Morphological and Anatomical Studies of Linaria species from South-west Spain: Fruits

A morphological and anatomical study of fruits of 24 taxa ofLinaria Miller from south-west Spain has been made. Followingexamination of these species, by scanning electron and lightmicroscopy, five morphological types are established relatingto hair types, symmetry and dehiscence of capsules. A key tothe different species or groups of species is provided. Finally,dehiscence mechanisms are discussed briefly. Copyright 1999Annals of Botany Company Pericarp, hairs, dehiscence, SEM, Antirrhineae.     

New Pythium Taxa Causing Root Rot on Mediterranean Quercus Species in South-west Spain and Portugal

Pythium spiculum, a recently described new taxon, has been frequently isolated from declining Quercus rotundifolia and Q. suber roots and rhizosphere since 2003 in southern Iberia. In soils of declining Quercus forests this species was found as frequently as Phytophthora cinnamomi which, until now, was the only oomycete described as a Quercus root rot pathogen in the region. Inoculation tests conducted on young Q. rotundifolia plants showed that Py. spiculum is an aggressive root pathogen, although producing severities of symptoms significantly lower than those of P. cinnamomi. This new pathogen could play a role as decline factor in southern Iberia. Another new species, Py. sterilum, was also found to be pathogenic to Quercus roots but there are presently only few records of this organism isolated from rhizosphere of declining oaks in central Spain. More than an active decline factor, this species should be considered as a potential risk for Quercus forests.     

Seed morphology of Linaria species from eastern Spain: identification of species and taxonomic implications

Seed morphology of 15 taxa of Linaria from eastern Spain has been studied using stereoscopic and scanning electron microscopy. Four different morphological types are described according to features of the seed-coat surface. The type that includes winged seeded taxa is divided into three subtypes. Seed morphology of each type and subtype is described, compared, illustrated and discussed according to its taxonomic and biological implications. A key to identify the different species or groups of species is also supplied. 2001 The Linnean Society of London     

Extremotolerance and Resistance of Lichens: Comparative Studies on Five Species Used in Astrobiological Research I. Morphological and Anatomical Characteristics

Lichens are symbioses of two organisms, a fungal mycobiont and a photoautotrophic photobiont. In nature, many lichens tolerate extreme environmental conditions and thus became valuable models in astrobiological research to fathom biological resistance towards non-terrestrial conditions; including space exposure, hypervelocity impact simulations as well as space and Martian parameter simulations. All studies demonstrated the high resistance towards non-terrestrial abiotic factors of selected extremotolerant lichens. Besides other adaptations, this study focuses on the morphological and anatomical traits by comparing five lichen species—Circinaria gyrosa, Rhizocarpon geographicum, Xanthoria elegans, Buellia frigida, Pleopsidium chlorophanum—used in present-day astrobiological research. Detailed investigation of thallus organization by microscopy methods allows to study the effect of morphology on lichen resistance and forms a basis for interpreting data of recent and future experiments. All investigated lichens reveal a common heteromerous thallus structure but diverging sets of morphological-anatomical traits, as intra-/extra-thalline mucilage matrices, cortices, algal arrangements, and hyphal strands. In B. frigida, R. geographicum, and X. elegans the combination of pigmented cortex, algal arrangement, and mucilage seems to enhance resistance, while subcortex and algal clustering seem to be crucial in C. gyrosa, as well as pigmented cortices and basal thallus protrusions in P. chlorophanum. Thus, generalizations on morphologically conferred resistance have to be avoided. Such differences might reflect the diverging evolutionary histories and are advantageous by adapting lichens to prevalent abiotic stressors. The peculiar lichen morphology demonstrates its remarkable stake in resisting extreme terrestrial conditions and may explain the high resistance of lichens found in astrobiological research.     

