The Effects of Different Types of Cytokinin on Shoot Formation and Plant Regeneration from Leaf Explants of Four Cultivars of Sagagiku Group in Chrysanthemum, Dendranthema grandiflorum(Ramat.) Kitamura.

Abstract

Four cultivars of Sagagiku group in chrysanthemum were treated with different types of cytokinin to form adventitious shoots from leaf explants. The maximum adventitious shoot formation rate, 82.2%, was observed in the medium with 2.5×10-5 M of thidiazuron (TDZ), an urea-type Cytokinin, in ‘Ogura-nishiki, ’ followed by ‘Sagano-aki’ (56.7%) in the medium with 2.5×10-6 M of N- (2-chloro-4-pyridyl) -N'-phenylurea (CPPU), an urea-type cytokinin, ‘Sagano-yuki’ (12.2%) in the medium with 2.5×10-6 M of 6-benzylamino purine (BA), a purine-type cytokinin, and ‘Sagano-haru’ (1.3%) in the medium with 5.0×10-6 M of TDZ. Vigorous roots and significantly higher root formation rates were observed in the medium without 3-indolebutyric acid. In ‘Sagano-haru, ’ however, no roots were differentiated and died during root induction culture. These results suggested that there were large differences in adventitious shoot formation ability among these four cultivars of Sagagiku group, and that TDZ and CPPU were effective for shoot formation in some cultivars of chrysanthemum.