墨兰组织培养植株的叶结构和生理特性

墨兰叶肉没有海绵组织和栅栏组织的分化,但在叶的不同部分的叶脉附近叶肉细胞有不同的形态变化。叶尖和叶中部中脉附近的叶肉细胞排列紧密。细胞明显伸长,似栅栏组织,叶基部中 叶肉细胞没有伸长,叶部叶绿体周径大,叶绿素含量高,光合速率亦较高,且Fv/Fm、φPSⅡ和qp均较叶的其他部分高。     

桂花叶解剖结构的研究

通过石蜡切片法制片,光学显微镜观察,研究了桂花叶的形态解剖结构。结果表明,桂花叶为典型的异面叶,表皮由1层排列紧密的形状不规则的表皮细胞构成,细胞外壁角质膜较厚,气孔只分布于下表皮。表皮上被有腺毛,腺毛及其周围排列整齐的表皮细胞形成环式结构。叶肉组织发达,栅栏组织由2～4层排列整齐的圆柱形细胞构成。叶肉中分布有少分枝或不分枝的石细胞,其细胞长轴与表皮垂直。叶脉结构较为复杂,主脉发达。上述特征与复杂多变的环境条件相适应。     

稀有植物香果树叶解剖结构的研究

通过石蜡切片法制片,光学显微镜观察,Motic显微摄像,研究了香果树（Emmenopterys henryi Oliv.）的叶形态解剖结构。结果表明,香果树叶为典型异面叶;表皮由一层紧密的形状不规则的表皮细胞组成,细胞外壁角质膜较薄;气孔类型为平列型,仅分布于下表皮;下表皮上零星分布着多细胞表皮毛;叶肉组织发达,栅栏组织由1~2层排列整齐的圆柱形细胞构成;海绵组织枝状分布,排列极为疏松,细胞间隙大;叶脉主脉发达;上述特征反映出植物结构与环境的统一性。     

榉树叶片解剖构造和叶肉细胞超微结构的观察

对取自不同季节的榉树(Zelkova schneideriana hand.-Mazz.)叶的解剖构造和叶肉细胞超微结构进行了观察。榉树叶表面被密集锥状单细胞毛,幼叶则还有头状腺毛。气孔多分布在叶下表面,为不规则型。上表皮细胞外壁具有明显的角质层加厚,局部上表皮由2层细胞组成。叶肉细胞分化为栅栏组织和海绵组织;栅栏组织1—2层细胞;海绵组织发达,常与气孔相连。叶肉有含晶细胞存在。叶脉的维管束鞘明显,是厚壁细胞。成熟叶肉细胞细胞器丰富,有8-9个周壁叶绿体,为巨大的长椭圆形,基粒片层清晰,有淀粉粒,少量脂滴。叶片开始转变颜色时,叶绿体由长椭圆形变得趋于圆形;基粒片层逐渐变得杂乱至模糊不清;脂滴数目增多。秋季叶色不同的榉树叶片解剖构造存在一定差异。     

光果甘草营养器官结构及其总黄酮的组织化学定位和含量研究

应用植物解剖学、组织化学和植物化学方法,对光果甘草各营养器官的结构、总黄酮的组织化学定位和含量差异进行了研究.结果显示:(1)光果甘草叶为异面叶,由表皮、叶肉和叶脉组成.叶表皮具腺毛,叶肉中具胶囊细胞,主脉发达;茎由表皮(周皮)、皮层、维管柱组成,其髓中具有粘液细胞;根由周皮、次生维管组织组成,周皮具厚木栓层,次生维管组织中次生木质部和纤维发达.(2)黄酮类物质在叶中分布在表皮、腺毛、胶囊细胞、厚角组织和韧皮部和木质部中的薄壁细胞中;茎中分布在周皮、韧皮部和粘液细胞中;在根中则分布在周皮中.(3)不同营养器官中黄酮类物质含量存在差异:叶＞根茎＞主根＞茎.(4)温度的下降促使黄酮类物质从地上合成器官向地下储藏器官的转运.建议每年可在果熟期和枯萎期之间采挖药材,地上部分收割也作药用,综合利用光果甘草资源.     

