Wang Bing, Li Bao-Hua, Dong Xiang-Li, Wang Cai-Xia, Zhang Zhen-Fang
College of Crop Protection and Agronomy, Qingdao Agricultural University; Key Lab of Integrated Crop Pests Management of Shandong Province, Qingdao, Shandong 266109, P. R. China.
Plant Dis. 2015 Feb;99(2):249-256. doi: 10.1094/PDIS-04-14-0361-RE.
Glomerella leaf spot (GLS) caused by Glomerella cingulata is a newly emergent disease that results in severe defoliation and fruit spots. Currently, GLS is not effectively controlled in China due to a lack of understanding of its epidemiology. Therefore, the effects of temperature, wetness duration, and moisture on conidial germination, infection, and the disease incubation period of GLS were examined by inoculating cv. Gala apple leaves with a conidial suspension and performing in vitro germination assays. Conidia could germinate and form appressoria at temperatures ranging from 5 to 35°C, with an optimum temperature of 27.6°C. The germination of conidia required free water or a nearly saturated relative humidity, with only a few conidia germinating and forming appressoria when the RH was less than 99%. The conidial germination dynamics at 10, 25, and 30°C were well represented by three logistic models. The infection of cv. Gala apple leaves by conidia occurred at temperatures ranging from 15 to 35°C. The minimum wetness duration required for infection by conidia at different temperatures was described using a polynomial equation, and the lowest minimum wetness duration was 2.76 h, which occurred at 27.6°C according to the polynomial. Successful infection by conidia was represented by the number of lesions per leaf, which increased with extended wetness durations at the conidial infection stage for six tested temperatures, with the exception of 10°C, when the minimum wetness durations were satisfied. The associations of successfully infected conidia with wetness duration at temperatures of 15, 20, 25, and 30°C were described by four logistic models. Conidia infections developed into visible lesions at temperatures ranging from 15 to 30°C, and the shortest incubation period of 2 days was observed at 25°C. These data and models can be used to construct forecasting models and develop effective control systems for Glomerella leaf spot.
由围小丛壳菌（Glomerella cingulata）引起的苹果炭疽叶枯病是一种新出现的病害，会导致严重落叶和果实斑点。目前，由于对其流行病学缺乏了解，在中国苹果炭疽叶枯病尚未得到有效控制。因此，通过用分生孢子悬浮液接种嘎啦苹果叶片并进行体外萌发试验，研究了温度、湿润持续时间和湿度对苹果炭疽叶枯病分生孢子萌发、侵染及病害潜伏期的影响。分生孢子在5至35°C的温度范围内均可萌发并形成附着胞，最适温度为27.6°C。分生孢子的萌发需要自由水或接近饱和的相对湿度，当相对湿度低于99%时，只有少数分生孢子萌发并形成附着胞。10、25和30°C下的分生孢子萌发动态可用三个逻辑模型很好地描述。分生孢子对嘎啦苹果叶片的侵染发生在15至35°C的温度范围内。用多项式方程描述了不同温度下分生孢子侵染所需的最短湿润持续时间，根据该多项式，最短的最短湿润持续时间为2.76小时，出现在27.6°C时。分生孢子成功侵染以每片叶上的病斑数表示，在六个测试温度下，除10°C（满足最短湿润持续时间时）外，在分生孢子侵染阶段，病斑数随湿润持续时间延长而增加。15、20、25和30°C温度下成功侵染的分生孢子与湿润持续时间的关系可用四个逻辑模型描述。分生孢子侵染在15至30°C的温度范围内发展为可见病斑，在25°C时观察到最短潜伏期为2天。这些数据和模型可用于构建苹果炭疽叶枯病的预测模型并开发有效的防治系统。
