凤尾竹硅酸体形态及其发生初探

利用光学显微镜、扫描电子显微镜对自然生长凤尾竹(Bambusa multiplex vat．nana(Roxb．)Keng f．)营养体各部分及生长发育各时期叶片的硅酸体进行观察研究。凤尾竹营养体各部分硅酸体形态分别为：叶片竹节形;叶鞘鞍形、钝方形;箨叶哑铃形;箨叶鞘鞍形;杆的表皮部位有少量椭圃形硅酸体,而内部来见成形的硅酸体;地下茎及根皆来见成形硅酸体。成熟硅酸体均沿脉横向排列。硅酸体在叶片、叶鞘、箨叶和箨叶鞘中基本上是按生长发育顺序从不成形到成形,由小到大变化的,分布由不规则到沿脉横列。同一叶从叶鞘到叶片呈现出由鞍形→钝方形(椭圆形)→竹节形渐变的趋势。光镜下,硅酸体内一般有折光率不同于其它部位的l到多个细小颗粒聚在一起形成的核状结构。凤尾竹不同生长发育期各部分硅酸体的晶核存在状况、硅酸体的形态和大小的演变趋势体现了硅质在植物器官表皮细胞上的连续沉积过程。     

白蜡虫7种寄主植物叶片解剖结构与寄主选择性的关系

用石蜡切片法在显微镜下观察白蜡虫[Ericerus pela(Chavannes)]7种寄主植物叶的解剖结构。结果表明,寄主植物的叶脉、表皮、栅栏组织、海绵组织、维管束解剖结构及数量性状特征在属、种间存在显著差异。7种寄主植物中,华南小蜡(Ligustrum calleryanum Decne.)和白蜡树(Fraxinus chinensis Roxb.)表皮被毛,华南小蜡表皮毛浓密,白蜡树表皮毛稀疏,其它寄主植物表皮无毛;女贞树(Ligustrum lucidum Ait.)栅栏组织、海绵组织和叶脉的厚度最厚、维管束直径最大,其它寄主植物相对较小。因此,叶片表面光滑、叶脉发达、叶片肥厚是白蜡虫优良寄主植物的重要解剖学特征。7种寄主植物中脉和侧脉发达,近轴面凹陷,远轴面突起,肉脉包埋在叶肉中,推测叶脉突起和凹槽可能是白蜡虫固定位点选择的关键线索。     

Midribs of cycad pinnae

Comparisons of midribs of three cycad genera,Chigua, Cycas, andStangeria, the only three genera characterized by midribs in the pinnae, show that those ofChigua andStangeria are very similar to each other and quite unlike those ofCycas. Midribs ofCycas include a single, median vein, and the pinnae of these species lack lateral veins. Pinnae midribs ofChigua andStangeria include several (2–5 and 2–8, respectively) longitudinal parallel veins, and dichotomizing lateral veins arising from the midrib. Pinnae of other cycads, includingZamia, with whichChigua appears to be most closely allied, exhibit evenly spaced, longitudinally parallel, dichotomizing veins, a character considered to be primitive. All veins in cycad leaves have a single mesarch protoxylem pole. The midrib condition inChigua andStangeria represents an advanced state in comparison to that in the leaf of the Marattiales, for example, where there is a single veined midrib but with numerous mesarch protoxylem poles. It would appear that the midrib has been derived independently at least three times within the cycads, once in each major group.     

Quantifying leaf venation patterns: two-dimensional maps

The leaf vasculature plays crucial roles in transport and mechanical support. Understanding how vein patterns develop and what underlies pattern variation between species has many implications from both physiological and evolutionary perspectives. We developed a method for extracting spatial vein pattern data from leaf images, such as vein densities and also the sizes and shapes of the vein reticulations. We used this method to quantify leaf venation patterns of the first rosette leaf of Arabidopsis thaliana throughout a series of developmental stages. In particular, we characterized the size and shape of vein network areoles (loops), which enlarge and are split by new veins as a leaf develops. Pattern parameters varied in time and space. In particular, we observed a distal to proximal gradient in loop shape (length/width ratio) which varied over time, and a margin-to-center gradient in loop sizes. Quantitative analyses of vein patterns at the tissue level provide a two-way link between theoretical models of patterning and molecular experimental work to further explore patterning mechanisms during development. Such analyses could also be used to investigate the effect of environmental factors on vein patterns, or to compare venation patterns from different species for evolutionary studies. The method also provides a framework for gathering and overlaying two-dimensional maps of point, line and surface morphological data.     

