Research Article
Swee-Suak Ko1
Abstract
Phalaenopsis orchid is one of the main commodities in international trade and global ornamental market. Phal orchids have distinctive biological and physiological characteristics. Phal aphrodite performs typical Crassulacean acid metabolism (CAM) photosynthesis and it has thick and succulent leaves. They evolved to maximize CO2 uptake and reduce water loss by opening stomata at night under drought environments; therefore, they acquire high water use efficiency. CAM orchid uptakes very low rate of CO2 (<6 μmol·m–2·s–1) at night [1] and that causes slow growth rate in orchids. Orchids also have other features such as unique flower shape and have a special ABCDE model for flower development [2]. In the mature capsules orchid seeds are immature and without endosperm [3], therefore, symbiosis with mycorrhizae is essential for orchid seed germination in nature [4]. However, numerous in vitro seed germination media containing appropriate nutrients have been developed and are beneficial for orchid seedling development. Besides, several characteristics for example polyploidy, huge and complexity of orchid genome size and lack of molecular toolkits still hinder basic research of this orchid.