潮滩红树植物抗低温适应的重庆研究

采用电导法演量测定了中国东南沿海红树植物叶片的抗寒力变化。结果表明：（１）海南琼山东寨港主要红树种类冬季抗寒力（半致死温度）介于－２．３￣－６．８℃之间,其中红树科植物抗寒力较强,多数种类属低温敏感性相对较弱的Ｌ类型：海桑科和楝科红树种类抗寒力较弱,属于低温敏感性较强的Ｈ类型。（２）随纬度升高（个别地点除外）,秋茄（Ｈａｎｄｅｌｉａ ｃａｎｄｅｌ）桐花树（Ａｅｇｉｃｅｒｓａ ｃｏｒｎｉｃｕｌａｔｕ     

草苁蓉大小孢子与雌雄配子体发育

草苁蓉大小孢子与雌雄配子体发育桂明珠,李桂琴,胡宝忠,陈雅君,王学东（东北农业大学,哈尔滨１５００３０）草苁蓉（Ｂｏｓｃｈｎｉａｋｉａｒｏｓｓｉｃａ）属列当科,草芯蓉属,为寄生植物。该植物常寄生于赤杨属（Ａｌｎｕｓ）的植物根上。它是我国东北地区重要的...     

丛枝菌根真菌对植物根尖分生区和根冠细胞的侵染*

一般说来,从枝菌根（ＡＭ）真菌大多数是从植物根系根毛区（成熟区）侵入和扩展的,在显微镜下往往看不到根尖分生区和根冠表皮细胞被ＡＭ真菌侵染的特征。这就很容易给人们造成一种假象,似乎ＡＭ真菌不能侵染根尖分生区和根冠表皮细胞,即它们对ＡＭ真菌是免疫的。然而笔者多次于显微镜下看到ＡＭ真菌侵染根尖分生区和根冠表皮细胞,并形成典型的泡囊、丛枝、菌丝等结构。这一现象导致作者在温室盆栽和大田条件下研究了玫瑰红巨孢囊霉（ Ｇｉｇａｓｐｏｒａ　ｒｏｓｅａ Ｎｉｃｏｌ　＆ Ｓｃｈｅｎｃｋ）、珠状巨孢囊霉（Ｇｉｇａｓｐｏｒａ　ｍａｒｇａｒｉｔａ　Ｂｅｃｋｅｒ　＆　Ｈａｌｌ）、根内球囊霉（Ｇｌｏｍｕｓ　ｏｍｔｒａｒａｄｉｃｅｓ　ｓｃｈｅｎｃｋ　＆　Ｓｍｉｔｈ、摩西球囊霉（Ｇｌｏｍｕｓ ｍｏｓｓｅａｅ （Ｎｉｃｏｌ　＆ Ｇｅｒｄ．） Ｇｅｒｄｅｍａｎｎ　＆ Ｔｒａｐｐｅ）、地表球囊霉（ Ｇｌｏｍｕｓ ｖｅｒｓｉｆｏｒｍｅ（ Ｋａｒｓｔｅｎ）Ｂｅｒｃｈ）和弯丝硬囊霉（ Ｓｃｌｅｒｏｃｙｓｔｉｓ　ｓｉｎｕｏｓａ　Ｇｅｒｄｅｍａｎｎ　＆ Ｂａｋｈｉ）对棉花（Ｇｏｓｓｙｐｉｕｍ　ｈｉｒｓｕｔｕｍ　Ｌ．）、烟草（Ｎｉｃｏｔｉａｎａ　 ｔａｂａｃｕｍ Ｌ．）和白     

四棱草属比较形态及其分类系统位置的研究：Ⅳ.四棱草属及其近…

四棱草属及其近缘属筋骨草属Ａｊｕｇａ,香科科属Ｔｅｕｃｒｉｕｍ（唇形科Ｌａｂｉａｔａｅ）,莸属Ｃａｒｙｏｐｔｅｒｉｓ,大青属Ｃｌｅｒｏｄｅｎｄｒｕｍ（马鞭草科Ｖｅｒｂｅｒｎａｃｅａｅ）５属,６种代表植物的叶表皮细胞形状、气孔类型和毛状体类型的比较研究结果是：（１）叶上表皮细胞形养 深小纹状不规则形,浅波纹状不规则形和浅波纹状四边形;（２）气孔类型是不规则型,平列型,横列型和等位模列型。（３）毛状体     

木属植物资源的利用

惚木属植物资源的利用李湘萍,王忠壮（南京林业大学,南京２１００３７）（第二军医大学,上海２００４３３）格木属（ＡｒａｌｉａＬ．）植物为五加科（Ａｒａｌｉａｃｅａｅ）落叶小乔木或多年生草本,其根、根白皮是民间广泛使用的草药,《本草拾遗》就有记载。早在唐...     

