Nucleo-cytoplasmic incompatibility in cybrid plants possessing an Atropa genome and a Nicotiana plastome.

Twenty-nine cybrids possessing an Atropa belladonna nuclear genome and a Nicotiana tabacum plastome were selected from two independent protoplast fusion experiments. In contrast to the previously described reciprocal, green and fertile cybrids with a Nicotiana nuclear genome and an Atropa plastome (Kushnir et al. 1987), the plants obtained were totally chlorophyll-deficient. An Atropa nuclear genome and a Nicotiana plastome from these chlorophyll-deficient cybrids were combined with an Atropa or a Scopolia plastome and a Nicotiana nuclear genome, respectively, in control fusion experiments. All of these nuclear genome/plastome combinations gave rise to normal, green plants. Therefore, we conclude that an N. tabacum plastome is incompatible with an A. belladonna nuclear genome.