Yu Shuyi, Li Baihong, Guan Tianshu, Liu Li, Wang Hui, Liu Changyuan, Zang Chaoqun, Huang Yuqian, Liang Chunhao
Institute of Plant Protection, Liaoning Academy of Agricultural Sciences, Shenyang 110161, China.
Plant Protection College, Shenyang Agricultural University, Shenyang 110866, China.
Plants (Basel). 2022 Aug 21;11(16):2175. doi: 10.3390/plants11162175.
Grape downy mildew (GDM) is a destructive grapevine disease caused by that occurs worldwide. In this study, we determined the characteristics of GDM epidemics and the grapevine canopy micro-climate in open-field, fungicide-spray, and rain-shelter plots during two constitutive years (2016 and 2017). It was found that rain shelter can significantly delay the disease occurrence by 28 and 21 days, reduce the epidemic phase by 28 and 21 days, and decrease the final disease index by 82% and 83%. Furthermore, it can block precipitation, reduce the relative humidity by 11% and 8%, and reduce the leaf wetness duration by 85% and 76% compared with open-field cultivation. A total of 3861, 783, and 1145 lesions were collected from the open-field, fungicide-managed, and rain-shelter plots, respectively, for analyses of the genetic diversity, population differentiation, and epidemic mode with seven microsatellite markers. In terms of genetic diversity, the Nei's diversity index ranged from 0.569 to 0.680 and Shannon's information index ranged from 0.958 to 1.226, showing high levels of diversity across populations. Similar to fungicide management, a rain shelter can significantly reduce the population's genetic diversity. Low pairwise values (0.003-0.047) and high gene flow ( = 1.548-20.699) were observed among the three populations each year. In addition, most of the genetic variation occurred within populations. The epidemic mode of GDM in the open-field, fungicide-managed, and rain-shelter cultivation showed moderate, low, and high levels of clonality, respectively, in the case study.
葡萄霜霉病（GDM）是一种由[病原体未提及]引起的具有破坏性的葡萄病害，在全球范围内均有发生。在本研究中，我们测定了连续两年（2016年和2017年）露地、喷施杀菌剂及避雨栽培地块中葡萄霜霉病的流行特征及葡萄树冠层小气候。结果发现，避雨栽培可显著延迟病害发生28天和21天，缩短流行期28天和21天，并使最终病情指数降低82%和83%。此外，与露地栽培相比，避雨栽培可阻挡降水，使相对湿度降低11%和8%，叶片湿润持续时间减少85%和76%。分别从露地、杀菌剂处理及避雨栽培地块收集了3861个、783个和1145个病斑，利用7个微卫星标记分析其遗传多样性、群体分化及流行模式。在遗传多样性方面，Nei多样性指数在0.569至0.680之间，Shannon信息指数在0.958至1.226之间，表明各群体具有较高的多样性水平。与杀菌剂处理类似，避雨栽培可显著降低群体的遗传多样性。每年在三个群体间观察到较低的成对[未提及具体值]值（0.003 - 0.047）和较高的基因流（= 1.548 - 20.699）。此外，大部分遗传变异发生在群体内部。在该案例研究中，露地、杀菌剂处理及避雨栽培中葡萄霜霉病的流行模式分别表现为中等、低和高克隆性水平。
