The Culture of Immature Pea Embryos

Pea embryos of a range of developmental stages were culturedin a defined medium in vitro for up to 16 days. The criticalfactor for successful culture was the osmotic pressure of themedium; for the stages studied this was provided by the incorporationof 18 per cent sucrose in the medium. The growth of embryosof a range of genotypes was compared; small seeded genotypescould grow at comparable rates in vitro to those attained invivo. The amount of protein synthesized in vitro was similarto that attained in vivo, whereas slightly higher and lowerlevels of starch and DNA respectively were attained in vitro.The roles of intrinsic and extrinsic factors in regulating embryogrowth were studied by comparing the growth in culture of embryosof different genotypes and of hybrid embryos derived from reciprocalcrosses. embryo culture, pea embryos, hybrid embryos, osmotic pressure