【摘要】 引起水稻白叶枯病的 Xanthomonasoryzae在用药剂处理过的水稻上鉴别为抗噻枯唑的突变体。致病力和胞外酶活性测定结果表明 ,抗药性突变体与野生敏感菌株没有明显差异 ,但抗药性突变体对离体稻叶的伤害作用及引起水稻体内脂质过氧化程度强于敏感菌株 ;胞外产物可以降低水稻白叶枯病菌对噻枯唑的敏感性 ,病菌产生抗药性与胞外产物关系密切 ;抗药突变体在无药平板上转移 10代后 ,抗药水平明显下降 ,但致病力变化在不同的突变体间表现出较大差异 ,有的保持较强的致病力 ,有的则完全失去致病力更多还原

【Abstract】 There was no significant difference between the resistant mutants(R)and the sensitive isolates(S)of Xanthomonas oryzae to Saikuzuo bactericide in pathogenicity and activities of extracellular enzymes.But the extracellular products of the mutants made more serious damage to the detached leaf pieces of rice than that of sensitives,and the level of lipid peroxidation induced by resistant mutants was higher than that by sensitive isolates.Extracellular products could decrease the sensitivity of X.oryzae to Saikuzuo,and the resistance of X.oryzae was closely related with its extracellular products.After 10 cycles of subculture on the bactericide free medium,the resistance degree decreased markedly,and the pathogenicity varied greatly among different mutants.Most of them kept their high virulence.But one isolate,AH99027 lost its pathogenicity totally.更多还原