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1.
镰形棘豆的一个新变型——白花镰形棘豆   总被引:2,自引:2,他引:0  
描述了豆科棘豆属镰形棘豆(Oxytropis falcata Bunge)的一个新变型:白花镰形棘豆(Oxytropis falcataBunge form.atbiflora Y.H.Wu).原变型的花冠为蓝紫色或紫红色,而新变型花冠为白色.  相似文献   

2.
采用硅胶柱层析、Sephadex LH-20和半制备HPLC等色谱手段对草原毒草黄花棘豆(Oxytropis ochrocephala Bunge)生物碱成分进行分离纯化,从全草提取物中分离得到8个生物碱成分。利用MS、1H NMR和13C NMR波谱技术鉴定化合物结构为槐定碱(1)、槐胺(2)、异槐定碱(3)、苦参碱(4)、7,11-去氢苦参碱(5)、槐果碱(6)、羽扇豆碱(7)和苦马豆素(8)。化合物1~6为首次从棘豆属植物中分离得到。  相似文献   

3.
新疆棘豆属棘豆组的修订   总被引:1,自引:0,他引:1  
通过对大量标本和文献的研究,并结合野外居群的观察分析,澄清了《中国植物志》棘豆组中存在的分类学问题,对新疆棘豆属棘豆组植物的分类进行修订,确认产于新疆的棘豆属棘豆组植物8种、1变型,并重新编制了新疆棘豆属棘豆组的分种检索表,以及各种的分类学处理及地理分布.研究结果表明:少花棘豆归并在宽瓣棘豆中,其中少花棘豆为新异名;冰河棘豆应改为球花棘豆;冰川棘豆的学名更正为Oxytropis proboscidea;将黑萼棘豆并入长茎棘豆组中.此外,棘豆组增加了3个类群:等瓣棘豆、伊朗棘豆和奇台棘豆,其中等瓣棘豆和伊朗棘豆为新疆新记录种,白花球花棘豆为新变型.  相似文献   

4.
作者对窄膜棘豆(Oxytropis moellendorffii Bunge)的分类学处理提出了新的观点:通过对原产地标本、资料的研究,认为五台山棘豆(O. wutaiensis Tatewakiet Hurusawa)实际上是窄膜棘豆(O. moellendorffii Bunge),对其变种(O. wutaiensis Tatew akiet Hurusaw a var. glabrata Tatewaki et Hurusawa)也进行了归并;另外本文中发表一个新等级--西灵山棘豆(O. moellendorffii Bunge var. sylinchanensis(Franch.)G.Z.Qian)。  相似文献   

5.
极密垫状矮灌木,分枝极多。叶柄硬化成刺;托叶与叶柄贴生。单花腋生;花萼二唇形;花冠紫色;龙骨瓣先端钝,无喙。荚果硬革质,长圆形,腹隔膜极窄,近一室。本亚属与胶黄芪状棘豆亚属Subgen.Traganthoxytropis Vass.相似,但单花,花萼二唇形和龙骨瓣无喙可与之区别。本亚属的模式种:刺垫棘豆Oxytropis grubovii Ulzij. 本亚属仅1组1种。分布于蒙古人民共和国(东戈壁和阿拉善戈壁)和中国(内蒙古巴音浩特)。根据刺垫棘豆Oxytropis grubovii Ulzij.的特征,我们同意N.Ulziykhutag的意  相似文献   

6.
宁夏豆科2种新记录植物   总被引:2,自引:2,他引:0  
报道了宁夏豆科2种新记录植物,高山豆(Tibetia himalaica(Baker)Tsui)和兴隆山棘豆(Oxytropis xin-glongshanica C.W.Chang).  相似文献   

7.
对6种棘豆属植物(Oxytropis)的13个居群样进行细胞学研究,其中黄花棘豆(O.ochrocephala)、绢毛棘豆(O.tatarica)、甘肃棘豆(O.kansuensis)和铺地棘豆(0.humifusa)为首次报道染色体数目(2n=16)和核型;在胀果棘豆(O.stracheyana)中(2n=48)首次发现B染色体。现有的细胞学资料表明:棘豆属植物中多倍体占总报道数的58%,这说明多倍化在本属植物的进化过程中起着非常重要的作用,但青藏高原仅有一种植物发现多倍体,多倍化并不占主导地位,而主要表现为二倍体水平上的结构变异,即核型不对称性的变化。  相似文献   

8.
报道了中国棘豆属二新记录种——黄绿花棘豆和丛棘豆。黄绿花棘豆主要分布于蒙古国,丛棘豆主要分布于蒙古国和俄罗斯,在中国为首次记录。文中凭证标本存放于内蒙古大学植物标本馆(HIMC)。  相似文献   

