Use of cytoplasmic hybrids for analysis of a chlorophyll deficiency mutation in Lycopersicon peruvianum var. dentatum

The nature of a chlorophyll deficiency mutation in Lycopersicon peruvianum var dentatum was studied by cybridization. To obtain cytoplasmic hybrids, m esophyll protoplasts of the investigated mutant were fused with gamma-irrad iated mesophyll protoplasts of Lycopersicon esculentum. The resulting cybri d plants contained the nuclear genome of Lycopersicon peruvianum var dentat um and the plastome of Lycopersicon esculentum. This was confirmed by isoen zyme, cytogenetic, morphological, and restriction analysis. Restitution of chlorophyll biosynthesis in the cytoplasmic hybrids indicated that chloroph yll deficiency in the Lycopersicon peruvianum var dentatum mutant was deter mined by a mutation in the chloroplast rather than nuclear genome.