贵州小檗属植物(小檗科)叶脉序研究

采用制作叶脉标本和透明叶标本的方法,对贵州产28种2变种小檗属植物叶脉特征进行比较研究。结果表明:贵州小檗属植物的脉序类型有5种:半达缘羽状脉、花环状半达缘羽状脉、简单弓形羽状脉、花环状弓形羽状脉和混合型。叶脉分支一般有五级:1一级脉构架均为羽状脉,粗度有很粗、粗、中等粗细和纤细四种类型,分支方式包括单轴分支和合轴分支;2粗二级脉构架中有分支达缘或分支均不达缘,与中脉夹角变化各异,内二级脉存在或缺失,细二级脉半达缘、真曲行或简单弓形,间二级脉类型复杂多变但频度种间有差异;3三级脉贯串型、结网型或分支型;4四、五级脉网状或自由分支且常混合在一起。脉间区从发育差到良好,小脉从不分支到不均等分支等各种类型均有,叶缘末级脉缺失、不完整、钉状和环状。大部分种类叶缘具齿,每1cm齿数目和齿内腺点的特性等特征在不同种类间有区别,具有鉴定价值,但齿其它特征复杂多变或种间区别较小,同时齿内脉性状也不稳定。此外,齿的有无会对脉序类型产生影响。小檗属植物叶脉类型存在种间差异,具有重要的分类学价值,叶脉类型的变化和复杂程度显示了该属植物的进化特点;叶齿的有无和齿特征具有分类学和系统学意义。基于叶脉特征的研究结果并结合重要的外部形态学特征编制了贵州小檗属植物的分种检索表。研究结果可为小檗属植物分类寻找新的依据并探讨其系统学意义。     

The pathways of water movement in leaves modified into tents by bats

A number of species of bats modify leaves into tents, which they use as roost-sites. Through this process, some areas of the leaf lamina are damaged or become detached from the midrib. Such injuries do not cause death of the leaf or the detached areas, indicating that water supply to these areas must be maintained. We examined the anatomy of the vascular systems and water transport in the leaves of three species of plants: Heliconia pogonantha L., Manicaria plukenetii Griseb. & H. Wendl., and Cryosophila warcsewiczii (H. Wend.) Bartlett. In altered leaves of all three species, detached areas of the laminae were supplied with water by minor transverse veins branching from the first major parallel vein that remained intact next to the cut. These transverse veins conducted water through single xylem elements of narrow diameter (approximately 10 urn) previously thought to supply water only to mesophyll cells in their immediate vicinity. The short lengths of these veins compensates their high resistance to water flow (a consequence of their small diameter xylem elements), indicating that small transverse veins have a large capacity for water transport. Water typically flowed through transverse veins into detached major and minor parallel veins, filled these parallel veins in both directions (i.e. toward the midrib and the leaf edge), and continued on into subsequent transverse and parallel veins, thereby supplying water to the entire leaf. Water conduction through these small transverse veins could support large areas of leaf lamina, keeping the leaf-tent alive for at least several months. The maintenance of the flow of water and nutrients to areas of leaves detached by bats during the tent-making process increases the longevity and decreases the conspicuousness of leaf-tents, and is likely a key factor in the success of this roosting strategy.     

Factors affecting components of fitness in a gall-making wasp (Cynips divisa Hartig)

Summary The galls of the agamic generation of the cynipid gall-wasp Cynips divisa were studied; these galls are found only on the main veins of the leaf. Galls are concentrated on the middle veins of leaves, and generally occur closer to the midrib than to the edge of the leaf. Survival of the gall-maker and fecundity of the energing wasp depend on wasp size and position of the gall. There is a striking pattern in gall size according to the number of galls on the vein. The number of galls on a vein appears therefore to have a strong effect on potential fecundity.     

