新疆天山一号冰川10种真藓属植物叶片结构的研究

对新疆天山一号冰川的10种真藓属植物的叶片结构进行解剖学观察,探究其叶片的形态特征与环境的关系和分类学意义,结果表明:这10种真藓植物叶片细胞中的细胞质较浓,中肋具大型的主细胞和较发达的小型厚壁细胞,叶的细胞壁加厚且在干时表面向内凹陷,大多数叶片表面具有颗粒及菱形、纵形等不同形状纹饰等,这些都是植物为了提高自身的抗寒耐旱性,减少水分蒸发,增强导水作用对环境的适应性。虽然有的种类亲缘关系很近,叶片具有相似之处,但用石蜡切片和扫描电镜相结合的方法可以较容易和准确地将它们区分开来,为真藓属植物的分类补充一些理论依据。     

冰川两种藓在超低温胁迫与恢复生长状态下叶肉细胞的超微结构

为了探讨高寒冰缘区的藓类植物在超微水平的抗寒机制,该文对一号冰川下不同基质两种藓类植物水中土生的金黄银藓(Anomobryum auratum)和岩面土生的刺叶墙藓(Tortula desertorum)在常温、超低温胁迫和经胁迫后的恢复状态的超微结构进行对比。结果表明:室温下藓类植物叶肉细胞结构完整、清晰。-80 ℃超低温胁迫处理后叶肉细胞的超微结构的变化为两种藓类植物叶肉细胞大多数未出现质壁分离,但会出现质壁结构模糊,细胞质收缩; 细胞器遭到破坏甚至解体的情况; 淀粉粒、脂滴和液泡数量大大增加。在室温恢复过程中,线粒体数量增加,各个细胞器结构比超低温胁迫状态下完整性增加。根据该文的亚显微结构的分析推测这些变化是为了适应细胞迅速恢复生理功能,-80 ℃超低温胁迫没有完全使藓类植物丧失生理功能,还可以进行恢复。岩面土生刺叶蔷藓的叶细胞胞壁厚度为1 100～1 300 nm,大于水中土生金黄银藓的叶细胞胞壁厚度(200～700 nm),刺叶墙藓叶细胞胞壁比金黄银藓更厚,分析推断刺叶墙藓细胞器的抗胁迫能力也更强。综上结果表明:一号冰川的这两种藓类植物抗寒能力极强,它们独特的抗寒机制不仅与超微结构下植物淀粉粒、细胞器的结构和功能完整有关,还与其生境有关。     

四种藓类植物叶片解剖结构观察

使用石蜡切片法对四川壤塘的 4种藓类植物叶片的结构进行解剖学观察和比较分析 ,结果表明扭口红叶藓Bryoerythrophylluminaequalifolium (Tayl.)Zand .、台湾拟金发藓Polytrichas trumformosum (Hedw .)G .Sm .和梨蒴珠藓BartramiapomiformisHedw .的中肋由多层细胞构成 ,并有明显的细胞分化 ,而长蒴紫萼藓GrimmiamacrothecaMitt.的中肋结构较简单 ,无明显的细胞分化。 4种藓类植物的叶片细胞都只有 1层 ,但台湾拟金发藓的叶片上有栉片 ,扭口红叶藓叶片细胞表面有细疣 ,长蒴紫萼藓的叶片细胞壁明显加厚。此外 ,4种植物的叶片厚度和中肋厚度 ,及其细胞密度之间差异都比较明显     

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。     

毛乌素沙地10种重要沙生植物叶的形态结构与环境的关系

10种重要沙生植物叶器官的比较解剖学研究表明其普遍特征是;叶片的表面积与体积比值小;叶表具表皮毛和厚的角质膜;气孔下陷、具孔下室;叶肉中栅栏组织发达;叶各类组织中普遍有含晶细胞和粘液细胞,具有发达的机械组织和输导组织。个别植物叶退化而由同比枝行使光合作用;部分植物具皮下层和异细胞层,以及具异常结构,以上特征是适应沙漠干旱环境的结果,反映出植物形态结构与环境的统一性。     

