Hybridization, Through Culture of Embryos and Immature Seeds, of a Range of Tomato Cultivars with a Tomato Somatic Hybrid [Lycopersicon esculentum (+) L. peruvianum]: Emergence of a Possible New Marker Gene for Tomato Breeding

Abstract

AbstractTwo hexaploid somatic hybrids [Sh; L. esculentum (+) L. Peruvianum] accessions 6 and 18 were back‐crossed with two diploid L. Esculentum cultivars ‘Moneymaker’ (mm) and ‘pusa Ruby’ (pr). Twenty‐two plants of the bc2 generation were produced by backcrossing 7 bcl 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 the four cultivars as female parent with three bc2 generation plants. The bc3 progeny derived from one pollen parent plant were produced without the need to culture immature seeds. They segregated with respect to pigmented anther cones and were self‐fertile. The anther cone pigmentation of the pollen parent plant was associated with increased seed set, greater fruit size and an orange‐red fruit colour. These features were transmitted to the fertile bc3 generation. Conversely, bc3 offspring involving the other two parent plants were only recovered by culture of immature seeds. The recovery of diploid plants in BCl and self‐fertility in BC2 resulted in almost total recovery of the tomato cultivar characteristics (fruit size, colour and number of seeds) by BC3.