PRODUCTION OF SOMATIC HYBRIDS BETWEEN LYCOPERSICON HIRSUTUM AND L. ESCULENTUM.

Unilateral incompatibility has limited the direction of crossing between L. esculentum and L. hirsutum ; the latter can only serve as the pollen parent. In an attempt to introduce the L. hirsutum cytoplasm into L. esculentum , thirty-three somatic hybrid plants have been regenerated following four separate fusions between leaf protoplasts of L. hirsutum PI 126445 and etiolated hypocotyl protoplasts of L. esculentum (`OH7870', `OH832', and `OH8245'). A 33% PEG solution supplemented with 10% DMSO was used as the fusogen. Selection of fusion products was based on treatment of L. hirsutum protoplasts with 1 mM iodoacetic acid and non-regenerability of the L. esculentum genotypes. Hybridity was initially confirmed by intermediate morphology, including leaf shape, type of trichomes, flower shape, stigma placement, and fruit size and color. Isozyme analysis for GOT, PGM, and 6-PDH verified hybridity. Six of the hybrids produced viable seed upon selfing. At least some of the hybrids contained chloroplast DNA from L. hirsutum, indicating that the wild species cytoplasm may be present in these plants.