Anoectochiluszhongshanensis (Orchidaceae), a new species from Guangxi, China

A new species of Anoectochilus (Orchidaceae) from Guangxi, China, A.zhongshanensis, is described here, which was identified based on phylogenetic studies adopting combined plastid markers (rbcL-matK-trnL-F), morphological observation and chemical analysis. Molecular phylogenetic results support the systematic status of A.zhongshanensis as a new species in Anoectochilus genus. Morphologically, this new species is similar to A.zhejiangensis and A.malipoensis, but differs by its characteristic labellum and column, including the hastate or scalpel-shaped lobes of epichile, forward curved and pinnately divided cristate lobes at both sides of the mesochile and inverted triangle column wings. Furthermore, HPLC-ELSD analysis of these three species revealed the interesting chemotaxonomic difference that the principle and characteristic lactone glycoside in this new species was kinsenoside, rather than its diastereoisomer, goodyeroside A, a major glycoside in A.zhejiangensis and A.malipoensis.

Novel insights into orchid mycorrhiza functioning from stable isotope signatures of fungal pelotons

Stable isotope signatures of fungal sporocarps have been instrumental in identifying carbon gains of chlorophyllous orchids from a fungal source. Yet, not all mycorrhizal fungi produce macroscopic sporocarps and frequently fungi of different taxa occur in parallel in orchid roots. To overcome this obstacle, we investigated stable isotope signatures of fungal pelotons extracted from orchid roots and compared these data to the respective orchid and reference plant tissues. Anoectochilus sandvicensis and Epipactis palustris represented specialized or unspecialized rhizoctonia-associated orchids. Epipactis atrorubens and Epipactis leptochila are orchids considered ectomycorrhiza-associated with different preferences for Basidio- and Ascomycota. ¹³ C enrichment of rhizoctonia pelotons was minor compared with plant tissues and significantly lower than enrichments of pelotons from ectomycorrhizal Epipactis species. ¹⁵ N values of pelotons from E. leptochila and E. atrorubens showed similar patterns as known for respective sporocarps of ectomycorrhizal Ascomycota and Basidiomycota, however, with an offset towards lower ¹⁵ N enrichments and nitrogen concentrations. Our results suggest an explicit fungal nutrition source of orchids associated with ectomycorrhizal fungi, whereas the low ¹³ C enrichment in rhizoctonia-associated orchids and fungal pelotons hamper the detection of carbon gains from fungal partners. ¹⁵ N isotopic pattern of orchids further suggests a selective transfer of ¹⁵ N-enriched protein-nitrogen into orchids.

Identification of Anoectochilus based on rDNA ITS sequences alignment and SELDI-TOF-MS

The internal transcribed spacer (ITS) sequences alignment and proteomic difference of Anoectochilus interspecies have been studied by means of ITS molecular identification and surface enhanced laser desorption ionization time of flight mass spectrography. Results showed that variety certification on Anoectochilus by ITS sequences can not determine species, and there is proteomic difference among Anoectochilus interspecies. Moreover, proteomic finger printings of five Anoectochilus species have been established for identifying species, and genetic relationships of five species within Anoectochilus have been deduced according to proteomic differences among five species.