五种紫萼藓科植物茎及叶的解剖学观察

对紫萼藓科紫萼藓属中的5种植物,运用石蜡切片法和扫描电镜法,对其茎的结构及叶表皮角质层皱褶、孔及纹饰等特征进行观察分析,结果表明：长枝紫萼藓（Grimmia elongata Kaulf.）茎呈多棱形,片状附属物沿叶腹面表皮连成带状,而叶背面角质层纹饰呈辐射状的裂片;圆蒴紫萼藓（Grimmia a pocarpa Hedw.）茎、叶细胞中内含物非常浓厚,细胞不透明,中助的角质层纹饰呈纵向的线状;高山紫萼藓（Grimmia alpicola Sw.ex Hedw.）中肋宽厚,孔呈梯形排列,叶背面角质层皱褶呈“菊花状”纹饰,叶腹面孔口处有“眼皮状”鳞片覆盖;卵叶紫萼藓（Grimmia o-valis(Hedw.)Lindb.）茎无明显的中轴部;中肋“导水细胞”发达,叶表面密布粗疣和网状排列的大孔,且孔深陷;毛尖紫萼藓（Grimmia pilifera P.Beauv.）茎的外皮部和内皮部之间有一层“鞘状”物质,叶背面孔的形状呈挤压状。     

紫萼藓科植物茎及叶的解剖学研究（续）

对在一号冰川这种极端环境下生长的4种紫萼科植物,茎及叶的内部结构和表面进行解剖学观察,结果表明：直叶紫萼(Grimmia elatior Bruth ex Bals. et Dt Not.)叶中肋背面突出不明显,表面角质层纹饰呈条状纵列;叶腹面有少量鳞片状附属物;卷边紫萼藓(Grimma donniana Sm.)茎表皮细胞强烈凹陷,使其表面呈波浪状,中肋细背面突出;垫状紫萼藓(Grimmia pulvinata (Hedw) Sm.)叶中肋在叶背、腹面均为凸型,无小形厚壁细胞,茎、叶细胞中均含大量的淀粉粒;南欧紫萼藓(Grimmia tergestina Tomm.ex B.S.G)叶背、腹面细胞凹陷明显,角质层厚,皱褶粗糙,遮盖着凹陷的表皮细胞,中肋凸出明显。这些细微特征可成为藓类植物分类学的依据之一。     

黄土丘陵区两种丛藓科植物展叶时长及关键影响因子

藓类植物是变水植物,展叶时长是影响其生长发育的关键。目前,干旱半干旱区藓类植物野外生长发育动态及其影响因子的研究鲜见报道。本研究以黄土丘陵区常见的土生对齿藓和扭口藓为对象,研究了9月5日—11月25日野外自然条件下两种藓类的展叶情况。结果表明: 9—10月,两种藓类叶片表现出有规律的“展开-闭合-展开”的日动态变化,并且土生对齿藓叶片在上午闭合时间较扭口藓平均提前0.68 h,下午叶片展开时间则推后了1.79 h。两种藓类在雨季时展叶时间较长,土生对齿藓展叶时长为251 min,较扭口藓(361 min)低30.4%。近地表大气相对湿度是影响藓株展叶时长的关键因子,藓种的形态结构也会影响展叶时长;相比于土生对齿藓,扭口藓植株较为低矮,中肋占叶片比例大,茎皮部细胞镶嵌结构更为突出,其展叶时的湿度阈值(54.3%)低于土生对齿藓(60.1%)。展叶时长主要受湿度的影响,扭口藓对环境的适应性更强。     

紫萼藓科植物一新种--曹氏紫萼藓北大核心CSCD

描述了新疆天山山脉紫萼藓科(Grimmiaceae)紫萼藓属(Grimmia)一新种——曹氏紫萼藓(Grimmia caotongiana D.P.Zhao,S.Mamtimin&S.He)。该新种与无齿紫萼藓(Grimmia anodon Bruch&Schimp.)最为相似,不同之处在于新种茎叶和雌苞叶均无白色毛尖,叶中部边缘背卷;近中肋细胞通常无色透明,且细胞壁比边缘细胞明显加厚。该研究对新种——曹氏紫萼藓进行了详细的特征描述,并提供了植物体形态显微解剖彩色照片以及相近种的分类学讨论。     