两种生境下的8种藓类植物茎结构的比较解剖学研究

对极端生境(旱生与水生)下的8种藓类植物,旱生条件下生长的虎尾藓(H edw ig ia cilia ta(H edw.)P.B eauv.)、欧黑藓东亚变种(And reaea rup estrisH edw.var.f auriei(B esch)T akak i)、长蒴紫萼藓(G rimm ia m acrothe-ca M itt.)、日本蓑藓(M acrom itrium jap on icum D oz.et M o lk)和簇生砂藓(R acom itrium aqua ticum(Schrad.)B rid.),水生条件下生长的大叶凤尾藓(F issid ens g rand if rons B rid.)、鳞叶水藓(F ontina lis squam osa H edw.)和短尖美喙藓(E urhynch ium angustirete(B roth.)T.K op.)进行了茎的横切及离析后细胞形态学的比较研究.结果表明:(1)生长在干旱条件下的5种藓类植物的茎无中轴分化,细胞壁厚;离析后可见细胞端尾和纹孔场数目多,端尾数目增多扩大了细胞间的接触表面积,纹孔场数目最多为2.60/细胞,显示出其机械组织发达,这些是对旱生生长环境的适应.(2)生长在水生条件下的3种藓类植物茎的中轴有或无,细胞壁薄;离析后可见细胞端尾和纹孔场数目少,纹孔场数目最少为0.37/细胞,茎表皮细胞壁薄且茎内有大量薄壁细胞,表明其机械组织不发达,这些特征与水生生长环境相适应.本文还对8种藓类植物茎的结构特征在分类中的应用进行了探讨,认为茎表皮、内外皮部宽度及细胞分化的比例、中轴的有或无等在属间种内的性状是稳定的,具分类学意义.     

四种旱生藓类植物的比较结构学观察

对新疆产的4种藓类植物茎、叶的表面及内部结构进行了观察,结果表明：尖叶大帽藓(Encalypta rhabdocarpa Schwaegr.)茎的中部结构类似于种子植物(单子叶)根的内皮层,其茎表皮也有类似于种子植物表皮毛(腺毛)的腺体。在阔叶紫萼藓(Grimmia laevigata (Brid.) Brid.)茎的中轴部,厚角组织发达,数层皮部厚壁组织也很发达。小石藓(Weisia controversa Hedw.)叶中肋之中有小形厚壁细胞。弯叶墙藓(Tortula reflexa Li)的茎呈多棱形,表皮层具很厚的“树皮状”老皮,其叶表皮细胞密被马蹄形及叉状粗疣。这些特征反映了该类群植物由低等向高等演化的趋势,并可作为分类学依据之一。     

冰缘区藓类植物叶中肋细胞生态适应性分析

对采自新疆天山一号冰川冰缘区的35种生长在不同生境的藓类植物，分别观察离析后其叶片的中肋导水细胞长、宽，细胞壁厚薄、细胞端尾和纹孔场的数目。湿土面、阴湿岩面、土面和岩面四种生境下的藓类植物叶中肋细胞，随着生境中水分条件由湿到干其细胞长度、细胞宽度和厚度均有变大的趋势；中肋细胞端尾的形式多样，生长在土面的藓类具有多个端尾，具有增强细胞间的联系，有效控制导水和物质交换速度，并提高机械固着和支撑作用。不同生境下叶中肋细胞侧壁的纹孔场数目并无明显差异。中肋细胞的特征反映出其对冰缘区极端而复杂的环境的适应策略，为进一步研究苔藓植物在高寒环境地区的导水机理及生态适应性提供了一定的参考依据。     

冰川退缩地26种丛藓科植物叶中肋细胞结构的研究

该研究应用离析方法,并通过光学显微镜对新疆天山一号冰川退缩地的26种丛藓科植物叶片中肋细胞的形态结构进行比较分析,结果表明:(1)丛藓科植物叶片的中肋细胞的长、宽和细胞壁厚度、纹孔场数目及细胞端尾数目在一定程度上存在着差异,反映出各中肋细胞的功能及导水作用在同属及不同属植物之间存在一定的差异。(2)中肋细胞的端尾多以及细胞壁的波状结构都具有增强细胞间的联系、提高机械固着和支撑作用。(3)不同生境下,中肋细胞侧壁的纹孔场数目能有效控制导水和物质交换的速度。这些特征可能都是冰川地区苔藓植物对恶劣生境的积极响应,具有一定的生态学和分类学意义。     

中国新记录——毛齿藓短蒴变种(新拟)

