High-frequency Shoot Regeneration from Roots of Japanese Persimmon

Abstract

Microshoots of Japanese persimmon (Diospyros kaki L. cv. Jiro) were rooted in vitro. The roots were excised and cultured on solidified Murashige and Skoog medium. After 20 days of culture, adventitious shoots formed spontaneously and directly from the roots. Of all the tested cytokinins, 10–5 m zeatin in combination with 10–8 m IAA was the most effective in stimulating production of adventitious shoots. CPPU and 2iP also were effective cytokinins. Addition of a high concentration of auxin, especially 2,4-D, to the medium inhibited adventitious shoot formation. The percentage of root segments forming adventitious shoots increased with increasing segment length. Almost all of the longest roots (4 to 6 cm) formed adventitious shoots. Chemical names used: 6-benzyladenine (BA); 2,4-dichlorophenoxyacetic acid (2,4-D); indole-3-acetic acid (IAA); 2-isopentenyladenine (2iP); N-phenyl-N′-(2-chloro-4-pyridyl)urea (CPPU).