Subjects: Biology >> Zoology submitted time 2021-06-21 Cooperative journals: 《古脊椎动物学报》
Abstract： Choristoderes were an important clade of semi-aquatic predators that occupied Laurasian freshwater ecosystems from the Middle Jurassic to the Miocene. During the Early Cretaceous, the neochoristodere lineage evolved large size and long snouts, converging on the body plan of modern crocodilians. Here, we describe a new longirostrine choristodere, Mengshanosaurus minimus gen. et sp. nov. from the Lower Cretaceous Mengyin Formation of Shandong Province, China. The holotype is the smallest reported neochoristodere individual, with a skull length of only 35 mm. The poorly ossified braincase, along with retention of a fontanel at the frontal-parietal suture, indicates this individual was a juvenile. Phylogenetic analyses recovered Mengshanosaurus as a neochoristodere, a placement supported by the presence of a single narial opening, fusion of the nasals, and expansion of the temporal fenestrae. In the Neochoristodera, Mengshanosaurus is sister to a clade consisting of Ikechosaurus, Tchoiria, Simoedosaurus, and Champsosaurus. It differs from other neochoristoderes in having the lacrimal foramen between the prefrontal and lacrimal, in addition to having large vomerine teeth (exceeding one-third the width of corresponding maxillary teeth). The closely arranged marginal teeth and large vomerine teeth suggest juvenile choristoderes may have fed on invertebrates and insects, similar to juveniles of modern crocodilians. However, the observation that very young neochoristoderes had similar skull proportions and marginal tooth shapes to adults, along with features suggesting a more fully aquatic ecology, suggest that neochoristoderes exhibited less pronounced ontogenetic niche shifts than modern crocodilians.
Subjects: Biology >> Microbiology submitted time 2021-06-17 Cooperative journals: 《干旱区地理》
Abstract： 土壤真菌群落对干旱区土壤生态系统功能的维持具有重要作用。为研究新疆干旱地区柽 柳沙包和非沙包土壤理化性质对土壤真菌群落结构的影响，该实验采集了塔里木河下游英苏断面附近沙包柽柳灌丛和非沙包柽柳灌丛的冠幅内部、冠幅边缘和灌丛边缘 3 个位置的土壤，基于高通量测序对沙包柽柳灌丛和非沙包柽柳灌丛土壤真菌群落结构及功能进行初步研究，结合土壤理化 性质，分析沙包和土壤因素对土壤真菌群落结构和功能的综合影响。结果表明：（1）土壤 pH、速效钾、全钾、铵态氮、速效磷在柽柳灌丛的不同位置存在显著性差异，而土壤含水量、电导率、总盐、有 机质、全氮、全磷、硝态氮在整个柽柳灌丛中均无显著性差异。（2）该区域柽柳灌丛土壤真菌分为 1 界，14 门，48 纲，110 目，227 科，410 属，557 种。在门水平上，子囊菌门、担子菌门和被孢霉门为该区域柽柳灌丛主要的优势菌门，在属水平上，链格孢属、曲霉属、Stolonocarpus、刺盘孢属、unidenti⁃fied_Saccharomycetales_sp、裸子囊菌属为柽柳灌丛的主要优势菌属。（3）通过分析土壤理化因子与土壤真菌群落的关系，发现全氮、速效钾、铵态氮是影响土壤真菌群落结构的主要环境因子，全磷与曲霉属、Microthelia、裸子囊菌属、Phialosimplex 均呈显著正相关关系，全氮与链格孢属呈显著正 相关关系。（4）基于 FUNGuild 真菌功能预测，在柽柳灌丛中共检测到腐生、共生、病理 3 类营养型和 5 类互有交叉营养型功能菌群，其中腐生营养型（30.0%）功能真菌在柽柳灌丛中占据主导优势，其 次是病理-腐生-共生营养型（10.6%）、病理-共生营养型（5.9%）、共生营养型（4.3%）在柽柳灌丛中 占据一定的优势。（5）研究发现柽柳沙包和柽柳冠幅对土壤养分和土壤真菌的富集效应不明显，但在沙包冠幅内功能真菌与其它组存在明显差异，说明柽柳灌丛沙包和冠幅的综合效对土壤真菌功能组成有较大的影响。
Subjects: Biology >> Microbiology submitted time 2021-06-17 Cooperative journals: 《干旱区地理》
Abstract： 采用高通量测序技术，对塔里木河下游不同生长时期（幼龄期、中壮期、过熟期、衰亡期）胡 杨根际土壤细菌进行测序，结合典范对应分析（CCA）与 Spearman 相关性分析，探讨细菌群落组成 与环境因子的相关性。结果表明：（1）土壤样品共获得 7287 个操作分类单元（OTUs），经过对比鉴 定共得到 73 门，165 纲，339 目，454 科，651 属和 205 种。（2）胡杨根际土壤细菌群落丰富度和多样性 随生长时期表现为先增加后降低的趋势，而不同生长时期间无显著差异。（3）胡杨根际细菌群落主 要的优势细菌门为变形菌门（Proteobacteria）、unidentified_Bacteria、Halobacterota，优势细菌属为海 杆菌属（Marinobacter）、嗜盐单胞菌属（Halomonas）、Woeseia，相较于门分类学水平，细菌群落组成在 属水平上存在较大差异，不同生长时期胡杨根际细菌群落的优势菌属不同。（4）不同生长时期胡杨根际土壤细菌群落组成可分为两大类，中壮期与衰亡期的土壤样品聚为一类，幼龄期与过熟期的 土壤样品聚为一类。（5）CCA 分析表明土壤含水量、全钾、总盐、pH 是显著影响胡杨根际土壤细菌 群落组成的环境因子（P<0.05）。研究结果为丰富干旱区根际微生物的研究、探讨干旱区植物-微 生物之间的相互作用提供科学依据。
