摘要
Variations in Caladium humboldtii cv. ＇Phraya Savet＇ from in vitro culture were observed. Callus and small shoots were induced from unexpanded leaf segments cultured on modified MS medium supplemented with 2.69 p.M l-Naphthalene acetic acid （NAA） and 17.76 μM N6-Benzyladenine （BA）. Shoots were transferred onto modified MS medium supplemented with 8.88 μM BA for shoot multiplication. Subsequently, roots were induced on MS without growth regulator. The regenerated plantlets were vigorously grown in glasshouse conditions. From 4 morphological groups （leaf color ratio, leaf color, petiole and leaf pattern）, the regenerated ＇Phraya Savet＇ caladium plants were divided into 6 types. The occurrence of variants was 52%. Most of the mutated plants were observed from only leaf color ratio （green ： white） and leaf shape. The most significance for commercial value from mutated clones was round leaf obtaining 20%. Characteristics of new clones from somatic hybridization between C humboldtii cv. ＇Phraya Savet＇ and C. bicolor cv. ＇Suvarnabhum＇ using thin cell layer technique from in vitro calli were investigated. Each thin cell layer of induced callus, about 0.5 - 1 mm thick, from both caladiums was alternately laid on the top of each other for 8 layers. Subsequently, the combination of thin cell layers was cultured and the regenerated plantlets were grown in glasshouse conditions. From 3 morphological groups （leaf pattern, leaf color and petiole）, the regenerated caladium plants were found dissimilarly to both original caladiums at 85 percent with 8 types of different characters. Somatic hybridization between C. humboldtii cv. ＇Phraya Savet＇ and C. bicolor cv. ＇Suvarnabhum＇ gave rise to a number of most hybrids with all conserving C. bicolor characters.