不同耐旱性大麦品种叶片发育的研究

选用耐旱性不同的两个大麦品种作为研究对象,分析其叶片结构的异同。结果表明:两个大麦品种的叶片发育可以分为幼叶萌发期、幼叶抽出期、幼叶生长期和叶片成熟期四个阶段,其中在幼叶萌发期,叶片结构无明显差异。经PAS染色,从幼叶生长期开始,耐旱性弱的Moroc 9-75,含淀粉粒的叶肉细胞少,淀粉粒颗粒小; 耐旱性强的HS 41-1,含淀粉粒的叶肉细胞多,淀粉粒颗粒大。遭受干旱胁迫后,两个品种的植株长势明显较弱,叶片短而窄; 表皮细胞角质层变厚,叶片中叶肉细胞变小,叶肉细胞胞间隙变大,叶肉细胞破裂现象增多; PAS染色反应显示,含淀粉粒的叶肉细胞减少,淀粉粒颗粒变小或基本没有; HS 41-1解体的细胞不如Moroc 9-75多。因此,在光镜下,叶片结构的差异,特别是细胞含有的淀粉粒大小与数量的区别,是植物对水分胁迫的一种适应; 同时叶脉对植物刚性的影响较大。     

两种寄生植物营养器官结构的研究

研究了槲寄生和北桑寄生茎、叶和吸器的结构,结果表明：槲寄生三年生茎稍肉质化,无周皮,有极厚的角质层;皮层有7个纤维束,薄壁组织发达;木质部中亦含有大量薄壁组织;韧皮部发达;簇晶及大量粘稠物质在茎中广泛分布。槲寄生叶肉质化,厚1.44 mm; 角质层发达,厚度为9.06～13.4 μm;叶肉无栅栏组织和海绵组织的分化。北桑寄生茎与正常木本植物茎的结构相似,木质部为典型的环孔材;韧皮部含有石细胞;髓部细胞壁厚,单纹孔明显。北桑寄生叶较薄,叶脉发达,无栅栏组织和海绵组织的分化。两种植物的吸器结构相似,由薄壁组织和螺纹导管组成,它们的螺纹导管长度相同,但槲寄生导管的直径是北桑寄生的2.5倍。     

家蚕消化管内桑叶的银染法研究

通过银染法对家蚕整体染色,结果表明:家蚕消化管内的桑叶由叶表皮、叶肉和叶脉组成。叶表皮包括上表皮和下表皮。上表皮细胞可分为三种:钟乳体细胞、绿色表皮细胞和黄色表皮细胞;下表皮内含有气孔;叶肉组织内含有晶体,其中海绵组织内的最多。家蚕消化管由前向后可分为前肠、中肠和后肠,由外向内依次为肌层、底膜、上皮细胞层、内膜。中肠最为发达,其发达的上皮细胞向内表面突起形成许多大的指突形皱褶;上皮细胞层内有圆筒形细胞、杯形细胞两种细胞,两者在形状、功能以及嗜银性等方面有所差异。家蚕消化管对桑叶不同组织的消化吸收效率有差异,上表皮吸收效率最高,下表皮和栅栏组织次之,最低的是海绵组织。采用动物细胞染色方法对植物细胞进行染色,并与常规植物学染色方法进行了比较;依据细胞嗜银性的不同,可将桑叶的上表皮细胞分为两种亚型。     

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。     

蚕用桑不同品种叶表皮形态和结构的比较研究Ⅰ

运用光学显微镜和扫描电镜对11种蚕用桑品种的叶表皮形态和结构进行观察研究。结果表明,品种间在表皮、叶肉和叶脉上的构造基本相似;主要差别在于气孔密度、上表皮细胞中的钟乳体细胞数目及叶肉中晶体的分布。基于表皮形态学特征的数量分析,结果表明,11个品种可分为6大类,这与传统分类结果基本一致。     

蕤核叶片解剖结构和组织化学定位研究

采用解剖学和组织化学方法,研究了蕤核(Prinsepia uniflora Batal.)叶片的解剖结构,并对叶片中的黄酮类、生物碱类及多糖的组织化学定位进行了研究。结果表明:蕤核叶片上表皮有角质层,下表皮有气孔分布,气孔密度为278个·mm-2,近轴面栅栏组织细胞2～3层,排列紧密而整齐,含有许多晶体;叶片主脉木质部发达,由多列导管组成。上述特征说明蕤核叶片的解剖结构与环境之间的适应性。组织化学定位显示黄酮多分布于栅栏组织和厚角组织,生物碱含量少,多糖均匀分布于叶肉中。     

