METHODS FOR EVALUATING EGGPLANT RESISTANC E TO BACTERIAL WILT CAUSED BY PSEUDOMONAS-SOLANACEARUM

Four methods of inoculation combined with four plant development stage s were used in order to define one reliable method to screen eggplant (Solanum melongena) germplasm for resistance to bacterial wilt caused by Pseudomonas solanacearum. Resistant and susceptible genotypes were best differentiated upon inoculation of plants with one pair of expand ed leaves, by wounding the stem with an entomological needle which pas sed through a 10 microlitre drop of a bacterial suspension containing 10(7) to 10(8) cfu/m1. When plants of 16 genotypes at the same growth stage were inoculated with stem wouding and without wounding (root ino culation), there was a correlation of 74 and 87% when disease was asse ssed at six and ten days after inoculation, respectively, indicating t hat the recommended wounding method is not so severe that could promot e resistance breakdown, what would result in elimination of resistant genotypes.