中国蜘蛛抱蛋属植物营养器官的解剖学研究

首次对中国蜘蛛抱蛋属 9种植物的营养器官进行了解剖学研究。结果表明 :该属 9种植物的解剖结构基本相同。根和根状茎都由表皮、皮层和维管柱组成。根表皮下有单层薄壁细胞 ;内、外皮层均为一层五面加厚的厚壁细胞 ,内皮层外切向壁薄 ,呈马蹄形 ,外皮层内切向壁薄而外切向壁特别加厚 ,并栓质化 ,在横切面上形成一明显的厚壁组织环带 ;根为多原形。根状茎有明显的内皮层 ,周木维管束散生于维管柱的基本组织中 ;具有次生结构 ,次生保护组织为周皮。叶为等面叶 ,具有C4植物结构特征 ;气孔在上、下表皮均有分布 ,保卫细胞肾形 ,属四轮列型。该属植物的解剖结构与其生态环境相适应 ,体现了结构与功能的统一。     

银州柴胡根的发育解剖学研究

本研究采用常规石蜡切片结合荧光显微镜技术对银州柴胡根的发育解剖学进行了研究。结果表明:（1）银州柴胡根顶端分生组织由原分生组织及其衍生的初生分生组织组成。原生分生组织细胞体积小、排列紧密、细胞质浓厚、细胞核大而明显，具有典型的分生组织的特点；（2）初生分生组织由根冠原、表皮原、皮层原和中柱原组成。在根发育过程中，表皮、皮层和维管柱共同组成其初生结构。银州柴胡根初生木质部为二原型或三原型，外始式；同时在根表皮细胞的径向壁观察到径向壁的细胞壁加厚；（3）在根次生生长过程中，位于初生木质部和初生韧皮部之间的原形成层恢复分裂能力产生维管形成层，维管形成层不断地向外产生次生韧皮部，向内产生次生木质部；同时位于根内皮层内方的中柱鞘细胞恢复分裂能力产生木栓形成层，木栓形成层向外形成木栓层，向内形成栓内层。在维管形成层和木栓形成层分裂的过程中，在次生韧皮部和中柱鞘组织中产生形态大小不同的分泌道，均为次生的裂生型分泌道。研究认为，银州柴胡根的结构类似于药典收录的北柴胡和红柴胡根的结构特点，但其根表皮细胞径向壁加厚、木纤维的分布、分泌道的大小和数量等有别于柴胡属其它植物，可作为柴胡属植物重要的分类鉴定依据。     

四棱草属比较形态及其分类系统位置的研究──Ⅳ．四棱草属及其近缘属叶表皮结构特征

四棱草属Ｓｃｈｎａｂｅｌｉａ及其近缘属筋骨草属Ａｊｕｇａ,香科科属Ｔｅｕｃｒｉｕｍ（唇形科Ｌａｂｉａｔａｅ）,获属Ｃａｒｙｏｐｔｅｒｉｓ,大青属Ｃｌｅｒｏｄｅｎｄｒｕｍ（马鞭草科Ｖｅｒｂｅｒｎａｃｅａｅ）５属,６种代表植物的叶表皮细胞形状、气孔类型和毛状体类型的比较研究结果是：（１）叶上表皮细胞形状是深波纹状不规则形,浅波纹状不规则形和浅波纹状四边形;（２）气孔类型是不规则型,平列型,横列型和等位横列型。（３）毛状体类型属单毛和鳞片毛二种类型。根据上述特征及其分布规律,作者认为四棱草属在唇形科与马鞭草科系统演化的框架里,是处于中间过渡类型的位置。     