Subjects: Biology >> Botany >> Applied botany submitted time 2021-06-02 Cooperative journals: 《广西植物》
Abstract： A new species, Selaginella pseudotamariscina (Selaginellaceae), is described from Vietnam. The placement of this species within Selaginella subg. Stachygynandrum is assessed based on a molecular phylogenetic analysis and morphological comparisons with related species. Molecular phylogenetic analyses suggested that S. pseudotamariscina is sister to S. digitata-S. imbricata clade. Morphologically, the new species is similar to S. tamariscina and S. pulvinata by sharing the rosette-forming habit, but distinguished by its dorsal leaves symmetrical, lanceate, sulcate on upper surface; strobili slightly dorsiventrally complanate and non-resupinate, sporophylls resembling vegetative leaves in form and arrangement, non-resupinate, the ventral sporophylls larger than the dorsal ones, dorsal sporophylls sterile, sporangia only borne on the base of ventral sporophylls.
Subjects: Biology >> Botany >> Applied botany submitted time 2021-06-02 Cooperative journals: 《广西植物》
Abstract： Pedicularis pandania (Orobanchaceae) was a new species discovered in the Wolong National Nature Reserve, Sichuan, China. This new species belongs to the alternative-leaved group that characterizing by having abundant basal leaves or only 1-3 cauline leaves, short-tubed and beaked corolla, and the lower lip completely enveloping the beaked galea. Due to the corolla tube was strongly twisted near the calyx, the corolla lower lip was completely upside down, which was distinguished from other Chinese species. Phylogenetic analyses showed that P. pandania fell into the Clade 7, as a sister to species in Series Flammeae, Pseudo-oederianae, Rhynchodontae, Filiculae and Macrorhynchae. Morphologically, however, the new species is easily discriminated from them in the corolla form as mentioned above.
Subjects: Biology >> Botany >> Applied botany submitted time 2021-06-02 Cooperative journals: 《广西植物》
Abstract： Based on literature, field work, collection, examination and identification of related specimens, we found a newly recorded species of Phyllanthaceae from China——Sauropus racemosus Beille. It differs from other species of Sauropus in having glabrous young branches,glabrous leaves, racemoses 3 to 5 clustered on the lower part of the old stem branchlets. In this paper, a detailed description, the photographs and geographical distribution of S. racemosus are given. In addition, we consider S. racemosus as ‘Endangered’ (EN) based on the IUCN categories and criteria. The discovery of S. racemosus enriched the diversity of plant species in the Sino-Vietnanese border area. It reflects that the Sino-Vietnanese border area are biodiversity hotspots in the world and key areas for biodiversity conservation. It also shows that the plant investigation in this area is not enough, and further investigation and research are needed.
