|Summary:||碩士 === 國立中興大學 === 園藝學系所 === 100 === The cyathiums of Euphrobia milii ‘Olympus’× E. geroldii ‘rg01’、‘rg02’、‘rg03’、‘rg10’ and ‘rg12’ were cultured in half strength MS medium supplemented with 5 mg L-1 BA. After 4 weeks, shoots were reversed from cultured cyathiums. The highest reversion rate was in ‘rg12’(63.9%), and 1.2-2.0 shoots were reversed from each cyathium. The higher multiplication of single-node explant of ‘rg01’, ‘rg02’ and ‘rg12’ was cultured on half strength of MS medium supplemented with 2 mg L-1 BA and 5 g L-1 agar. Buds of each explant were 4.3, 3.7 or 2.8 respectively.
Soaking in 5 g L-1 Colchicine or 0.03 g L-1 Oryzalin solution for 12, 24 or 48 hr, the seeds of E. geroldii didn`t develop polyploidy plants. The shoot tips of E. geroldii dipped or pasted with 5 g L-1 Colchicine at cotyledon stage for 2 days had the highest mutation rate(28.1%) and 36 polyploidy plants were propagated in this experiment. Lateral buds of E. milii × E. geroldii ‘rg12’ dipped with 5 g L-1 Colchicine had the highest mautation rate(15.5%). The mutant ‘rg12-M1’ was separated. The leaf thickness, bract length, bract width, bract thickness and gland diameter of ‘rg12-M1’ were longer than that of original plant ‘rg12’, and its pollen germination rate was 56.7%.
In the interspecific hybridization of E. lomi ‘Sri Aumphorn’× E. geroldii, two progenies were obtained. The thorns of these 2 plants were changed from single thorn to palmate thorn but became softer and broken easily. And the leaves, cyathiums color and shape were similar to that of E. lomi ‘Sri Aumphorn’. In the interspecific hybridization of E. lomi ‘Supo Roek’ × E. millotii, the ovules was cultured in half strength MS medium after 5-7 days of pollination. Only a few number of ovules developed into plantlets. The morphology of stems and leaves were between their parents. The thorns of the hybrids became softer and were borkern easily, but cyathiums color and shape were similar to that of E. lomi ‘Supo Roek’.