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1.
王毅  王燕 《植物科学学报》2010,28(6):696-697
报道了中国海南兰科植物一新记录种,奇花玉凤兰Habenaria anomaliflora H.KurzweilS.Chan-tanaorrapint。本种的主要特征是花不规则,花萼与花瓣相似且唇瓣无距。  相似文献   

2.
报道中国兰科植物(Orchidaceae)玉凤花属(Habenaria Willd.)一新记录种——宽叶玉凤花(H. lindleyana Steud.),并提供了该种的形态描述和野外照片。凭证标本存放于中国科学院广西植物研究所标本馆(IBK)。  相似文献   

3.
报道了自云南发现的中国兰科植物一新记录种:缘毛玉凤花(Habenaria chlorina E.C. Parish & Rchb.f.),其花苞片边缘明显被毛而不同于属内其它种类.本种在植株和花部特征上与凸孔坡参(H. acuifera Wall. ex Lindl.)和坡参(H. linguella Lindl.)相似,但其唇瓣在距口的前缘不具有一个横生的脊而明显区别于后两者.  相似文献   

4.
中国兰科玉凤花属一新记录种——勐远玉凤花   总被引:1,自引:0,他引:1  
报道了中国云南兰科植物一新记录种,勐远玉凤花(Habenaria myriotricha Gagnep)。该种主要特点是唇瓣侧裂片的外侧几乎至基部具多数深的线状裂条。其侧萼片反折,唇瓣上具有红色锈斑可与版纳玉凤花(H.medioflexa Turrill.)明显区别开。  相似文献   

5.
报道了中国云南兰科植物一新记录种,岩生玉凤花(Habenaria vidua E.C.Parish &Rchb.f).该种主要特点是生长在腐殖质比较丰富的石灰岩缝隙中,不同于属内其它物种.在植株和花部特征相似于丛叶玉凤花H.tonkinensis,但侧萼片与唇瓣绿色、唇瓣侧裂片明显上举而区别于后者.  相似文献   

6.
2007年9月,对广东省惠州市新墟镇白云嶂进行植物学考察时,在一个斜坡上的一片次生阔叶林的潮湿林缘,发现了兰科植物细裂玉凤花Habenaria leptoloba Benth.。此植物的模式产地为香港,第一次采集时间为1857年,后来虽在香港仍有发现,但事隔150年后才在广东发现。  相似文献   

7.
报道了中国云南兰科植物一新记录种,岩生玉凤花(Habenaria vidua E.C.ParishRchb.f)。该种主要特点是生长在腐殖质比较丰富的石灰岩缝隙中,不同于属内其它物种。在植株和花部特征相似于丛叶玉凤花H.tonkinensis,但侧萼片与唇瓣绿色、唇瓣侧裂片明显上举而区别于后者。  相似文献   

8.
报道了自云南发现的中国兰科植物一新记录种:缘毛玉凤花(Habenaria chlorina E.C.ParishRchb.f.),其花苞片边缘明显被毛而不同于属内其它种类。本种在植株和花部特征上与凸孔坡参(H.acuifera Wall.ex Lindl.)和坡参(H.linguella Lindl.)相似,但其唇瓣在距口的前缘不具有一个横生的脊而明显区别于后两者。  相似文献   

9.
广东发现细裂玉凤花   总被引:1,自引:0,他引:1  
2007年9月,对广东省惠州市新墟镇白云嶂进行植物学考察时,在一个斜坡上的一片次生阔叶林的潮湿林缘,发现了兰科植物细裂玉凤花Habenaria leptoloba Benth。此植物的模式产地为香港,第一次采集时间为1857年,后来虽在香港仍有发现,但事隔150年后才在广东发现。  相似文献   

10.
报道中国兰科植物(Orchidaceae)玉凤花属(Habenaria Willd.)一新记录种——宽叶玉凤花(H.lindleyana Steud.),并提供了该种的形态描述和野外照片。凭证标本存放于中国科学院广西植物研究所标本馆(IBK)。  相似文献   

