Department of Plant Protection, College of Advanced Agricultural Sciences, Zhejiang A&F University, Hangzhou 311300, China.
Department of Plant Protection, College of Advanced Agricultural Sciences, Zhejiang A&F University, Hangzhou 311300, China.
Pestic Biochem Physiol. 2023 Aug;194:105500. doi: 10.1016/j.pestbp.2023.105500. Epub 2023 Jun 14.
Hickory trunk canker (HTC), primarily caused by Botryosphaeria dothidea, is an aggravating disease that threatens an important regional economic tree species of Chinese hickory and few information is available in the control of this disease. Here, the sensitivity of 93 isolates to fludioxonil and the resistance risk were investigated. All the isolates tested were sensitive to fludioxonil and the EC ranged from 0.0028 to 0.0569 μg/mL. The tamed fludioxonil-resistant mutants remained highly resistant to fludioxonil even after 10 consecutive transfers to fludioxonil-free PDA plates. As for fitness penalty, the fludioxonil-resistant mutants demonstrated a reduction in conidia production and virulence as well as increased sensitivity to high osmotic stress. While, variations in mycelial growth and responses to SDS and HO were not detected in all the resistant mutants. In addition, the resistant mutants demonstrated positive cross-resistance to iprodione but not to fungicides of other modes of action. Sequential analysis of BdNik1 showed that premature stop codon occurred in all the resistant mutants despite of point mutation (BD16-22R9 and BD16-22R20) or frameshift mutation (BD16-22R8, BD16-22R11 and BD16-22R18). Our study suggested that fludioxonil exhibited excellent inhibition activity on mycelial growth of B. dothidea in vitro, the resistance risk of B. dothidea to fludioxonil should be low to moderate and fludioxonil would be a nice candidate in controlling HTC caused by B. dothidea.
山核桃干腐病（HTC）主要由 Botryosphaeria dothidea 引起，是一种严重威胁中国山核桃重要区域经济树种的病害，目前关于该病的防治信息较少。本研究调查了 93 个分离株对氟啶酮的敏感性和抗风险。所有测试的分离株均对氟啶酮敏感，EC 范围为 0.0028 至 0.0569μg/mL。驯化的氟啶酮抗性突变体在连续 10 次转移到无氟啶酮 PDA 平板后仍保持对氟啶酮的高度抗性。至于适应性惩罚，氟啶酮抗性突变体的产孢量和毒性降低，对高渗透压胁迫的敏感性增加。然而，所有抗性突变体的菌丝生长和对 SDS 和 HO 的反应没有变化。此外，抗性突变体对异菌脲表现出正交叉抗性，但对其他作用模式的杀菌剂没有表现出抗性。BdNik1 的序列分析表明，所有抗性突变体都出现了提前终止密码子，尽管发生了点突变（BD16-22R9 和 BD16-22R20）或移码突变（BD16-22R8、BD16-22R11 和 BD16-22R18）。我们的研究表明，氟啶酮在体外对 B. dothidea 菌丝生长具有良好的抑制活性，B. dothidea 对氟啶酮的抗风险应处于低至中度水平，氟啶酮将是控制由 B. dothidea 引起的 HTC 的一个不错的候选药剂。
