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71.
为了解金沙江上游奔子栏到羊拉约130 km河段范围内干旱河谷的植被特征, 作者采用样带与典型样方相结合的方法, 对该河段进行了植物群落调查。结果显示: (1)研究区域记录到野生维管植物51科95属111种(含种下等级), 其中, 蕨类植物4科4属6种; 无裸子植物; 被子植物中双子叶植物40科71属84种; 单子叶植物7科20属21种。(2)群落物种以草本为主, 达67种, 占总物种数的60.36%; 生活型以地面芽植物为主, 占总物种数的32.43%, 矮高位芽次之, 占27.93%; 叶型以微型和小型叶为主, 微型叶有30种, 占统计总数(50种)的60%, 小型叶有11种, 占总数的22%。(3)用双向指示种分析方法可将93个样方分为5个群系。分布最广、物种丰富度最高的是小叶荆 + 小叶野丁香(Form. Vitex microphylla + Leptodermis pilosa var. microphylla)群系。(4)根据对该河谷区域的气候特点、干旱程度、植被特征(植株矮化、叶片小、植物毛被发达、植株具刺、部分植物有吸湿反应性特征等)的分析, 综合植物群落的外貌、结构、物种构成和植物形态, 可以确认金沙江上游干旱河谷植被具有亚热带荒漠植被类型的 特征。  相似文献   
72.
何月秋  池树友  杜永均 《昆虫学报》2015,58(10):1081-1090
【目的】研究旨在深入探讨中国黄杨绢野Diaphania perspectalis 的雌蛾性信息素组成及诱蛾活性。【方法】利用气质联用仪(GC-MS)对黄杨绢野螟正常型性成熟雌蛾的性腺体提取物和合成标样比较分析,并用反-11-十六碳烯醛(E11-16:Ald) 、顺-11-十六碳烯醛(Z-11-16:Ald)、顺-9-十六碳烯醛(Z-9-16:Ald)、顺-11-十六碳烯醇(Z-11-16:OH)等物质进行触角的电生理测定,最后开展田间诱集比较试验以筛选出最佳性信息素混合物。【结果】Z-11-16:Ald为中国黄杨绢野螟正常型性信息素主要组分,E-11-16:Ald的含量极低,Z-11-16:OH未检测到。正常型雄性黄杨绢野螟触角对Z-11-16:Ald, E-11-16:Ald, Z-9-16:Ald和Z-11-16:OH产生强烈的EAG反应,并随着浓度的提高而显著增加;而对Z-11-16:Ac和E-11-16:Ac的嗅觉反应较弱,低于对植物绿叶气味顺3-己烯乙酸酯(Z-3-6:Ac)的反应。单一Z-1-16:Ald对正常型雄性黄杨绢野螟具有强烈的诱集效果,加入E-11-16:Ald有一定的增效作用,但在统计上则不显著。单一Z-11-16:Ald组分对黑化型雄性黄杨绢野螟无引诱活性,必需加入一定比例的E-11-16:Ald才显示诱蛾活性。Z-11-16:Ald:E-11-16:Ald的比例为250 μg:250 μg时诱集到的黑化型雄性黄杨绢野螟数量最多,而Z-11-16:Ald:E-11-16:Ald的比例为429 μg:71 μg时则诱集到的正常型雄性黄杨绢野螟数量最多。同时,单一Z-11-16:Ald也可引诱大量雄性粘虫Mythimna separata,但E-11-16:Ald抑制其活性。【结论】中国黄杨绢野螟的性信息素主成分是Z-11-16:Ald,单一组分即可在田间强烈引诱雄蛾,E-11-16:Ald的功能只起到微弱的增效作用,但也可能起种的专一性的作用。正常型与黑化型黄杨绢野螟对性信息素的嗅觉反应存在差异,黑化型黄杨绢野螟的性信息素接近日本种,即性信息素组成为Z-11-16:Ald和E-11-16:Ald 的混合物,其比例为1:1,且E-11-16:Ald为必需。  相似文献   
73.
