烟草青枯病菌生理分化的研究

On the Physiological Differentiation of Pseudomonas solancearum E. F. Smith From Tobacco

1996年～1997年从福建和贵州两省采集分离30个菌株，在田间分区组用21个菌株做接种鉴定。依据它们在一套鉴别品种上的反应，可以区分为致病力强弱不同的4个苗系群，其中Ⅰ群最弱，Ⅳ群最强。福建省以Ⅲ群首系占优势，出现频率75％，贵州省则以Ⅳ群苗系占优势，出现频率达76．9％，该苗系对K326品种有很强的致病力，这是导致近年来该省部分地方K326品种成片枯死的主要原因。生理生化反应测定表明，30个菌株均能利用3种双情和3种已醇，但在硝酸盐还原上显示出有能否产气的明显差异。30个菌株在L-酪氨酸培养基上均能产生褐色素，但产生的量有明显差异。细菌素测定表明，30个菌株对指示窗的拮抗率达83．3％。

In 1996 ~ 1997, 30 isolates of Pseudomonas solancearum E. F. Smith were collectedfrom tabacco in Fujian and Guizhuo provinces, 21 isolates were inoculated by field blockexperiment. On the basis of host reactions, they were grouped into 4 clusters that haddifferential pathogenicties, among them, cluster Ⅰ was the lowest, cluster Ⅳ the highest. Cluster Ⅲ was the dominant in Fujian, its frequency was 75%, but cluster Ⅳ dominant in Guizhuo, its frequency 76. 9% that had a strong pathogenicty against K 326 ，which was the prime reason that vast stretches of K 326damped off at local region, Thephysio-biochemial reaction showed that 30 isolates could utilizate 3 disaccharides and 3hexose alcohols, but showed the marked differences of N2 value on nitrate reduction。 30isolates could produce brown pigment on L-tyrosine medium, but the vaule had cleardifference. The mersuring of bacteriotoxin showed that 30 strains had antagonism of83. 3% against the indicator bacteria.