Subjects: Biology >> Botany >> Applied botany submitted time 2021-06-02 Cooperative journals: 《广西植物》
Abstract： In order to reveal the effects of different vegetation restoration modes on soil microbial communities in karst areas, this study took pure Dalbergia odorifera plantation (PDOP), pure Acrocarpus fraxinifolius plantation (PAFP) and their mixed plantation (MADP) as research subjects. The soil microbial biomass and microbial community structure of different plantations were analyzed by chloroform fumigation extraction method and phospholipids fatty acid (PLFA) method. The results were as follows: The soil microbial biomass carbon (MBC) and microbial biomass nitrogen (MBN) contents of PDOP were significantly higher than those of PAFP and MADP, and that of PAFP was significantly higher than that of the MADP. The contents of soil fungi, arbuscular mycorrhizal fungi (AMF) and total PLFA were not significantly different among the three plantations, but the contents of soil bacteria, actinomycetes, AMF and total PLFA in PDOP were higher than those in PAFP and MADP, and those in the PAFP were higher than those in MADP. The PLFA contents of bacteria, gram-positive bacteria, gram-negative bacteria and actinomycetes in PDOP were significantly higher than those in MADP. The ratio of fungi to bacteria in MADP was significantly higher than that in PDOP, but there were no significant differences between MADP and PAFP. Redundancy analysis showed that soil cation exchange capacity, pH, and C∶N were the most important factors affecting the functional group composition of soil microbial community. From the perspective of soil microbial biomass and microbial community structure of the three plantations, MADP in karst area did not show the advantage of mixed forest in acid soil region to improve soil microbial community structure. However, the ratio of fungi to bacteria in the mixed plantation is the highest, which is more conducive to improving the stability of soil ecosystem.
Subjects: Biology >> Botany >> Applied botany submitted time 2021-06-02 Cooperative journals: 《广西植物》
Abstract： To improve the economic value of phytoremediation, three flowers i.e. Tagetes patula, Cosmos bipinnata and Centaurea cyanus were chosen in this study to investigate their remediation and reutilization potentials. The pilot-scale experiments were carried out in Cd, As and Pb contaminated farmland near the mining area in Guangxi. The metal amounts, bioconcentration factor (BCF) and biotranslocation factor (BTF) of the flowers towards Cd, As and Pb were analyzed and calculated. In order to develop a novel reutilization method of the harvested plants, the essential oil was extracted from the biomasses. The antibacterial effects of the oil as well as in the sanitizer were also investigated. The results showed that the studied flowers had good resistance to high-level contamination of Cd, As and Pb in the soil. Tagetes patula and Cosmos bipinnata extracted higher contents of Cd and Pb from the soil, whilst Cosmos bipinnata showed the lowest metal enrichment amounts. These flowers possessed high level of BCFs and BTFs towards Cd, moderate level for Pb, but the lowest level for As. In general, the metal extraction ability of the flowers in descending order was Tagetes patula > Cosmos bipinnata > Centaurea cyanus, and the metal enrichment preference was Cd>Pb>As. Given the high metal accumulation in Tagetes patula, no significant amounts of metals were detected in the extracted oil. The Tagetes patula oil was found to have a good inhibition effect (<10 CFU穖L-1) towards Escherichaia coli,Staphyloccocus aureus and Salmonella typhimurium. It also prolongated the antibacterial effect of the sanitizer as long as 480 min. Therefore, Tagetes patula is preferred in the phytoremediation of metal-contaminated farmland. The essential oil extracted from the harvested biomasses can be developed as an antibacterial agent in the future. This study broadens the reutilization potential of harvested plants after the phytoremediation.
