放牧对土壤理化性状及植被多样性的影响

放牧是家畜饲养方式之一,是草地最简单而又有效的利用方式,但放牧中的家畜家禽通过采食牧草、践踏土壤和牧草以及粪便排泄影响着草地植被和土壤,不同强度的放牧对地下土壤与地上植被的影响不同。本研究综述了近几年来放牧对地下部土壤有机质、氮、磷、钾、土壤容重、有机碳以及微生物多样性的影响,对植被多样性及草群成分的影响等,旨在为今后家畜放牧行为研究以及放牧科学研究提供理论依据。     

Mycoplasma pneumoniae induces IL-1β production through activating NLRP3 inflammasome by ROS in RAW264.7 cells

AIM: To investigate whether Mycoplasma pneumoniae (Mp)-induced interleukin-1β (IL-1β) production in RAW264.7 cells is through the activation of NLRP3 inflammasome via reactive oxygen species (ROS). ME-THODS: RAW264.7 cells were randomly divided into 3 groups. In normal group, RAW264.7 cells were treated without Mp. In model group, RAW264.7 cells were treated with 1∶ 10 multiplicity of infection (MOI) of Mp. In NAC group, RAW264.7 cells were pretreated with N- acetylcysteine (NAC) at a concentration of 5 mmol/L for 30 min before infection with Mp. The RAW264.7cells were infected with Mp (1∶ 10 MOI) for 4, 8, 16 and 24 h in model group and NAC group, respectively. The intracellular ROS level was analyzed by flow cytometry. The mRNA expressions of NLRP3, ASC and caspase-1 were detected by real-time PCR. The protein levels of NLRP3, ASC and caspase-1 p20 were determined by Western blot. The levels of pro-inflammatory cytokine IL-1β in the supernatant were measured by ELISA. RESULTS: Compared with normal group, the production of ROS were significantly increased at 4, 8, 16 and 24 h after infection, the mRNA expression of NLRP3, ASC and caspase-1 were increased at 8, 16 and 24 h after infection, the protein levels of NLRP3, ASC and caspase-1 p20 were increased at 16 and 24 h after infection, and the releases of IL-1β were increased at 24 h after infection in model group (P<0.01). Compared with the model group, the level of ROS in NAC group decreased, so as the expression of NLRP3, ASC and caspase-1 at mRNA and protein levels and the releases of IL-1β in the supernatant at the corresponding time points. CONCLUSION: Mp may stimulate the ROS production to activate NLRP3 inflammasome in RAW264.7 cells.     

Asterosaponins: Structures,Taxonomic Distribution,Biogenesis and Biological Activities

Asterosaponins are a class of steroid oligoglycosides isolated from starfish with characteristic structures and diverse biological activities. In this review, we have attempted to combine the most important data concerning asterosaponins and give a list of these secondary metabolites with their structural peculiarities. The purpose of this review is to provide a brief but as complete as possible principal information about their chemical structures, taxonomic distribution in the marine environment, distribution in different geographical areas and depths, some properties, biological activities, and functions. Some other rare steroid metabolites from starfish, closely related in structures and probably biogenesis to asterosaponins, are also discussed.     

极小种群野生植物八蕊单室茱萸的种群状况研究

八蕊单室茱萸为云南省特有的极小种群野生植物和濒危物种。通过查阅相关文献并结合访问调查,确定八蕊单室茱萸可能分布的区域,开展种群资源调查。结果显示:八蕊单室茱萸目前仅在普洱市和西双版纳州有10个天然种群,其种群规模已低于最小可存活种群,属极小种群野生植物和濒危物种,亟需开展保护工作。生境破坏和生境片段化是导致八蕊单室茱单室茱萸濒危的人为因素。提出收集种质资源、营建和管护近地保护种群、建立迁地和回归种群等保育建议。     

Cultivar Specific Response of CO2 Fertilization on Two Tropical Mung Bean (Vigna radiata L.) Cultivars: ROS Generation,Antioxidant Status,Physiology, Growth,Yield and Seed Quality