该研究首次报道了毛齿藓短蒴变种(新拟)在中国的分布和毛齿藓属在新疆的分布。研究表明：(1)毛齿藓短蒴变种的主要识别特征为：叶基部鞘状,突然狭窄成线状披针形,背仰,叶缘平展,中肋充满叶上部,背面粗糙,远轴面有厚壁细胞束分化,叶细胞长方形至短长方形;有假根生芽胞;孢蒴椭球形,稍弓形弯曲,蒴齿线状披针形,二裂至近基部。(2)毛齿藓属的3个分类单位在中国均有分布,毛齿藓短蒴变种以较短的孢蒴和蒴柄区别于原变种,以有根生芽胞、叶基部呈明显鞘状、叶缘平展区别于云南毛齿藓的无假根生芽胞、叶基部略呈鞘状、叶缘背卷。(3)在牛毛藓科中有许多类群与毛齿藓短蒴变种形态相似,但仅有毛齿藓属的叶在横切面上主细胞的远轴面有厚壁细胞束,而其他类群的叶在横切上主细胞的近轴面和远轴面均有厚壁细胞束。该变种的叶背仰不同于牛毛藓科其他属的叶直立;以具鞘部的叶、表面光滑的孢蒴、内弯的蒴齿区别于无鞘部的叶、表面有纵沟槽的孢蒴、直立的蒴齿的牛毛藓属。(4)该变种属北极 高山分布类型,表现出了明显的欧洲 亚洲 北美洲间断分布模式,可作为研究气候变化、海陆变迁的重要材料。     

Vinealobryum guangdongensis (Pottiaceae,Musci), a new species with multicellular axillary gemmae from Guangdong,China

A new species belonging to Didymodon sensu lato, Vinealobryum guangdongensis, is described and illustrated from Nanling National Forest Park of Guangdong, China. It is characterized by noteworthily thick‐walled cells of the cauline central cylinder, ovate‐lanceolate leaves that are appressed when dry, acuminate to acute leaf apices, leaf base abruptly broadened and quickly narrowed to the insertion, leaf margins recurved in proximal 2/3 to 3/4, short‐excurrent costa with 0–1 layer of ventral stereids, laminal cells with conical or elliptical papillae either over the lumina or over transverse walls, presence of gemmae in the leaf axils, and KOH laminal color reaction red to reddish orange. This new species is compared with the most similar species and its ecology is discussed.     

云南秋海棠属植物叶片横切面比较解剖研究

报道30种主产于云南的秋海棠属植物叶片的横切面解剖构造特征。采用常规石蜡切片法切片观察,结果表明:云南秋海棠属植物叶片薄、横切面均为异面叶、呈典型的阴叶结构,叶肉组织虽有栅栏组织和海绵组织的分化,但栅栏组织不发达,占叶肉组织的比例较小。表皮多为单表皮,极稀复表皮,表皮毛均由多细胞组成。气孔集中于下表皮,孔下室或下陷气孔特大、通气组织极发达;角质层形状多样,呈均匀增厚、瘤状和片状突起;叶绿体椭球形、数多、个体大,主要分布于叶肉组织,集中于栅栏组织。解剖构造特征在各分类组内呈现不完全一致性,而在相同茎的形态类型中有些较一致的特征,在不同种间解剖特征各有差别;根状茎和直立茎类型种类的横切面组织结构表现为表皮细胞壁外的角质层薄、栅栏组织与叶肉组织厚度比例较小等弱光照、湿生等适应性较弱的特征。球茎类型的种类表现为角质层较厚、栅栏叶肉组织厚度比例较大等适应略为干燥和较强光照的特征。     

Didymodon mesopapillosus sp. nov. (Pottiaceae) from Tibet,China

Didymodon mesopapillosus J. Kou, X.‐M. Shao & C. Feng is described and illustrated as a new species from Tibet, China. It is characterized mainly by its ovate to ovate‐lanceolate leaves appressed to weakly erect when dry, margins recurved from leaf base to apex, laminal cell superficial walls markedly thicker than the internal walls, laminal papillae present only on both sides of costa, short‐excurrent costa, undifferentiated basal cells and differentiated perichaetial leaves. This species is compared with similar species and its ecology is discussed.     

