Abstract
Interspecific somatic hybrids were obtained by electric protoplast fusion of cotyledon protoplasts of Lycopersicon esculentum Mill. cv. Kyoryokutoko treated with iodoacetamide (IOA) and suspension-culture-derived protoplasts of L. chmielewskii (LA1330). A multiple-step selection procedure was used in selecting the hybrids depending on IOA treatments and a culture medium that only allows cotyledon protoplasts to regenerate. Plants were regenerated on the calli derived from fused protoplasts. After acclimation, the hybrid plants with fruits through self-pollination were obtained. Identification of the regenerated putative hybrid plants was carried out by morphological, chromosomal and random amplified polymorphic DNA (RAPD) analysis, as well as restriction fragment length polymorphism (RFLP) comparison of parental and hybrid plants. The hybrids showed unique morphologies in leaf, flower and stem compared with that of two fusion partners, 2n = 4x = 48, 47, 69-72 chromosomes, both of the parental-specific RAPD bands, and genomic recombination and elimination occurred in mitochondria level. Cell fusion technique shows its new potential in foreign gene transformation between L. esculentum and L. chmielewskii.
