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1.
王思齐  朱章明 《生态学报》2022,42(1):209-219
物种丰富度的大尺度地理格局及其成因是宏观生态学及生物地理学的中心议题之一。蔷薇属(Rosa L.)植物具有很高的经济价值和生态价值,探讨中国蔷薇属植物的丰富度分布格局及其影响因素可为该属植物资源的保护和合理开发利用乃至其系统进化研究提供重要依据。基于蔷薇属植物在中国的15451条分布数据和11种地理、气候等环境因子进行了物种丰富度分析和相关性分析,研究结果显示:(1)蔷薇属植物在中国分布不均匀。在水平方向上,蔷薇属植物于26.19°—34.29°N带内有较高的物种丰富度,之后随着纬度的增加而降低,且随着经度的增加表现为先增加后减少,于99.10°—108.47°E间存在明显的峰值;在垂直方向上,蔷薇属植物的物种丰富度随海拔的增加表现为先增加后减少,956.46—3518.60m范围内的丰富度最高。西南横断山区为蔷薇属物种分布的中心地区,新疆北部及东北长白山周边地区为局部聚集区。(2)蔷薇属物种丰富度与各能量、水分和生境异质性因子均呈正相关关系,与气候稳定性因子呈负相关关系。表明中国蔷薇属植物在水分和热量条件好、气候季节性变化小且生境异质性程度高的地方,有着更高的物种丰富度。(3)蔷薇属...  相似文献   

2.
蔷薇属38个野生种果实的维生素含量及其与分组的关系   总被引:6,自引:0,他引:6  
对蔷薇属 (Rosa) 38个野生种果实 (以下简称蔷薇果 )的经济性状进行了分析 ,并测定了 VC、VE 和胡萝卜素等重要维生素的含量。蔷薇果 VC 含量在该属种间差异很大 ,以秦岭蔷薇 (R.tsinglingensis)的含量为最高 (2 576mg/ 1 0 0 g) ,德钦蔷薇 (R.deqenensis)的含量为最低 (49mg/ 1 0 0 g)。胡萝卜素含量种间差异明显 ,以软条七蔷薇 (R.henryi)的含量为最高 (1 9.2 4 mg / 1 0 0 g) ,黄刺玫 (R.xanthina)的含量为最低 (0 .0 6 mg/ 1 0 0 g)。 VE 含量种间差异较小 ,在 1 .34 mg/ 1 0 0 g(黄刺玫 )至 3.86 mg/ 1 0 0 g(硕苞蔷薇R.bracteata)之间。对蔷薇亚属 54种野生种果实重要维生素含量的统计分析表明 ,维生素含量与分组具有一定相关性 ,尤以 VC 含量与分组的相关性最为明显 ,桂味组和小叶组 Vc含量很高 (均值都高于 1 80 0mg/ 1 0 0 g) ;合柱组、月季组、木香组和硕苞组含量很低 (均值都在 30 0 mg/ 1 0 0 g以下 ) ,芹叶组除宽刺蔷薇 (R.platyacantha) VC含量很高外 ,其余种类含量都很低 (均值为 1 90 mg/ 1 0 0 g)。胡萝卜素含量与分组也具有一定相关性 ,桂味组、芹叶组、合柱组和硕苞组的胡萝卜素含量较高 ,均值在 6 mg/ 1 0 0 g以上 ;月季组、小叶组和木香组含量较低 ,均值在 0 .4mg/ 1 0 0 g以下。V  相似文献   

3.
本文研究了哀牢山徐家坝地区优势种群木果石栎的自我调节,其自疏指数为 –2.8208。采用重要值百分数求取竞争系数,以优势种群在正常纯林中的优势度作为其容纳量,并用Lotka—Volterra竞争方程讨论木果石栎群落的优势种群木果石栎、景东石栎、腾冲栲的竞争,结果表明平衡时,相对优势度分别为29.52%、39.90%、30.58%。即木果石栎群落将由木果石栎,景东石栎,腾冲栲三种植物共优组成。  相似文献   

