辣椒根腐病菌对咯菌腈的敏感性及其抗性突变体的生物学性状

为明确辣椒根腐病致病菌腐皮镰孢Fusarium solani对咯菌腈的抗性风险，采用菌丝生长速率法测定了采自未使用过咯菌腈的5个省份的102株腐皮镰孢对咯菌腈的敏感性。结果表明：咯菌腈对102株腐皮镰孢的EC₅₀范围为0.029 0～0.183 4 mg/L,平均EC₅₀为(0.106 2±0.031 5)mg/L,敏感性频率分布为连续单峰曲线，所以可将其作为供试5个省份腐皮镰孢对咯菌腈的敏感基线。通过药剂驯化和紫外诱导并结合抗性遗传稳定性最终共获得4株腐皮镰孢抗咯菌腈突变体，抗性水平在6.94～32.43倍之间，突变频率分别为3.51×10^-4(SDWF1914-Y336和SDWF1914-Y017)和7.41×10^-9(SDWF1914-ZR717和JSXZ1906-ZR496)。腐皮镰孢抗咯菌腈突变体生物学性状的研究表明，抗性突变体在菌丝生长速率、产孢量与致病力方面与亲本菌株不存在显著差异。交互抗性测定结果显示，腐皮镰孢对咯菌腈与嘧菌酯、醚菌酯、多菌灵和福美双均无交互抗性。结果表明，供试腐皮镰...

Sensitivity of Fusarium solani to fludioxonil and the biological characteristics of its resistant mutants

The mycelial growth rate method was used to determine the sensitivity of 102 isolates of Fusarium solani to fludioxonil from five provinces where fludioxonil had not been used, aiming to clarify the resistance risk of F. solani to fludioxonil. The results indicated that the EC50 values of these isolates to fludioxonil ranged from 0.029 0 mg/L to 0.183 4 mg/L, with a mean EC50 value of (0.106 2±0.031 5) mg/L. The frequency distribution of susceptibility was a continuous unimodal curve, which could be used as the susceptibility baseline of the tested F. solani isolates to fludioxonil in five provinces. Four fludioxonil resistant isolates of F. solani were obtained through medicament domestication and ultraviolet induction combined with a resistance genetic stability test. The resistance level was between 6.94 and 32.43 fold, with a mutation frequency of 3.51×10-4(SDWF1914-Y336 and SDWF1914-Y017) and 7.41×10-9 (SDWF1914-ZR717 and JSXZ1906-ZR496), respectively. The biological characteristics of the fludioxonil resistant mutants of F. solani exhibited no significant difference from the parental isolates in terms of hyphal growth rate, sporulation, and pathogenicity. In addition, no cross resistance was observed in F. solani isolates between fludioxonil and azoxystrobin, kresoxim methyl, carbendazim, and thiram. The results suggested that the tested F. solani isolates were relatively sensitive to fludioxonil, and showed low to moderate resistance. In summary, fludioxonil is an ideal agent for controlling pepper root rot, but should be mixed or alternately used with other fungicides with various mechanisms of action in agricultural production.