Obtaining advanced generations from <Emphasis Type="Italic">Solanum peruvianum</Emphasis> PI 126944 in the genetic background of <Emphasis Type="Italic">S. lycopersicum</Emphasis> by immature seed culture

The accession Solanum peruvianum PI 126944 has been reported as resistant to different biotic and abiotic stresses. In previous works of the group, advanced generations were derived from two interspecific hybrids, including up to pseudo-F₆ generations and backcrosses to the cultivated species of some of the pseudo-F_n generations. Moreover, resistance to Tomato yellow leaf curl virus (TYLCV) and Tomato spotted wilt virus (TSWV) was confirmed in some of the plant materials obtained. Here we describe the development of some advanced backcross generations between the cultivated tomato and S. peruvianum. Three backcross assays were carried out. In the first assay, 16 plants belonging to pseudo-F₄, pseudo-F₅ and pseudo-F₆ generations were backcrossed as male parents to cultivated tomato. Immature seeds from the 408 fruits obtained were platted and 77 plants were regenerated. A total of 21 descendants obtained in the first assay were backcrossed as male parents in the second assay, which allowed the obtaining of 599 fruits and regeneration of 365 plants. The 19 male parents used in the third assay were obtained either in the first or in the second one. Seventeen of them were obtained in the first assay and two in the second. A total of 339 plants were regenerated from 519 fruits. A high number of the plants obtained in these assays has been acclimated. Some plants set fruits with viable seeds.