Interspecific Variation in RGR and the Underlying Traits among 24 Grass Species Grown in Full Daylight

Abstract: A growth analysis was conducted with 24 central European grass species in full daylight to test whether traits underlying interspecific variation in relative growth rate (RGR) are the same in full daylight as they are at lower light, and whether this depends on the ecological characteristics of the studied species, i.e., their requirements with respect to nutrient and light availability.
In contrast to studies with herbaceous species at lower light, net assimilation rate (NAR) contributed more than leaf area ratio (LAR) or specific leaf area (SLA) to interspecific variation in RGR. This was associated with a larger interspecific variation in NAR than found in experiments with lower light. Without the two most shade-tolerant species, however, the contribution of LAR and its components to interspecific variation in RGR was similar or even higher than that of NAR.
Leaf dry matter content correlated negatively with RGR and was the only component of LAR contributing in a similar manner to variation in LAR and RGR. There was a positive correlation between NAR and biomass allocation to roots, which may be a result of nutrient-limited growth. RGR correlated negatively with biomass allocation to leaves. Leaf thickness did not correlate with RGR, as the positive effect of thin leaves was counterbalanced by their lower NAR.
Low inherent RGR was associated with species from nutrient-poor or shady habitats. Different components constrained growth for these two groups of species, those from nutrient-poor habitats having high leaf dry matter content, while those from shady habitats had thin leaves with low NAR.     

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。     

Effects of leaf litter on the growth of boreal feather mosses: Implication for forest floor development

Question: What is the effect of leaf litter on growth and mortality of feather mosses. Three experiments were conducted to isolate the shading effect from the effect of leaching of soluble compounds from the leaf litter effect on feather moss mortality and growth. Location: Edmonton, Alberta and the northern boreal coniferous forest, west‐central Alberta, Canada. Methods: In a field experiment Populus tremuloides (aspen) leaf litter was applied to beds of feather mosses dominated by Hylocomium splendens. Treatments were one layer of leaves held in place with netting; one layer of leaves coarsely ground, sprinkled over the moss layer; a shade cloth equivalent to one layer of leaves; and a control. In two growth chamber experiments, the application of aqueous extracts of P. tremuloides and Pinus contorta leaf litter and the effect of shade and soluble carbohydrates were tested on the growth and mortality of Ptilium crista‐castrensis. Results: Mortality of Hylocomium was greatest under the intact leaves, followed by the treatments using shade cloth and ground leaves and finally the control. The application of aqueous extracts of aspen leaf litter resulted in senescence or death of nearly all Ptilium shoots compared to no effects for the control or for similar extracts of pine needle litter. Extracts from aspen litter had greater concentrations of phenolic compounds and soluble sugars than pine extracts. Addition of sugars to Ptilium allowed it to grow and accumulate carbohydrates, even in low light conditions. Conclusions: Results suggest that broad‐leaved deciduous overstory species can limit the growth of feather mosses through their leaf litter and by implication affect the humus form, nutrient cycling, and understory composition of these forests.     

喀斯特退化天坑阴坡阳坡壳斗科植物的功能性状特征

喀斯特退化天坑的负地形生境中阴坡和阳坡的局域环境具有显著差异,导致植物群落类型差异明显。本研究以云南沾益退化天坑深陷塘为例,探究退化天坑阴坡与阳坡壳斗科植物功能性状特征,有助于揭示天坑的物种多样性保护库价值。结果表明: 阴坡土壤营养物质含量高于阳坡,阴坡壳斗科植物的叶面积、比叶面积和叶干重显著大于阳坡,叶厚度显著小于阳坡,叶干物质含量小于阳坡;阴坡壳斗科植物功能性状的主要环境影响因子是土壤全钾和土壤含水量,全磷是阳坡的主要环境影响因子。阴坡的叶功能性状变异程度小于阳坡,主要是以改变叶干重增加植物体内光合速率和碳积累能力的方式适应阴坡生境;阳坡通过保持较小比叶面积,增加叶面积变异程度来获得更多的资源。退化天坑深陷塘阴坡植物群落演替速度明显快于阳坡,壳斗科植物优势在阴坡逐渐减小,在阳坡仍是优势建群种。     

Chenia zanderi C.Feng & J.Kou (Pottiaceae,Musci), a new species from Yunnan,China

A new species, Chenia zanderi C.Feng & J.Kou, from Xishan Forest Park in Yunnan Province, China is described and illustrated. Particularly distinctive features of the new species are the fragile stems and leaves fragile along their insertions, narrow leaves usually constricted near the middle, broadly rounded leaf apices with a long apiculus, large distal laminal cells with numerous solid and bifurcate papillae, a narrow groove on the distal ventral surface of the costa, and absence of a costal stereid band. A key for the species recognised in Chenia R.H.Zander is also provided.