Tankam Chedjou Israël, Montarry Josselin, Fournet Sylvain, Hamelin Frédéric M
Institut Agro Univ Rennes, INRAE, IGEPP Rennes France.
Evol Appl. 2024 Sep 19;17(9):e70012. doi: 10.1111/eva.70012. eCollection 2024 Sep.
The pale cyst nematode, , is a pest that poses a significant threat to potato crops worldwide. The most effective chemical nematicides are toxic to nontarget organisms and are now banned. Alternative control methods are therefore required. Crop rotation and biological control methods have limitations for effectively managing nematodes. The use of genetically resistant cultivars is a promising alternative, but nematode populations evolve, and virulent mutants can break resistance after just a few years. Masculinizing resistances, preventing avirulent nematodes from producing females, might be more durable than blocking resistances, preventing infection. Our demo-genetic model, tracking both nematode population densities and virulence allele frequencies, shows that virulence against masculinizing resistance may not be fixed in the pest population under realistic agricultural conditions. Avirulence may persist despite the uniform use of resistance. This is because avirulent male nematodes may transmit avirulent alleles to their progeny by mating with virulent females. Additionally, because avirulent nematodes do not produce females themselves, they weaken the reproductive rate of the nematode population, leading to a reduction in its density by at least 20%. This avirulence load can even lead to the collapse of the nematode population in theory. Overall, our model showed that combining masculinizing resistance, rotation, and biocontrol may achieve durable suppression of in a reasonable time frame. Our work is supported by an online interactive interface allowing users (i.e., growers, plant health authorities, researchers) to test their own control combinations.
苍白孢囊线虫对全球马铃薯作物构成重大威胁。最有效的化学杀线虫剂对非靶标生物有毒，现已被禁用。因此需要替代控制方法。作物轮作和生物防治方法在有效管理线虫方面存在局限性。使用抗线虫品种是一种有前景的替代方法，但线虫种群会进化，毒性突变体在短短几年后就可能打破抗性。雄性化抗性，即阻止无毒线虫产生雌性，可能比阻止感染的阻断抗性更持久。我们的示范遗传模型跟踪线虫种群密度和毒力等位基因频率，结果表明，在现实农业条件下，害虫种群中针对雄性化抗性的毒力可能无法固定。尽管统一使用抗性，无毒状态可能会持续存在。这是因为无毒雄性线虫可能通过与有毒雌性线虫交配将无毒等位基因传递给后代。此外，由于无毒线虫自身不产生雌性，它们会削弱线虫种群的繁殖率，导致其密度至少降低20%。从理论上讲，这种无毒负荷甚至可能导致线虫种群崩溃。总体而言，我们的模型表明，结合雄性化抗性、轮作和生物防治，可能在合理的时间框架内实现对苍白孢囊线虫的持久抑制。我们的工作得到了一个在线交互式界面的支持，该界面允许用户（即种植者、植物卫生当局、研究人员）测试他们自己的防治组合。
