Derivation and Comparison of Androgenic and Gynogenic Monoploid Potato Families

Abstract

Monoploid potato (2n = 1x = 12) can be derived either paternally through anther/microspore culture or maternally through crossing with a haploid-inducing pollinator. Evidence from other genera suggests that androgenic and gynogenic haploid populations derived from the same parent may differ due to gametic selection and/or epigenetic factors. Our objectives were to derive androgenic and gynogenic monoploid populations from each of two diploid (2n = 2x = 24) Solanum phureja clones and compare their phenotypic characteristics in a greenhouse study. A haploid-inducing pollinator, S. phureja IVP101, was crossed to two selections of S. phureja (PP5 and BARD1-3). A total of 185 fruit was obtained from PP5 and 398 from BARD1-3, resulting from 85% and 65% fruit set, respectively. Seed lacking the dominant embryo spot marker carried by IVP101 were selected and germinated in vitro. From 29,300 PP5 × IVP101 seeds, 278 were spotless, resulting in 27 monoploids. Approximately 35 monoploids were obtained from the 99,500 BARD1-3 × IVP101 seeds, of which 500 were spotless. In anther culture, PP5 and BARD1-3 yielded 0.16 and 1.67 embryos per anther, respectively, of which 51% and 44% of the regenerants were monoploid. A total of 32 anther-derived monoploids has been obtained from PP5 and 130 from BARD1-3. Rooted cuttings of 21 androgenic and 21 gynogenic PP5 monoploids were established in a greenhouse in each of three randomized complete blocks. Data were collected on height, vigor, and stem number. Although the gynogenic monoploids appeared slightly more vigorous, there were no significant differences between the androgenic and gynogenic populations for vigor and stem number (P > 0.05). Mean height of the gynogenic monoploid population (13 cm) was significantly greater at 4 weeks than the androgenic monoploid population (9 cm); P < 0.05.