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DETERMINATION OF THE TRANSMISSION OF Ralstonia solanacearum IN TRUE POTATO SEED (TPS) AND TOMATO SEED.

SAENZ, E. C.; BORDA, C. C.; GUTARRA, L. & PRIOU, S. Determinação da transmissão de Ralstonia solanacearum na semente verdadeira de batata (TPS) e semente de tomate.
Bacterial wild caused by the soilborne bacterium R. solanacearum, is one of the most destructive bacterial diseases of economically important crops. Tomato seed and mesocarp extracts were inoculated with different concentrations of R. solanacearum race 3/biovar II (10 to 108 ufc/ml in tenfold serial dilutions) and incubated at room temperature for 6, 12, 24 and 48 hours with constant agitation (150 r.p.m.) previously incubated at 40C for 2 hours. After enrichment, the extracts were analyzed in plated on medium SMSA, ELISA and double-PCR to repeat the methodology with TPS and potato mesocarp.The method developed in tomato seed inoculated was applied to samples of tomato seed and mesocarp obtained from plants with bacterial wild symptoms from field infested and plants inoculated in greenhouse with R. solanacearum, were analyzed to check the effectiveness of the detection method. Different infected plant parts (roots, stem and fruit) were examined to confirm the presence of the pathogen. The analyses demonstrated the method affectiviness and that R. solanacearum is a bacterial that infects tomato seed. Finally, it was examined samples of TPS and mesocarp of two resistant varieties and two susceptible varieties of potato, obtained from plants with bacterial wild symptoms from fields infected. The analyzes demonstrated that neither TPS nor mesocarp from wild plants of 4 varieties harbor R. solanacearum.