黑龙江槭树属植物导管分子解剖学研究

利用扫描电子显微镜,通过管道铸型技术,对黑龙江槭树科（Aceraceae）槭树属（Acer Linn.）中8种植物导管分子的微形态结构进行了比较研究。结果表明：该属植物导管分子长度,除白牛槭 （Acer mandshurica Maxim.）较长外,其余植物种类导管分子长度在133.00～187.50 μm;导管管腔宽度,在17.06～28.00 μm之间;纹孔排列方式以对列式、互列式单独存在,或以两者形式并存;管间纹孔成群分布且大部分呈现一定形状;讨论了导管分子管腔的主要特征及其与生境的关系。     

A New Species of Coronilla (Loteae, Fabaceae) from Southeastern Spain: Evidence from Morphological and Molecular Data

Currently, there are nine species classified within the genus Coronilla (Loteae, Fabaceae); however, some populations discovered in the province of Almería, SE Spain, have features that are not present, as a whole, in the other known species. These plants are related to Coronilla juncea and C. minima, although several features of branches, leaves, flowers and seeds (zigzag branches; fleshy, deciduous leaves without hyaline margin; connate reddish stipules; very narrow seeds with fluted foveolae) are usually recognized as belonging to distinct species. To clarify the taxonomic status of these populations, morphological and genetic studies have been performed. The results obtained suggest that their separate classification is appropriate. Accordingly, a new species, Coronilla talaverae, whose currently recorded range is restricted to three populations in southeastern Spain is described here. Regarding its risk of extinction, the IUCN red list criteria have been followed to assess its category, proposing the status EN B1ab(i,ii,iii,v)+2ab(i,ii,iii,v). In addition, an identification key is provided for the species of the genus Coronilla.     

水龙骨亚科植物(水龙骨科)的形态解剖学研究

对水龙骨科水龙骨亚科5属16种植物的孢子形态、叶表皮结构、叶柄和根状茎的横切、根状茎上的鳞片以及叶脉特征进行了详细的观察和分析,探讨了该亚科植物的系统位置和亲缘关系。结果表明,在该亚科植物类群中,主要分布于亚洲亚热带地区的篦齿蕨属、拟水龙骨属和水龙骨属的亲缘关系较近,而主要分布于亚洲热带地区的棱脉蕨属和亚洲温带地区的多足蕨属的系统位置则分别较孤立。     

爬山虎属三种植物吸盘的解剖学研究

运用常规石蜡切片法,对3种爬山虎属(Parthenocissus)植物的吸盘结构进行了观察研究.结果表明:吸盘膨大部位、吸附方式、卷须长短及托叶可以作为种的分类依据;3种植物的吸盘均由表皮、皮层、维管柱组成,未吸附表皮细胞外弦壁增厚,具角质层;吸盘膨大主要是由维管柱扩大而非表皮细胞膨大引起;吸盘未吸附部位的皮层细胞含有较多晶体;吸盘膨大时维管柱转变成维管束,维管形成层活动期较短.3种植物的吸附结构由表皮及皮层细胞反分化分裂形成多层指状细胞构成.     

高寒冰缘区15种藓类植物茎的形态结构研究

采用石蜡切片方法和扫描电镜方法,对高寒冰缘区生长的15种藓类植物茎的结构进行解剖学观察分析,为高寒冰缘区藓类植物在极端环境下的生存机理及其生态应用提供依据。结果表明:高寒冰缘区的15种藓类植物的茎分为表皮、皮部、中轴三部分。茎表皮细胞多为一层,长短不一,细胞壁表面粗糙,表面纹饰多为鳞片状、颗粒状、浅窝点状,表皮细胞的细胞壁加厚程度不同;皮部所占面积最大,大部分有内、外皮部的分化,细胞壁由外向内逐渐变薄,细胞由小到大又到小的整齐或镶嵌排列;中轴分化但其细胞数多少不一,细胞壁多具角隅加厚。研究认为,高寒冰缘区藓类植物具有典型的耐寒、耐旱结构特征,这些结构特征能够增强藓类植物的支撑和传导水分的作用,以抵御长期寒冷、干旱、多强风等恶劣环境;其中细胞的形状、数目、细胞表面的纹饰等微形态结构特征也具有潜在的分类学意义。     

四川当归属8种植物果实和叶柄解剖学研究

通过对四川当归属植物果实的解剖研究表明,果实均背腹压扁,背棱槽油管多为1,合生面油管多为2,在少数种间有一定差异,如茂汶当归和紫花前胡合生面多于2;侧棱翅状,较果体宽,或与果体近等宽,也有的窄于果体;胚乳腹面微凹或平直．偶有凸出。果实的油管特征、侧棱翅发达程度和胚乳的形状等特征可以为种间关系提供参考。叶柄类型多样,包括圆环型、“西”型、星散型等。叶柄横切面的形状、近轴面沟槽的有无、髓腔的有无以及叶柄横切面上维管束的数目和排列类型等特征比较稳定,并且具有明显的种间差异,可以作为本属分类的重要依据。     

