豆薯细菌性角斑病的病原鉴定

IDENTIFICATION OF BACTERIAL STRAIN CAUSING ANGULAR LEAFSPOT OF YAM BEAN

在安徽滁州的豆薯叶片上发现一种由细菌侵染引起角斑症状的病害,从角斑上分离到具有致病性的非荧光的杆状细菌,菌株的表型特征、细菌学特征、LOPAT 试验和生理生化试验表明该细菌与丁香假单胞菌(Pseudom onas syringae van Hall)相似,BIOLOG 系统鉴定结果与丁香假单胞菌豌豆致病变种(P.syringae pv. pisi)相近,接种试验表明豆薯菌株能侵染大豆、菜豆和眉豆,但对豌豆的致病性差;在豇豆、绿豆和蚕豆上不表现症状。结果表明豆薯细菌性角斑病是一种新病害,病原菌属于丁香假单胞菌群的一个新的致病变种,命名为 P.syringae pv. pachyrhizus

Angular spots were observed on leaves of yam bean( Pachyrhizus tuberosus Spreng.) in Anhui province. Numerous water soaked angular leafspots, each with a yellow halo were observed on the diseased leaves. Non fluorescent bacterium was consistently isolated from infected tissues. Results from morphological study, LOPAT test and physiological and biochemical tests indicated that this strain was similar to Pseudomonas syringae . BIOLOG analysis suggested that it was close to P.syringae pv. pisi . Comparative inoculations performed on legume plants showed that the virulent strain from yam bean can infected soybean kidney bean and snapbean. Sporadic leafspot occurred on pea. No symptoms were recorded from other hosts tested. Results indicated that this bacterial angular leafspot of yam bean can be considered as a new disease caused by a non fluorescent member, a new pathovar of P. syringae , named as Pseudomonas syringae pv. pachyrhizus nov.