The genus Triptilion is endemic to central Chile, the Mendoza Province and western Patagonia in Argentina. It is currently composed of seven species: T. achilleae, T. benaventii, T. berteroi, T. capillatum, T. cordifolium, T. gibbosum, and T. spinosum. The main objectives of this paper were to determine the phylogenetic relationships of species of Triptilion. We also traced the evolution of annual and perennial life-forms. Historically a close relationship has been described between genera Triptilion and Nassauvia. Phylogenetic analysis of the genus Triptilion and more closely related genera was undertaken using two nuclear (ITS, ETS) and two chloroplast (trnL-F, rpl32-trnL) markers. The topology of the Bayesian inference tree shows that the genus Triptilion is paraphyletic, because Nassauvia lagascae, the only representative of Nassauvia section Caloptilium grouped with T. achilleae, Clade I. The other species of Triptilion form two clades: Clade II composed of T. cordifolium and T. gibbosum and Clade III that includes T. benaventii, T. berteroi, T. capillatum, and T. spinosum. The genus Triptilion originated and diverged during the Miocene. The results of the life history reconstructions indicate that the common ancestor of Triptilion and Nassauvia was perennial. The annual habit appears to be derived in Triptilion. The life-form of the common ancestor of Triptilion was ambiguous; it may have been annual or perennial.  相似文献   
74.
Acetylcholinesterase (AChE) is an important enzyme responsible for Alzheimer’s disease, as per report, keto-enol form of curcumin inhibits this enzyme. The present study aims to understand the binding mechanism of keto-enol curcumin with the recombinant human Acetylcholinesterase (rhAChE) from its conformational flexibility, intermolecular interactions, charge density distribution, and the electrostatic properties at the active site of rhAChE. To accomplish this, a molecular docking analysis of curcumin with the rhAChE was performed, which gives the structure and conformation of curcumin in the active site of rhAChE. Further, the charge density distribution and the electrostatic properties of curcumin molecule (lifted from the active site of rhAChE) were determined from the high level density functional theory (DFT) calculations coupled with the charge density analysis. On the other hand, the curcumin molecule was optimized (gas phase) using DFT method and further, the structure and charge density analysis were also carried out. On comparing the conformation, charge density distribution and the electrostatic potential of the active site form of curcumin with the corresponding gas phase form reveals that the above said properties are significantly altered when curcumin is present in the active site of rhAChE. The conformational stability and the interaction of curcumin in the active site are also studied using molecular dynamics simulation, which shows a large variation in the conformational geometry of curcumin as well as the intermolecular interactions.  相似文献   
75.
The paper reconstructs the history of the problem of mental development using material from children’s play. This study shows how researchers in the school of cultural-historical psychology identified the developmental function of play, established a qualitative leap in its development and attempted to re-create it, beginning with the works of L.S. Vygotsky, then of his followers (the activity-based approach in the interpretation of narrative role-playing: A.N. Leontiev, D.B. Elkonin, N.Ia. Mikhailenko, N.A. Korotkova, etc.), and, finally, of the researchers who studied a specific act of development in play (L.I. El’koninova, T.V. Bazhanova, K.O. Iur’eva). This research presents the view that the concept of the cultural form of play, containing a Challenge (defined by the boundaries of the possibilities of action and by risk) and the subsequent Response is the basis not only of narrative role-playing but also of games with rules, as well as computer games. The Challenge entails action that changes the action situation; it typifies all forms of play, which are supposed to tie together what is disjointed in a child’s daily life into a semantic knot.  相似文献   
76.
77.
Aims To clarify whether variation in leaf traits with climate differs with scale, i.e. across species and within a species, and to detect whether plant functional group affects species-specific response.Methods Leaf dry matter content (LDMC), specific leaf area (SLA), mass- and area-based leaf N (N mass, N area) and leaf P concentrations (P mass, P area) and leaf chlorophyll concentration (SPAD) were measured for 92 woody plant species in two botanical gardens in China. The two gardens share plant species in common but differ in climate. Leaf trait variation between the two gardens was examined via mean comparison at three scales: all species together, species grouped into plant functional groups and within a species. A meta-analysis was performed to summarize the species-specific responses.Important findings At the scale of all species together, LDMC, SLA, P mass and N mass were significantly lower in the dry-cold habitat than in the wet-warm one, whereas N area and SPAD showed an inverse pattern, indicating a significant environmental effect. The meta-analysis showed that the above-mentioned patterns persisted for SLA, N area and SPAD but not for the other variables at the species-specific scale, indicating that intraspecific variation affects the overall pattern of LDMC, P mass and N mass and P area. In terms of species-specific response, positive, negative or nonsignificant patterns were observed among the 92 species. Contrary to our prediction, species-specific responses within a functional group were not statistically more similar than those among functional groups. Our results indicated that leaf trait variation captured climatic difference yet species-specific responses were quite diverse irrespective of plant functional group, providing new insights for interpreting trait variability with climate.  相似文献   
78.