4.
第10号染色体同源缺失性磷酸酶-张力蛋白(phosphatase and tensin homolog deleted on chromosome ten,PTEN)是继P53之后发现的又一抑癌基因,其编码的蛋白产物包括了张力蛋白样结构域和双重特异性的磷酸酶结构域。令人吃惊的是,2013年研究人员发现该抑癌基因的mRNA在翻译过程中因选择不同的翻译起始密码子,会产生一种具有类似于病毒穿膜机制的蛋白产物,该蛋白产物稍长于PTEN,也具有抑癌作用,故命名为PTEN-Long。由于PTEN-Long既具有分泌和穿过细胞膜的能力,又能像传统抑癌蛋白那样对肿瘤起杀伤作用,这使得PTEN-Long在肿瘤治疗中具有很好的前景。PTEN和PTEN-Long既有共性,又有各自的特异性,本文就PTEN和PTEN-Long基因及其编码的蛋白在结构和功能的异同及其抑瘤作用作一综述,为进一步研究PTEN和PTEN-Long提供理论基础。  相似文献   

5.
电镜下观察并研究了假瘤蕨属植物的叶片附属结构。报道了蜡质颗粒、片层、柔毛和鳞片。叶片附属结构在数量及性质上的差别显示出种类与环境的适应性不同。结果表明,假瘤蕨属植物中土生的种类具有较多的蜡质颗粒、柔毛及鳞片,而附生的种类具有较多的颗粒及片层,这些叶片特征均与亚热带常绿阔叶林的生态环境相适应。  相似文献   

6.
植物种群自疏过程中构件生物量与密度的关系   总被引:3,自引:0,他引:3  
黎磊  周道玮  盛连喜 《生态学报》2012,32(13):3987-3997
不论是在对植物种群自疏规律还是在对能量守衡法则的研究中,个体大小(M)大多针对植物地上部分生物量,地下部分和构件生物量及其动态十分重要又多被忽视。以1年生植物荞麦为材料研究了自疏种群地下部分生物量、包括地下部分的个体总生物量以及各构件生物量与密度的关系。结果表明:平均地上生物量和个体总生物量与密度的异速关系指数(γabove-ground和γindividual)分别为-1.293和-1.253,与-4/3无显著性差异(P>0.05),为-4/3自疏法则提供了有力证据;平均根生物量-密度异速指数γroot(-1.128)与-1无显著性差异(P>0.05),与最终产量恒定法则一致;平均茎生物量-密度异速指数γstem(-1.263)接近-4/3(P>0.05),平均叶生物量-密度异速指数γleaf(-1.524)接近-3/2(P>0.05),分别符合-4/3自疏法则与-3/2自疏法则;而繁殖生物量与密度的异速关系指数γreproductive(-2.005)显著小于-3/2、-4/3或-1(P<0.001)。因此,不存在一个对植物不同构件普适的生物量-密度之间的关系。光合产物在地上和地下构件的生物量分配格局以及构件生物量与地上生物量之间特异的异速生长关系导致不同构件具有不同的自疏指数。无论对于地上生物量还是个体总生物量,荞麦种群能量均守衡,而对于地下生物量,荞麦种群能量不守衡。  相似文献   

7.
应用因子分析法研究茎瘤芥(榨菜)性状间的关系   总被引:1,自引:0,他引:1  
应用因子分析法可把23份茎瘤芥品种资源的15个数量性状集约在5个主因子上,采用正交因子和斜交因子模型分析了性状间的遗传作用关系,并探讨了各因子间的关系及其生物学意义。  相似文献   

8.
徐清燕  梁惠  秦松 《生物磁学》2009,(24):4656-4659
目的:观察重组别藻蓝蛋白(rAPC)对接种H22肝癌细胞小鼠的抑瘤活性及其免疫作用。方法:昆明小鼠随机分为5组(10只/组),即模型组、rAPC低、中、高剂量组(25,50,100mg/kg·d)、环磷酰胺组(CY对照组)。建立小鼠肝癌H22移植瘤模型,次日除模型组外,其余4组分别以不同剂量的rAPC、CY灌胃,于15d后处死,完整剥离出肿瘤、胸腺、脾脏,准确称重,计算抑瘤率、胸腺指数和脾指数,并采用放免法(RIA)测定血清中白细胞介素-6(IL-6)、肿瘤坏死因子-α(TNF-α)的水平。结果:rAPC低剂量组小鼠H22肿瘤质量增长较模型组缓慢(P<0.05),中、高剂量组较模型组显著缓慢(P<0.01),抑瘤率分别为25.2%、36.7%、43.1%;rAPC各剂量组能升高胸腺指数、脾指数和血清中细胞因子IL-6、TNF-α的水平。结论:rAPC可有效抑制H22肝癌的生长,促进小鼠胸腺和脾脏的生长发育,提高小鼠的免疫功能,从而抑制肿瘤的生长。  相似文献   

