中国玉米南方锈病初侵染源的多源性

由多堆柄锈菌Puccinia polysora Underw.引致的玉米南方锈病是广泛分布在热带、亚热带地区的重要病害,在温带地区也时常发生。玉米南方锈病在中国20个省份有发生记载,已成为黄淮海夏玉米区突发性、爆发性、生产危害性极大的病害。掌握病害发生规律是病害防控的基础,中国玉米南方锈病初侵染源来源及其传播规律一直未有明确答案。本研究通过对多堆柄锈菌夏孢子生物学特性的研究、11省份病菌不同地理种群遗传相关性解析以及病害突发性与热带气旋活动相关性分析,证明中国各地域发生的玉米南方锈病初侵染源具有不同的来源,来自中国台湾的病菌引起黄淮海夏玉米区、辽宁以及福建、浙江地区的南方锈病,也是广东春季南方锈病的菌源地;来自菲律宾的病菌引起广东、广西及海南的南方锈病;来自泰国等东南亚国家的病菌引起云南、贵州的南方锈病。云南、贵州等西南地区的南方锈病初侵染源由西南季风传播,其他地区的初侵染源主要由不定期形成的西太平洋热带气旋所携带。

Multiorigins of Initial Infection Sources of Puccinia polysora Causing Southern Rust of Maize in China

Southern rust caused by Puccinia polysora Underw. in maize is a major disease and widely distribut-ed in tropical and subtropical regions, and occurred in temperate region. In China, maize southern rust has been recorded in twenty provinces and was a destructive disease which is sudden outbreak in the Huanghuaihai summer maize region. Understanding the occurrence regularity of disease is the basis of disease control. However, it is not clear where are from the pathogen origins of primary infection sources and how the pathogen is transmitted to the maize fields. Based on the biological characters of urediospore, analysis of genetic relationship of 11 geographic populations of P. polysora in China, and correlation analysis of southern rust to tropical cyclones, this study proved there are three origins of primary infection sources of P. polysora causing southern rust in China. P. polysora come from Taiwan, China, is the initial infection source causing the disease in summer maize in Huanghuaihai region, spring maize in Liaoning and maize in Zhejiang and Fujian provinces, as well as for spring maize in Guangdong. The pathogen from Philippines is the origin source causing southern rust in Guandong, Guangxi and Hainan provinces. The induced disease occurred in Yunnan and Guizhou is caused by the pathogen originated from Thailand and other neighboring countries. The pathogen in Taiwan, China or Philippines was carried by unfixed tropical cyclones in western Pacific to maize growing regions in China, and P. polysora in Yunnan and Guizhou was transmitted from Thailand and other countries by Southwest Monsoon.