Taxonomic Study of Linaria depauperata and L. supina Complexes in Eastern Spain

Morphological characteristics were studied in two groups ofclosely related taxa of sectionSupinae , Linaria depauperataand L. supina, from eastern Spain. Vegetative, floral and seedcharacteristics were of little use in distinguishing betweenthese taxa as the ranges for all the taxa studied overlapped.Flower colour could be used as a diagnostic character for somebut not all of these taxa. Seed coat characters were of hightaxonomic value, both when trying to distinguish among thesetwo groups, and the taxa included within them, and also whenestablishing relationships among the taxa studied. Some differenceswere found in the indumentum distribution and density. Threetypes of trichomes were identified, two of them eglandular andcommon to all taxa. The third type of trichome was a simplegland, that varied in the number of cells in the stalk and gland.Trichome length and wall width of stalk cells allowed severalgroups of taxa to be distinguished. Similarity relationshipsamong the samples studied are shown in a UPGMA phenogram. Accordingto these results, two new species, L. cardonica and L. sulphurea,are described. L. arabiniana is conspecific with L. depauperatasubsp. hegelmaieri. A key to identify the different taxa isprovided. Copyright 2001 Annals of Botany Company Scropulariaceae, Antirrhineae, taxonomy, morphological characters, seed-coat, trichomes, Linaria depauperata,Linaria supina     

新疆18种木灵藓属(Orthotrichum Hedw.) 植物解剖结构研究

采用徒手切片法对新疆木灵藓属（Orthotrichum Hedw.）18种植物孢蒴上的气孔、茎和叶进行了比较解剖学观察。研究结果表明,木灵藓属植物茎横切结构形状稳定,由表皮和皮层组成,无中轴细胞分化;除半裸木灵藓（Orthotrichum hallii Sull.et Lesq.）外,其它种叶上部均为单层细胞;叶中部边缘外卷,叶细胞具有高度不同的分叉疣或单疣。在确定气孔显、隐型的基础上,茎和叶横切面的颜色、茎表皮和皮层细胞组成及细胞壁加厚程度、叶细胞疣的高度、叶中肋横切面的形状、中肋的宽度、细胞组成以及芽孢形态等特征可作为该属种间分类的依据。还根据18种木灵藓属植物孢蒴上的气孔显、隐型,及茎、叶的比较解剖学特征,编制了新疆木灵藓属植物的分种检索表。     

新疆18种木灵藓属(Orthotrichum Hedw.)植物解剖结构研究

采用徒手切片法对新疆木灵藓属(Orthotrichum Hedw.)18种植物孢蒴上的气孔、茎和叶进行了比较解剖学观察。研究结果表明,木灵藓属植物茎横切结构形状稳定,由表皮和皮层组成,无中轴细胞分化;除半裸木灵藓(Orthotrichum hallii Sull.et Lesq.)外,其它种叶上部均为单层细胞;叶中部边缘外卷,叶细胞具有高度不同的分叉疣或单疣。在确定气孔显、隐型的基础上,茎和叶横切面的颜色、茎表皮和皮层细胞组成及细胞壁加厚程度、叶细胞疣的高度、叶中肋横切面的形状、中肋的宽度、细胞组成以及芽孢形态等特征可作为该属种间分类的依据。还根据18种木灵藓属植物孢蒴上的气孔显、隐型,及茎、叶的比较解剖学特征,编制了新疆木灵藓属植物的分种检索表。     

The Proteaceous Pistil: Morphological and Anatomical Aspects of the Pollen Presenter and Style of Eight Species Across Five Genera

The morphology and anatomy of pollen presenters, styles andpollen of species ofBanksia, Dryandra, Hakea, IsopogonandMacadamiawerestudied. Serial sections of pistils and SEM images of pollenwere quantified to determine whether the low fertility observedin the Proteaceae has a structural basis. Pollen access to thestigma was investigated. There were three types of stigmaticcavity. A groove in which the stigmatic papillae were enclosedwas present inDryandra, BanksiaandHakea. Macadamiahad a groovewith protruding papillae, andIsopogonhad a tube which enclosedthe papillae. Anatomical studies showed the pollen presenterto be structurally complex but overall to have similar internalanatomy across the species studied. The species could be groupedaccording to presence or absence of transfer tissue and presenceor absence of sclerenchyma, but these groups were not mutuallyexclusive. In the pistil there were three structural filtersto pollen tube passage. The first was at the stigma, where pollengrain access could be limited by the diameter or length of thestigmatic groove or the capacity of the pollination chamberin relation to pollen volume. The second and third related toa narrowing of the transmitting tissue tract within the pollenpresenter and in the lower style which could influence pollentube passage to the ovule.Copyright 1999 Annals of Botany Company Proteaceae,Banksia coccinea, Banksia ericifolia, Dryandra formosa, Dryandra nana, Dryandra quercifolia, Hakea bucculenta, Isopogon cuneatus, Macadamia integrifolia,stigmatic cavity, fertility, pollen presenter, structural limitation, stigma, pollen grain, image analysis, transfer tissue.     

