ALLOPLASMATIC INCOMPATIBILITY IN CYBRID P LANTS POSSESSING A LYCOPERSICON-ESCULENTUM MILL GENOME AND LYCOPERSICON-PERUVIANUM VAR DENTATUM DUN PLASMAGENES

Fourteen shoots of a single cytoplasmic hybrid, obtained by fusion of protoplasts of cultivated tomato Lycopersicon esculentum (plastome chl orophyll-deficient mutant of the cultivar Friihe Liebe, 2n = 2x = 24) with gamma-irradiated protoplasts of the wild tomato L. peruvianum var . dentatum (line 3767, 2n = 2x = 24), were grafted in the greenhouse f or a detailed analysis of phenotypic, biochemical, and cytogenetic tra its. The cybrid nature of the grafted plants was confirmed. Analysis o f isozymes (acid phosphatase, peroxidase, glutamate oxaloacetate trans aminase, and malate dehydrogenase) and blot hybridization of the nucle ar DNA with the 25S ribosomal ;RNA gene showed that these plants posse ssed a nuclear genome of tomato. Restriction analysis of the chloropla st and mitochondrial DNA revealed that the cybrid under study inherite d the plastome from L. peruvianum var. dentatum, while the chondriome was presumably represented by the recombinant DNA. Chromosome number w as diploid 2n = 2x = 24. With respect to most morphological traits of stems, leaves, inflorescences, flowers, and fruits, the-cybrid was ind istinguishable from the tomato cultivar Quedlinburger Friihe Liebe. Ho wever, cybrid plants were characterized by stunted growth and developm ent (only by grafting we succeeded in obtaining plants capable of norm al vegetation), partial chlorophyll deficiency (marbled variegation an d light-green leaves), heterostyly, and male sterility. Based on our d ata and numerous published reports, we conclude that specific characte rs expressed in cybrid plants containing an L. esculentum nucleus, L. peruvianum var. dentatum plastids, and hybrid mitochondria are due to nuclear-cytoplasmic incompatibility.