墨兰试管苗植株的发育解剖学研究

用石蜡切片和扫描电镜对墨兰试管苗植株的生长发育进行了研究。发现幼叶中脉附近的叶肉细胞类似栅栏组织,随着叶片的不断成熟,叶片基部中脉附近的叶肉细胞逐渐变为近圆形或椭圆形,而叶尖部和叶中部中脉附近的叶肉细胞仍似栅栏组织。茎的发育经历了原球茎、根状茎和假鳞茎3个阶段。原球茎的大部分细胞都含有淀粉粒,根状茎的皮层细胞含淀粉粒,而假鳞茎几乎不含淀粉粒。幼根没有髓,皮层细胞含淀粉粒：成熟根具含淀粉粒的髓。出瓶苗上即带有4个芽,一般只有最外侧叶腋的1个花芽和最内侧叶腋的1个叶芽发育。     

青藏高原草地植物叶解剖特征

运用常规石蜡制片技术对我国青藏高原66种草地植物优势种的叶解剖特征进行研究,并分析了叶解剖特征与海拔、生长季降水及生长季均温之间的关系.结果表明:青藏高原草地植物叶片具有很多适应高寒环境的结构特征,如表皮层厚且表皮细胞大小差异显著,表皮毛等表皮附属物发达,异细胞丰富,通气组织普遍发达等;叶片各组成部分厚度的变异程度不同,其中海绵组织厚度变异最大,其次为上角质层、下表皮层、下角质层、上表皮层、栅栏组织,叶片厚度的变异最小;青藏高原草地植物叶片各组成部分的厚度存在协同进化,上下角质层厚度呈强烈正相关,海绵组织厚度与叶片厚度相关性最强;青藏高原草地植物叶片各组成部分的厚度与海拔、生长季降水、生长季均温3个重要环境变量呈较弱的相关性,总体表现为随海拔升高叶片各组成部分的厚度减小,而随生长季降水和生长季均温的增加叶片厚度增加.     

Improved Methods for the Measurement of Total Cell Surface Area in Leaf Mesophyll Tissue

Two improved methods are described for the measurement of thetotal surface area of mesophyll cells in leaf tissue. The firstinvolves stereological measurements on suspensions of enzymicallyisolated mesophyll cells; the second involves measurements ofthe total perimeter of mesophyll cell profiles on transversesections of the leaf, with allowance for curvature of the cellsurfaces by means of theoretically based correction factors.Application of the two methods to the mesophyll tissue of tobaccoleaves gave results which were in very good agreement with eachother. Both methods avoid the inaccuracies and uncertaintiesof previous methods for measurement of mesophyll cell surfaceareas. Key words: Mesophyll, Surface: Area     

Spatial distributions of expansion rate, cell division rate and cell size in maize leaves: a synthesis of the effects of soil water status, evaporative demand and temperature

The spatial distributions of leaf expansion rate, cell division rate and cell size was examined under contrasting soil water conditions, evaporative demands and temperatures in a series of experiments carried out in either constant or naturally fluctuating conditions. They were examined in the epidermis and all leaf tissues. (1) Meristem temperature affected relative elongation rate by a constant ratio at all positions in the leaf. If expressed per unit thermal time, the distribution of relative expansion rate was independent of temperature and was similar in all experiments with low evaporative demand and no water deficit. This provides a reference distribution, characteristic of the studied genotype, to which any distribution in stressed plants can be compared. (2) Evaporative demand and soil water deficit affected independently the distribution of relative elongation rate and had near-additive effects. For a given stress, a nearly constant difference was observed, at all positions of the leaf, between the relative elongation rates of stressed plants and those of control plants. This caused a reduction in the length of the zone with tissue elongation. (3) Methods for calculating cell division rate in the epidermis and in all leaf tissues are proposed and discussed. In control plants, the zone with cell division was 30 mm and 60 mm long in the epidermis and in whole tissues, respectively. Both this length and relative division rate were reduced by soil water deficit. The size of epidermal and of mesophyll cells was nearly unaffected in the leaf zone with both cell division and tissue expansion, suggesting that water deficit affects tissue expansion rate and cell division rate to the same extent. Conversely, cell size of epidermis and mesophyll were reduced by water deficit in mature parts of the leaf.     

