胡萝卜软腐欧氏杆菌菌落突变型生物学性状的研究

从腐烂马铃薯块上分离的221株Erwinia.carotouora pv.carotovora(以下简称ECC)中有91株为菌落突变型,在营养琼脂上生长不良,在TZC平板上菌落乳白色。与野生型菌株相比,它们的耐酸能力弱,存活时间短,对马铃薯块的致病力弱,其胞壁水解酶(果胶裂解酶和蛋白酶)活性低。从继代培养中分离的类似突变株可通过接种马铃薯块而得到恢复,而自然条件下分离的则不能。

BIOLOGICAL CHARACTERISTICS OF COLONIAL MUTANT OF ERWINIA CAROTOVORA PV. CAROTOVORA FROM POTATO TUBERS

91 out of 221 isolates of Erwinia carotovora pv. carotovora were colonial mutants of which the bacteriological characteristics were very similar to wild strain. The wild strain produced red colonies on the triphenyl-tetrazolium medium, in contrast with it, the mutants produced white colonies. The murants could not grow and survive well on the nutrient agar The other biological charecteristics of the mutants were the diminished acid-tolerent ability, the lower virulence and extracellular enzyme production including polygalacturonase, pectate lyase and protease. The mutants from natural condition coud not be reversed by repeated inculation on potato tubers, but the mutant induced from wild type by succesive growth onthe nutrient agar could be reversed by the same method.