超干处理对几种芸苔属植物种子生理生化和细胞超微结构的效应

几种芸苔属植物种子经过超干处理后,发芽力和活力不受影响,耐藏性大为提高。超干及老化后种子的脱氢酶、超氧物歧化酶、过氧化物酶、过氧化氢酶等酶系统保持完好;丙二醛和挥发性醛类物质等劣变产物相应减少;电导率测定表明,细胞膜系统的完整性良好;透射电镜(TEM)和扫描电镜(SEM)观察表明,细胞超微结构及功能保持完好。不同干燥方法和不同干燥剂的系列实验证实,生石灰的脱水效果并不亚于冰冻真空干燥法,且经济实用。     

Morphological and anatomical studies on fruits of Veronica from south-west Spain

Following examination by scanning electron and light microscope of the fruit features of 12 species of Veronica from south-west Spain, morphological and anatomical studies revealed that these taxa can be differentiated on the basis of these features. Phenetic analysis with 28 characters additionally revealed several groups of species in Veronica to be closely related on the basis of their seed morphology. A key distinguishing the different taxa is provided. Finally, dehiscence mechanisms are briefly discussed.     

风毛菊属3种植物叶的解剖结构比较

采用石蜡切片法对分布于祁连山海拔5 000 m左右流石滩上菊科风毛菊属水母雪兔子（Saussurea medusa Maxim）、鼠曲雪兔子（Saussurea gnaphalodes (Royle) Sch.）、红叶雪兔子（Saussurea paxiana Diels.）3种植物叶片的解剖结构进行了比较研究,结果表明：叶片表皮细胞均为单层,上下表皮都有气孔分布,气孔不下陷;角质层较厚,叶表面均被单列细胞的表皮毛。3种植物均为异面叶;叶肉栅栏组织较发达,通常由2～3层细胞组成,但栅栏组织细胞排列较疏松;海绵组织存在大量的细胞间隙;叶肉中通气组织发达,且均有不规则裂生性气腔。叶脉维管束中韧皮部都具有异细胞存在。这些共同特征是3种植物对高山地区缺氧、低温、强辐射等自然条件长期适应的结果。但是,3种植物在叶片的外部形态特征、叶肉栅栏组织细胞的特点、维管束发育程度、内分泌结构、不规则裂生气腔等方面又存在明显的不同,表现出3种植物对环境的适应也是存在差异的。     

3种同域分布的杓兰属植物的种子及杂交种子特征分析

杂交种子研究在一定程度上能说明是否存在杂种不活机制,在植物生殖隔离研究中具有重要意义。通过对同域分布的西藏杓兰(Cypripedium tibeticum)、黄花杓兰(C.flavum)和褐花杓兰(C.calcicola)的自交、异交、杂交种子的形态特征及活性进行分析,发现3种杓兰属植物两两之间均可产生杂交种子,且杂交种子活性较高,杂交种子与其他处理所得种子的外观、表面纹饰无显著性差异;种子宽度、种子长度、有胚率、着色率并没有比自交或异交种子显著低。这一结果表明这3种同域杓兰属植物种与种之间具有相当高的亲和性,它们之间不存在明显的杂种不活机制。黄花杓兰与西藏杓兰或褐花杓兰间的传粉者大小明显不同,黄花杓兰由丽蝇和熊蜂工蜂传粉,而西藏杓兰和褐花杓兰由体形较大的熊蜂蜂王传粉,传粉者隔离已使得它们之间的物种界限比较清晰,因此已经没有必要再产生杂种不活等其他隔离机制。而西藏杓兰与褐花杓兰的传粉者相同,又没有明显的杂种不活隔离机制,暗示它们之间有其他合子后隔离机制或应将其合并为一个种。