中文摘要：

为明确西南地区水稻细菌性条斑病菌链霉素抗性情况、建立链霉素敏感基线、筛选抗性突变菌株,本研究采用离体法检测了云南、贵州和四川三地条斑病菌株对链霉素的敏感性,利用紫外诱变、药剂驯服的方法诱导抗链霉素突变菌株并检测其突变位点.结果显示：不同地理来源的菌株对链霉素的敏感性存在一定差异;三地菌株的链霉素EC5o值范围是0.165 ～1.532 μg/mL,将其均值0.667 μg/mL作为西南地区水稻细菌性条斑病菌对链霉素的敏感基线;紫外诱变获得对链霉素抗性最高的突变菌株30-U-3,其EC50值为57.544 μg/mL,抗性倍数达138.661倍;链霉素抗性基因（rpsL基因）中第43位氨基酸由赖氨酸（AAG）突变为精氨酸（AGG）.可见,西南地区目前虽无抗链霉素的自然突变菌株,但云南楚雄已发现抗性较高的菌株,应该采取积极的抗药性治理措施.

英文摘要：

For the analysis of streptomycin resistance of X. oryzae pv. oryzicola in Southwest, the establishment of streptomycin-sensitive baseline, screening resistant mutant strains. The strains of X. oryzae pv. oryzicola which from Yunnan, Guizhou and Sichuan provinces were used to examined the sensitivities of streptomycin sulfate in vitro. UV mutagenesis and pharmaceutical tame approach were used to induced the streptomycin resistant mutant strains. We also detected the mutation site of streptomycin resistance gene （rpsL gene）. The results showed that there were sensitivity differences among the strains; The EC50 values of streptomycin sulfate to all tested strains ranged from 0. 165 - 1. 532 μg/mL with the average of 0. 667 μg/mL; The average EC50 0. 667 μg/mL was the baselinesensitivity of X. oryzae pv. oryzicola from Yunnan, Guizhou and Sichuan provinces to streptomycin sulfate; A resistant mutant strain 30-U-3 was induced by UV mutagenesis; The EC50 values of 30-U-3 was 57. 544 μg/mL, which resistance increased 138. 661 times; The mutation site was the first 43 amino of rpsL gene ; The acid lysine （AAG） was mutated to arginine （AGG） on this site. This research showed that： although there were no natural streptomycin resistant mutant strains in Southwest currently, but a high resistant strain has been found in Chuxiong city, so the use of streptomycin in Chuxiong should be attract our attention.