Effects of colchicine and irradiation in Spathoglottis 'yellow' (Orchidiaceae)

Spathoglottis 'Yellow' is usually grown as a flowering plant. The big yellow flowers are borne on thin long spikes and if improved can be used as cut flowers. One method to accomplish this is by mutation breeding. One set of embryos from selfed flowers were cultured in germinating media with colchicines, another set were irradiated with gamma rays and another one treated with colchicine and gamma rays combined. Germination of embryos grown in media with 0.01 percent and 0.05 percent colchicine germinated 5 weeks later than the control. In addition, they did not develop roots. Plants in 0.05 percent colchicine are shorter with thicker leaves. On the other hand, embryos irradiated with gamma rays (500 r, 800 r, 1 Kr and 2 Kr) germinated 5 months after planting. Although no root formation was observed among the treated plants, shoot development is the same as the control. Combined colchicine and irradiation treatments caused much delayed germination (10 months) and no root formation. Higher doses resulted in failure to germinate