Ratchanee Petchang2011-02-212011-02-212011-01-242011-01-24Journal of Science and Technology Mahasarakham University - วารสารวิทยาศาสตร์และเทคโนโลยี มหาวิทยาลัยมหาสารคาม; Volume.29 Numer.4 october-december 2010; 413-419http://imsear.searo.who.int/handle/123456789/131200The purpose of this research was to study the effects of colchicine concentration and treated duration time on growthand chromosome number inDendrobium draconis Rchb.f.. The protocorm of Dendrobium draconis Rchb.f. after onemonth germination was treated with 0.05 %, 0.10 % and 0.50 % (w/v) colchicine for 4 and 5 days. The protocormswere then cultured in VW medium for 14 weeks. Growth and chromosome number from root tips were examined.Height and leaf number of the control and colchicine treatment groups were not significantly different but stems of thecolchicine treatment groups were bigger than those of the control group. Moreover the leaves were greener than thecontrol group. The thickness and length of the stomata, and the thickness of leaf directly related to the colchicine concentration. The chromosome number from root-tips of the control group and the treatment groups with colchicineconcentration 0.05% were 2n=2x=38 while the chromosome number of treatment groups with colchicine concentration0.10% and 0.50 % (w/v) for 4 and 5 days were 2n=4x=76. The level of ploidyDendrobium draconis Rchb.f. wasconfirmed by flow cytometer. The results indicate that treatment of protocorms with 0.10 % (w/v) colchicine for 4 dayswas suitable to induce polyploidy in Dendrobium draconis Rchb. f..en-USDivision of Research Supporting and Extension, Mahasarakham University, Mahasarakham, ThailandResearch Articles