Perpustakaan Digital ITB

ABSTRACT: Bacterial Wilt caused by Pseudomonasso/anacearum E.F. Smith is an important disease of potato (So/anum tuberosum L.) worldwide. The bacteria can survive in soils in areas of mild to warm climates (Kelman 1953). The pathogen has a wide host range representing 44 families (He et al. 1983). It can be a limiting factor for growing potato in Indonesia (Hanudin and Gaos, unpublished data). The main characteristic symptom of the disease is sudden wilting of the potato plant. The bacterium cause vascular disease, and it is called brown rot disease of potato. When diseased potato tubers or stems are cut across, a white bacterial ooze may appear, cream like drops of sticky liquid containing bacteria are exuded from the vascular bundles (Mehrotra, 1980). Recent investigations have shown that it attacks several woody perennials, including cashew (Anacardium occidenta/e) (Shiomi et al. 1989), custard apple (Annona spp.) (Mayers and Hutton 1987) and Alexandra palm (Archontophoeni/ xa/exandrae) (Akiew and Hams 1990). Among the solanaceous crops, potato, tobacco and tomato are greatly affected by the disease (Perera et al, 1993). Cultivated potato is one of the most important vegetable crop. Granola is a main cultivar in farmer fields in Indonesia, more than 90% of potato farmers cultivate Granola cultivar, even though Granola is a susceptible one to bacterial wilt disease (Sahat et al., 1996). In vitro plant breeding using callus induction is expected in yielding the somaclonal variation such as resistance to P. solanacearum. Callus selection by filtrate of P. solanacearum is estimated be able to narrow and at the same time to improve the resistance of somaclones to bacterial wilt disease (Bulk, 1991). Resistant varieties offer an effective means of controlling bacterial wi It. There has been some success with resistant varieties of tomato, tobacco and peanut. In potato, resistance genes from wild species have been introduced into cultivated species (Schmiediche, 1986).