5种红树科植物叶片的比较解剖及其生态适应研究

用石蜡切片法对红树（Rhizophora apiculata Bl.）、红海榄（R.stylosa Griff.）、秋茄（Kandelia candel(Linn.) Druce）、木榄（Bruguiera gymnorrhiza(Linn.) Savigny）和海莲（B.sexangula(Lour.) Poir.）等5种红树科植物的叶片进行解剖学的观察和研究,结果表明：5种红树科植物叶片的表皮均有厚的角质膜和下皮层,表皮和下皮层的细胞常含有单宁;上表皮无气孔器;栅栏组织多层;木质部非常发达。说明了红树科植物的叶片具有很强的耐旱能力;同属植物的叶片在解剖结构上有着相似的特征。     

澳门红树林植物组成及种群分布格局的研究

调查工作于１９９２年４月～１９９４年９月在路环及凼仔红树林区内进行．路环红树林面积约７．１１５ｈｍ２,凼仔红树林面积约５７．２０５ｈｍ２．在两地区的海滩中,红树林植物计有４科４种,分属于红树科（Ｒｈｉｚｏｐｈｏｒａｃｅａｅ）、紫金牛科（Ｍｙｒｏｉｎａｃｅａｅ）、马鞭草科（Ｖｅｒｂｅｎａｃｅａｅ）和爵床科（Ａｃａｎｔｈａｃｅａｅ）．海岸半红树植物计有１５科２７种．利用样带法研究澳门红树林种群的分布格局,除秋茄为随机分布外,桐花树、白骨壤及老鼠勒均趋于集群的分布格局．结合数据分析８个研究区域种群生态位序列,只有凼仔红树林研究区最具有显著的生态位序列．     

The Studies on the Development,Structure and Ecological Adaptation of Aboveground Root Apices of the Mangrove Plants

The aboveground root apices of 15 species of the mangrove plants have been observed. The species belong to 9 genera and 6 families, which are distributed in the intertidal region along tropical to subtropical coast in Hainan and Guangdong provinces. The histology of the prop root apices (aerial) of 4 genera of the Rhizophoraceae was characterized markedly by columnar meristematic area, columella and suberized sheath of root cap. The prop root apices (aerial) of Acanthus and Avicennia as well as pneumatophore apices of Avicennia and Sonneratia possessed short columella and thin suberized sheath, or showed growth layer in the phellem of root cap. Most of the mangrove plants started procambial activity very early. Under the epidermis exodermis usually and in the subepidermal layer periderm was developed. All these have shown the selectivity of environment and adaptive convergence in mangrove.     

REEXAMINATION OF PORE WATER SULFIDE CONCENTRATIONS AND REDOX POTENTIALS NEAR THE AERIAL ROOTS OF RHIZOPHORA MANGLE AND AVICENNIA GERMINANS

Soil redox potentials and pore water sulfide concentrations on a mangrove island in the Belizean barrier reef system were significantly correlated with the presence of the aerial roots of mangrove trees. Sulfide concentrations were three to five times lower near the prop roots of Rhizophora mangle (red mangrove) and the pneumatophores of Avicennia germinans (black mangrove) than in adjacent (≤ 1 meter away) unvegetated sediment. Soil redox potentials were also significantly higher near the aerial roots. A comparison of the two species revealed that sulfide concentrations in the rhizosphere of R. mangle were as low as that of A. germinans. However, sulfide concentrations in areas occupied by the black mangrove were variable and a function of pneumatophore density. The occurrence of an oxidized rhizosphere around the roots of both species suggests that the adult trees are equally capable of exploiting reduced sediments as long as their respective pathways for root aeration are functional.     

钦州湾红树林丛枝菌根初步研究

海漆 (Excoecaria agallocha)、桐花树 (Aegiceras corniculatum)、秋茄 (Kandlia candel)、白骨壤 (Avi-cennia marina)是钦州湾分布广、生长量大的 4种红树植物 ,该项研究初步调查了丛枝菌根真菌在这四种植物根系的定居情况。在这四种植物的根际土壤均分离到丛枝菌根真菌孢子 ,其孢子密度以海漆根际的最高 ,其次为桐花树、秋茄、白骨壤。同时 ,海漆根系的侵染率和物种丰富度也最高 ,但在所取的白骨壤根样中没有观察到丛枝菌根的侵染。菌根侵染主要是以根内菌丝、胞内菌丝膨大扭曲、泡囊等形态出现。海水和土壤质地是影响菌根侵染率的主要因素。在所采土样中仅发现球囊霉属 (Glomus)、无梗囊霉属 (Acaulospora)丛枝菌根真菌 ,计有 1 7种和多个未确定种。     

