| Summary: | 碩士 === 國立中興大學 === 國際農學研究所 === 101 === Erycina pusilla is a miniature orchid with obvious yellow flower and can constantly produce flowers within in vitro condition. Thus, Erycina pusilla is considered as a suitable orchid to develop in vitro ornamental products. In this study, flowering regulation and transportation was examined in in vitro Erycina pusilla.
Physical wounding on plants, modifying the direction of inserting plants into the medium, modulating the composition of inorganic nitrogen and sucrose concentration in the culture medium were conducted in regulating in vitro Erycina pusilla flowering. The results showed that performing physical injury alone and combination treatment of physical injury and different placement led to lower inorganic nitrogen content, higher starch and total carbohydrate content. Thus, the C/N ratio of plants was regulated to higher value, and more flower stalks production were observed after 14 weeks of culture. In the part of plant condition, performing mechanical injury led to more browning roots and leaves, and heavier plant weight. Modulating the concentration of inorganic nitrogen to 1/16 (118.75 mg L-1 KNO3 and 103.125 mg L-1 NH4NO3) in culture medium promoted the production of flower bud and flower, fewer abortive flower buds, and no severe damage was detected on plant growth. More flower bud and flower production were observed when increasing sucrose concentration to 40 g L-1 in medium. However, thicker leaves were observed in treatment of increasing sucrose concentration from 40 to 60 g L-1.
Both simulated transportation and practical transportation were conducted in in vitro ornamental products of Erycina pusilla. The simulated transportation of in vitro Erycina pusilla lasted under the range of 15-30℃ and darkness for a week without losing its quality. For the simulated transportation in darkness for 4 weeks, the suitable storage temperature is 20-25℃. More abortive flower buds resulting from 4-week dark treatment in 15-30℃was recorded. In addition, severe browning leaves and browning flower stalks were observed on plants with 4-week darkness at 30℃. As for the practical transportation, severe damage of broken culture medium and plant displacement from shipment handling and transportation resulted in no intact ornamental products. Moreover, the low temperature around 10℃ during winter caused serious deterioration of browning and flower production. More factors such as preventing serious vibration, contamination problem, unknown environmental change, and Customs quarantine should be considered to avoid the loss in practical transportation.
According to these experiments, flower regulation and transportation for 1 to 4 weeks could be applied on in vitro Erycina pusilla. These finding showed that Erycina pusilla is an ideal plant material for developing in vitro ornamental product of orchid.
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