闽楠叶形态与叶脉网络性状关系对城市生长环境的响应

植物叶形态与叶脉网络功能性状的协同变异与权衡关系,对深入理解植物叶脉网络功能性状对环境变异的生态适应,以及预测植物物种生活习性对城市化过程的响应具有重要意义。闽楠作为珍贵的常绿阔叶树种,正在城市绿化中逐步推广。针对不同生长环境中（行道与植物园混交林）的闽楠,开展了叶形态与叶脉网络功能性状关系对城市生长环境的响应研究。研究结果表明：闽楠叶性状值基本满足正态分布,各性状变异系数保持在10%-20%之间,群体内性状变异较为丰富,单因素方差分析表明两种环境对叶形态性状的影响比叶脉网络系统的影响更明显;两种生长环境下闽楠叶形态性状组与叶脉网络功能性状组都具有极显著相关性,行道和植物园混交林典型性相关系数分别为0.804和0.795,叶形态性状与叶脉直径呈显著正相关,形态性状、叶脉直径与初级脉密度呈显著负相关;闽楠在响应城市生长环境的过程中呈现出相应的经济权衡机制,行道环境中闽楠以较大的初级脉密度和较小叶面积来确保水分获取和光合之间的平衡,植物园闽楠则采用较低初级叶脉密度、较高叶面积和叶脉直径的叶形态和叶脉网络构建模式。在选择闽楠作为城市绿化树种时,可将叶片形态性状组与叶脉网络功能性状组的协同变化和权衡关系作为选种依据,以提高闽楠在城市环境中的成活率和适应性。     

The contribution of foliar micromorphology and anatomy to the circumscription of species within the <Emphasis Type="Italic">Chusquea ramosissima</Emphasis> informal group (Poaceae,Bambusoideae, Bambuseae)

Chusquea is a diverse but monophyletic genus of Neotropical woody bamboos from primarily montane forests that comprises four well-supported lineages: subg. Magnifoliae, subg. Platonia, subg. Rettbergia, and the Euchusquea clade (comprising subg. Swallenochloa and subg. Chusquea). However, the relationships among clades or taxa within the Euchusquea clade inferred from molecular data are mostly not congruent with those inferred from morphological evidence, consequently limiting our ability to understand species relationships. In this study we generated foliar micromorphological and anatomical data for the Chusquea ramosissima informal group (Chusquea ramosissima, C. tenella, and C. tenuiglumis), and for the putative new species from Bolivia in this group, in order to test the value of these types of data for defining species and to seek potential synapomorphies for this group. Our results demonstrate that epidermal features, mainly with regard to the stomatal apparatus, proved to be more valuable in distinguishing species than anatomical characters. The presence of horizontally elongated silica cells over the veins and adaxial arm cells with invaginations from the abaxial side was shared by all the studied species but is not unique to this group. The type of trichomes, shape of silica bodies, type of arm cells, and midrib structure may be useful to lesser degree. All four species exhibited intraspecific variation in development of the papillae on the long cells. Support for the recognition of the new species from Bolivia is provided by micromorphological characters. An identification key based on leaf blade features is provided for the four studied species.     

叶脉结构与功能及其对叶片经济谱的影响

叶脉由贯穿于叶肉内部的维管组织及其外围机械组织构成,多样化的脉序及网络结构使叶脉系统发生变异和功能分化。该文综述了叶脉系统结构与功能的最新研究进展。通过聚焦叶脉分级系统的结构与功能及其在叶片经济谱(LES)中的重要性,解释叶脉性状与其它叶片功能性状之间的关系及机制。不同等级叶脉在机械支撑与水分运输方面存在功能分化,其中1–3级粗脉在维持叶片形状和叶表面积以及物理支撑方面发挥重要作用,有利于维持叶片最大受光面积;4级及以上细脉具有水分调节功能,它们与气孔相互协调,影响叶片水分运输、蒸腾散热和光合作用速率。叶片生长过程与叶脉发育的动态变化模式决定叶脉密度,并影响叶脉密度与叶片大小之间的关系:叶面积与粗脉密度呈显著负相关,与粗脉直径呈显著正相关,而与细脉密度无关。与叶脉性状相关的叶片经济谱框架模型预测,叶脉密度较高的叶片寿命短、比叶重较小,叶片最大碳同化速率、代谢速率以及资源获取策略潜力较高。     

Foliar sclereids in the Magnoliaceae

The foliar sclereids in 136 species representing 11 of the 12 genera of Magnoliaceae were studied and compared. Sclereids occur in four different cell assemblages within the leaf: diffuse idioblasts, mesophyll, dermal system, and the vein sheath including terminal elements. Tropical members tend to have the most highly sclerified leaves. In species of Manglietia the leaves have sclerified spongy mesophyll and either sclerified epidermis or hypodermis. In Talauma , sclerification affects the vein sheath and terminal cells of veinlets, with a specialized thick marginal vein in the Asian taxa but not in the American ones. Liriodendron and the magnolias native to the north temperate zone have only minimal sclerification, which usually is confined to the vein sheath of the midrib and the main lateral veins, and as idioblastic sclereids in the petiole and the midrib near the base of the blade. The two largest genera Magnolia and Michelia are heterogeneous and include species which vary as to their combinations of sclerified elements among the four possible types.     

