Department of Plant Breeding, Swedish University of Agricultural Sciences, Uppsala, Sweden.
Theor Appl Genet. 1981 Nov;59(6):381-90. doi: 10.1007/BF00276454.
Based on the gene-for-gene relation in race-specific resistance versus virulence, racial complexity of a pathogen population can be revealed by using host lines each with a single gene for resistance as detector. Such inventories of cereal rusts have shown: i. Genes for virulence may have pleiotropic effects acting on general fitness and their relative prevalence. ii. Genes for virulence are, as most other genes, dependent on genetic background for their general fitness. iii. Specific and general gene erosion in a pathogen population submitted to the assortative function of a race-specific host selection pressure is proportional to the degree of existing recombination and thus ultimately upon mode of reproduction (sexual or asexual). iv. Genetic storage capacity is dependent on ploidy constitution. v. Host alternation for safe annual survival favours a genetic system able to store temporarily unnecessary genes for virulence. - Due to shifting circumstances, pathogens like rusts will even inside the same forma specialis show different strategies. The trend may lead to a process of stabilizing selection and dependence on immediate and provisional flexibility just as typical of true haploids. It may lead to a pattern of preparedness: i.e. accumulation of 'unnecessary' genes for virulence. In the latter case, the modern concept of gene diversification in breeding for disease resistance is less effective. In the former case, gene accumulation can also work.
基于专化性抗病性与毒性之间的基因对基因关系，可以利用具有单个抗性基因的寄主品系作为检测物来揭示病原种群的种族复杂性。对谷物锈病的这种清查表明：i. 毒性基因可能具有多效性作用，影响一般适应性，其相对流行程度。ii. 毒性基因与大多数其他基因一样，其一般适应性取决于遗传背景。iii. 在受到专化性寄主选择压力的 assortative 功能作用下的病原种群中，特异性和一般性基因侵蚀与现有重组的程度成正比，因此最终取决于繁殖方式（有性或无性）。iv. 遗传储存能力取决于倍性构成。v. 为了安全的年度生存而进行的寄主交替有利于一种能够暂时储存不必要的毒性基因的遗传系统。-由于情况的变化，像锈病这样的病原体即使在同一专化型内也会表现出不同的策略。这种趋势可能导致稳定选择的过程和对即时和临时灵活性的依赖，这与真正的单倍体一样典型。它可能导致一种预备模式：即积累“不必要的”毒性基因。在后一种情况下，现代抗病育种中基因多样化的概念效果较差。在前一种情况下，基因积累也可以起作用。
