Self-fertile cybrids Nicotiana tabacum (+Hyoscyamus aureus) with a nucleo-plastome incompatibility

Abstract.

Cytoplasmic hybrids (cybrids) in a novel inter-generic combination, Nicotiana tabacum (+Hyoscyamus aureus), were generated by fusion of protoplasts from a plastome tobacco albino mutant (line R100a1) and γ-irradiated green protoplasts of H. aureus. Cybrids possessed a plastome of H. aureus and a rearranged mitochondrial DNA. The cybrids displayed a syndrome of nucleo-plastome incompatibility expressed as a partial chlorophyll-deficiency of cotyledonary and true leaves at the early stage of vegetative development of plants grown from seeds in soil. During later development, the plants restored a normal green coloration. This character is phenotypically indistinguishable from the same syndrome in previously generated cybrids N. tabacum (+H. nigrum). In contrast to the cybrids N. tabacum (+H. nigrum), cybrids N. tabacum (+H. aureus) were self-fertile, and did not manifest other features that were interpreted as nucleo-mitochondrial incompatibilities in N. tabacum (+H. nigrum) plants. Therefore, the cybrids N. tabacum (+H. aureus) present a self-propagating system of Nicotiana (+Hyoscyamus) nucleo-plastome incompatibility in its pure form.