油菜黑腐病病原细菌的鉴定

近年来,在湖北省油莱上发生一种病害,油菜抽薹后,主轴上产生暗绿色水渍状长条斑,病部溢出大量乳黄色粘稠物,后为黑褐色腐烂,其主轴萎缩卷曲,角果干秕、枯死。被害维管束变褐,髓部变黄。叶片上很少见病斑。从这种病株上分离到了致病细菌,经全面、系统鉴定,确定为黑腐病黄色单胞杆菌Xanthomonas campestris(Pammel)Dowsom]。由黑腐病菌引起的上述症状,国内外未曾报道过。另外,对来自六种十字花科寄生的七个黑腐病菌株,作了致病力比较测定,结果差异显著,以油莱两个黑腐病菌株致病力最强,表明可能存在不同生理型。

INDENTIFICATION OF THE PATHOGENIC BACTERIA OF BLACK ROT ON RAPE

In recent years a disease was discovered on rape in Hubei province.After bolting of rape the darkgreen water soaked irregular spot appears on the main stalks with a lot of bacterial slime.The infection results blackbrown rot and curl of the main stalk,pods become drying and plant finally die.The vascular bundles of the diseased plants are blacken.On the leaves the spots rare appear.The pathogenic bacteria have been isolated from the diseased plants and indentified as Xanthomonas campestris(Pammel)Dowson.The above described symptoms produced by this pathogen haven''t been reported either in our country or abroad.The virulence of seven isolates of X. campestris from six different cruciferous hosts is compared on seven host plants.The two isolates from rape seem to be the most virulent.Different physiological types may be present.