乌兰坝紫萼藓(紫萼藓科)成熟孢子体的发现（英文）

最近在中国内蒙古发现了乌兰坝紫萼藓(Grimmia ulaandamana J. Mu?oz, C. Feng, X.L. Bai&J. Kou)的可育植株,介绍了乌兰坝紫萼藓成熟孢子体、雌株和雄株的特征。孢子体的孢蒴长于蒴柄,蒴柄弯曲,蒴壶表面具纵褶,蒴壁中部表皮细胞厚壁,环带细胞方形或短长方形,蒴盖有喙;蒴齿具疣并在上部分叉,蒴齿在基部分开,蒴齿基部低于蒴壶口,蒴壁表皮细胞和蒴齿之间存在一层小型细胞,蒴齿骨小梁在基部1/3处强烈凸出;蒴帽基部完整。最内侧雌苞叶较茎叶大。乌兰坝紫萼藓具有重要的形态特征变异,可育植株与相似种直叶紫萼藓(G. elatior)易于区分。对乌兰坝紫萼藓进行了全面的描述并配显微图,探讨了孢子体对确定其系统发育位置的重要性。     

中国藓类植物新记录属—筛齿藓属

作者在芬兰赫尔辛基大学植物标本馆(H)研究Dr.T.Koponen 1970年在台湾采集的部份苔藓标本时,发现了筛齿藓(Coscinodon cribrosus (Hedw.) Spruce)。筛齿藓属(Coscinodon Spreng)为中国植物新记录属,特此报道。筛齿藓的主要区别特征为:(1)植物体矮小,呈丛生垫状,叶先端具透明毛尖;(2)叶披针形,中肋两侧具明显长纵褶;(3)叶基部细胞长形至长方形,薄壁;(4)蒴柄短,孢蒴内隐于孢叶之中;(5)蒴帽大,钟形,具纵褶,覆盖大部孢蒴;(6)蒴齿具筛孔。     

应用典范对应分析探讨长白山金发藓科植物的生态位分化

应用典范对应分析(Canonical Co rrespondence Analysis, CCA)对长白山主要生态系统30个样点中的13种金发藓科植物分布与环境因子间的关系进行了研究。发现在长白山地区,金发藓科植物在海拔高度、土壤含砂量、含水量、酸度、光照条件等资源维上存在明显的生态分化现象。13种金发藓科植物中,球蒴金发藓(Polytrichum sphaerothecium(Besch.)C.Mull.、高山异发藓短叶变种(Polytrichastrum alpinum var. brevifolium(R.Br.)Brid.)在海拔上,拟异发藓(Polytrichastrum formosum(Hedw.)G.L.Smith)、变形异发藓(Polytrichastrum dicipensLimpr.)、毛尖金发藓(Polytrichum piliferum Schred.ex Hedw.)、桧叶金发藓(Polytrichum juniperinum Willd.ex Hedw.)在光照上以及大金发藓(Polytrichum commune Hedw.)、直叶金发藓(Polytrichum juniperinum ssp. strictum(Brid.)Nhy.&Sael.)在土壤酸度与水分上的生态要求比较接近。     

不同生境下十七种藓类植物叶的比较解剖学

使用石蜡切片法,对不同生境下的17种藓类植物的叶片进行了解剖观察和比较分析,结果表明不同种类的藓类植物在中肋导水主细胞的有无、厚壁细胞是否分化、中肋细胞层数及细胞密度、叶片细胞层数、叶表附属物、叶片细胞密度等方面存在显著差异。藓类植物叶的解剖结构具有生态适应意义,旱生环境下的藓类植物,叶片细胞胞壁具不同程度的增厚,有些藓类植物叶片具附属结构,藓类植物中肋的有无,反映了对水分吸收和运输方式的不同。例如,荫湿生环境下的羽枝青藓Brachythecium plumosum,其中肋细胞胞壁较薄,无导水主细胞和副细胞的分化,也没有厚壁细胞分化,能够在阴湿环境下吸收水分和养分;钝叶匍灯藓Plagiom niumrostratum具有与旱生藓类植物相似的中肋结构,叶片较厚,中肋具导水主细胞,中肋背面具厚壁细胞,这些特点使该种藓类植物能够分布于间隙性干旱胁迫的环境中;水灰藓Hygro-hypnum luridum叶片纤细柔弱,仅1层细胞,细胞胞壁薄,叶表无附属结构,中肋细胞层数少,无导水主细胞分化,也没有厚壁细胞,这些特点使得水灰藓能够生长在水生环境中;东亚小金发藓Pogonatum inflexum和波叶仙鹤藓Atrich umundulatum的叶腹面覆盖着栉片,东亚砂藓Racomitrium japonicum、大羽藓Thuidium cym-bifolium、福氏蓑藓Macromitrium ferriei、东亚短颈藓Diphyscium fulvifolium、扭口藓Barbula unguiculata和角齿藓Ceratodon purpureus的叶片表面有乳头状突起或疣状物,这些附属结构使它们能够适应于旱生的环境中。     