胡杨雌雄株叶片的比较解剖学研究

应用石蜡切片法对胡杨(Populus euphratica Oliv.)雌、雄株叶片进行比较解剖研究,结果表明:(1)胡杨雌、雄株叶片都由表皮、叶肉与叶脉构成,表皮由2层细胞构成复表皮;上、下表皮内均分化出了2～3层栅栏组织细胞,栅栏组织之间有少量海绵组织细胞;主脉维管束通常1个,由木质部、韧皮部、少量形成层及类似禾本...     

菠萝蜜花药发育及花粉萌发研究

研究花药发育过程和花粉萌发条件是菠萝蜜稳产优质的基础。采用石蜡切片和离体培养的方法,对菠萝蜜花药的发育和花粉萌发进行了研究,结果表明：菠萝蜜的花药有4个花粉囊;减数分裂的胞质分裂有连续型和同时型两种形式,形成了等双面体排列和四面体排列的四分体;成熟花药的表皮细胞积累有大量的单宁。160 g·L^-1的蔗糖和0.25 g·L^-1的硼酸混合溶液对菠萝蜜花粉萌发具有明显的促进作用,CaCl₂对菠萝蜜花粉萌发作用不明显。     

Leaf biomechanics, morphology, and anatomy of the deciduous mesophyte Prunus serrulata (Rosaceae) and the evergreen sclerophyllous shrub Heteromeles arbutifolia (Rosaceae)

Leaf tensile properties were compared between the mesic deciduous tree Prunus serrulata (var. "Kwanzan") and the xeric and sclerophyllous chaparral evergreen shrub Heteromeles arbutifolia (M. Roem). All values for biomechanical parameters for H. arbutifolia were significantly greater than those of P. serrulata. The fracture planes also differed between the two species with P. serrulata fracturing along the secondary veins, while H. arbutifolia most often fractured across the leaf irrespective of the vein or mesophyll position, thus yielding qualitative differences in the stress-strain curves of the two species. Anatomically, P. serrulata exhibits features typical for a deciduous mesophytic leaf such as a thin cuticle, a single layer of palisade mesophyll, isodiametric spongy mesophyll, and extensive reticulation of the laminar veins. Heteromeles arbutifolia leaves, however, are typically two- to three-fold thicker with a 35% higher dry mass/fresh mass ratio. The vascular tissue is restricted to the interface of the palisade and spongy mesophyll near the center of the leaf. Both epidermal layers have a thick cuticle. The palisade mesophyll is tightly packed and two to three layers thick. The spongy mesophyll cells are ameboid in shape and tightly interlinked both to other spongy cells as well as to the overlying palisade layer. We conclude that the qualitative and quantitative biomechanical differences between the leaves of these two species are likely due to a complex interaction of internal architectural arrangement and the physical/chemical differences in the properties of their respective cell walls. These studies illustrate the importance that morphological and anatomical correlates play with mechanical behavior in plant material and ultimately reflect adaptations present in the leaves of chaparral shrubs that are conducive to surviving in arid environments.     

Intraspecific variation in morphology of spiny pollen grains along an altitudinal gradient in an insect-pollinated shrub

• Intraspecific variations in pollen morphological traits are poorly studied. Interspecific variations are often associated with pollination systems and pollinator types. Altitudinal environmental changes, which can influence local pollinator assemblages, provide opportunities to explore differentiation in pollen traits of a single species over short distances. The aim of this study is to examine intraspecific variations in pollen traits of an insect-pollinated shrub, Weigela hortensis (Caprifoliaceae), along an altitudinal gradient.
• Pollen spine phenotypes (length, number and density), pollen diameter, lipid mass (pollenkitt) around pollen grains, pollen production per flower and pollinator assemblages were compared at four sites at different altitudes.
• Spine length and the spine length/diameter ratio of pollen grains were greater at higher altitudes but not correlated with flower or plant size. Spine number and density increased as flower size increased, and pollen lipid mass decreased as plant size increased. Bees were the predominant pollinators at low-altitude sites whereas flies, specifically Oligoneura spp. (Acroceridae), increased in relative abundance with increasing altitude.
• The results of this study suggest that the increase in spine length with altitude was the result of selection favouring longer spines at higher-altitude sites and/or shorter spines at lower-altitude sites. The altitudinal variation in selection pressure on spine length could reflect changes in local pollinator assemblages with altitude.