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1.
本文对南极菲尔德斯半岛3种黑藓属植物的形态特征进行了描述,讨论了种间的差异。并用扫描电子显微镜详细观察了黑藓属植物孢子体的形态结构,丰富了该地区苔藓学研究资料。  相似文献   

2.
通过对新疆白齿藓属(Leucodon)标本的系统整理,确认该属在新疆共有4种,其中3种为新疆新记录种,分别为朝鲜白齿藓(L.coreensis Cardot.)、垂悬白齿藓(L.pendulus Lindb.)和中华白齿藓(L.sinensis Thér.)。本文对上述4个种的形态特征、生境和地理分布等进行了详细描述,并提供了显微形态图版和墨线图。依据白齿藓属植物在我国的地理分布,推测秦岭地区可能是白齿藓属植物在我国的分布和分化中心。  相似文献   

3.
采用经典分类方法,对1989~2012年采自新疆各地的赤藓属植物360余号标本进行鉴定。结果表明:(1)共鉴定出新疆赤藓属(Syntrichia Brid.)植物11种(含1变种),其中3种为新疆新记录种。(2)新疆首次发现的3个新记录种为:北方赤藓(Syntrichia norvegica)、双齿赤藓(S.bidentata)和齿肋赤藓异叶变种(S.caninervis var.spuria),其中双齿赤藓为中国濒危物种。(3)对新疆赤藓属植物11种的形态特征及其在新疆的分布进行了描述,并编制了新疆赤藓属植物的分种检索表。  相似文献   

4.
河南省湿地藓属的初步研究   总被引:3,自引:0,他引:3  
在研究标本的基础上,根据配子体和孢子体的外部形态及其解剖结构和文献中对中国湿地藓属(Hyophila)系统位置的主要观点,鉴定出河南省分布有该属植物6种,其中花状湿地藓(H.nymaniana)、四川湿地藓(H.setschwanica)、匙叶湿地藓(H.spathulata)3种为河南省藓类新记录.编制了河南省湿地藓属植物分种检索表,对每个种的生境、分布及识别特征进行了概述.并对湿地藓属的系统演化位置以及该属植物在河南省的分布进行了讨论.  相似文献   

5.
以采自新疆各地的350余份芦荟藓属植物为材料,对新疆芦荟藓属植物的分类及其分布进行研究。结果显示,新疆产芦荟藓属植物3种:短喙芦荟藓(Aloina brevirostris(Hook.&Grev.)Kindb.)、斜叶芦荟藓(A.obliquifolia(Müll.Hal.)Broth.)和钝叶芦荟藓(A.rigida(Hedw.)Limpr.)。其中斜叶芦荟藓为新疆新记录种。对它们的形态特征进行了描述,明确了各种的识别特征,并提供了生境、产地与分布地等信息及显微照片,编制了新疆芦荟藓属植物分种检索表。  相似文献   

6.
报道了河北省丛藓科典型旱生藓类芦荟藓属(Aloina Kindb.)和盐土藓属(PterygoneurumJur.)植物4种,其中盐土藓属为河北新记录属,盐土藓[Pterygoneurum subsessile(Brid.)Jur.]和刺叶芦荟藓(Aloina cornifolia Delgad.)为河北新记录种。讨论了各种的主要识别特征、生境和地理分布特点,绘制了形态结构图,并编写了河北省丛藓科芦荟藓属的分种检索表。  相似文献   

7.
以采自新疆各地的350余份芦荟藓属植物为材料,对新疆芦荟藓属植物的分类及其分布进行研究。结果显示,新疆产芦荟藓属植物3种:短喙芦荟藓(Aloina brevirostris(Hook.Grev.) Kindb.)、斜叶芦荟藓(A.obliquifolia (Müll. Hal.) Broth.)和钝叶芦荟藓(A. rigida (Hedw.) Limpr.)。其中斜叶芦荟藓为新疆新记录种。对它们的形态特征进行了描述,明确了各种的识别特征,并提供了生境、产地与分布地等信息及显微照片,编制了新疆芦荟藓属植物分种检索表。  相似文献   

8.
对四川省黑水县达古冰川苔藓植物的调查采集和标本鉴定过程中,发现了密叶黑藓(Andreaea densi folia)的一个新的地理分布记录.该文对密叶黑藓的形态特征进行了详细记录与拍照,并对以往描述和绘图进行了比较分析,丰富了密叶黑藓的研究资料,对研究中国黑藓属植物具有重要的意义.  相似文献   

