Organ Formation and Plant Regeneration from Internodal Segments of Actinidia kolomikta Maxim. in in-vitro Culture

Abstract

To culture internodal segments of Actinidia kolomikta Maxim. and establish an efficient method for vegetative propagation and possibly for genetic improvement, BW medium (Sugawara et al., 1994, a combined medium of half strengths of both broad-leafed tree medium and woody plant medium) and Miller's medium supplemented with 16 combinations of CPPU (0, 0.01, 0.1 and 1 μM) and IBA (0, 0.01, 0.1 and 1 μM) were used.1. Callus formation was promoted by increasing CPPU and IBA concentrations. In BW medium, the rate of shoot formation was 100% with CPPU above 0.1 μM, and IBA of 0.01 μM. The rate of shoot formation and the number of shoots per segment were higher in the BW medium than were those in Miller's medium.2. The callus actively proliferated in Miller's medium containing 1 μM NAA and 10 μM BA. The rate of shoot formation was 100% in the culture of internodal segments and the 1st subculture of callus. The number of differentiated shoots per segment increased significantly, because multiple shoots were formed in the 1st subculture of callus.3. When the whole shoots were transferred to the medium supplemented with combinations of NAA (0, 0.1, 1 and 10 μM) and BA (0 and 1 μM), 100% rooting was obtained in a medium containing 1 μM NAA, and the plantlets obtained were healthy and grew vigorously. When the plantlets were transplanted into a soil: vermiculite mixture (4 : 1, v/v) and acclimated, nearly all plantlets developed into nursery stocks 40 days later.