Increasing atmospheric carbon dioxide concentration (CO₂) is an important component of global climate change that will have a significant impact on the productivity of crop plants. In recent years, growth and yield of agricultural crop plants have been shown to increase with elevated CO₂ (EC) and have enticed considerable interest due to variation in the response of crop plants. In this study, comparative response of two mung bean cultivars (HUM‐2 and HUM‐6) was evaluated against EC at different growth stages under near‐natural conditions for two consecutive years. The plants were grown in ambient as well as EC (700 ppm) in specially designed open‐top chambers. Under elevated CO₂, marked down‐regulation of reactive oxygen species (ROS) levels, membrane disruption and activities of superoxide dismutase and catalase were noticed in both the cultivars, but the extent of reduction was more in HUM‐6. As compared to ambient CO₂, EC increased total chlorophyll, photosynthetic rate, growth and yield parameters. Cultivar‐specific response was noticed as HUM‐6 showed higher increase in yield attributes than HUM‐2. Under CO₂ treatment, soluble protein and reducing sugars decreased while total soluble sugars and starch showed an opposite trend. Principal component analysis showed that both the cultivars responded more or less similarly to EC in their respective groupings of physiological and growth parameters, but the magnitude of ROS and antioxidative enzymes was variable. The experimental findings depict that both the cultivars of mung bean showed contrasting response against EC and paved the way for selecting the suitable cultivar having higher productivity in a future high‐CO₂ environment.     

灰霉菌侵染对番茄幼苗活性氧积累及抗氧化酶活性的影响

为进一步分析活性氧和抗氧化防御系统在番茄抗病信号调控机制中的作用,为提高产量和品质提供科学依据,以4叶1心的番茄幼苗为试验材料,比较番茄幼苗受灰霉菌侵染后叶片O_2~-·以及抗氧化酶、内源褪黑素等的变化。结果表明:番茄幼苗接种灰霉菌后,随着时间的延长,幼苗叶片上病斑斑点逐渐增多,灰霉菌含量显著增多,叶色逐渐变浅,植株表现明显的发病症状;灰霉病菌侵染后番茄体内O_2~-·活性爆发,超氧化物歧化酶(SOD)和过氧化物酶(POD)活性下降,过氧化氢酶(CAT)和谷胱甘肽还原酶(GR)活性上升,褪黑素含量增加;上述变化都是番茄幼苗为了抵御灰霉菌的生物胁迫而发生的应激反应。综上,植物在遭受病原菌等生物胁迫时不能简单地推断SOD、CAT和POD等抗氧化酶活性一定升高,植物抵御病原菌侵染更多地依赖于抗性信号路径中信号物质的激活和积累。     

海南被子植物分布新资料(Ⅱ)

报道了海南岛被子植物5个新记录种。新记录种分别为三室黄麻(Corchorus trilocularis L.)、钻叶紫菀(Symphyotrichum subulatum(Michx.)G.L.Nesom)、光果姜(Zingiber nudicarpum D.Fang)、线纹香茶菜(Isodon lophanthoides(Buch.-Ham.ex D.Don)H.Hara)、狭序泡花树(Meliosma paupera Hand.-Mazz.)。凭证标本保存于中国热带农业科学院植物标本室(ATCH)。     

新式墙面绿化在广州和深圳的应用研究

新式墙面绿化对日益缩减的城市绿化环境至关重要,通过实地调查广州和深圳30个新式墙面绿化场所,分析其种植形式、植物种类、植物配置与景观效果,总结出深圳和广州新式墙面绿化的植物应用现状和景观效果,并讨论其发展前景。     

抚育间伐对燕山北部山区山杨林物种多样性的影响

为了了解抚育间伐对燕山北部山区山杨林物种多样性的影响,对山杨林抚育间伐前后的物种多样性进行了调查和分析,结果表明:抚育后林地草本植物的物种多样性高于未抚育林地,抚育间伐林地草本植物的Patrick指数、Margarlef指数、Simpson指数和Shannon-Wiener指数分别为35.0、6.13、0.89和2.76,未抚育样地分别为29.0、4.90、0.32和1.91;抚育林地灌木的Patrick指数、Margarlef指数、Simpson指数和Shannon-Wiener指数分别为9.0、1.41、0.43和0.98,未抚育林地则分别为8.0、1.48、0.68和1.51,除Patrick指数外,抚育林地的其他多样性指数都低于未抚育林地;抚育间伐使乔木层优势种的优势更为明显。由此得出结论,抚育间伐对山杨林的物种多样性有明显影响,但草本、灌木与乔木对抚育间伐的响应有所不同。     

Lactation-related mammary gland pathologies—A neglected emergency in the bitch

Mastitis is a common reproductive disorder in bitches, reaching a prevalence of 0.71%. Mastitis has a wide range of forms, from asymptomatic to severe gangrenous mastitis that can lead to septic shock and death of the bitch and nurslings. However, most of the time it is overlooked, undiagnosed or mistreated. The present systematic review was performed to revise and summarize the existing knowledge related to this disorder, including diagnosis, treatment and prevention.