9.
通过光学显微镜(LM)和扫描电镜(SEM)观察了17属国产丛藓科(Pottiaceae)植物叶中上部细胞的形态特征,结果表明:丛藓科植物的叶中上部细胞的形状、大小及表面形态等特征上具较大相似性;据细胞表面特征,叶细胞可分为无疣或具乳突、具圆疣以及具分枝的马蹄形疣3种类型,且该特征在丛藓科不同属、种间有较大的区别。因此,叶细胞形态特征可为丛藓科植物属级和亚科级的划分提供细胞形态学依据。  相似文献   

10.
真藓属(Bryum Hedw.)蒴齿形态特征及其分类学意义   总被引:1,自引:1,他引:1  
李利博  赵建成 《植物研究》2009,29(6):651-658
通过光学显微镜和扫描电子显微镜观察了中国产真藓属(Bryum Hedw.)12种植物蒴齿的形态特征。结果显示,根据真藓属齿片的曲向可以分为近直立、齿片伸入齿条间和齿片向外反曲等3种类型。根据齿毛的有无,也可分为3个类群。同时利用STATISTICA 6.0统计软件对12种真藓属植物进行聚类分析及主成分分析。研究结果显示,齿片的曲向类型、齿毛是否发育等形态特征可作为真藓属植物种间的分类依据,为藓类植物蒴齿形态特征与分类和系统进化关系的研究提供了新的资料。  相似文献   

11.
A synopsis of the genus Atypus (Araneae, Atypidae)   总被引:1,自引:0,他引:1  
Twelve of sixteen Atypus species previously described, and one undescribed, are examined. Atypus javanus Thorell is re-diagnosed and the male is described. The vulva of this species, and of A. coreanus Kim and A. karschi Dönitz, arc illustrated for the first time. The taxonomic characters given by Kraus & Baur [ Verh, naturw. Ver. Hamb. 17 : 85–116(1974)] and additional details of male-and female genital organs are discussed. A granular texture on male chelicerae and front legs, presumably a stridulatory apparatus, is noted and used for distinguishing species. A deep cymbial pit of unknown function is illustrated and discussed. Specific character combinations for the species examined are presented in a table. Notes on relationships, habitat, zoogeography, web, phenology and development are given.  相似文献   

12.
The histology and internal morphology of the male valve in a broad sample of Fritillary butterflies are examined. A large internal ridge to which the extensor of the valve muscle fastens is probably an autapomorphy for the tribe Argynnini. A large glandular pocket is found in the valves of all examined Heliconiinae, but is missing in other examined Nymphalidae. The pocket shows considerable variation between the higher taxa. In the higher Fritillaries (subtribe Argynnina) the pocket probably has an effective closing mechanism allowing the male to store a considerable amount of glandular secretion. It has earlier been suggested that the secreta from the pocket glands are transferred to the female during copulation, where they probably have an antiaphrodisiac effect, preventing other males from mating a once mated female. All examined male Fritillaries also have glands in the anellus, the terminal membrane between the valves. In Boloria these glands are extremely well developed and abundant, a condition that is probably an autapomorphy for that genus. The obtained characters are tested against a known phylogeny of the tribe Argynnini.  相似文献   

13.
Four species of adult herbivorous surgeonfishes (Family Acanthuridae) were collected from the remote South-Pacific island system of Tuvalu. Their intestinal contents were examined, and of four populations of ciliated protists, two new species were discovered and are described. Ciliates were examined after protargol staining and, in some cases, scanning electron microscopy. Members of each population were examined and 10 characters measured for the balantidia, and 13 for the paracichlidotherids. A new Balantidium is described which has an unusually large dextr-oral field of cilia. A new species of Paracichlidotherus was discovered which has a macronucleus significantly smaller and well anteriad the cytoplasmic portion of the oral polykinetids relative to the type species.  相似文献   

14.
A test of the cognitive social learning model of type A behavior   总被引:1,自引:0,他引:1  
Portions of the cognitive social learning model proposed by Price as an explanation for the development and maintenance of Type A behavior were examined empirically. Specifically, the hypothesis that Type A behavior is fostered by various beliefs and fears and that these same beliefs and fears arise, in part, as the result of certain parental characteristics was investigated. A questionnaire assessing Type A behavior and the beliefs, fears, and parental characteristics proposed by Price was constructed and administered to a sample of males and females. The results indicated moderate associations between the variables examined for both males and females, with no significant gender differences in the pattern of relationships. The findings are congruent with relationships proposed by Price's model. Implications of the model are discussed in terms of additional research needed.  相似文献   

