du Toit Lindsey J, Derie Mike L, Hernandez-Perez Pablo
Vegetable Seed Pathologist.
Agricultural Research Technologist.
Plant Dis. 2005 Jan;89(1):4-11. doi: 10.1094/PD-89-0004.
There are no previous reports of Verticillium wilt in fresh and processing spinach (Spinacia oleracea) crops in the United States. In 2002, a hybrid spinach seed crop in the Pacific Northwest developed late-season wilt symptoms. Assays of the harvested seed and stock seed of the male and female parents revealed 59.5, 44.0, and 1.5%, respectively, were infected with Verticillium dahliae. Assays of 13 stock or commercial seed lots grown in 2002 and 62 commercial lots harvested in 2003 in Denmark, Holland, New Zealand, and the United States revealed the prevalence of Verticillium spp. in commercial spinach seed. Sixty-eight lots (89%) were infected with Verticillium spp. at incidences ranging from 0.3 to 84.8%. Five spinach seed isolates of V. dahliae were pathogenic on each of three spinach cultivars by root-dip inoculation. V. dahliae was detected on 26.4% of the seed from 7 of 11 inoculated plants but on none of the seed from 6 control plants, demonstrating systemic movement of V. dahliae. Seed-to-seed transmission was also demonstrated by planting naturally infected seed lots. This is the first report of Verticillium wilt of spinach in the primary region of spinach seed production in the United States.
此前在美国新鲜菠菜和加工用菠菜（菠菜属）作物中没有黄萎病的相关报道。2002年，太平洋西北地区的一种杂交菠菜种子作物在生长后期出现了萎蔫症状。对收获种子以及父母本的原种种子进行检测发现，分别有59.5%、44.0%和1.5%感染了大丽轮枝菌。对2002年种植的13个原种或商业种子批次以及2003年在丹麦、荷兰、新西兰和美国收获的62个商业种子批次进行检测，发现商业菠菜种子中存在轮枝菌属。68个批次（89%）感染了轮枝菌属，感染率在0.3%至84.8%之间。通过浸根接种，从5个菠菜种子中分离得到的大丽轮枝菌菌株对3个菠菜品种都具有致病性。在11株接种植株中的7株上，26.4%的种子检测到了大丽轮枝菌，但在6株对照植株的种子上均未检测到，这表明大丽轮枝菌能够进行系统传播。通过种植自然感染的种子批次也证实了种子到种子的传播。这是美国菠菜种子主要生产地区首次报道菠菜黄萎病。
