Flow-cytometric analyses of DNA content were performed on chopped in vivo, in vitro, and protoplast-derived in vitro nuclei of Solanum phureja. An anther-derived monoploid genotype and a diploid and tetraploid clone, derived from callus culture of the monoploid genotype, were used to characterize the influence of in vivo and in vitro environment and explant ploidy level on the extent of endopolyploidization. In addition, protoplast-derived nuclei, from nine anther-derived monoploid genotypes, were examined for genotypic influences on endopolyploidization. DNA distributions of the anther-derived monoploid and callus-derived clones in vivo contained peaks corresponding to 1C, 2C, and 4C DNA levels. By comparison, diploid and tetraploid clones cultured in vitro did not contain 1C DNA peaks. Nuclear DNA content beyond the 4C level was not observed in any of the samples tested. The frequency of monoploid nuclei did not vary significantly among protoplast-derived nuclei from the monoploid genotypes; however, significant differences were detected between replications over time. Variability among the monoploid genotypes was shown for frequency of endoreplicated (4C) nuclei, indicating a genotypic influence on monoploid stability.
Owen, Henry R.; Veilleux, R. E.; Levy, D.; and Ochs, D. L., "Environmental, genotypic, and ploidy effects on endopolyploidization within a genotype of Solanum phureja and its derivatives" (1988). Faculty Research & Creative Activity. Paper 140.