马铃薯品种多样性介导的晚疫病菌抗药性进化规律研究

Previous studies have shown that increasing host diversity by combining cultivars with similar agronomic and biological characters but different resistance into a single population is an environment and ecology friendly approach to control plant diseases, which can reduce the epidemic degree of crop diseases and the evolution speed of pathogens. However, information on how host diversity may affect the development of fungicide resistance in pathogens is limited. Our previous studies found that the evolution of fungicide resistance of Phytophthora infestans regulated by potato genetic background and temperature, and our preliminary data showed that P. infestance isolates with low fungicide resistance were more likely to appear in high potato diversity. Those results indicate that potato diversity might negatively regulate fungicide resistance evolution of P. infestans. Here, the proposed project arms to investigate the evolutionary response of fungicide resistance to host diversity using P. infestans-potato interaction as a model and the combination of field experiment, molecular biology, the common garden experiment and genetic statistics as tools. The responding pattern of resistance to host diversity among different modes of fungicides will be evaluated by correlation analysis of two tolerance profiles at individual (isolate) and population levels. Results from this project will uncover the effect of host diversity on the evolution of fungicide resistance in pathogen population, which is essential for formulating ecological strategies to slow down the evolution of fungicide resistance of plant pathogen and reduce the use of fungicides in agricultural systems.

已有研究表明品种多样性可降低作物病害的流行程度和病原菌的演化速度，是作物病害生态防控的重要策略，但作物品种多样性对病原菌抗药性进化如何调控仍不清楚。前期研究表明晚疫病菌抗药性进化受马铃薯品种抗性和温度调控，同时预实验显示高马铃薯品种多样性更倾向于选择低抗药性晚疫病菌株，推测马铃薯品种多样性可能会负调控晚疫病菌抗药性的进化。鉴于此，本项目拟以马铃薯和晚疫病菌互作体系为模式，以作物品种多样性为切入点，采用田间试验进化、分子生物学、同质园实验和遗传统计等手段，研究马铃薯品种多样性对晚疫病菌抗药性进化的影响，同时用关联分析法从个体和群体水平上检测寄主多样性是否以相同模式调控晚疫病菌对不同类型农药抗药性的演化，揭示病原菌抗药性形成的进化生态学机制。研究结果有望为利用作物品种混作等生态手段降低病原菌抗药性进化速度、减少农药使用量提供依据。

已有研究表明品种多样性可降低作物病害的流行程度和病原菌的演化速度，是作物病害生态防控的重要策略，但作物品种多样性对病原菌抗药性进化如何调控仍不清楚。前期研究表明晚疫病菌抗药性进化受马铃薯品种抗性和温度调控，同时预实验显示高马铃薯品种多样性更倾向于选择低抗药性晚疫病菌株，推测马铃薯品种多样性可能会负调控晚疫病菌抗药性的进化。鉴于此，本项目以马铃薯和晚疫病菌互作体系为模式，以作物品种多样性为切入点，采用田间试验进化、分子生物学、同质园实验和遗传统计等手段，研究马铃薯品种多样性对晚疫病菌抗药性进化的影响，同时用关联分析法从个体和群体水平上检测寄主多样性是否以相同模式调控晚疫病菌对不同类型农药抗药性的演化。我们发现寄主多样性对晚疫病菌抗药性演化有显著影响。高寄主多样性可有效增加晚疫病菌群体对单靶标治疗型杀菌剂和多靶标保护型杀菌剂的敏感性。同时寄主多样性增加可降低晚疫病菌群体的抗药性变异，使晚疫病菌群体进化出高抗药菌株的概率降低，进而延缓晚疫病菌抗药性的产生。在此过程中，表型塑性对晚疫病菌抗药性演化的贡献显著高于遗传力。此研究结果表明寄主多样性增加可有效降低化学农药的使用量，进而降低病原菌抗药性演化的定向选择压力，使病原菌演化出高抗药菌株的概率大大降低，是作物病害绿色防控的有效措施。