9.
刺叶柄棘豆的一个新变型--白花刺叶柄棘豆   总被引:5,自引:5,他引:0  
描述了棘豆属(豆科)刺叶柄棘豆(Oxytropis acipblla Ledeb.)的一个新变型:白花刺叶柄棘豆O.aciphylla Ledeb.f.albiflora Z.Y.Chang,Z.H.Wu et L.R.Xu。原变型的花冠为红紫色或蓝紫色,而新变型的花冠为白色。  相似文献   

10.
对12种34个地理种群的内蒙古棘豆属植物核糖体ITS区段和5.8S基因序列进行比较分析,并采用Maximum Likelihood法构建系统发育树.结果表明:支持棘豆属植物为单系起源,支持《内蒙古植物志》将黄毛棘豆(Oxytropis ochrantha)、多叶棘豆(O.verticillaris)、二色棘豆(O.bicolor)和砂珍棘豆(O.racemosa)归入真棘豆亚属(Subgen.Euoxytropis)轮叶棘豆组(Sect.Baicalia Stell.ex Bunge)的观点.推测多叶棘豆和砂珍棘豆ITS2区段出现的C/T转换可能是其部分种群混杂在其他物种中的主要原因,但基因转换对于系统发育的影响仍尚未可知.研究不支持传统分类学上对鳞萼棘豆(O.squammulosa)与刺叶柄棘豆(O.aci ph ylla)的划分,系统发育树显示二者聚为一支,而非与传统分类学上界定的同组或同亚属植物形成一支;结合植物地理学研究结果,认为刺叶柄棘豆与鳞萼棘豆为地理替代种.推测刺叶柄棘豆可能为多系起源物种.线叶棘豆(O.fili formis)和东北棘豆(O.coerulea与真棘豆亚属物种构成姐妹群,而非单室棘豆亚属植物.研究认为在物种界定过程中,只将少数几个形态学特征作为主要分类依据欠妥.  相似文献   

11.
海蛎是一种营养和医药价值较高的咸水双壳类动物,在世界各地被广泛养殖。海蛎壳副产品是一种天然生物质资源,由95%的碳酸钙和5%的有机基质组成。海蛎壳的多尺度、多层次“砖-泥”独特结构,使其具有良好的机械稳定性、生物相容性、可降解性和优异的吸附特性。首先,介绍了海蛎壳生物质的理化性质和天然独特微纳米结构,总结了海蛎壳在农业、工业、生物医药领域的研究现状,详细阐述了其在污水治理、土壤改良、天然抗菌剂(食品工业和生物医药)、骨组织工程、医药原料、生物填料、工业催化剂及分散载体、建筑工业填料、功能化涂料等领域的研究现状。其次,概述了利用生物转化技术将海蛎壳转化为生物能源、新型生物质材料等方面的研究进展。最后,展望了海蛎壳生物质资源及其衍生物未来在工业、农业、医药领域的潜在应用。  相似文献   

12.
随着智能手机和人工智能技术的发展, 以手机app为载体的植物识别软件慢慢走进公众生活、科普活动和科研活动的各个方面。植物识别app的识别正确率是决定其使用价值和用户体验的关键因素。目前, 国内应用市场上有许多植物识别app, 它们的开发目的和应用范围各异, 软件本身的关注点、数据库来源、算法、硬件要求也存在很大差异。对于不同人群, 植物识别app有不同的意义, 如对于科研人员来说, 识别能力强的app是提高效率的一大工具; 对植物爱好者来说, 具一定准确率的识别app可以作为入门的工具。因此, 对各app的识别能力进行分析与评价显得尤为重要。本文选取了8款常用的app, 分别对400张已准确鉴定的植物图片进行识别, 其中干旱半干旱区、温带、热带和亚热带4个区各选取100张。这些图片共计122科164属340种, 涵盖了乔木、灌木、草本、草质藤本和木质藤本5种生长型, 包含23种国家级保护植物。种、属、科准确识别正确分别计4分、2分、1分, 以此标准对软件识别能力按总得分进行排序, 正确率得分由高到低依次为花帮主、百度识图、花伴侣、形色、花卉识别、植物识别、发现识花、微软识花。  相似文献   

13.
中国昆虫染色体研究现状与展望   总被引:13,自引:1,他引:12  
简要叙述了中国昆虫染色体研究的现状,包括研究涉及的昆虫类群、核型分析结果、研究方法和手段、染色体有丝分裂、减数分裂、染色体形态变异、结构变异和数量变异等。我国学者对昆虫染色体研究从20世纪30年代开始,迄今已对蜉蝣目、蜚蠊目、直翅目、半翅目、同翅目、鞘翅目、鳞翅目、双翅目、蚤目和膜翅目等10目481种昆虫的核型进行了研究,主要集中在蝗虫、蝽类、蚜虫、蚕类、果蝇、摇蚊及实蝇等。在染色体行为方面的研究主要有:蚕类和果蝇等有丝分裂;蜚蠊类、蝗类、蝽类和蚕类的减数分裂及性别决定机制;部分昆虫的联会复合体分析。染色体结构变异的研究主要集中在果蝇和蚊类昆虫的唾腺染色体;果蝇的B染色体;蚕类和蚊类昆虫染色体的缺失、易位和倒位等变异;蚕蛾类的数量变异。研究结果多应用于昆虫系统分类和进化的探讨,揭示昆虫遗传与变异规律。通过与国外研究成果对比,提出昆虫染色体研究的必要性,并对我国未来昆虫染色体研究进行了展望。  相似文献   

