Institutional Repository of Chengdu Institute of Biology, CAS
Not a member yet
6513 research outputs found
Sort by
Stoichiometric Characteristics of Carbon,Nitrogen and Phosphorus in Quercus Sect. Heterobalanus Shrubs in the Hengduan Mountain,China
No full text为了解横断山区高山栎组[Quercus sect Heterobalanus(Oerst.) Menits.]灌木型植物不同器官碳(C) 、氮(N) 、磷(P)生态化学计量特征及分布格局,该文采用随机抽样方法布设18个高山栎组植物灌丛样地,采集高山栎组植物的根、茎、叶、枝器官样品,分析样品C、N、P含量。结果表明: (1)高山栎组植物C、N、P在各器官中分别表现为叶(477.88 g·kg ~(- 1)) >枝(469.29 g·kg ~(- 1)) >茎(445.26 g·kg ~(- 1)) >根(431.42 g·kg ~(- 1)), 叶(13.83 g·kg ~(- 1)) >茎(6.08 g·kg ~(- 1)) >枝(5.82 g·kg ~(- 1)) >根(4.70 g·kg ~(- 1)), 叶(1.26 g·kg ~(- 1)) >枝(1.21 g·kg ~(- 1)) >根(1.16 g·kg ~(- 1)) >茎(0.71 g·kg ~(- 1)), 分配到叶中的营养元素相对较多; (2)各器官中C含量较N、P含量相对稳定,其中变异系数最大值发生在根部; (3)各器官C: N范围为36.50 ~ 105.33,最大值在根中,最小值在叶中,C: P范围为418.15 ~ 768.36,最大值在茎中,最小值在枝中,N: P范围为4.89 ~ 11.69,最大值在叶中,最小值在枝中; (4)各器官C与N、P间均呈负相关关系,N与P间均呈正相关关系,但相关关系是否显著在不同器官中不同; (5)各器官C、N、P含量受海拔的影响较小,仅叶片C含量、枝P含量与海拔间存在弱负相关关系。由此可见,高山栎组灌木型植物各器官营养元素的含量与其生长期及相应器官的功能结构密切相关
A CLASSIFICATION OF THE FERN GENUS TECTARIA (TECTARIACEAE: POLYPODIALES) BASED ON MOLECULAR AND MORPHOLOGICAL EVIDENCE
No full textThe pantropical genus Tectaria Cay. (Tectariaceae) is one of the largest fern genera. It has been estimated to contain ca. 210 mostly tropical species in Africa, the Americas, Asia, and the Indian Ocean and Pacific Ocean islands. Tectaria had perhaps been the most confusing fern genus in terms of its circumscription and phylogeny. Recent studies have recircumscribed Tectaria and resolved the relationships within the genus. However, no efforts have been made to propose an infrageneric classification of the genus based on molecular and morphological evidence. In the present study, we synthesize chloroplast and nuclear DNA evidence, morphology, and/or distribution information and divide Tectaria into four subgenera: Tectaria subg. Ctenitopsis (Ching ex Tardieu & C. Chr.) Li Bing Zhang & Liang Zhang (comb. & stat. nov.), Tectaria subg. Phlebiogonium (Fee) Li Bing Zhang & Liang Zhang (comb. & stat. nov.), Tectaria subg. Tectaria, and Tectaria subg. Tectaridium (Copel.) Li Bing Zhang & Liang Zhang (comb. & stat. nov.). The latter three are further divided into seven, two, and two sections, respectively. Sixteen generic names are synonymized to individual infrageneric taxa, while four generic names are only synonymized to Tectaria because of inadequate data. A key to the infrageneric taxa is given. A nomenclatural account of each infrageneric taxon is provided
Domestic honeybees affect the performance of pre-dispersal seed predators in an alpine meadow
No full textFlowering plants interact simultaneously with mutualistic pollinators and antagonistic herbivores such that plant-mediated interactions between pollinators and herbivores must exist. Although the effects of herbivores on pollinator behavior have been investigated extensively, the effect of pollinators on herbivore performance has seldom been explored. We hypothesized that insect pollinators could improve the survival and growth of pre-dispersal seed predators by increasing seed production. We tested this hypothesis along three transects radiating from well-established apiaries in an alpine meadow by supplementing pollination in sites close to and distant from apiaries and subsequently examining seed production of the dominant nectariferous plant species Saussurea nigrescens (Asteraceae) and the performance of three dominant pre-dispersal seed predators (tephritid fly species). Pollen supplementation (1) significantly increased seed set and mass of developed seed per capitulum (i.e., flowerhead) in the distant but not the close sites, (2) did not change the survival and growth rates of the smaller-bodied species (Tephritis femoralis and Campiglossa nigricauda) at either site, but (3) improved the performance of the larger-bodied seed predator (Terellia megalopyge) at distant sites but not close sites. In addition, the larger-bodied tephritid fly showed higher infestation rates and relative abundance in the close sites than in the distant sites, whereas the smaller-bodied species had lower relative abundances in the close sites and similar infestation rates in both site types. These observations demonstrate contrasting effects of plant mutualists on the performance of antagonists with potential consequences for population sizes of insect herbivores
A New Species of the Asian Toad Genus Megophrys sensu lato(Amphibia: Anura: Megophryidae) from Guizhou Province, China