9.
本文概述了豆科茎瘤植物的某些特性,其结瘤数量多,固氮能力强,抗涝,耐酸碱,耐铵,可用于改土培肥。文中还论述了毛萼田菁等绿肥植物在水稻田中的应用。  相似文献   

10.
细胞自噬是一种存在于真核细胞内的溶酶体依赖性降解途径,是细胞的一种先天免疫机制。该机制可帮助细胞对破损细胞器进行降解,并将降解后的生物大分子等营养物质重新提供给细胞进行物质的重新利用。病毒侵入宿主细胞后细胞启动自噬系统进行自我吞噬并以此来保护机体将病毒对机体的损害降到最低。但研究发现部分病毒在侵染宿主细胞后也可利用细胞的自噬机制来加速自身在胞内的复制。由此可见病毒与细胞自噬间的相互作用是一个复杂且多向化的过程。为对自噬与病毒感染之间的关系进行更进一步的探究,本综述从自噬的发生机制、自噬的检测方法、自噬与病毒感染的关系、病毒感染与抗肿瘤作用等方面进行了阐述。  相似文献   

11.
嫁接试验是研究结瘤自调控的有效方法。本文优化了百脉根的嫁接方法,并应用该方法初步研究了百脉根突变体rel3根瘤数目减少的机理。结果表明,rel3突变体根瘤数目减少的表型是由来自于茎的信号决定。  相似文献   

12.
Eighty soybean cultivars were assessed for their potential for nodulation and nitrogen fixation with indigenous rhizobia in a Nigerian soil. Seventy-six days after planting (DAP) 87%, 3% and 10% of the soybean cultivars had from 0 to 30, 31 to 60 and over 61 nodules/plant, respectively. Only 8% had a nodule dry weight of 600 to 1100 mg/plant. At 84 DAP the proportion of nitrogen derived from the atmosphere (Ndfa) ranged from 0 to 65% 16% of the cultivars derived 51 to 65% of their N2 from the atmosphere. The diversity of soybean germplasm and the variation in nodulation and N2 fixation permitted the selection of the five best cultivars in terms of their compatibility with indigenous rhizobia, % Ndfa and the amount of N2 which they fixed.  相似文献   

13.
Kinetin at 10 mg l–1 increased the number of flowers produced on Rosa damascena plants while GA3 inhibited flowering. In the leaves of non-flowering plants GA-like activity was high while specific cytokinin activity (fraction-II) was significantly higher in flowering plants. A novel compound 10- methyldihydrozeatin riboside and isopentenyl-adenine were identified from TLC fraction-II while TLC fraction-I yielded zeatin and 2-hydroxy-6-methylaminopurine.Abbreviations TLC thin layer chromatography - BA N6-benzyladenine - GA3 gibberellic acid CIMAP communication No. 92-40J  相似文献   

14.
将刺梨提取物用于卷烟加料,用二氯甲烷同时蒸馏萃取刺梨提取物,分别用极性柱和非极性柱进行GC/MS分析.结果表明,刺梨提取物与烟香谐调,具有增加香气质和香气量、掩盖杂气、改善余味的作用,是安全有效的天然烟用香料;采用双柱分析的方法共检出62种化合物,比用单一极性柱分析更能相对客观、全面的反映刺梨提取物中的致香成分的状况;...  相似文献   

