VIEW ARTICLE

Ecology and Epidemiology

Chemotaxis of Fluorescent Pseudomonads Towards Seed Exudates and Germinating Seeds in Solarized Soil. A. Gamliel, Department of Plant Pathology and Microbiology, The Hebrew University of Jerusalem, Faculty of Agriculture, Rehovot 76100, Israel; J. Katan, Department of Plant Pathology and Microbiology, The Hebrew University of Jerusalem, Faculty of Agriculture, Rehovot 76100, Israel. Phytopathology 82:328-332. Accepted for publication 15 July 1991. Copyright 1992 The American Phytopathological Society. DOI: 10.1094/Phyto-82-328.

We investigated the chemotaxis of fluorescent pseudomonads towards seeds exudates and germinating tomato seeds. Chemotaxis of Pseudomonas putida and P. fluorescens in a capillary tube was more pronounced towards exudates originating from seeds that were germinated in solarized soil than towards comparable exudates from seeds that were germinated in nonsolarized soil. Movement of these bacteria was enhanced also towards a mixture of either amino acids or amino acids and sugars, but not of sugars alone. Chemotaxis of fluorescent pseudomonads from solarized soil through sterile sand towards exudates originating from seeds germinated in solarized soil was more pronounced than movement of these bacteria from nonsolarized soil. Chemotaxis of streptomycin-resistant pseudomonads in soil also was enhanced towards exudates and germinating seeds in solarized soil. We suggest that the improved capacity of fluorescent pseudomonads to move towards attractants and compete for exudates may contribute to their rapid establishment in the rhizosphere and roots of plants in solarized soils.