IMPROVEMENT OF LEVELS OF BACTERIAL WILT RESISTANCE IN EGGPLANT THROUGH BREEDING

Significant differences in Kaplan-Meier survival curves were calculated by the log-rank test for root-dip inoculated parental lines and their corresponding S3 families in five of seven eggplant (Solanum melongena) accessions. The accessions from the U.S. Department of Agriculture's Plant Introduction (PI) Collection had been selected based on resistance to bacterial wilt. Resistance in one of these seven S3 families was significantly greater than that of the parents. The survival curves were plotted for 21 days after inoculation of 3-wk-old seedlings with a broth culture of Pseudomonas solanacearum, based on time from inoculation to initial wilt symptoms for plants grown in a greenhouse at temperatures of 33-37 C in daytime and 24-27 C at night. Significant differences were found in the survival curves of parental PI lines and their corresponding F3 families of all four crosses in the hybridization program. Resistance in three of the four families was significantly improved over levels expressed by the parents. Levels of resistance that equalled the most resistant parent were found in the fourth family. Both crossing and selfing of resistant eggplants offer promise in developing lines with improved bacterial wilt resistance.