河北省凤尾藓属植物的初步研究

报道了河北省产凤尾藓属（Fissidens Hedw.)植物7种,其中,直叶凤尾藓（F.strictu-lus C.Muell.)、二形凤尾葡（F.geminiflorus Doz.et Molk.)、尖肋凤尾藓（F.becketii Mitt.)、卷叶凤尾藓（Fissidens dubius P.Beauv.)、透明凤尾藓（F.hyalinus Hook.et Wils.l)和裸萼凤尾藓（F.gymnogymus Besch.)6种为河北省藓类新记录种,文中对它们的生境、识别特征和地理分布特点作了初步的讨论。并给出了河北省凤尾藓属植物的分种检索表。     

基于形态学特征和分子数据的中国缺齿藓科初步研究

为探讨缺齿藓类与真藓科、提灯藓科的系统关系,理清缺齿藓科的系统位置和中国缺齿藓科分类问题,该研究以中国分布的缺齿藓科植物和相关类群4 000余份标本为材料,进行详细的形态学研究,并选用其中35种、40份样品的4个DNA片段(rps4、trnG、trnL-trnF、atpB-rbcL)联合数据用于分子系统分析,采用邻接法(NJ)和最大似然法(ML)构建分子树。结果表明:(1)在分子树中,缺齿藓类与真藓科植物分别聚在具有高支持率的不同分支上,叶形、叶细胞等形态学特征也有较大差异,缺齿藓类应从广义的真藓科分出。(2)在分子树中,虽然缺齿藓类与提灯藓科植物聚在同一分支中,但无形态学的共源性状,二者不应视为一个单系类群。(3)缺齿藓科是一个自然类群,缺齿藓科内属间存在着密切的系统关系,缺齿藓科的主要识别特征为:植物体小型,茎常分枝;叶形和叶细胞为丝瓜藓型(Pohlia-like),披针形至长椭圆形,中上部细胞狭长,线状菱形或蠕虫形;生殖苞多生于新生枝顶;蒴齿为互生双齿层,常有不同程度的退化或一层蒴齿缺失,稀双层蒴齿缺失。(4)中国缺齿藓科包含有5属,即缺齿藓属(Mielichhoferia)、丝瓜藓属(Pohlia)、拟丝瓜藓属(Pseudopohlia)、合齿藓属(Synthetodontium)和小叶藓属(Epipterygium),目前为止共计34种(含种下分类单位)。     

Heteroblasty in the moss,Aphanoregma patens (Physcomitrella patens), results from progressive modulation of a single fundamental leaf developmental programme

Abstract

Leaves at the apex of a mature Aphanoregma patens (Hedw.) Lindb. (Physcomitrella patens (Hedw.) Bruch Schimp. in B.S.G.) gametophore differ markedly in size and form from those at its base. To determine how these differences are produced during development, we first examined qualitative and quantitative differences between successive leaves along the stem and among leaves at different developmental stages. Differences between successive leaves were slight and cumulative. Local changes in cell number and size combined to produce a regularly shaped and approximately bilaterally symmetrical leaf suggesting that cell division and cell expansion are regionally regulated and coordinated at the organ level. The midrib and marginal teeth are discrete characters, which were prefigured by changes in cell shape in leaves that lacked these characters. In leaf primordia, cell proliferation was responsible for most of the changes in leaf form and size early in development and may have continued as cell expansion took over as the primary contributor to leaf growth and morphogenesis. Thus, leaf heteroblasty in Physcomitrella probably results from modulation of a single developmental programme by external and/or internal forces, which alter progressively in intensity as a gametophore grows. We applied exogenous cytokinin and auxin separately to growing cultures to explore their effects on leaf growth. Cytokinin and auxin stimulated leaf cell division and leaf cell elongation, respectively. Also, young upper leaves of gametophores exposed to exogenous auxin closely resembled basal leaves of untreated plants. Therefore, endogenous cytokinins and auxins may be among the modulating internal forces involved in leaf morphogenesis and the establishment of leaf heteroblasty.     

