Somatic hybridization of an atrazine resistant biotype of Solanum nigrum with Solanum tuberosum : Part 1: Clonal variation in morphology and in atrazine sensitivity. 
Plants were regenerated from protoplast fusion experiments with haploid Solanum tuberosum L. and an atrazine resistant biotype of the normally susceptible S. nigrum L. Sixty clones which were unlike the parents were selected by types of hairs and leaf pigmentation of young shoots and characterized by: chromosome numbers, response to atrazine, branching, hairs of the calyx, shapes and pigmentation of leaves, and morphology of flowers.  Twenty five clones showed vegetatively stable differences from the parental clones; enough combinations of mixed characters suggested the clear origin from fusants of at least nine clones.  Observed diversities within and between protoplastderived clones are interpreted as expressions of variation during the development of the regenerants.