稻瘟病,由稻瘟病引起的,导致与叶子和脖子受伤相关的产量损失,后者通常比前者重要得多。关于叶片和颈部爆炸之间的关系仍然存在许多问题,包括与病原体的种群生物学有关的问题。我们的目的是检验米曲霉分离株对它们感染的器官类型的适应性假设。为了这个目标,测量了源自叶子和脖子的分离株的侵袭性成分。感染效率,潜伏期,孢子形成强度,并在叶片和颈部测量病变大小。单变量和多变量分析表明,源自叶子的分离株的侵袭性低于源自颈部的分离株。当在叶子和脖子上测量攻击性成分时,表明在病原体群体中没有关于被感染器官类型的专门化。该结果表明,在作物周期的营养阶段,与叶子上的流行病有关的更具侵略性的分离株感染脖子的可能性更高。并且在疾病从叶子传播到脖子的过程中可能会发生人口转移。讨论了对疾病管理的影响。
Rice blast, caused by
Magnaporthe oryzae, causes yield losses associated with injuries on leaves and necks, the latter being in general far more important than the former. Many questions remain on the relationships between leaf and neck blast, including questions related to the population biology of the pathogen. Our objective was to test the hypothesis of adaptation of M. oryzae isolates to the type of organ they infect. To that aim, the components of aggressiveness of isolates originating from leaves and necks were measured. Infection efficiency, latent period, sporulation intensity, and lesion size were measured on both leaves and necks. Univariate and multivariate analyses indicated that isolates originating from leaves were less aggressive than isolates originating from necks, when aggressiveness components were measured on leaves as well as on necks, indicating that there is no specialization within the pathogen population with respect to the type of organ infected. This result suggests that the more aggressive isolates involved in epidemics on leaves during the vegetative stage of the crop cycle have a higher probability to infect necks, and that a population shift may occur during disease transmission from leaves to necks. Implications for disease management are discussed.