Clavibacter nebraskensis causing Goss's wilt of maize: Five decades of detaining the enemy in the New World.

Abstract

Large (2-15 cm) tan to grey elongated oval lesions with wavy, irregular water-soaked margins on the leaves. The lesions often start at the leaf tip or are associated with wounding caused by hail or wind damage. Small (1 mm in diameter), dark, discontinuous water-soaked spots, known as "freckles", can be observed in the periphery of lesions. When backlit, the freckles appear translucent. Early infection (prior to growth stage V6) may become systemic and cause seedlings to wilt, wither, and die. Coalescence of lesions results in leaf blighting. Maize (Zea mays) is the only economic host of the pathogen. A number of Poaceae species are reported to act as secondary hosts for C.nebraskensis. Class: Actinobacteria; Order: Micrococcales; Family: Microbacteriaceae; Genus: Clavibacter; Species: Clavibacter nebraskensis. Corynebacterium nebraskense (Schuster, 1970) Vidaver & Mandel 1974; Corynebacterium michiganense pv. nebraskense (Vidaver & Mandel 1974) Dye & Kemp 1977; Corynebacterium michiganense subsp. nebraskense (Vidaver & Mandel 1974) Carlson & Vidaver 1982; Clavibacter michiganense subsp. nebraskense (Vidaver & Mandel 1974) Davis et al. 1984; Clavibacter michiganensis subsp. nebraskensis (Vidaver & Mandel 1974) Davis et al. 1984. ATCC 27794T ; CFBP 2405T ; ICMP 3298T ; LMG 3700T ; NCPPB 2581T . Cells are gram-positive, orange-pigmented, pleomorphic club- or rod-shaped, nonspore-forming, nonmotile, and without flagella, approximately 0.5 × 1-2.0μm. The pathogen is restricted to Canada and the United States. EPPO code CORBNE.