PRODUCTION AND CHARACTERIZATION OF SOLANUM AMPHIDIPLOIDS AND THEIR RESISTANCE TO BACTERIAL WILT

Efforts to generate amphidiploid hybrids between eggplant Solanum melongena L. and Solanum integrifolium Poir. were made in order to obtain easily propagated and disease-resistant rootstocks for eggplant and tomato production. In vitro treatment of shoot tip explants of sterile interspecific hybrids, between S. melongena and S. integrifolium, with 0.05% colchicine induced a high percentage of amphidiploids. The amphidiploids had larger anthers containing approximately 70% viable and larger pollen than those of the interspecific hybrids. The amphidiploid plants produced a profuse number of viable seeded fruits, while the interspecific hybrids produced no fruit or a poor number of parthenocarpic fruits. The seeds of the amphidiploids were bigger than those of the interspecific hybrids. Chromosome number from pollen mother cell and root tips, nucleus volume of the histogenic layers and stomata size assisted in identifying true amphidiploids and chromosomal chimeric types. Seed-grown amphidiploid seedlings were found resistant to two of the most virulent strains of bacteria.