Mycorrhizae play a vital role in the life cycle and evolutionary history of orchids. The genera Cypripedium and Paphiopedilum, both belonging to the subfamily Cypripedioideae of the Orchidaceae, are very well known as slipper orchids in horticultural science. However, due to the environment disruption and over collection of the orchids, all species in the two genera are listed in the Appendix of the Convention on International Trade in Endangered Species of Wild Fauna and Flora.
Prof. Hu Hong, header of horticulture research team, in cooperation with Prof. Yang Zhuliang , header of a fungal research group, studied the mycorrhizal fungi for several species in genera Paphiopedilum and Cypripedium by the molecular phylogenetics. Studies showed genera Paphiopedilum have closely related mycorrhizal fungi of Cypripedium. The most frequently detected fungi belonged to the Tulasnellaceae. They never shared identical fungal ITS sequence types in common, but their fungal taxa sometimes occurred in the same major clade of the phylogenetic tree. The fungal sequence type spectra of different species of Paphiopedilum from similar habitats sometimes overlapped, however, the dominant sequence types differed among the species, and so did the sequence type spectra within Cypripedium. Orchids of P. micranthum and P. armeniacum transplanted from the field and grown in two greenhouses had a greater number of mycorrhizal associations than those sampled directly from the field. Root specimens from P. micranthum taken from the greenhouses were preferably associated with mycobionts of the Tulasnella calospora complex, while those from the field had mycorrhizal associations of other tulasnelloid taxa. Such plasticity in mycorrhizal associations makes ex situ conservation or even propagation by means of mycorrhization of axenically grown seedlings possible. The research results have been published on the journal of Mycorrhiza (20/8) in 2010. This study supported by the National Natural Science Foundation of China (NSFC) and the Joint Funds of NSFC and Yunnan Provincial Government, Knowledge Innovation Project of the Chinese Academy of Sciences.
slipper orchids (Picture by KIB)
slipper orchids (Picture by KIB)
