Indifference of potato anther culture to colchicine and genetic similarity among anther-derived monoploid regenerants determined by RAPD analysis

Effects of colchicine on androgenesis of diploid potato (Solanum phureja Juz. & Buk.) and ploidy of anther-derived plants were examined in three experiments. In the first, no significant difference was found for mean embryos per anther of an interspecific potato clone after application of five colchicine treatments (0, 25, 50, 100 and 200 mg l^-1) for 24 h to freshly excised anthers containing late uninucleate microspores. The same colchicine treatments were applied to six hybrid potato families in the second experiment. Families differed for number of embryos per anther and embryo regeneration frequency; however, androgenic response did not differ significantly among colchicine treatments. The 312 regenerated plants included 233 (75%) monoploids. The third experiment examined durations (0, 90 s vacuum infiltration, 24, 48 and 72 h) of high colchicine treatment (200 mg l^-1) on anther culture of seedlings representing one family. Mean embryos per anther, though not statistically significant, ranged from 0.96 to 1.90 for 48 h colchicine and 90 s vacuum infiltration, respectively. There were 126 plants regenerated of which 62% were monoploid. Frequency of monoploid plants regenerated from colchicine treatments did not differ significantly. RAPD analysis was conducted on 26 anther-derived monoploids of one family, based on common flasks of origin. The 13 decamer primers revealed 54 polymorphic loci. These were used to characterize the monoploids genetically. From one flask, two pairs of monoploids among six examined were genetically indistinguishable. Examination of a second and third flask revealed, six of seven and three of seven monoploids that were genetically indistinguishable. These data suggest the regeneration of genetic clones within flasks and may indicate the occurrence of secondary embryogenesis during anther culture. This revised version was published online in June 2006 with corrections to the Cover Date.