HYBRIDIZATION, THROUGH CULTURE OF EMBRYOS AND IMMATURE SEEDS, OF A RANGE OF TOMATO CULTIVARS WITH A TOMATO SOMATIC HYBRID [LYCOPERSICON ESCULENTUM(-PERUVIANUM] - EMERGENCE OF A POSSIBLE NEW MARKER GENE FOR TOMATO BREEDING()L)

Two hexaploid somatic hybrids [SH; L. esculentum (+) L. peruvianum] ac cessions 6 and 18 were backcrossed with two diploid L. esculentum cult ivars 'Moneymaker' (MM) and 'Pusa Ruby' (PR). Twenty-two plants of the BC2 generation were produced by backcrossing 7 BC1 plants (MM x SH, 6 , 18) with five tomato cultivars. Fourteen of the BC2 plants were self -fertile, five produced anther cones with anthocyanin pigmentation not present in the parents. A BC3 generation was developed by crossing th e four cultivars as female parent with three BC2 generation plants. Th e BC3 progeny derived from one pollen parent plant were produced witho ut the need to culture immature seeds. They segregated with respect to pigmented anther cones and were self-fertile. The anther cone pigment ation of the pollen parent plant was associated with increased seed se t, greater fruit size and an orange-red fruit colour. These features w ere transmitted to the fertile BC3 generation. Conversely, BC3 offspri ng involving the other two parent plants were only recovered by cultur e of immature seeds. The recovery of diploid plants in BC1 and self-fe rtility in BC2 resulted in almost total recovery of the tomato cultiva r characteristics (fruit size, colour and number of seeds) by BC3.