Optimization of ISSR-PCR Reaction System and Preliminary Construction of ISSR Fingerprinting of Some Species in Bryaceae

[Objective] The aim was to provide molecular basis for the identification of species in the moss family Bryaceae by the construction of inter-simple sequence repeats （ISSR） fingerprinting. [Method] In order to seek standardizing PCR reaction set-up, an orthogonal design was used to optimize ISSR-PCR amplification system of Bryaceae in five factors （Mg2＋, dNTPs, primer, DNA template, Taq DNA polymerase） at four levels respectively. [Result] A suitable ISSR reaction system was obtained, namely： 20 μl reaction system containing 5 ng of DNA template, 0.2 μmol/L primer, 2.25 mmol/L MgCl2, 0.6 U of Taq DNA polymerase, 0.4 mmol/L dNTPs. Proper annealing temperature was found at 48-50 ℃.The above system and six ISSR-PCR primers were used for the PCR amplification of 14 samples from Bryaceae and the related species in Mniaceae. A total of 86 bands were amplified, all showed polymorphism. NJ cluster analysis showed a star-shaped cladogram. [Conclusion] The results manifested that ISSR fingerprinting could provide the appropriate degree of polymorphism at low taxonomic level, so it would be a useful tool to provide additional evidence for resolving taxonomic relationships at the species level of Bryaceae.

Classification and applied uses of Bryaceae sensu lato(Musci) in China

The Bryaceae is a large, cosmopolitan, taxonomically difficult moss family. Recent studies based on molecular data alone or in combination with morphological data have greatly changed the understanding of phylogenetic relationships in the Bryaceae s.l. and indicate that the Bryaceae is not monophyletic. Based on phylogenetic analyses of sequence data for four cpDNA regions and morphological data, we revise the traditional Bryaceae in China and transfer six genera to other families. The Mielichhoferiaceae was redefined previously by Hill et al. based on the presence of much-branched stems, apparently lateral gametangia, Pohlia-like leaves, and a more-or-less reduced peristome. Five genera of Mielichhoferiaceae are present in China: Mielichhoferia(four species), Pohlia(27 species, two varieties), Pseudopohlia(one species), Epipterygium(two species), and Synthetodontium(one species). The genera Orthodontium and Leptobryum are transferred from the Bryaceae s.l. to Orthodontiaceae and Meesiaceae, respectively. Members of the recircumscribed Bryaceae belong to five genera: Anomobryum(five species), Brachymenium(14 species), Bryum(54 species, two varieties), Plagiobryum(three species), and Rhodobryum(four species). Bryaceae diversity is high in China. The species have potential uses in medicine, landscaping, environmental protection, and other fields. Rhodobryum roseum(Hedw.) Limpr., Bryum argenteum Hedw., and Rhodobryum giganteum(Schw gr.) Paris have long been used to cure cardiovascular disease in China. Some bioactive compounds will be leading compounds for the future design of novel drugs. In recent years, many species of Bryaceae have been used for landscaping. Bryum spp. are the dominant biotic species in biological soil crusts, which serve important ecological protective functions.