Crown gall disease of grapevines: quantification of agrobacterium vitis in vineyard soil

葡萄农杆菌是导致葡萄冠瘿病的病原菌，是寒冷气候葡萄种植区重要的经济病害。这种疾病经常发生在奥肯那根葡萄园，限制了葡萄的产量和葡萄园的寿命。这种病原体通过受感染的葡萄藤苗木或在滋生葡萄球菌的土壤中种植的健康葡萄藤传播。在葡萄藤干或藤上的伤口，由于冬天的冰冻或机械损伤，导致溃疡的发展。在我们早期的参与资助的研究中，我们开发了一种快速和敏感的方案来量化葡萄苗木中的葡萄球菌。这使我们能够在种植到葡萄园之前筛选葡萄行业购买的葡萄藤。为了防止土壤中葡萄球菌感染健康种群，迫切需要一种葡萄球菌土壤种群量化方案。在这里，我们建议扩大现有的方案，以量化葡萄球菌从原始和葡萄园土壤。我们还将在温室试验中确定葡萄球菌在土壤中的阈值浓度，这将导致冠瘿病的发展。这将为种植者在建立新葡萄园时确定感染风险提供有价值的信息。我们的方案将为未来项目中冠瘿病生物防治的发展奠定基础。

Agrobacterium vitis is the causal agent of grapevine crown gall, an economically important disease in coldclimate viticulture regions. The disease occurs frequently in Okanagan vineyards and limits grape productionand lifespan of vineyards. The pathogen spreads either through infected grapevine nursery stock or infectshealthy grapevines planted in soil harbouring A. vitis. Wounds in the grapevine trunk or canes due to winterfreezing or mechanical injuries lead to the development of galls. In our earlier Engage grant-funded study wedeveloped a rapid and sensitive protocol to quantify A. vitis in grapevine nursery stock. This allows us toscreen grapevines that have been purchased by the grape industry before planting into a vineyard. To preventinfection of healthy stock from A. vitis residing in soil, a protocol to quantify the A. vitis soil population isurgently needed. Here we propose to expand the existing protocol to quantify A. vitis from virgin and vineyardsoil. We will also determine the threshold concentration of A. vitis in soil that will result in the development ofcrown gall disease in a greenhouse experiment. This will lead to valuable information for growers to determinethe risk of infection when a new vineyard is established. Our protocols will form the basis for the developmentof a biocontrol for crown gall disease in future projects.