Identifying resistance to plant-parasitic nematodes in yams is a major challenge in yam breeding programmes due partly to insufficient planting material (tubers) for evaluation. Susceptible yam cultivar, TDr 93-31 was inoculated with 0 (control), 200, 500, 1000 and 2000 eggs/individuals each of Meloidogyne incognita , Scutellonema bradys and Pratylenchus brachyurus . Vine cuttings of two cultivars each of Dioscorea rotundata , D. alata and D. dumetorum were compared to conventional minisett method in a second experiment. Planted vines and minisetts were inoculated with 500 and 5000 eggs/individuals respectively. Data were collected on percentage vine survival, fresh root and tuber weight, number of tubers and nematode population and damage. Vine survival was not significantly different between control and inoculated vines. Maximum damage rating (>60%) was observed with initial inoculum of 1000 eggs of M. incognita and 200 individuals of S. bradys and P. brachyurus . The two cultivars of D. alata and D. rotundata developed visible symptoms and supported nematode reproduction while the D. dumetorum cultivars did not. The reaction of yam cultivars planted as vines was consistent with results from conventional minisett method. The lowest inoculum of 200 egg/juveniles was sufficient to elicit a reaction from vines in the vertical sack system.

中文翻译：

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用于评估山药抗线虫性的节点藤蔓切割技术

鉴定山药对植物寄生线虫的抗性是山药育种计划的主要挑战，部分原因是用于评估的种植材料（块茎）不足。用0（对照）、200、500、1000 和 2000 个鸡蛋/个体接种南方根结线虫、Scutellonema bradys 和 Pratylenchus brachyurus 的易感山药品种 TDR 93-31。在第二个实验中，将 Dioscorea rotundata、D. alata 和 D. dumetorum 的两个栽培品种的葡萄插条与传统的 minisett 方法进行比较。种植的葡萄藤和小型植物分别接种了 500 和 5000 个卵/个体。收集了葡萄藤存活百分比、新鲜根和块茎重量、块茎数量和线虫数量和损害的数据。对照和接种的葡萄树之间的葡萄树存活率没有显着差异。用 1000 个南方 M. incognita 卵和 200 个 S. bradys 和 P. brachyurus 个体的初始接种观察到最大损伤等级 (>60%)。D. alata 和 D. rotundata 的两个品种出现了明显的症状并支持线虫繁殖，而 D. dumetorum 品种则没有。作为藤蔓种植的山药品种的反应与常规 minisett 方法的结果一致。最低接种量 200 个鸡蛋/幼鱼足以引起垂直麻袋系统中葡萄藤的反应。作为藤蔓种植的山药品种的反应与常规 minisett 方法的结果一致。最低接种量 200 个鸡蛋/幼鱼足以引起垂直麻袋系统中葡萄藤的反应。作为藤蔓种植的山药品种的反应与常规 minisett 方法的结果一致。最低接种量 200 个鸡蛋/幼鱼足以引起垂直麻袋系统中葡萄藤的反应。