of the order 4-6%, the avirulent races being fitter. These values are considerably smaller than has frequently been assumed and imply that the use of multiline cultivars is more likely to provide directional selection in favor of complex rather than simple races of pathogens.