Genetic variation in latent period among isolates of Puccinia recondita f sp tritici on partially resistant wheat cultivars
Genetic variation in latent period among isolates of Puccinia recondita f sp tritici on partially resistant wheat cultivars
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DOI：
10.1094/phyto-86-633
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发表时间：
1996-06-01
期刊：
影响因子：
3.2
通讯作者：
Shaner, G
中科院分区：
文献类型：
--
作者：
Lehman, JS;Shaner, G
部分抗性小麦品种对小麦叶锈病的持久性取决于病原体隐秘柄锈菌种群内寄生适应性的遗传变异量。 sp。小麦。为了评估部分抗性的持久性，对潜伏期的表型变异（寄生适应性的主要组成部分）进行了量化，并将其分为 P. recondita f 分离株的遗传和非遗传成分。 sp。小麦对敏感和部分抗性品种的影响。对于个别部分抗性品种，分离株之间的潜伏期差异为 24% 至 27%。在模拟流行病中，潜伏期短的分离株引起的疾病增加了 2 至 2.5 倍，并克服了四个部分抗性品种 13% 至 35% 的抗性。 P. recondita f 分离株潜伏期的遗传力估计。 sp。小麦对部分抗性品种的影响范围为 0.28 至 0.76。这些结果表明，潜伏期短的分离株应该受到自然选择的青睐，并且可以克服部分抗性小麦品种的部分抗性，前提是潜伏期短与其他降低适应性的性状无关。尽管潜伏期很长，但预计小麦品种 CI 13227 的持久抗性最差，因为“CI 13227”上的病原体分离株在潜伏期内变化最大，而且“CI 13227”似乎与病原体分离株相互作用的特异性最高。
The durability of partially resistant wheat cultivars to wheat leaf rust depends on the amount of genetic variation in parasitic fitness within populations of the pathogen Puccinia recondita f. sp. tritici. To assess the durability of partial resistance, phenotypic variation in latent period (a major component of parasitic fitness) was quantified and partitioned into genetic and nongenetic components for isolates of P. recondita f. sp. tritici on susceptible and partially resistant cultivars. Latent periods among isolates differed by 24 to 27% on individual partially resistant cultivars. In simulated epidemics, isolates with short latent periods caused 2 to 2.5 times more disease and overcame 13 to 35% of the resistance of four partially resistant cultivars. Heritability estimates for latent period of isolates of P. recondita f. sp. tritici on partially resistant cultivars ranged from 0.28 to 0.76. These results suggest that isolates with short latent periods should be favored by natural selection and could overcome a portion of the resistance of partially resistant wheat cultivars provided that short latent period is unlinked to other traits that reduce fitness. Despite a long latent period, wheat cultivar CI 13227 was anticipated to have the least durable resistance because pathogen isolates on 'CI 13227' were the most variable for latent period and because 'CI 13227' appeared to interact with pathogen isolates with the greatest specificity.