Efficient Propagation Method of Tara Vine (Actinidia arguta Planch.) by Etiolation Culture

Abstract

Nodal segments of current shoots of wild tara vine (Actinidia arguta Planch.) were cultured (primary culture), and the nodal segments with one lateral bud from the primary culture were transferred and subcultured (secondary culture) repeatedly on Miller medium containing NAA and BA at 25 °C under light or dark condition.1. In the primary culture of wild tara vine, the rate of shoot formation increased with the addition of BA, and decreased with high concentrations of NAA, whereas shoot elongation was promoted by the combination of BA and NAA. the number of lateral buds per shoot was largest on the medium containing 1 μM NAA and 10 μM BA. Roots formed on the medium with NAA.2. In the secondary culture, shoot formation was suppressed with a high concentration of NAA, but was promoted with the addition of BA. In the dark, etiolated shoots with long internodes grew more rapidly and formed more lateral buds, compared with those grown under light.3. When etiolated shoots were subcultured in the dark, shoot length, internode length, and number of lateral buds increased more promptly compared with those in cultures under light.4. When the propagating-culture procedure was repeated at 15, 20, and 25 days (unit culture duration) under darkness, shoot length and number of lateral buds on etiolated shoots increased significantly with the lengths of unit culture duration, but did not vary after the 3rd subculture among the 3 treatments.5. The number of lateral buds propagated was greater on the 15-day unit culture duration than it was on the 20-and 25-day unit.6. The number of propagated lateral buds, N in the total culture duration D is represented by N=bD-r/b (b: number of buds available for the next etiolation culture; r: propagation rate). When b became equal to e, the total number of propagated lateral buds, N, attained maximum value as expressed by: Nmax= eD•r/e; the unit culture duration, p, was expressed by p=e/r. The relationship between the propagational number N and the unit culture duration p was represented by N= (r•p)D/P.