Abstract
A description is provided for Xanthomonas oryzae. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On Oryza sativa. Natural infection of Leersia oryzaides, Leersia oryzaides var. japonica and Zizania latifolia[Zizania aquatica] is known (Mizukami & Wakimoto, 1959). Natural infection of Cyperus rotundus and C. difformis was reported in India (48, 460), but inoculation of these hosts in the Philippines failed (48, 1689). By inoculation many wild species of Oryza (45, 1789), Leptochloa filiformis (48, 1689), L. chinensis, L. panacea and Zizania aquatica (48, 1683) have all been found susceptible. DISEASE: Bacterial blight of rice and kresek disease of rice. Blight most commonly appears on leaves of young plants, after planting out, as water-soaked stripes at the margins. These enlarge and coalesce to give the characteristic yellowish lesions with wavy edges that occur mainly along the margins of the upper parts of the leaves. These lesions may later expand to cover much of the leaf, which turns whitish or greyish and dies. Leaf sheaths of the more susceptible varieties may be affected. Kresek, which occurs in tropical regions, is a strong systemic infection in which leaves or whole young plants wither and die. In older plants the leaves become pale yellow. GEOGRAPHICAL DISTRIBUTION: Limited to Asia (CMI Map 304, ed. 2, 1964). Occurrences not shown on this map include Korea, Taiwan and Indonesia (Mizukami & Wakimoto, 1969). TRANSMISSION: Spread locally by wind and rain and also by flood and irrigation waters; gains entry to the field in infected planting material, to the nursery in seed, and to both nursery and field from volunteer rice plants and weed hosts usually via the irrigation water. Overwintering may occur on volunteers, on or in the rhizospheres of weed hosts, in stored infected straw and in seed, but it is unlikely in soil and plant debris exposed to the weather, at least under Japanese conditions (Mizukami & Wakimoto, 1969). Infection is through hydathodes and wounds. Penetration through stomata results in a build-up of bacteria in the intercellular spaces, but it is not until they have been exuded on to the leaf surface and re-admitted through the hydathodes and thence into the vascular system, that symptoms of the disease appear (46, 2720).
Interactions and Effects on Cysteine Synthase Activity of Aminooxyacetate and Boc-Aminooxyacetate on the Bioherbicides <i>Colletotrichum truncatum</i> and <i>Alternaria cassia</i> and Their Weed Hosts
