Identifying hotspots for grassland endangered plant species in the Sanjiangyuan Nature Reserve based on the MaxEnt model
Biodiversity Science,2018,Vol 26,No. 02
【Abstract】 Sanjiangyuan, located in the hinterland of the Qinghai-Tibetan Plateau, one of the global biodiversity hotspots, is a centralized distribution area of alpine grassland biodiversity. However, in the past decades, human disturbance and climate change have caused severe degradation to the alpine grassland, making grassland biodiversity vulnerable to enormous threats. In this study, MaxEnt model was used to simulate the distribution of hotspots of 40 endangered plant species under the current and the future climatic conditions in Sanjiangyuan region. The results showed that the area of hotspots of endangered plant species in Sanjiangyuan, estimated through the MaxEnt model, was approximately 89,438 km 2, and those hotspots were mainly located in Nangqian County, Yushu City, Banma County, Jiuzhi County and Henan County. Under the increasingly warm and humid climatic conditions in the future, the hotspots of endangered plant species of grassland in Sanjiangyuan Nature Reserve simulated by MaxEnt model will expand to the northwestern part, which will be favorable for maintaining and improving plant diversity. However, the model simulations also found that Nangqian County, Yushu City, Banma County, Jiuzhi County, and Henan County all contained the hotspots with more than 25 endangered plant species not covered by key reserves, with the total area reaching 4,423 km 2. These hotspots are classified as general reserves where livestock production activities can be carried out. These hotspots, which are more likely to be subjected to human disturbance, should be given more attention to and conservation for.
Comparison of phylogenetic diversity and ecological types of root-associated fungi on Aquilaria sinensis and Dalbergia odorifera seedlings in an endangered plant restoration nursery of Hainan Island
Microbiology China,2018,Vol 45,No. 05
【Abstract】 [Background] Root-associated fungi (RAF) are essential for seedling survival, establishment and growth. However, little is known about the identity and ecological characteristics of RAF naturally established on seedling roots. [Objective] To reveal phylogenetic diversities and ecological types of RAF naturally established on nursery grown seedling of Aquilaria sinensis and Dalbergia odorifera and to evaluate the host effects on RAF community structuring. [Methods] Root samples were collected to extract DNA, from which fungal ITS region was amplified, cloned and sequenced by using both universal and specific fungal primer pairs. Phylogenetic placements of fungi were inferred by ITS sequence analysis. The putative trophic modes and guilds of RAF were assigned by functional analysis with the FUNGuild software. Effects of plant species, height, basal diameter and leaf area on root-associated fungal species composition were determined by non-metric multidimensional scaling (NMDS) analysis. [Results] A. sinensis and D. odorifera seedlings grown in nurseries were naturally colonized by a highly diverse suite of RAF, including Mucoromycota (51%), Ascomycota (43%) and Basidiomycota (6%). These RAF can be assigned to multiple trophic modes and guilds including symbiotroph (29 species) representing by Glomeromycetes sp. 2, Rhizophagus irregularis, and saprotroph (5 species) representing by Talaromyces pinophilus and Rhizopycnis vagum. In addition, two fungal species, Mycoleptodiscus sp. and Fusarium phaseoli were assigned to pathotroph, while ecological characteristics of 15 species are unclear. NMDS analysis indicated that the effects of host plant species, plant height, basal diameter and leaf area of seedling on root-associated fungi were not significant. However weak effect of plant height was found in Arbuscular mycorrhiza fungi fungal community. [Conclusion] The RAF inoculum is high in culture media of this nursery that seedlings were associated with phylogenetically distant and multiple trophic modes and guilds of fungi. Diversity of AMF might be underrepresented when universal primers such as ITS1F/ITS4 were applied to investigate the diversity of RAF community.
Comprehensive evaluation of quality of Nardostachys Radix et Rhizoma and Nardostachys Herba by multidimensional statistical analysis
Chinese Traditional and Herbal Drugs,2018,Vol 49,No. 04
【Abstract】 Objective Based on the premise of wild resources protection of Nardostachys jatamansi, whether Nardostachys Herba (NH) could be equal to Nardostachys Radix et Rhizoma (NRR) specified in pharmacopeia for medical use or not, and to discuss the scientificity of using NH as the commodity specifications in market circulation. Methods The gray correlation, regression analysis and PCA, and HCA analysis were used to analysis the data, including the root length, plant height, dry weight, content of volatile oil, water-soluble extract, content of nardosine, moisture, total ash, acid-insoluble ash, in order to comprehensively evaluate the quality of NH and NRR. Results The qualities of NH and NRR were mainly correlated with the contents of volatile oil and water soluble leach of NRR. Two variables corresponding to the dependent variable, aqueous extract and volatile oil, of total eight variables had significant influences between NH and NRR ( P < 0.01). Conclusion The multidimensional statistical analysis of medicinal material quality illustrated an obvious difference between NH and NRR. It was conformed once again the NRR was to be the best for medical use, which was the same indexed regulation in different versions of Chinese Pharmacopoeia. The NH was not absolutely substituted for NRR.