正昆仑针茅(Stipa roborowskyi)是青藏高原特有的寒旱生多年生密丛型禾草,广泛分布于藏南喜马拉雅山北坡和雅鲁藏布江谷地、阿里地区、羌塘高原中南部和昆仑山地,以及印度和克什米尔地区(Wu et al.,2006;中国科学院中国植被图编辑委员会,2007)。昆仑针茅草原是西藏重要的草原类型之一,但分布较为零散,没有像紫花针茅(S.purpurea)草  相似文献   
79.
竹亚科刚竹属植物新资料   总被引:2,自引:0,他引:2  
描述了竹亚科Bambusoideae刚竹属Phyllostachys Sieb. et Zucc.的2个新种和5个新变型:瓜竹Ph. longiciliata、浙江甜竹Ph. zhejiangensis、黄槽黄古竹Ph. angusta f. flavosulcata、绿槽人面竹Ph. aurea f. koi、蝶毛竹 Ph. edulis f. abbreviata、黄条燥壳竹Ph. hirtivagina f. flavovittata和花竹Ph. nidularia f. basipilis;作出3个新组合变型:厚皮毛竹Ph. edulis f. pachyloen、安吉锦毛竹Ph. edulis f. anjiensis和花秆早竹Ph. violascens f. viridisulcata;对金条竹Ph. aureosulcata f. flavostriata、对花竹Ph. bambusoides f. duihuazhu、黄槽斑竹Ph. bambusoides f. mixta和黄皮毛竹Ph. edulis f. holochrysa的模式标本给予了重新指定。  相似文献   
80.
为了明确褐飞虱Nilaparvata lugens、 白背飞虱Sogatella furcifera和灰飞虱Laodelphax striatellus 3种稻飞虱翅型分化的遗传规律与差异, 采用翅型筛选与杂交遗传的实验方法, 研究了3种飞虱在秧苗期水稻上的翅型选择响应与杂交遗传规律。结果表明: 3种稻飞虱的翅型具有较强的选择响应, 并且长翅型纯系在白背飞虱中最易筛选得到, 灰飞虱的次之, 而褐飞虱的最难。3种稻飞虱的长翅(M)雄虫与短翅(B)雌虫配对(M♂×B♀)筛选3~5代后, 95%~100%的雄虫和雌虫分别稳定为长翅型和短翅型。筛选和杂交实验结果表明, 褐飞虱的翅型决定基本符合常染色体上的一对等位基因调控的从性性状遗传规律, 雄虫中长翅为显性, 而雌虫中短翅为显性。翅型的表型还受除基因型外的其他条件的影响, 利用长翅雄虫与长翅雌虫后代中出现的极少数的短翅雄虫与短翅雌虫进行配对, 其后代中各翅型出现的比率与长翅雌虫和长翅雄虫配对的无显著差异; 同样, 在短翅雄虫与短翅雌虫配对的后代中也有相同的结果。白背飞虱和灰飞虱在该筛选条件下很少有短翅雄虫出现, 两者翅型的遗传调控较为相似, 可用由两对等位基因控制的性状来解释筛选和杂交实验的结果, 其中一对等位基因位于性染色体上, 调控雄性的翅型, 且长翅为显性; 另一对位于常染色体上, 调控雌性的翅型, 且短翅为显性。据此认为, 3种飞虱翅型决定基因的显隐性在不同性别间的差异, 以及翅表型与基因型的不一致性, 是稻飞虱种群在不同条件下均可灵活调控翅型的重要遗传机制。  相似文献   
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