14.
Mental disorders frequently begin in childhood or adolescence. Psychotropic medications have various indications for the treatment of mental dis­orders in this age group and are used not infrequently off‐label. However, the adverse effects of these medications require special attention during developmentally sensitive periods of life. For this meta‐review, we systematically searched network meta‐analyses and meta‐analyses of randomized controlled trials (RCTs), individual RCTs, and cohort studies reporting on 78 a priori selected adverse events across 19 categories of 80 psychotropic medications – including antidepressants, antipsychotics, anti‐attention‐deficit/hyperactivity disorder (ADHD) medications and mood stabilizers – in children and adolescents with mental disorders. We included data from nine network meta‐analyses, 39 meta‐analyses, 90 individual RCTs, and eight cohort studies, including 337,686 children and adolescents. Data on ≥20% of the 78 adverse events were available for six antidepressants (sertraline, escitalopram, paroxetine, fluoxetine, venlafaxine and vilazodone), eight antipsychotics (risperidone, quetiapine, aripiprazole, lurasidone, paliperidone, ziprasidone, olanzapine and asenapine), three anti‐ADHD medications (methylphenidate, atomoxetine and guanfacine), and two mood stabilizers (valproate and lithium). Among these medications with data on ≥20% of the 78 adverse events, a safer profile emerged for escitalopram and fluoxetine among antidepressants, lurasidone for antipsychotics, methylphenidate among anti‐ADHD medications, and lithium among mood stabilizers. The available literature raised most concerns about the safety of venlafaxine, olanzapine, atomoxetine, guanfacine and valproate. Nausea/vomiting and discontinuation due to adverse event were most frequently associated with antidepressants; sedation, extrapyramidal side effects, and weight gain with antipsychotics; anorexia and insomnia with anti‐ADHD medications; sedation and weight gain with mood stabilizers. The results of this comprehensive and updated quantitative systematic meta‐review of top‐tier evidence regarding the safety of antidepressants, antipsychotics, anti‐ADHD medications and mood stabilizers in children and adolescents can inform clinical practice, research and treatment guidelines.  相似文献   

15.
Extracellular (EC) adenosine, hypoxanthine, xanthine, and inosine concentrations were monitored in vivo in the striatum during steady state, 15 min of complete brain ischemia, and 4 h of reflow and compared with purine and nucleotide levels in the tissue. Ischemia was induced by three-vessel occlusion combined with hypotension (50 mm Hg) in male Sprague-Dawley rats. EC purines were sampled by microdialysis, and tissue adenine nucleotides and purine catabolites were extracted from the in situ frozen brain at the end of the experiment. ATP, ADP, and AMP were analyzed with enzymatic fluorometric techniques, and adenosine, hypoxanthine, xanthine, and inosine with a modified HPLC system. Ischemia depleted tissue ATP, whereas AMP, adenosine, hypoxanthine, and inosine accumulated. In parallel, adenosine, hypoxanthine, and inosine levels increased in the EC compartment. Adenosine reached an EC concentration of 40 microM after 15 min of ischemia. Levels of tissue nucleotides and purines normalized on reflow. However, xanthine levels increased transiently (sevenfold). In the EC compartment, adenosine, inosine, and hypoxanthine contents normalized slowly on reflow, whereas the xanthine content increased. The high EC levels of adenosine during ischemia may turn off spontaneous neuronal firing, counteract excitotoxicity, and inhibit ischemic calcium uptake, thereby exerting neuroprotective effects.  相似文献   

16.
This study describes a method for predicting and classifying oxygen-binding pro- teins. Firstly, support vector machine (SVM) modules were developed using amino acid composition and dipeptide composition for predicting oxygen-binding pro- teins, and achieved maximum accuracy of 85.5% and 87.8%, respectively. Sec- ondly, an SVM module was developed based on amino acid composition, classify- ing the predicted oxygen-binding proteins into six classes with accuracy of 95.8%, 97.5%, 97.5%, 96.9%, 99.4%, and 96.0% for erythrocruorin, hemerythrin, hemo- cyanin, hemoglobin, leghemoglobin, and myoglobin proteins, respectively. Finally, an SVM module was developed using dipeptide composition for classifying the oxygen-binding proteins, and achieved maximum accuracy of 96.1%, 98.7%, 98.7%, 85.6%, 99.6%, and 93.3% for the above six classes, respectively. All modules were trained and tested by five-fold cross validation. Based on the above approach, a web server Oxypred was developed for predicting and classifying oxygen-binding proteins(available from http://www.imtech.res.in/raghava/oxypred/).  相似文献   

