Dihaploid plants of roses (Rosa x hybrids, cv 'Sonia') obtained by parthenogenesis induced using irradiated pollen and in vitro culture of immature seeds

Abstract

'Sonia' var rose ovules produced plants through in vitro culture after being pollinated with irradiated (gamma rays) pollen. A 500-Gy minimum dose was sufficient to inactivate polien and induce in situ parthenogenesis; in vitro culture was necessary for embryo rescue. The dihaploid plants originated from small embryos which occupied only a part of the carpel cavity; they were clearly distinguished from tetraploid plants by miniaturization of all organs. The dihaploid plants were observed under glass-house conditions until flowering presented a normal gynoecium. They produced a small amount of pollen of reduced but regular size; growth and development were faster than the tetraploid controls in summer. © 1994.