喀纳斯自然保护区6种藓类植物的解剖学研究

应用石蜡切片技术及扫描电镜方法,对喀纳斯自然保护区生长的6种藓类植物茎、叶的内部结构及其表面的角质层纹饰、疣、孔等进行比较研究,结果表明:垂枝藓(Rhytidium rugosum(Hedw.)Kindb.)叶背、腹面表皮细胞外壁均有细疣状突起,而纵列相邻细胞的壁表面角质层纹饰长,成束状平行排列;山羽藓(Abietinella abietina(hedw.)fleisch.)茎的中轴不明显,中肋背部具棘刺状突起的疣,叶背、腹面的疣倒向凹陷的细胞壁,呈遮盖状;直叶珠藓(Bartramia ithphyllaBrid.)叶背、腹面表皮细胞外壁具泡状隆起,孔不凹陷,孔口被角质层纹饰所遮盖;沼泽皱蒴藓(Aulacomnium palustre(Hedw.)Schwagr.)叶背面的粗疣由凹陷细胞壁中突出,角质层纹饰呈带状,叶腹面孔大,并多在细胞壁相交处呈张开状;塔藓(Hylocommium splendens(Hedw.)B.S.G.)叶背部粗疣呈宽刺状,叶背、腹面粗疣高,上端倒向凹陷的细胞壁;角齿藓(Ceratodon purpureus(hedw.)Brid.)叶背、腹面细胞凹陷不规则,相邻细胞壁厚,具密集的细疣。     

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。     

Anatomical Injury Induced by the Eriophyid Mite Aceria anthocoptes on the Leaves of Cirsium arvense

Anatomical injury of the leaves of the invasive species, Cirsium arvense (L.) Scop., caused by the eriophyid mite Aceria anthocoptes (Nal.), which is the only eriophyid mite that has been recorded on C. arvense worldwide, is described. The injury induced by the mite feeding on the leaves of C. arvense results in visible russeting and bronzing of the leaves. Other conspicuous deformations are folding and distortion of the leaf blade and curling of leaf edge, as well as gradual drying of leaves. The anatomical injury of the mature leaves of field-collected plants was limited to the epidermis of the lower leaf surface. However, on young leaves of experimentally infested plants, rust mite injuries extend to epidermal cells on both leaf surfaces and to those of deeper mesophyll layers. On these leaves, lesions on the lower leaf surface even affected the phloem of the vascular bundles. Leaf damage induced by A. anthocoptes is discussed with regard to the mite’s potential as a biological control agent of C. arvense.     

Leaf expansion and carbon assimilation in cotton leaves grown at two photosynthetic photon flux densities

Increasing photosynthetic photon flux density (PPFD) received during development from 5.5 to 31.2 mol m^-2 d^-1 resulted in greater leaf and mesophyll cell surface areas in cotton (Gossypium hirsutum L.). The relationships between the amounts of these surface areas and potential CO₂ assimilation by these leaves were evaluated. Leaf area (epidermal surface area of one side of a leaf), mesophyll cell surface area, and net rate of CO₂ uptake (P_n) were measured from the time leaves first unfolded until P., was substantially reduced. At the higher PPFD, leaf and mesophyll surface areas increased more rapidly during expansion, and P_n per unit leaf area was greater than at the lower PPFD. Although leaves at the higher PPFD reached the maximum P., per unit mesophyll cell surface area 4 to 5 days earlier than leaves at the lower PPFD, the maxima for these P., were similar. Leaves grown at the higher PPFD had the potential to assimilate 2.2, 3.5, or 5.8 times the amount of CO₂ as leaves from the lower PPFD when P., was expressed per unit mesophyll surface, per unit leaf surface, or per whole leaf, respectively. Greater and earlier development of both P., and mesophyll cell surface area at higher PPFD apparently had a compounding effect on the potential for carbon assimilation by a leaf.     