15.
按照《中国药典》(附录XB)测定金樱子鞣质含量;采用氧化时间法、超氧阴离子清除率测定法、总还原力法评价金樱子体外抗氧化活性;采用培养基饲养果蝇方法研究金樱子根对果蝇生育力的影响。金樱子根、茎、叶、成熟果实的鞣质含量分别为5.33%、2.00%、6.52%、1.83%;根、茎、叶、果实氧化时间分别为7.8 s、31.1 s、10.3 s、28.9 s;超氧阴离子清除率分别为49.71%、55.46%、52.53%、52.05%;总还原力的吸光度分别0.667、0.357、0.668、0.540;金樱子根2.0%、4.0%、8.0%浓度组对果蝇F1的增殖率分别为20.51%、44.62%(P0.05)、65.64%(P0.05);对果蝇F2的增殖率分别为68.23%(P0.05)、138.67%(P0.01)、71.82%(P0.01)。结果表明金樱子各部位均含有鞣质,有不同程度抗氧化活性;金樱子根能显著提高果蝇的生育力。  相似文献   

16.
Kosenko  L. V.  Zatovskaya  T. V. 《Microbiology》2004,73(3):292-299
A comparative study of the lipopolysaccharides (LPS) isolated from Sinorhizobium meliloti SKHM1-188 and two of its LPS mutants (Tb29 and Ts22) with sharply decreased nodulation competitiveness was conducted. Polyacrylamide gel electrophoresis with sodium dodecyl sulfate revealed two forms of LPS in all three strains: a higher molecular weight LPS1, containing O-polysaccharide (O-PS), and a lower molecular weight LPS2, without O-PS. However, the LPS1 content in mutants was significantly smaller than in the parent strain. The LPS of the strains studied contained glucose, galactose, mannose, xylose, three nonidentified sugars (X 1 (TGlc 0.53), X 2 (TGlc 0.47), and X 3 (TGlc 0.43)), glucosamine, and ethanolamine, while the LPS of S. meliloti SKHM1-188 additionally contained galactosamine, glucuronic and galacturonic acids, and 2-keto-3-deoxyoctulosonic acid (KDO), as well as such fatty acids as 3-OH C14:0, 3-OH C15:0, 3-OH C16:0, 3-OH C18:0, nonidentified hydroxy X (T3-OH C14:0 1.33), C18:0, and unsaturated C18:1 fatty acids. The LPS of both mutants were similar in the component composition but differed from the LPS of the parent strain by lower X 2, X 3, and 3-OH C14:0 contents and higher KDO, C18:0, and hydroxy X contents. The LPS of all the strains were subjected to mild hydrolysis with 1% acetic acid and fractionated on a column with Sephadex G-25. The higher molecular weight fractions (2500–4000 Da) contained a set of sugars typical of intact LPS and, supposedly, corresponded to the LPS polysaccharide portion (PS1). In the lower molecular weight fractions (600–770 Da, PS2), glucose and uronic acids were the major components; galactose, mannose, and X 1 were present in smaller amounts. The PS1/PS2 ratio for the two mutants was significantly lower than for strain SKHM1-188. The data obtained show that the amount of O-PS–containing molecules (LPS1) in the heterogeneous lipopolysaccharide complex of the mutants was smaller than in the SKHM1-188 LPS; this increases the hydrophobicity of the cell surface of the mutant bacteria, which supposedly contributes to their nonspecific adhesion to the roots of the host plant, thus decreasing their nodulation competitiveness.  相似文献   

17.
以吉林珲春自然群落的野生玫瑰(Rosa rugosa Thunb.)为试验材料,探究野生玫瑰在果实形成过程中种子的发育及休眠性的形成和变化。选取青果期(1~35 d)、转色期(35~60 d)、红果期(60~75 d)的果实及种子,结合形态学、组织细胞学观察法及高效液相色谱技术,对果实各发育时期的种子形态、种胚及内果皮的发育进行研究,并分析种子内源激素含量变化与果实发育、种子休眠之间的关系。结果表明:果实和种子在青果期(1~35 d)时发育速度最快,种胚在花后24 d发育完全,种子不存在形态休眠。花后24 d内果皮开始沉积木质素并逐渐木质化,种子开始产生机械休眠。种子激素含量的变化与果实的发育、转色及内果皮的木质化密切相关,种子内源GA3和ABA含量在青果期(1~35 d)达到峰值,内源IAA含量在果实转色期(35~60 d)达到最大值,高浓度的ABA含量是种子尚未脱离果实时便已进入生理休眠的主要原因。  相似文献   

