Interspecific hybrids in nicotiana through in vitro culture of fertilized ovules nicotiana stocktonii x nicotiana tabacum sexual hybrid nicotiana nesophila x nicotiana tabacum sexual hybrid nicotiana repanda x nicotiana tabacum sexual hybrid
Reed, S.M.; Collins, G.B.
Journal of Heredity 69(5): 311-315
ISSN/ISBN: 0022-1503 Accession: 005734542
N. repanda, N. stocktonii and N. nesophila were crossed reciprocally with diploid and tetraploid N. tabacum. Seed was obtained only when the wild species was used as the female parent and diploid N. tabacum was used as the pollen parent. While none of the seed germinated, all 3 desired hybrids were obtained by in vitro culture of hybrid ovules. This technique involved aseptically excising hybrid ovules from ovaries at various times following pollination and placing them on a chemically defined artificial nutrient medium. While all N. repanda .times. N. tabacum hybrid plants died shortly after being removed from aseptic conditions, both N. stocktonii .times. N. tabacum and N. nesophila .times. N. tabacum plants grew to maturity. In both hybrids little pairing between the 2 parental genomes was seen at metaphase I of meiosis, and pollen staining indicated 0% pollen fertility. Plants with a doubled chromosome number and partially restored fertility were obtained for both hybrids. Attempts are being made to use these interspecific hybrids to transfer race 1 black shank (Phytophthora parasitica var. nicotianae) resistance into commercial tobacco.