Corynebacterium tritici . [Descriptions of Fungi and Bacteria

Abstract

Abstract A description is provided for Corynebacterium tritici . Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On Triticum aestivum . Sabet (1954a) obtained infection artificially on T. dicoccum, T. durum and T. pyramidale , using the nematode vector. Williams (1964) claimed infection of Dactylis glomerata and Secale cereale , but no details of the inoculation method used have been published. DISEASE: Yellow slime or 'tundu' disease of wheat. Infected parts bear yellow slimy bacterial exudate. Wheat ears covered by such slime become distorted or fail to emerge properly and produce little or no grain. On leaves and sheaths long slimy yellow spots may be seen. The bacterium has an obligate association with the ear-cockle nematode, Anguina tritici . GEOGRAPHICAL DISTRIBUTION: India and Egypt (CMI Map 156a, ed. 1, 1966), to which should be added W. Australia (6, 216), China (Hopei & Kweichow) (26, 446), Cyprus (17, 15), Ethiopia (48, 3413a) and Iran (49, 445). TRANSMISSION: The bacterium is carried with the seed in infected galls of the ear-cockle nematode Anguina tritici . The presence of the nematode is considered essential for the establishment of the bacteria in the plant, and many different attempts to inoculate wheat artificially in the absence of the nematode have failed to produce infection (e.g. Hutchinson, 1917; 4, 470; 6, 216; 26, 446; 51, 2391). Chaudhury (14, 571) claimed successful inoculation of the bacteria alone, but later workers have refuted this. Severin & Docea (50, 1047y) and Williams (1917) reported successful artificial inoculations, but little or no details of the methods are given. Neither report mentions use of nematodes. The bacteria carried by galls can remain viable for at least 5 years (45, 3125), while the nematodes within the galls are known to remain viable for even longer periods. Experiments of Swarup & Singh (43, 1299) indicate that the bacteria are not carried within the galls on or inside the larvae, but probably on the gall surface.