Get PDFWe describe a new species of the genus Megophrys sensu lato from Guizhou Province, China. Molecular phylogenetic analyses based on mitochondrial DNA and nuclear DNA sequences all strongly supported the new species as an independent lineage in Megophrys (Panophrys) clade. The new species is distinguished from its congeners by a combination of the following morphological characteristics: (1) small body size with SVL < 38.8 mm in male and SVL < 42.3 mm in female; (2) vomerine teeth absent; (3) tongue not notched behind; (4) a small horn-like tubercle at the edge of each upper eyelid; (5) tympanum distinctly visible, rounded; (6) two metacarpal tubercles in hand; (7) relative finger lengths: II < I < V < III; (8) toes with rudimentary webbing at bases; (9) heels overlapping when thighs are positioned at right angles to the body; (10) tibiotarsal articulation reaching the level between tympanum to eye when leg stretched forward; (11) an internal single subgular vocal sac in male; (12) in breeding male, the nuptial pads with black nuptial spines on the dorsal bases of the first and second fingers
A Rapid, Non-invasive Method for Anatomical Observations of Tadpole Vertebrae in Vivo
Get PDFThe tadpole is a critical stage in the amphibian life cycle and plays an important role during the transition from the aquatic to the terrestrial stage. However, there is a large gap in tadpole research, which represents a vital component of our understanding of the diversity and complexity of the life history traits of amphibians, especially their developmental biology. Some aspects of this gap are due to limited research approaches. To date, X-ray microcomputed tomography (micro-CT) has been widely used to conduct osteology research in adult amphibians and reptiles, but little is known about whether this tool can be applied in tadpole studies. Thus, we compared the results of two methods (the bone-cartilage double-staining technique and micro-CT) to study vertebrae in tadpole specimens. The results revealed no significant difference between the two methods in determining the number of vertebrae, and micro-CT represents a rapid, non-invasive, reliable method of studying tadpole vertebrae. When scanning tadpoles, voltage is the most critical of the scanning parameters (voltage, current and scan time), and moderate scanning parameters are recommended. In addition, micro-CT performed better using specimens stored in 70% ethanol than those preserved in 10% formalin. Finally, we suggest that micro-CT should be more widely applied in herpetological research to increase specimen utilization
Molecular Characterization of Thyroid Hormone Receptors (TRs) and their Responsiveness to T3 in Microhyla fissipes
Get PDFTo explore and enrich the molecular mechanisms of thyroid hormone receptors (TRs) in the metamorphosis of amphibians, the cDNA sequences of TR alpha and TR beta in Microhyla fissipes were cloned and characterized. TR alpha was 1 706 bp in length with an open reading frame (ORF) of 1 257 bp encoding a predicted protein of 418 amino acids and TR beta was 1 422 bp with an ORF of 1 122 bp encoding a predicted protein of 373 amino acids. Their protein sequences contained 4 conserved domains of the nuclear receptor superfamily with two highly conserved cysteine-rich zinc fingers in the DNA-binding domain, whereas TR beta was 42 amino acids shorter in its A/B domain than TR alpha. Highly-conserved sequences and structures indicated their conserved functions during metamorphosis. TR alpha expression reached peak at 12 h and then decreased from 12 h to 48 h. While dramatically up-regulated TR beta was observed after exposure of T3 within 24 h, and it was down-regulated from 24 h to 48 h. The expression pattern of TR beta is similar to that in the natural metamorphosis. Furthermore, tadpoles treated 24 h also resembled the climax of metamorphosis tadpoles and TR beta expression had higher responsiveness than TR alpha to T3 in M. fissipes. These results suggest M. fissipes may serve as the model to assay environmental compounds on TH signaling disruption
Ethnopharmacological profile of anti-arthritic plants of Asia-a systematic review
No full textBackground: Arthritis is not an inherited disease but caused by stimulation of some hidden arthritis susceptible genes lowering the quality of life throughout the world, particularly in developing countries. Objectives: To present a comprehensive review on ethnomedicinal and ethno-pharmacological information of Asian anti-arthritic plants. Data sources: Research articles published in English were searched using six search engines (1979-2017). A few additional records searched from other sources i.e. floras, inventories and bibliographies were also included. Data Extraction: Information regarding ethnobotany, pharmacology, phytochemistry and toxicity of plants used against arthritis was extracted from the selected literature. Results: A total of 159 medicinal plants that were reported to be used against arthritis belonging to 71 families among which Asteraceae and Lamiaceae were dominant. Most of the plants were from India (37 plant