No abstract

To establish a plant-regenerating system through frequent somatic embryogenesis, a detailed investigation was undertaken on the effects of kinds, concentrations, and combinations of growth regulators on callus and somatic embryo formation from spinach root segments. Although no somatic embryogenesis occurred on the culture medium containing auxins alone, a low frequency of somatic embryo formation was shown on culture media containing auxins combined with natural cytokinins, namely 10 ,ƒÊM NAA with 10 ƒÊM zeatin, 30 ,ƒÊM NAA with 10 ,ƒÊM 2-iP, and 1 ƒÊM 2, 4-0 with 0.1 ƒÊM zeatin or 10 ƒÊM 2-iP. Somatic embryos also formed on culture madia containing auxins combined with GA3. From 50 to 70% of the root segment differentiated somatic embryos on culture media containing 10 to 30 ƒÊM NAA combined with 1 to 100 ƒÊM GA3. These results show that spinach somatic embryogenesis is most facilitated by NAA combined with GA3.

by the tissues of spinach. These results show that a low concentration of fructose in the culture medium promotes a high frequency of embryogenesis in spinach tissue culture.

No abstract

‘Hayward’ kiwi fruit (Actinidia chinensis Planch.) samples collected at 20-day intervals after full bloom, May 18, until harvest in late October, were analyzed for carbohydrates, protein, organic acids including ascorbic and dehydroascorbic acids, tannins and polyphenolic substances, and cytokinin-like compounds. Starch is a predominant carbohydrate stored in the carpellary tissue which becomes hydrolyzed as the fruit approach maturity. Quinic acid was the main organic acid in young fruit which disappeared concurrently with the appearance of ascorbic acid. Mature fruit has low concentrations of tannins and polyphenolic substances but many raphides. Types of cytokinins changed as the fruit developed.