Clavibacter michiganensis subsp. nebraskensis. [Descriptions of Fungi and Bacteria].
A description is provided for Clavibacter michiganensis subsp. nebraskensis. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Zea mays is the natural host. By inoculation Euchlaena mexicana, Saccharum officinarum, Sorghum bicolor, S. sudanense and Tripsacum dactyloides are infected (Schuster et al., 1973). DISEASE: Leaf freckles and wilt, or Goss's bacterial wilt and blight. The disease is characterized by the appearance of discrete, water-soaked spots, dark green to blackish at first, becoming brown and more freckle-like, then coalescing and inducing a leaf scorch. The spots may arise from direct infection or via systemic infection from roots and stems (Schuster et al., 1973). GEOGRAPHICAL DISTRIBUTION: USA (IA, IL, KS, NE). (IMI Distribution Map 549, ed. 1, 1982; 67, 4495). TRANSMISSION: The bacterium can overwinter in debris from diseased corn, particularly stubble and this is a source of primary inoculum in the new growing season. It is also present within the seed where it can remain viable for more than a year. However, experiments suggest that seed transmission is rare (Schuster et al., 1973).