Bundle sheath lignification mediates the linkage of leaf hydraulics and venation

The lignification of the leaf vein bundle sheath (BS) has been observed in many species and would reduce conductance from xylem to mesophyll. We hypothesized that lignification of the BS in lower‐order veins would provide benefits for water delivery through the vein hierarchy but that the lignification of higher‐order veins would limit transport capacity from xylem to mesophyll and leaf hydraulic conductance (K_leaf). We further hypothesized that BS lignification would mediate the relationship of K_leaf to vein length per area. We analysed the dependence of K_leaf, and its light response, on the lignification of the BS across vein orders for 11 angiosperm tree species. Eight of 11 species had lignin deposits in the BS of the midrib, and two species additionally only in their secondary veins, and for six species up to their minor veins. Species with lignification of minor veins had a lower hydraulic conductance of xylem and outside‐xylem pathways and lower K_leaf. K_leaf could be strongly predicted by vein length per area and highest lignified vein order (R² = .69). The light‐response of K_leaf was statistically independent of BS lignification. The lignification of the BS is an important determinant of species variation in leaf and thus whole plant water transport.     

中国水青冈属 （壳斗科） 叶结构及分类学意义

叶结构对壳斗科(Fagaceae)现存植物和化石的鉴定具有重要意义。通过对水青冈属5种植物叶结构特征进行细致的研究,结果发现水青冈属植物叶脉有羽状弓形脉、羽状半达缘脉两种类型;三级脉有波状对生贯穿、互生贯穿及混合贯穿三种类型;小脉缺失、简单无分支或一次分支;脉间区发育良好,网眼有三边形、四边形和五边形三种类型,排列规则;具齿种类叶齿由齿主脉和齿侧脉构成,齿侧脉环状。研究结果表明水青冈属二级脉与更高级脉序形成的结构稳定且存在种间差异,具重要分类学价值。基于水青冈属叶结构特征观察结果,本次研究编制了水青冈属植物的分种检索表;参照已有研究结果并结合重要外部形态学特征,编制了壳斗科相关类群分属检索表。     

福建山樱花形态多样性分化的研究

以闽、赣、粤、台4省13个种群292份福建山樱花种质为分析材料,对16个形态性状进行聚类分析和主成分分析。结果表明:福建山樱花不同个体间各性状均有明显差异,变异系数较大,优株选择潜力很大。系统聚类分析可将292份参试材料划分为2个表征群4个亚表征群,除重瓣型福建山樱花外,单瓣型福建山樱花的形态特征在种群间总体上无明显的分化规律,不同种群的个体交叉聚在同一个表征群内,但在同一亚表征群内,同一种群的多数个体常能聚在一起,表明种群之间在形态上发生了一定程度的分化,只是这种分化还不能清楚地区分不同的种群。主成分分析结果表明叶形、叶尖、叶缘、分枝能力、60 d苗高、花色和花形是造成福建山樱花形态分化的主要因素。     

Leaf mechanics and herbivory defence: How tough tissue along the leaf body deters growing insect herbivores

Research on herbivory defence often focuses on leaf chemistry but less on how plant mechanical properties like leaf veins deter herbivores. Herbivores often eat tough, complex plant tissue, yet how mechanical properties affect feeding performance as the consumer grows is unclear. We measured the toughness and strength of five types of leaf tissue – the midrib, the secondary and marginal veins and the lamina inside (inner) and outside (outer) the marginal vein – in mature Eucalyptus viminalis and Eucalyptus ovata leaves with punch tests. Leaf veins were, on average, 6.2 times tougher than lamina. Marginal veins were uniformly strong and tough along the leaf body, while midribs were less strong and secondary veins less tough toward leaf tips. We correlated the force required to puncture leaf tissue with the feeding performance of a chewing insect herbivore (the spiny leaf insect, Extatosoma tiaratum (Phasmida)) across four instar stages to explore the role of tough leaf veins as potential feeding barriers. Larvae more often ate less tough leaf tips and tougher tissue as they grew. However, younger larvae were capable of penetrating the tough marginal vein when starved. We suggest tough leaf veins and consumer position along the leaf body influence insect herbivore feeding performance over their lifetime.     