17.
Allenic and cumulenic lipids   总被引:1,自引:0,他引:1  
Nowadays, about 200 natural allenic metabolites, more than 2700 synthetic allenic compounds, and about 1300 cumulenic structures are known. The present review describes research on natural as well as some biological active allenic and cumulenic lipids and related compounds isolated from different sources. Intensive searches for new classes of pharmacologically potent agents produced by living organisms have resulted in the discovery of dozens of such compounds possessing high anticancer, cytotoxic, antibacterial, antiviral, and other activities. Known allenic and cumulenic compounds can be subdivided on several structural classes: fatty acids, hydrocarbons, terpenes, steroids, carotenoids, marine bromoallenes, peptides, aromatic, cumulenic, and miscellaneous compounds. This review emphasizes the role of natural and synthetic allenic and cumulenic lipids and other related compounds as an important source of leads for drug discovery.  相似文献   

18.
At one spectrum extreme, Astrobiology conjectures that for exoplanets with Goldilocks conditions, terrestrial-like life is inevitable. Moreover, it is envisaged that via panspermia, terrestrial-like life and its precursors are transferred among galaxies, stars, and within solar systems via transiting comets, asteroids, and planetoids. In addition, expelled stars, which have solar systems, it is inferred, transfer life as well. However, at the other extreme, we propose a paradigm shift that on some planets, subject to non- Goldilocks conditions, metal machine life could arise, ab initio, and evolve viruses, intelligence, and civilizations, conjointly. Accordingly, intelligent mechanized civilizations could readily and efficiently commence space exploration. Furthermore, as a counter paradigm shift, such civilizations could experiment and produce non-metallic life, based on carbon and other non-metal elements, under suitable conditions, related to Goldilocks life. Even a single example of validated interstellar or intergalactic communication received on the Earth would support the existence of life elsewhere. However, the communication platform should not be restricted to electromagnetic radiation. Other platforms should be included as well - one such example, which would require sophisticated technology, is neutrino communication. This is the case for any advanced civilization, be it metal-machine based, biological-based, and carbon-based. In sum, civilizations based on machine life, would be highly productive due to the longevity and hardiness of machine life. However, significant caveats are raised in this brief report, because possibly dissimilar psychologies and intelligence may lead to conflicts between metal machine life and biological life, inter-paradigm conflict.  相似文献   

19.
Summary This review is given on the origin and interrelationship of blackgram and greengram: the symptoms, mode of transmission, and host range of important diseases, namely: mungbean yellow mosaic virus, leaf crinkle virus, leaf curl virus, mosaic mottle virus, Cercospora leaf spot, powdery mildew, root and stem rots, bacterial leaf spot and halo blight. The screening for resistance, sources of resistance, including interspecific hybridization, and induced mutations, as well as the genetics of resistance are treated along with suggestions for future breeding strategies of these crops.Greengram is relatively drought tolerant. It is cultivated in India, Pakistan, Bangladesh, Srilanka, Thailand, Laos, Kampuchea, Vietnam, eastern Malaysia, Southern China and in the relatively dry eastern parts of Java, (Jain and Mehra 1978). In the recent past it has been introduced into the eastern and central parts of Africa, the West Indies and the U.S.A. It is also grown in the Philippines, Nepal, Taiwan and Indonesia. Blackgram has greater water requirements than greengram. It is grown in India, Pakistan, Srilanka and Burma (Jain and Mehra 1978).  相似文献   

20.
We review current knowledge of the most abundant sugars, sucrose, maltose, glucose and fructose, in the world's major crop plants. The sucrose‐accumulating crops, sugar beet and sugar cane, are included, but the main focus of the review is potato and the major cereal crops. The production of sucrose in photosynthesis and the inter‐relationships of sucrose, glucose, fructose and other metabolites in primary carbon metabolism are described, as well as the synthesis of starch, fructan and cell wall polysaccharides and the breakdown of starch to produce maltose. The importance of sugars as hormone‐like signalling molecules is discussed, including the role of another sugar, trehalose, and the trehalose biosynthetic pathway. The Maillard reaction, which occurs between reducing sugars and amino acids during thermal processing, is described because of its importance for colour and flavour in cooked foods. This reaction also leads to the formation of potentially harmful compounds, such as acrylamide, and is attracting increasing attention as food producers and regulators seek to reduce the levels of acrylamide in cooked food. Genetic and environmental factors affecting sugar concentrations are described.  相似文献   

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