Subjects: Biology >> Botany >> Applied botany submitted time 2021-06-02 Cooperative journals: 《广西植物》
Abstract： In order to understand the limiting factors of photosynthesis of Phyllostachys edulis seedlings under nitrogen addition and short-term of irradiance change, an improved Farquhar model was used to study the photosynthetic characteristics of P. edulis seedlings with nitrogen addition. The light response curve and CO2 response curve were measured under different short-term light radiation conditions (high light：1 200 μmol‧m-2‧s-1, low light：200 μmol‧m-2‧s-1). The results showed that the biomass of P. edulis seedlings treated with nitrogen addition was significantly higher than that of control, and PLmax, CE, Vcmax and Jmax were significantly higher than those of control. In addition, PCmax, CE, gm, Tp and CSP of P. edulis seedlings under high light level were significantly higher than those of low light level. What’s more, gm has no difference after nitrogen addition, but it reduced 60.31% while the decrease of short-term radiation. In conclusion, P. edulis seedlings with nitrogen treatment increased the quantity and activity of Rubisco protease in photosynthesis process, promoted photosynthetic phosphorylation and NADPH synthesis, and improved the reqeneration rate of RuBP through higher Vcmax and Jmax, in order to fully assimilate photosynthetic carbon, promote the high growth and biomass accumulation. Therefore, it could be inferred that the content and activity of Ribulose bisphosphate carboxylase oxygenase (Rubisco) and regeneration capacity of RuBP were the limiting factors of the photosynthesis rate, for the control P. edulis seedlings with no nitrogen. Light heterogeneity affect the photosynthetic physiological and biochemical changes inside the leaves of P. edulis, the decreased of light intensity effectively regulated the change of gm and Tp, indicating that the photosynthesis of P. edulis seedlings was mainly limited by gm and Tp. Nitrogen addition and the changes of short-term irradiance affected the photosynthesis and carbon acquisition of P. edulis seedlings, and also affected its growth and regeneration.
Subjects: Biology >> Botany >> Applied botany submitted time 2021-06-02 Cooperative journals: 《广西植物》
Abstract： Resurrection plants usually grow in extreme habitats and have the capacity to survive from lower relative water content to 10%. There are many resurrection plants in Gesneriaceae family, and the resuscitating mechanism of different species may be different. In order to investigate whether the two species have resurrection characteristics and their physiological mechanisms in response to drought, two species of Gesneriaceae, Paraboea rufescens and Oreocharis cordatula, which are distributed in subtropical and temperate limestone areas respectively, were selected in this study. Their leaves were dehydrated for 1, 2 and 3 d respectively, and then rehydrated for 1 day respectively. The leaf morphology, relative water content, photosynthetic activity, photosynthetic pigments, membrane integrity and osmotic adjustment substances during different dehydration and rehydration treatments were detected and analyzed. The results showed that the leaf discs of Paraboea rufescens folded inward after dehydration, and the leaf upper epidermis was completely wrapped after dehydrated for 2 days, and the chlorophyll fluorescence parameter Fv/Fm, which characterized the maximum photosynthetic potential, was inhibited. Comparatively, the leaf discs of Oreocharis cordatula shrunk slightly, and they maintained the Fv/Fm level, and had higher photoprotection ability [Y(NPQ)]. The leaf discs of both species spread out and Fv/Fm recovered following rewatered. After two days of dehydration, the relative water content (RWC) of the two species decreased to about 5%, the conductivity increased to 51.8% and 56.2%, respectively, and the content of soluble sugar content increased significantly. During the following rewatered, RWC, conductivity and soluble sugar all recovered to the control level. After further dehydration for 3 days, RWC of leaf discs of two species reached about 1.5%, the conductivity increased to about 95% after rehydration, and Fv/Fm disappeared. Chlorophyll a+b content of P. rufescens decreased by 50% during resuscitable dehydration and rehydration, while Oreocharis cordatula remained basically unchanged, which indicated that both of them were homoiochlorophyllous desiccation tolerance species and could quickly resume photosynthesis after rehydration following dehydration. During dehydration and rehydration, the contents of malonic dialdehyde (MDA) had no significant change, and remained extremely low level, which indicated two species could keep their membrane lipids from being oxidized under extreme drought conditions. To sum up, these two species can survive from dehydration to lower level of 5% RH, therefore they are both resurrection plants. Under severe dehydration，Paraboea rufescens can avoid the damage from excessive light absorption by curling its leaves; however, Oreocharis cordatula can spread the excessive energy by heat dissipation through photoprotection of PS II, thus protecting its photosynthesis organs.