A quantitative estimation of sequential foliage development and fertility inDryopteris crassirhizoma

The foliage development ofDryopteris crassirhizoma Nakai was quantitatively estimated by measurements of shape and size of leaves from different developmental stages of sporophytes, to lead to an understanding of the life history characteristics of the species. The number of midrib branches (NV, number of veins) of the leaf corresponds to the leaf-shape complexity (DI, dissection index; shape complexity from a circle) and length of leafblade (BL). Some quantitative characters, such as leaf uniformity (decrease in NV variation), changes in shape and increase in number of leaves, vary progressively during foliage formation. The sequence of foliage development can be quantified using the parameter NV: for example, 15-NV for leaf uniformity, 30-NV for leaf-shape change from triangular to oblanceolate, 60-NV for increase in leaf number and leaf fertility in the course of sporophyte ontogeny. Contribution No. 3297 from the Institute of Low Temperature Science, Hokkaido University.     

中国水青冈属（壳斗科）叶结构及分类学意义

叶结构对壳斗科（Fagaeeae）现存植物和化石的鉴定具有重要意义。通过对水青冈属5种植物叶结构特征进行细致的研究,结果发现水青冈属植物叶脉有羽状弓形脉、羽状半达缘脉两种类型;三级脉有波状对生贯穿、互生贯穿及混合贯穿三种类型：小脉缺失、简单无分支或一次分支：脉间区发育良好,网眼有三边形、四边形和五边形三种类型,排列规则;具齿种类叶齿由齿主脉和齿侧脉构成,齿侧脉环状。研究结果表明水青冈属二级脉与更高级脉序形成的结构稳定且存在种问差异．具重要分类学价值。基于水青冈属叶结构特征观察结果,本次研究编制了水青冈属植物的分种检索表：参照已有研究结果并结合重要外部形态学特征,编制了壳斗科相关类群分属检索表。     

Germination and seedling morphology of four South American Smilax (Smilacaceae)

Species of Smilax, also known as greenbrier, are widely distributed in Brazil and their commercial trades are carried out by the extractivism of native species. We the aim to provide information about the germination and development of seedlings in four Smilax species, different experiments were developed under controlled conditions. We evaluated two germination treatments: temperature (30 degrees C and 20-30 degrees C) and light (presence/ absence), and for few cases the tetrazolium treatment was applied. A different treatment response was observed among the studied species. Light had a significant influence in S. brasiliensis, with the highest germination rates at 20-30 degrees C in dark conditions. S. campestris showed significant differences among temperature treatments, but not to light; while S. cissoides showed high germination rates (66-78%), independently of treatment. However, S. polyantha had low germination rates (19-24%). After one year, the expanded leaves showed different characteristics among the studied species. Leaves of S. brasiliensis were ovate, coriaceous, three main veins and prickle-like structures only on the midrib on abaxial face. S. campestris leaves were oblong, coriaceous and prickle-like structures were located at the leaf midrib and margin. S. cissoides had ovate-elliptic, membranaceous leaves, with three main veins with prickle-like structures on the abaxial face. S. polyantha leaves showed ovate-elliptic, coriaceous leaves, with three main veins, translucent secondary veins and no prickle-like structures. A seedling identification key was elaborated based on morphological characteristics.     

An insect countermeasure impacts plant physiology: midrib vein cutting, defoliation and leaf photosynthesis

One type of specialised herbivory receiving little study even though its importance has frequently been mentioned is vein cutting. We examined how injury to a leaf's midrib vein impairs gas exchange, whether impairment occurs downstream or upstream from injury, duration of impairment, compared the severity of midrib injury with non-midrib defoliation, and modelled how these two leaf injuries affect whole-leaf photosynthesis. Leaf gas exchange response to midrib injury was measured in five Asclepiadaceae (milkweed), one Apocynaceae (dogbane), one Polygonaceae and one Fabaceae species, which have been observed or reported to have midrib vein cutting injury in their habitats. Midrib vein injury impaired several leaf gas exchange parameters, but only downstream (distal) from the injury location. The degree of gas exchange impairment from midrib injury was usually more severe than from manually imposed and actual insect defoliation (non-midrib), where partial recovery occurred after 28 d in one milkweed species. Non-midrib tissue defoliation reduced whole-leaf photosynthetic activity mostly by removing photosynthetically active tissue, while midrib injury was most severe as the injury location came closer to the petiole. Midrib vein cutting has been suggested to have evolved as a countermeasure to deactivate induced leaf latex or cardenolide defences of milkweeds and dogbanes, yet vein cutting effects on leaf physiology seem more severe than the non-midrib defoliation the defences evolved to deter.