%0 Journal Article
%T 烟草青枯病菌在烟草根际的定殖及最适发病条件<br>Colonization of Ralstonia solanacearum on tobacco roots and factors affecting virulence
%A 李想
%A 刘艳霞
%A 蔡刘体
%A 张恒
%A 石俊雄
%A Li Xiang
%A Liu Yanxia
%A Cai Liuti
%A Zhang Heng
%A Shi Junxiong
%J 植物保护学报
%D 2016
%R 10.13802/j.cnki.zwbhxb.2016.05.013
%X 为明确烟草青枯病菌在根际的定殖情况和最适发病条件，采用绿色荧光蛋白（gfp）标记病原菌，监测其在根际的定殖位置及数量动态变化，并运用荧光定量PCR法测定病原菌在根际和土体土壤的数量，通过响应曲面法探索病原菌致病的临界浓度、发病最适温湿度以及对烟株青枯病发病的影响。结果表明，从贵州省烟田土壤中分离到烟草青枯病病原菌茄科劳尔氏菌Ralstonia solanacearum，gfp-标记的茄科尔劳尔氏菌主要定殖于根尖和根毛区，少数菌落定殖于初生根的延长区，定殖部分表现为非连续性；第10、15、20天根际土壤的茄科劳尔氏菌数量均显著高于土体土壤数量，分别是土体土壤中的1.15、1.33、1.42倍；当土壤中每克土病原菌数量为106.82 CFU、温度为30.55℃、相对湿度为81.42%以上时，烟草青枯病的病情指数最高为91.13，烟株易发生青枯病。表明茄科尔劳尔氏菌在根际土壤中比土体土壤更易定殖，烟草青枯病发病条件主要取决于病原菌浓度、温度以及相对湿度3项指标。<br>To find out factors affecting the colonization and virulence of Ralstonia solanacearum, the pathogen that causes tobacco bacterial wilt, a virulent strain of the bacteria was isolated from tobacco field in Guizhou Province and tagged with green fluorescent protein (gfp) to monitor bacterial locations and survival dynamics on rhizoplane under different conditions. The populations of R. solanacearum in rhizosphere and bulk soil were quantified by real-time PCR method. Response surface methodology (RSM) was used to evaluate the impact of bacterial quantity, the optimum temperature and humidity on the development tobacco bacterial wilt disease. The results showed that the gfp-R. solanacearum (gfp-Rs) densely colonized on root tips and root hairs although some bacteria were also observed in the elongation zone of primary roots, suggesting a discontinuous distribution of bacteria during colonization. The populations of the gfp-Rs in rhizosphere were 1.15, 1.33 and 1.42 times the size of those in bulk soil 10, 15 and 20 days after transplanting, respectively, indicating that more bacteria colonized in rhizosphere than that in bulk soil. The highest wilt incidence was calculated as 91.13 when the bacterial density reached 106.82 CFU/g soil, and when the environmental temperature was 30.55℃ and relative humidity over 81.42%. In conclusion, the gfp-Rs colonized in rhizosphere more easily than in bulk soil. The development of tobacco bacterial wilt disease depends on the population of the pathogen, the environmental temperature and the relative humidity.
%K 烟草青枯病 茄科劳尔氏菌 绿色荧光蛋白标记 发病条件 响应曲面法&lt
%K br&gt
%K tobacco bacterial wilt Ralstonia solanacearum green fluorescent protein (gfp)-labeling factors affecting virulence response surface methodology (RSM)
%U http://www.zwbhxb.cn/ch/reader/view_abstract.aspx?file_no=20160513&flag=1