11.
沙冬青淀粉粒及其与叶绿体发育的关系   总被引:5,自引:0,他引:5  
沙冬青叶绿体中的淀粉粒一般为1-3个,主要有4种类型。第1种外周部分电子密度较高,中央部分较低,但每个部分的电子密度十分均匀。它们近似椭圆形,附近的类囊体形态正常,结构清晰。第2种电子密度由外向内逐渐变低,多为椭圆形,附近的类囊体较清晰。第3种外周部分的电子密度很高,中央部分不均匀,形状多种多样,附近的类囊体有的不清晰。第4种电子密度很低,十分均匀,形状不规则,附近的类囊体已经解体或正在解体。分析表明,淀粉的形态变化明显与叶绿体发育有关。  相似文献   

12.
Failure to Maintain Glycolysis in Anoxic Nerve Terminals   总被引:8,自引:6,他引:2  
Synaptosomal glycolysis is stimulated eight- to 10-fold when the respiratory chain is inhibited by cyanide or by anoxia. However, the stimulation is transient and after 15 min declines toward the preanoxic rate. The decline is not seen when Ca2+ is absent or when the respiratory chain is inhibited by rotenone. The decline in glycolysis is reversible, is not due to substrate exhaustion, and is the cause, rather than the effect, of lowered synaptosomal ATP/ADP ratios. The failure to maintain glycolysis when the terminal oxidase of the respiratory chain is inhibited may have relevance to the sensitivity of the brain to anoxic damage.  相似文献   

13.
路娟  陈非 《生物技术》1994,4(5):34-37
药敏药片经临床对金黄色葡萄球菌、大肠埃希氏菌、铜绿假单胞菌等235株考核.表明药片工艺研究先进,药片与培养基结合牢固,无断裂、崩解,不渗出颗粒,抑菌圈呈同心园扩散.边缘清楚。药物含量均匀,释放度好。药片抑菌差仅1~3mm;而纸片抑菌差为2~12mm。药片变黑系数CV为2.71~4.21;而纸片CV为3.82~14.36。表明纸片片间差大,药片精密度明显好于纸片。  相似文献   

14.
For a subdivided population the consequences of dominance and gene flow for the maintenance of multilocus polymorphism, local adaptation, and differentiation are investigated. The dispersing population inhabits two demes in which selection acts in opposite direction. Fitness is determined additively by two linked diallelic loci with arbitrary intermediate dominance (no over- or underdominance). For weak as well as strong migration, the equilibrium structure is derived. As a special case, a continuous-time continent–island model (CI model) is analyzed, with one-way migration from the continent to the island. For this CI model, the equilibrium and stability configuration is obtained explicitly for weak migration, for strong migration, for independent loci, and for complete linkage. For independent loci, the possible bifurcation patterns are derived as functions of the migration rate. These patterns depend strongly on the degree of dominance. The effects of dominance, linkage, and migration on the amount of linkage disequilibrium (LD) and the degree of local adaptation are explored. Explicit formulas are obtained for D   (=x1x4x2x3) and r2 (the squared correlation in allelic state). They demonstrate that dominant island alleles increase D and decrease r2. Local adaptation is elevated by dominance of the locally adaptive alleles. The effective migration rate at a linked neutral locus is calculated. If advantageous alleles are dominant, it is decreased only slightly below the actual migration rate. For a quantitative trait that is determined by two additive loci, the influence of dominance on measures of differentiation is studied. Explicit expressions for QST and two types of FST at equilibrium are deduced and their relation is discussed.  相似文献   