15.
A total of 301 blue whiting, Micromesistius poutassou Risso, 1826, ranging in length from 17 to 28 cm, from Motril Bay (Mediterranean coast, south Spain) were examined for anisakid nematodes, as these fish are common items in the Spanish Mediterranean diet. Three anisakid species were morphologically identified with a total prevalence of 10.63%. Anisakis simplex s.l. Rudolphi, 1809 had a prevalence value of 6.65%, compared with 2.66% for A. physeteris Baylis, 1923 and 2.33% for Hysterothylacium aduncum Rudolphi, 1802. Variations in prevalence values with season and host size are discussed. Allozyme markers (leucine aminopeptidase-1) were used to identify anisakid nematodes assigned to the A. simplex complex and all examined larvae were found to correspond genetically to A. pegreffii Nascetti et al., 1986.  相似文献   

16.
A survey is presented of computer-assisted statistical mechanical methods. The general theoretical background is described and special methods are discussed in detail. Practical procedures allowing for the calculation of binding energies are examined. A recent perturbation-relaxation procedure is summarized.  相似文献   

17.
The correlation of series of two darkly-staining lines in the tooth cementum of tropical African mammals from areas of bimodal equatorial rainfall is briefly reviewed, and contrasted with the findings in southern Africa where bi-annual lines are claimed for areas of unimodal rainfall. A sample of African buffalo teeth from a unimodal rainfall area in southern Tanzania was examined and the conclusion reached that, in general, one dark line per year was formed. A miscellaneous selection of mainly known age animals was also examined with varied results. Anomalies in the apparent formation of cementum lines are discussed.  相似文献   

18.
A phylogenetic method is a consistent estimator of phylogeny if and only if it is guaranteed to give the correct tree, given that sufficient (possibly infinite) independent data are examined. The following methods are examined for consistency: UPGMA (unweighted pair-group method, averages), NJ (neighbor joining), MF (modified Farris), and P (parsimony). A two-parameter model of nucleotide sequence substitution is used, and the expected distribution of character states is calculated. Without perfect correction for superimposed substitutions, all four methods may be inconsistent if there is but one branch evolving at a faster rate than the other branches. Partial correction of observed distances improves the robustness of the NJ method to rate variation, and perfect correction makes the NJ method a consistent estimator for all combinations of rates that were examined. The sensitivity of all the methods to unequal rates varies over a wide range, so relative-rate tests are unlikely to be a reliable guide for accepting or rejecting phylogenies based on parsimony analysis.  相似文献   

19.
Botulinum neurotoxins (BoNTs) are the most potent of the known biological toxins, and consequently are listed as category A biowarfare agents. Currently, the only treatments against BoNTs include preventative antitoxins and long-term supportive care. Consequently, there is an urgent need for therapeutics to counter these enzymes--post exposure. In a previous study, we identified a number of small, nonpeptidic lead inhibitors of BoNT serotype A light chain (BoNT/A LC) metalloprotease activity, and we identified a common pharmacophore for these molecules. In this study, we have focused on how the dynamic movement of amino acid residues in and surrounding the substrate binding cleft of the BoNT/A LC might affect inhibitor binding modes. The X-ray crystal structures of two BoNT/A LCs (PDB refcodes=3BTA and 1E1H) were examined. Results from these analyses indicate that the core structural features of the examined BoNT/A LCs, including alpha-helices and beta-sheets, remained relatively unchanged during 1 ns dynamics trajectories. However, conformational flexibility was observed in surface loops bordering the substrate binding clefts in both examined structures. Our analyses indicate that these loops may possess the ability to decrease the solvent accessibility of the substrate binding cleft, while at the same time creating new residue contacts for the inhibitors. Loop movements and conformational/positional analyses of residues within the substrate binding cleft are discussed with respect to BoNT/A LC inhibitor binding and our common pharmacophore for inhibition. The results from these studies may aid in the future identification/development of more potent small molecule inhibitors that take advantage of new binding contacts in the BoNT/A LC.  相似文献   

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