桃树溃疡病侵染循环的研究

本文报道了昆明地区由扁桃壳梭孢(Fusicoccum amygdali Dalacr. )侵染而引起的桃溃疡病。这一病害主要发生在桃树一年生枝条上。在叶痕和当年生枝条基部形成深褐色病斑。据1987年观察,病害在6月初开始发生,到10月发展至高峰。病原菌于11月进入休眠期。接种试验表明,病原菌只能从寄主受伤组织侵入,潜育期约为10天。研究结果认为这一病害具有潜伏侵染现象。病原菌以菌丝体和分生孢子在病枝上越冬,也能在果园内脱落在地面的病枝上存活。分生孢子在雨季内随雨滴飞溅大量传播,以7月后期至8月初数量最多。

THE INFECTION CYCLE OF PEACH CANKER

Peach canker disease in Kunming aera of Yunnan Province is caused by Fusicoccum amygdali Delacr.. The disease mainly affects 1-year-old twigs of peach tree. The symptom appears dark-brown lesion at leaf scars and bases of the current season's twigs. In 1987 the early infection in orchard occurred at early June, and the disease reached its climax in October. The pathogen developed into dormant stage in November. The inoculation of pathogen showed that the incubation period lasted about 10 days and the successful invasion of the pathogen only appears on injured tissues. The studies indicated that the disease had latent infection. The pathogen winters in the infected twigs in the stage of conidium and mycelium. It can survive in fallen diseased shoots on the orchard ground in winter. The conidia in the rainy season are most dispersed in late July or early August, and their dissemination is related to rainfall.