18.
The self-thinning rule defines a straight upper boundary line on log-log scales for all possible combinations of mean individual biomass and density in plant populations. Recently, the traditional slope of the upper boundary line, -3/2, has been challenged by -4/3 which is deduced from some new mechanical theories, like the metabolic theory. More experimental or field studies should be carried out to identify the more accurate self-thinning exponent. But it's hard to obtain the accurate self-thinning exponent by fitting to data points directly because of the intrinsic problem of subjectivity in data selection. The virtual dynamic thinning line is derived from the competition-density (C-D) effect as the initial density tends to be positive infinity, avoiding the data selection process. The purpose of this study was to study the relationship between the virtual dynamic thinning line and the upper boundary line in simulated plant stands. Our research showed that the upper boundary line and the virtual dynamic thinning line were both straight lines on log-log scales. The slopes were almost the same value with only a very little difference of 0.059, and the intercept of the upper boundary line was a little larger than that of the virtual dynamic thinning line. As initial size and spatial distribution patterns became more uniform, the virtual dynamic thinning line was more similar to the upper boundary line. This implies that, given appropriate parameters, the virtual dynamic thinning line may be used as the upper boundary line in simulated plant stands.  相似文献   

19.
在元谋干热河谷冲沟发育典型的三个样区(沙地村、金雷村、苴林村)采集48条冲沟的植物样方数据和冲沟沟底的坡度数据,运用重要值方法对植被优势种进行判别和筛选,以灌木优势种和草本优势种为主要研究对象,探讨植被优势种与冲沟沟底坡度的关系。结果表明:(1)灌木优势种为车桑子Dodonaea viscosa和山合欢Albizia kalkora,重要值分别为0.486和0.342,占灌木总体的83%;草本优势种为扭黄茅Heteropogon contortus、孔颖草Bothriochloa pertusa和茅草Imperata cylindrica,重要值分别为0.386、0.140及0.196,占草本总体的72%。(2)除草本优势种中的茅草盖度与坡度相关性显著(P<0.05)外,样区冲沟沟底坡度与灌木优势种和草本优势种相关性均不显著(P>0.05),表明在元谋干热河谷地区,冲沟沟底坡度对植被优势种生长状况影响较小。  相似文献   

20.
This paper deals with changes in leaf photosynthetic capacity with depth in a rose (Rosa hybrida cv. Sonia) plant canopy. Measurements of leaf net CO2 assimilation (Al) and total nitrogen content (Nl) were performed in autumn under greenhouse conditions on mature leaves located at different layers within the plant canopy, including the flower stems and the main shoots. These leaves were subjected (i) to contrasting levels of CO2 partial pressure (pa) at saturating photosynthetic photon flux density (I about 1000 μ mol m ? 2 s ? 1) and (ii) to saturating CO2 partial pressure (pa about 100 Pa) and varying I, while conditions of temperature were those prevailing in the greenhouse (20–38 °C). A biochemical model of leaf photosynthesis relating Al to intercellular CO2 partial pressure (pi) was parameterized for each layer of leaves, supplying corresponding values of the photosynthetic Rubisco capacity (Vlm) and the maximum rate of electron transport (Jm). The results indicated that rose leaves growing at the top of the canopy had higher values of Jm and Vlm, which resulted from a higher allocation of nitrogen to the uppermost leaves. Mean values of total leaf nitrogen, Nl, decreased about 35% from the uppermost leaves of flower stem to leaves growing at the bottom of the plant. The derived values of non‐photosynthetic nitrogen, Nb, varied from 76 mmolN m ? 2leaf (layer 1) to 60 mmolN m ? 2leaf (layer 4), representing a large fraction of Nl (50 and 60% in layer 1 and 4, respectively). Comparison of leaf photosynthetic nitrogen (Np = NlNb) and I profiles supports the hypothesis that rose leaves acclimate to the time‐integrated absorbed I. The relationships between I and Np, obtained during autumn, spring and summer, indicate that rose leaves seem also to acclimate their photosynthetic capacity seasonally, by allocating more photosynthetic nitrogen to leaves in autumn and spring than in summer.  相似文献   

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