Gent David H, Lang Jillian M, Schwartz Howard F
National Forage Seed Production Research Center, USDA-ARS, Corvallis, OR 97331.
Department of Bioagricultural Sciences and Pest Management, Colorado State University, Fort Collins 80523-1177.
Plant Dis. 2005 Jun;89(6):558-564. doi: 10.1094/PD-89-0558.
Xanthomonas leaf blight of onion (Allium cepa), caused by Xanthomonas axonopodis pv. allii, and common bacterial blight of dry bean (Phaseolus vulgaris), caused by Xanthomonas axonopodis pv. phaseoli, are perennial problems in the Central High Plains of the United States. Onion and dry bean are commonly grown in rotation in Colorado, but it is unknown if X. axonopodis pv. allii and X. axonopodis pv. phaseoli survive epiphytically or pathogenically on dry bean and onion, respectively. Under high humidity growth chamber conditions, epiphytic X. axonopodis pv. allii populations increased on alfalfa, chickpea, dry bean, lentil, and soybean, but the epiphytic populations were at least 10-fold greater on onion. When artificially inoculated under field conditions, epiphytic populations of X. axonopodis pv. allii were recovered from dry bean, lentil, and onion, but the bacterium did not persist on chickpea or soybean. Epiphytic X. axonopodis pv. phaseoli was recovered from symptomless onion plants in fields cropped to dry bean the prior year, but not from fields cropped to a host other than dry bean. Close rotation of onion and dry bean may allow X. axonopodis pv. allii and X. axonopodis pv. phaseoli to persist epiphytically, and crop rotation schemes may need to be altered to reduce survival of these pathogens in onion and dry bean cropping systems.
由葱黄单胞菌引起的洋葱叶斑病以及由菜豆黄单胞菌引起的菜豆普通细菌性疫病，是美国中部高平原地区长期存在的问题。在科罗拉多州，洋葱和菜豆通常轮作种植，但尚不清楚葱黄单胞菌和菜豆黄单胞菌是否分别能在菜豆和洋葱上以附生或致病的方式存活。在高湿度生长室条件下，附生的葱黄单胞菌在苜蓿、鹰嘴豆、菜豆、小扁豆和大豆上数量增加，但在洋葱上的附生菌数量至少高出10倍。在田间条件下人工接种后，葱黄单胞菌可从菜豆、小扁豆和洋葱上回收，但该细菌在鹰嘴豆或大豆上不能持续存在。附生的菜豆黄单胞菌可从上年种植菜豆的田块中无症状的洋葱植株上回收，但从种植非菜豆寄主作物的田块中无法回收。洋葱和菜豆的紧密轮作可能会使葱黄单胞菌和菜豆黄单胞菌以附生方式持续存在，可能需要改变作物轮作方案以减少这些病原菌在洋葱和菜豆种植系统中的存活。