Subjects: Biology >> Botany >> Applied botany submitted time 2021-06-02 Cooperative journals: 《广西植物》
Abstract： This study aims to explore potential new bacterial species and bioactive substances in mangrove plants, which can enrich the diversity of mangrove microorganisms and provide strain resources for the development of new active products. 22 samples were collected from three true mangrove plants of Kandelia candel, Bruguiera gymnorrhiza, Rhizophora stylosa, and their habitats, in Guangxi coastal area. Then 22 samples were divided according to different parts such as roots, stems, leaves, flowers, fruits and muds. Eight different culture mediums were used to isolate culturable bacteria, and 16S rRNA gene sequences were used to identify bacteria and analyze diversity. For cultured bacteria, the antibacterial and enzyme activities of fermented crude extracts were screened with Kirby-Bauer method and spot planting method, respectively. The results were as follows:（1）Based on sequencing results of 16S rRNA gene, a total of 35 culturable bacteria were isolated, belonging to 28 genera and 23 families. Bacillus accounted for 14.3% of the total bacteria, which was the dominant bacteria. Meanwhile, 11 potential new bacterial species were found. （2）Four strains of bacteria showed antibacterial activities, 16 strains had enzyme activities, and Bacillus was the dominant strain in enzyme activities. The above results showed that Guangxi true mangrove plants were rich in bacterial diversity, and some bacteria showed antibacterial activities and enzyme activities. The new bacterial species and active strain had certain development potential in the new antibiotics and enzymes application.
Subjects: Biology >> Botany >> Applied botany submitted time 2021-06-02 Cooperative journals: 《广西植物》
Abstract： Secondary coniferous and broad-leaved mixed forests is very common in subtropical regions. Studying the community succession characteristics and regeneration rules of the secondary coniferous and broad-leaved mixed forests will provide a scientific basis for vegetation restoration and forest management in this area. Using two datasets (2013 and 2018) from a permanent 1 hm2 secondary coniferous and broad-leaved mixed forest plot in DBS, we analyzed the dynamics changes of tree species composition, community species diversity, species important values, and size class structure and so on. The results were as follows: (1) Species richness and individual numbers were significantly reduced in the community during 2013-2018 (P<0.05); (2) In the plot, 1 505 individuals DBH≥1 cm died, with an average annual mortality rate of 6.40%, and 71 new individuals recruited, with an average annual recruitment rate of 0.35%; (3) The community species diversity indexes declined significantly (P<0.05), of which Margalef richness index changed greatly, decreased by 25.03%, and Shannon-Wiener index decreased by 11.88%; (4) The dominant position of evergreen broad-leaved tree species were strengthening, while coniferous tree species were gradually reduced; (5) During the five years, the proportion of large and medium size class plants gradually increased, while the proportion of small size class plants gradually decreased. In general, the species composition and structure dynamics of the secondary coniferous and broad-leaved mixed forest community in DBS changed significantly during 2013-2018. The community is in a rapid succession stage from secondary coniferous and broad-leaved mixed forest to evergreen broad-leaved forest.
Subjects: Biology >> Botany >> Applied botany submitted time 2021-06-02 Cooperative journals: 《广西植物》
Abstract： Guizhou Province is rich in ecological resources, and the establishment of a country is conducive to centralized and standardized management of ecological resources. Analyze the spatial distribution characteristics of national nature reserves in Guizhou Province, will help to screen out the advantageous landscape resource gathering areas for the selection of national parks, and provide reference for the establishment of a national park-based nature reserve system. With the help of ArcGis spatial analysis tool, we analyze the spatial distribution characteristics of 113 protected areas in 5 categories, and screens out the candidate areas of national park pilot and evaluates their resources. The results were as follows: (1) The national nature reserves in Guizhou Province are distributed in a cohesive way with a high degree of overlap, and eight national park pilot candidate areas are delimited by taking the reserve gathering area as the landscape advantage area. (2) Based on the analysis of the main representative resources of the gathering areas and the experts’scores, the concentration areas with the highest scores can be recommended as the national park pilot areas, the highest scores in Chishui-Xishui area could be selected as the national park experimental area. (3) The national representativeness, suitability, state-owned and social feasibility of Chishui-Xishui area resources can meet the basic principle of setting up national parks with priority to integrate overlapping protected areas, and its plant diversity conservation is of great value. The results of this study provide a new idea for the location of national parks and a reference for the conservation of plant diversity in national parks.
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