Effects of gamma radiation on somatic embryogenesis and androgenesis in various in vitro cultured plant tissues

Gamma irradiation with 1000 rad stimulates somatic embryogenesis in carrot plants and androgenesis in tobacco and Datura. The numerous somatic embryos formed are incapable of germination, whereas the androgenetic plantlets develop normally. A cytological study is described. Higher radiation doses of 2,000-10,000 rad have an adverse, or inhibiting, effect on in vitro induced embryogenesis. In the case of tobacco, the formation of albino plantlets is sometimes observed. Genetic changes caused by the action of ionizing radiation should be more distinctly expressed in haploid or diploid individuals and homozygotes formed by androgenesis. (author)