The role of auxin-binding protein 1 in the expansion of tobacco leaf cells

Tobacco leaf was used to investigate the mechanism of action of auxin-binding protein 1 (ABP1). The distributions of free auxin, ABP1, percentage of leaf nuclei in G2 and the amount of auxin-inducible growth were each determined in control tobacco leaves and leaves over-expressing Arabidopsis ABP1. These parameters were compared with growth of tobacco leaves, measured both spatially and temporally throughout the entire expansion phase. Within a defined window of leaf development, juvenile leaf cells that inducibly expressed Arabidopsis ABP1 prematurely advanced nuclei to the G2 phase. The ABP1-induced increase in cell expansion occured before the advance to the G2 phase, indicating that the ABP1-induced G2 phase advance is an indirect effect of cell expansion. The level of ABP1 was highest at the position of maximum cell expansion, maximum auxin-inducible growth and where the free auxin level was the lowest. In contrast, the position of maximum cell division correlated with higher auxin levels and lower ABP1 levels. Consistent with the correlations observed in leaves, tobacco cells (BY-2) in culture displayed two dose-dependent responses to auxin. At a low auxin concentration, cells expanded, while at a relatively higher concentration, cells divided and incorporated [3H]-thymidine. Antisense suppression of ABP1 in these cells dramatically reduced cell expansion with negligible effect on cell division. Taken together, the data suggest that ABP1 acts at a relatively low level of auxin to mediate cell expansion, whereas high auxin levels stimulate cell division via an unidentified receptor.     

关于野大豆盐腺问题的探讨

以中国3个省的盐生野大豆(Glycine soja Sieb. et Zucc.)为材料,在沙基培养、溶液培养和大田种植3种种植条件下用不同浓度的盐处理,观测了茎叶表面附着物的形态分布和腺毛的超微结构,测定了叶片腺毛分泌物中和叶片组织内部Na^ 和Cl^-的含量变化,并对腺毛的3个细胞以及表皮细胞和叶肉细胞内的Na^ 相对含量变化进行了X射线微区分析。结果发现：盐生野大豆茎叶表皮上生长的附着物中只有表皮毛和腺毛,腺毛的形态类似于禾本科植物中的一些盐腺,叶片上的腺毛均生长在叶脉上;腺毛细胞内部结构具有一般盐腺的特点,如有大液泡,稠密的细胞质,大量的线粒体、叶绿体、胞间连丝以及较厚的细胞壁等。通过测定在无盐对照、盐处理和盐处理加盐腺泌盐抑制剂条件下盐生野大豆叶片腺毛分泌物中和叶片组织内部的Na^ 和Cl^-含量,结果显示,盐生野大豆腺毛具有泌盐功能,加入泌盐抑制剂后,其泌盐作用停止;腺毛的3个细胞以及表皮细胞和叶肉细胞内的Na^ 在不同的盐浓度下的微区定位分析结果表明,盐生野大豆叶片的腺毛细胞有较强的积累Na^ 的能力。综合分析认为,盐生野生大豆的腺毛就是具有泌盐功能的盐腺,没有发现其他类型的盐腺。     

Leaf anatomy of a rheophyte,Dendranthema yoshinaganthum (Asteraceae), and of hybrids between D. yoshinaganthumand a closely related non-rheophyte,D. indicum

The rheophyte Dendranthema yoshinaganthum(Makino ex Kitam.) Kitam. is endemic to a region along the Naka River in Shikoku, Japan. Resembling other rheophytes that have adapted to environments along rivers, D. yoshinaganthumhas narrow leaves. In the native habitat of D. yoshinaganthumin Tokushima, Japan, natural hybridization with Dendranthema indicum (L.) Des Moul. has resulted in a species complex with conspicuous variation in leaf shape and, in particular, in leaf width. In this study, D. yoshinaganthum and hybrids with natural variation in leaf shape were cultivated under identical conditions and the anatomy of their leaves was examined. Variation in leaf width in the species complex was attributable, for the most part, to variation in the number of cells per leaf lamina and also, to some extent, to variation in cell size. This is the first report of natural variation in leaf width that is attributable to variation in both the size and the number of leaf cells.