species) followed by Thailand (21), China (16), and Iraq (12). Twelve percent of plants were reported to be traditionally used in more than one country. Most of the plants were used against rheumatoid arthritis (65). The majority of the documented herbal preparations consisted of leaves (22%) followed by roots (13%) and the dominant formulation method was decoction (21 plants). Only six plants were reportedly evaluated for their in-vitro and 15 plants for in-vivo activities. Five pure compounds (allicin, thymoquinone, polyphenols, 1'-acetoxychavicol acetate and ginger oil) were reportedly isolated from the documented plants and tested against different arthritis models. Toxicity of certain plants was also reported. Conclusion: The present review summarizes the ethnomedicinal information of anti-arthritic plants and discloses scientific gaps in current knowledge. The majority of reported plants have not yet been scientifically authenticated and should be given more attention in future, especially those plants i.e. Carica papaya L. being used in more than one country
Impacts of Land-Use and Climate Change on Ecosystem Service in Eastern Tibetan Plateau, China
No full textPast years have witnessed the transformation of land use at a high frequency and a warmer and drier climate in the Eastern Tibetan Plateau region. To fully understand the spatial-temporal variation of ecosystem services against the changing global backdrop and to provide scientific ecosystem management measures for decision-making, a study was conducted to investigate the major ecosystem services: water yield, soil conservation and crop production from 1990 to 2015 in the Eastern Tibetan Plateau region. Three scenarios climate change only, land use change only and both land use and climate change-were included in this study to analyze the response of ES to the above-mentioned global changes. The results show that (1) the total quantity of ES reduced in all the three scenarios, the annual ES change was scenarioll < scenarioIII < scenariol and the periodical characteristics are present in this region; (2) the ES change in spatial distribution varied with different climate change patterns and land use transfer directions; (3) the ES composition of each ecosystem varied with different driving scenarios and different responses of the forest and wetland on climate change and land use changes were observed. Moreover, the trade-off under land use change and climate change respectively was observed in this study. Based on the results, we recommend that the local government take this trade-off and climate change into account when making decisions, continue with desertification control and improve the quality of grassland as well as forests-these efforts should enable us to achieve sustainable development of human beings and the natural ecosystem
Effects of Formic or Acetic Acid on the Storage Quality of Mixed Air-Dried Corn Stover and Cabbage Waste, and Microbial Community Analysis
No full textA mixture of air-dried corn stover and cabbage waste was ensiled to preserve lignocellulosic biomass for use as biofuel. Furthermore, the effects of different fresh mass fractions (0.3 and 0.6 %) of formic or acetic acid on the mixed silage quality were evaluated to guarantee its quality. The application of formic or acetic acid prior to mixing the silage led to higher water-soluble carbohydrate fractions than the negative control, indicating that both acids contributed to preservation of water-soluble carbohydrates during storage for 170 days. The dry matter content was also increased after storage from 90 to 170 days. It was found that the content of neutral and acid detergent fibre, cellulose and holocellulose (the sum of cellulose and hemicellulose) in mixed silage treated with formic or acetic acid was significantly lower than that obtained in the negative control. The pH and the ratio of ammoniacal nitrogen to total nitrogen in mixed silage treated with acetic acid also significantly decreased. Furthermore, the addition of formic or acetic acid significantly weakened the fermentation intensity of lactic acid, depending on the ratio of lactic to acetic acid, as well as the ratio of lactic acid to total organic acids. The number of bacterial species and their relative abundance shifted during silage mixing, wherein microbial communities at phylum level mainly consisted of Proteobacteria and Firmicutes. The dominant bacteria were also observed to shift from Lactobacillus and Enterobacter in presilage biomass to Lactobacillus and Paralactobacillus. Specifically, Enterobacter disappeared after 130 days of storage. In conclusion, the addition of a low dose of acetic acid to fresh mass (0.3 %) could effectively improve the fermentation quality and is conducive to the preservation of the organic components