Files
Abstract
Bacterial wilt (BW} is due to Pseudomonas solanacearum (Smith) Smith, a soilborne and a xylem-invading bacteria. These properties and high variation in strains, aggressiveness, depending on environmental factors, make it difficult to bring this tropical world-wide disease under control. Fren research projects including co-workers from different institutes (CIRAD, INRA, ORSTOH) based in metropolitan France and in overseas departments are briefly reported. Recent results obtained by INRA-CRAAG's phytobacteriological laboratory include: The behavior of P. solanacearum in receptive and suppressive soils; Characteristics of local strains, especially host range and aggressiveness; The existence of healthy carriers among tomato plants, i.e., plants bearing latent infections in vascular tissues, Programs are being developed according to two complementary control strategies interdependent from results obtained by molecular biologists and breeders. They are: Biological control of BW using genetically constructed avirulent mutants; and BW resistance mechanisms, with particular attention to bacterial colonization (density, localization) and to incidence of environmental factors on resistance of cultivars.