True breeding tobacco lines with new morphological phenotypes obtained from X-Irradiated protoplasts.

Tobacco (Nicotiana tabacum) plants regenerated from dihaploid and amphidiploid (normal) protoplasts after X-irradiation showed several morphological alterations in vegetative and reproductive organs. The inheritance of these alterations was followed in sexual progeny. Despite a high incidence of chromosomal aberrations in the M1 plants, true breeding lines with specific morphological alterations were obtained. The utilization of such lines for the elucidation of the control mechanisms regulating morphogenesis is discussed.