杨梅与油橄榄癌肿病病原细菌的比较研究

A COMPARATIVE STUDY ON PATHOGENIC BACTERIA CAUSING KNOT DISEASE ON MYRICA RUBRA L. AND ON OLIVE

对我国14株杨梅癌肿病菌菌株和2株油橄榄癌肿病菌模式菌株在细菌学特性、血清学反应及寄主范围等方面进行了比较研究。两者细菌学特性基本相同,在测定27项生理生化反应中仅在硝酸盐还原、淀粉水解及对甜菜碱、乳糖、麦芽糖和纤维二糖的利用上存在着差异,两菌株的mol%G+C相近,杨梅菌株在59.90—60.89之间,油橄榄菌株PODCC4352-75为59.90;在寄主范围上差异明显,不能交互侵染各自的寄主产生典型肿瘤症状,杨梅菌株不能侵染夹竹桃产生癌瘤;血清学反应表明两者有一定的同源性。认为杨梅癌肿菌是一个新的致病变种,命名为丁香假单胞萨氏亚种杨梅致病变种[Pseudomonas syringae subsp.savastanoi(Janse)pv.myricae(Choei)nom.comb.Zhang et He].

Fourteen strains of bacteria causing knot disease on Myrica rubra in China were compared with reference strains of Pseudomonas syringae subsp. savastanoi pv.olea from olive, PDDCC4352-75 and PB230, in their bacteriological characteristics. There were only a few differences in 27 biochemical and physiological tests, i.e.strains from Myrica couldn't use betaine, lactose and maltose as sole source of carbon, but the olive strains did. Moreover, in contrast with olive strains,the Myrica strains showed postive reaction in nitrate reduction and negative reaction in starch hydrolysis.The strains from both hosts showed partial homology in serological reaction.G+C mol% of DNA of Myrica strains was 59.90-60.89,which was similar to that of olive strains. In cross inoculation tests on hosts, however, Myrica strains couldn't produce typical knots on olive and oleander stems as the olive strains did, similarly, olive strains couldn't infect Myrica rubra as the Myrica strains did. On basis of above mentioned results the Myrica strains were identified as a new pathovar of Pseudomonas syringae subsp. savastanoi, named Pseudomonas syringae subsp. (?)avastanoi pv. myricae (Chaoei Ogimi et al.) comb.nov.