Clonal Growth Characteristic of Epiphytic Orchid <i>Dendrobium sinense</i>

Abstract

Dendrobium sinense  is a perennial epiphytic orchid, which belongs to the genus of  Dendrobium  and the family of Orchidaceae. Under natural conditions,  D. sinense  has a low seed setting rate and the environmental requirements for its seed germination a very stringent. Besides sexual propagation, asexual ways like clonal propagation is also found in  D. sinense.  In this study, five transects were set up in Bawang Ridge of Hainan Province to monitor the dynamic change of  D. sinense  population and study the influence of clonal propagation on population ecology of  D. sinense . The main results are as follows:  D. sinense  belongs to a bulbous clonal plant, Spacer between pseudobulbs is only 0.35 cm around. Buds are tillered on the base of the one-year pseudobulb and deveiopment through the energy transfer between the ramets to continuation the genet life. Branching intensity enhanced as genet grow up. And different ramet from the genet have big difference in growth situation. The scale of genet cannot expansion infinitely,  D. sinense  can adjust expend speed according to the density of ramets. Clonal growth provides material and energy reserves to sexual reproduction and create more sites for flowering by increasing the growth axis.