【摘要】 于2017年10月—2018年11月间,对银杏叶枯病的发生以及银杏叶枯病发病原因进行了调查,结果表明:银杏叶枯病在南京地区发生较为普遍。从5月开始发生(平均病情指数为7.28),7,8月病害达高发期(平均病情指数分别为24.15,41.57),10月病害发生较为严重,此时大量病树叶片枯黄脱落,平均病情指数达到62.35;对采集的银杏叶枯病病叶进行标本镜检,并参考相关的资料,认为叶枯病病原或致病因素包括真菌性病原、细菌性病原和环境因素,而真菌性病原包括链格孢菌、镰刀菌、盘多毛孢菌、盘圆孢和叶点霉菌;另有部分患病植株叶片,未发现和分离出相关病原。推测可能是由环境因素或营养条件所造成的非侵染性病害,具体原因尚需进一步研究。更多还原

【Abstract】 The Ginkgo leaf blight occurence and its pathogenic factors were investigated from October 2017 to November 2018. The results showed that: 1.Gingko leaf blight was relatively common in Nanjing area, where it began to occur in May. The average disease index in May was 7.28. The disease entered the period of high incidence in July and August, with average disease index of 24.15 and 41.57 respectively. The disease occurred more severely in October when a large number of ginkgo leaves withered and shed. The average disease index in October was 62.35. 2. By the way of microscopic examination and pathogens separation, and referring to the relevant data, it was found that the pathogenic factors of leaf blight might include fungi, bacteria and environmental factors. Fungal pathogens might include Alternaria sp, Fusarium sp, Pestalotia sp, Gloeosporium sp and Phyllosticta sp.Yet, the related pathogen of some diseased leaves not been isolated, they might be caused by environmental factors or nutritional conditions. The specific reasons need further study.更多还原