15.
短柄五加大,小孢子发生和雌,雄配子体发育的研究   总被引:6,自引:2,他引:4  
王仲礼  田国伟 《植物研究》1998,18(2):177-183
短柄五加花药5枚,每个花药四个花粉囊。小孢子母细胞减数分裂时,胞质分裂为同时型,产生正四面体形的四分体。花药壁由表皮、药室内壁、中层和绒毡层四层细胞组成,其发育类型为双子叶型。腺质绒毡层,其细胞为二核。三细胞型花粉。子房5室,每室两个胚珠,上胚珠败育,下胚珠可育。下胚珠倒生,具单珠被,厚珠心。大孢子母细胞减数分裂形成线性排列的四个大孢子,雌配子体发育属蓼型。开花当天,花粉散开,雌配子体尚未成熟,处  相似文献   

16.
矮沙冬青雌配子体及胚胎发育研究   总被引:5,自引:0,他引:5  
周江菊  唐源江  廖景平   《广西植物》2006,26(5):561-564
矮沙冬青子房单心皮1室,边缘胎座,弯生胚珠,胚珠具双珠被、厚珠心。大孢子孢原细胞发生于珠心表皮下,大孢子母细胞减数分裂形成直线排列的四分体,合点端大孢子具功能,并按蓼型胚囊发育,雌配子体成熟于4月中旬。双受精后,胚乳发育为核型。在矮沙冬青大孢子发生、雌配子体和胚胎发育过程中未发现异常现象,因此认为矮沙冬青濒危不存在雌性生殖结构与发育过程异常的内在因素。  相似文献   

17.
糖、糖、“糖”——什么是糖?   总被引:1,自引:0,他引:1  
糖类是自然界中最常见的一类生物分子,但是糖类因不同的人群可以有三种不同的理解.一是科学上的糖类,二是生活中的糖类,三是作为甜味剂的"糖"类.因为甜味是一个生理上的感觉,凡能与甜味受体相互作用的均是甜味剂,其中有些是糖的"糖",也有不是糖的"糖".  相似文献   

18.
杉木人工林水量平衡和蒸散的研究   总被引:1,自引:0,他引:1       下载免费PDF全文
 本文根据我们严密设计的小集水区径流场连续6年的水文测定数据,进行了杉木人工林水量平衡和蒸散的研究。结果表明:集水区年平均降雨量1065.5mm, 在林冠作用面降雨量的分配中,林冠截留雨量264.6mm,截留率24.8%;穿透过林冠层的雨量799.82mm,树干径流量1.08mm,分别占降雨量的75.1%和0.1%。林内降水到达林地时,在枯枝落叶层这个作用面上净降水进行再分配,其中,地表径流量9.27mm,地下径流量203.00mm,总径流系数0.199。土壤蓄水量月变化较大,但年变化很小,占降雨量的1.2%。系统水量最大的输出是蒸散,每年以气态形式返回大气的水量866.03mm,占降雨量81.3%。在蒸散的水量中,林冠截留雨量的直接物理蒸发量为264.6mm,占总蒸散量的31.6%。  相似文献   

19.
A general three-stage discrete-time population model is studied. The inherent net reproductive number for this model is derived. Global stability of the origin is established provided that the inherent net reproductive number is less than one. If it is larger than one the existence of a unique positive fixed point is proved and the persistence of the system is established. Finally, for certain parameter ranges global stability of the positive fixed point is proved.  相似文献   

20.
The rate of NADH oxidation with oxygen as the acceptor is very low in mouse liver plasma membrane and erythrocyte membrane. When vanadate is added, this rate is stimulated 10- to 20-fold. The absorption spectrum of vanadate does not change with the disappearance of NADH. The reaction is inhibited by superoxide dismutase, and there is no activity under an argon atmosphere. This indicates that oxygen is the electron acceptor and the reaction is mediated by superoxide. The vanadate stimulation is not limited to plasma membrane. Golgi apparatus and endoplasmic reticulum show similar increase in NADH oxidase activity when vanadate is added. The endomembranes have significant vanadate-stimulated activity with both NADH and NADPH. The vanadate-stimulated NADH oxidase in plasma membrane is inhibited by compounds, which inhibit NADH dehydrogenase activity: catechols, anthracycline drugs and manganese. This activity is stimulated by high phosphate and sulfate anion concentrations.  相似文献   

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