Nilusmas Samuel, Mercat Mathilde, Perrot Thomas, Djian-Caporalino Caroline, Castagnone-Sereno Philippe, Touzeau Suzanne, Calcagno Vincent, Mailleret Ludovic
Université Côte d'Azur, INRAE, CNRS, ISA Sophia Antipolis France.
Université Côte d'Azur, INRIA, INRAE, CNRS, Sorbonne Université, BIOCORE Sophia Antipolis France.
Evol Appl. 2020 May 22;13(9):2206-2221. doi: 10.1111/eva.12989. eCollection 2020 Oct.
Root-knot nematodes, ., are soil-borne polyphagous pests with major impact on crop yield worldwide. Resistant crops efficiently control avirulent root-knot nematodes, but favour the emergence of virulent forms. Since virulence is associated with fitness costs, susceptible crops counter-select virulent root-knot nematodes. In this study, we identify optimal rotation strategies between susceptible and resistant crops to control root-knot nematodes and maximize crop yield. We developed an epidemiological model describing the within-season dynamics of avirulent and virulent root-knot nematodes on susceptible or resistant plant root-systems, and their between-season survival. The model was fitted to experimental data and used to predict yield-maximizing rotation strategies, with special attention to the impact of epidemic severity and genetic parameters. Crop rotations were found to be efficient under realistic parameter ranges. They were characterized by low ratios of resistant plants and were robust to parameter uncertainty. Rotations provide significant gain over resistant-only strategies, especially under intermediate fitness costs and severe epidemic contexts. Switching from the current general deployment of resistant crops to custom rotation strategies could not only maintain or increase crop yield, but also preserve the few and valuable R-genes available.
根结线虫，例如，是土壤传播的多食性害虫，对全球作物产量有重大影响。抗性作物能有效控制无毒根结线虫，但却有利于毒性形式的出现。由于毒性与适合度代价相关，感病作物会反选毒性根结线虫。在本研究中，我们确定了感病作物和抗性作物之间的最佳轮作策略，以控制根结线虫并使作物产量最大化。我们开发了一个流行病学模型，描述了无毒和有毒根结线虫在感病或抗性植物根系上的季内动态及其季间存活情况。该模型与实验数据拟合，并用于预测产量最大化的轮作策略，特别关注流行严重程度和遗传参数的影响。发现在现实参数范围内作物轮作是有效的。它们的特点是抗性植物比例低，并且对参数不确定性具有鲁棒性。轮作相对于仅种植抗性作物的策略有显著收益，特别是在中等适合度代价和严重流行的情况下。从目前抗性作物的普遍种植转向定制轮作策略不仅可以维持或提高作物产量，还能保留现有的少数珍贵抗性基因。