ONTOGENETIC REORGANIZATION OF THE ROOT MERISTEM IN THE COMPOSITAE

The organization of the root meristem in selected Compositae was investigated to determine whether changes in the pattern of cell arrangement occurred during root growth in species other than Helianthus annuus. Embryonic, short, and long primary roots of one species of each of twelve genera were prepared for microscopic examination. Additional intermediate growth stages were prepared for Echinacea pallida. The meristem of embryonic roots showed layers of initials typical for dicotyledons. The meristem in many of the short roots of eight species was reorganized by the development of a secondary columella. The long roots showed patterns similar to the embryonic roots. In three species which maintained closed meristems, two layers of cortical initials were common in the embryonic root, and as a general trend, a single layer of cortical initials became more common during root elongation. The cellular changes that resulted in the initiation of a secondary columella are characterized by the conversion of cortical initials to secondary columella initials by a shift in their plane of cell division. It is proposed that the size and shape of the quiescent center changes as the conversion takes place. No intermediate stages were observed which could account for the reduction of two layers of cortical initials to one layer.     

广西英罗湾红树植物群落的研究

 对广西英罗湾红树植物群落的种类组成、类型、外貌、结构、物种多样性和演替等进行了较系统的探讨。组成群落的优势红树植物有木榄、红海榄、秋茄、桐花树、白骨壤和海漆6种,隶属6属4科。主要的群落类型有木揽群落、木榄+红海榄群落、红海榄群落、红海榄+秋茄群落、秋茄群落、秋茄+桐花树群落、秋茄+白骨壤群落、桐花树群落、白骨壤群落、白骨壤+桐花树群落和海漆群落等11个群系。群落外貌由单叶、革质、全缘、中型叶的高位芽植物决定。群落层次结构简单．单层或两层。和陆地植物群落相比较,组成群落的红树植物的物种多样性较低。受潮滩土壤质地、养分状况、环境盐度和潮淹程度以及红树植物自身对盐渍生境的适应性等因子制约,群落的分布形成了明显的生态系列。随着海平面的相对降低和土壤理化性质的改善,群落具有向陆生植物群落演化的趋势。     

广西的红树林

本文主要讨论广西沿海的红树林的植物种类成分、外貌、适应形态学特点、群落类型和演替规律,以及生产管理问题。 该地区的红树植物种类计有8科、12属、12种,以红树科植物占优势。群落类型有:白骨壤群落、桐花树群落、秋茄-桐花树群落、红海榄群落、木榄群落、木榄-桐花树群落、桐花树-海漆稀树群落和红海榄+秋茄-桐花树群落等。     

A MORPHOMETRIC ANALYSIS OF CELLULAR DIFFERENTIATION IN THE ROOT CAP OF ZEA MAYS

In order to quantify the ultrastructural changes associated with cellular differentiation, we have performed a morphometric analysis of the ultrastructure of the calyptrogen, columella, and peripheral cells of the root cap of Zea mays. The relative volumes of the nucleus, nucleolus, and mitochondria in the protoplasm gradually decrease as a cell moves through the root cap. The relative volume of plastids increases 240% during the differentiation of calyptrogen cells into columella cells. This increase is transient, however, since the relative volume of plastids as well as starch in plastids decreases markedly as columella cells differentiate into peripheral cells. Dictyosomes and spherosomes increase more gradually than plastids, peaking in relative volume in the innermost peripheral cells (PCI). The relative volume of the vacuome decreases as calyptrogen cells differentiate into columella cells, after which it increases during the differentiation of peripheral cells. By the time the outermost peripheral cells (PCIII) are sloughed from the cap, the relative volume of the vacuome has almost tripled. These results indicate that each cell type comprising the root cap of Zea mays is characterized by a distinctive ultrastructure. Furthermore, the ultrastructural changes associated with the differentiation of these cells are organelle specific. The results of this study are discussed relative to the function of the various cell types of the root cap.     

DEVELOPMENTAL ANATOMY OF LIGHT-INDUCED ROOT NODULATION BY ZAMIA PUMILA L. SEEDLINGS IN STERILE CULTURE

The developmental anatomy of Zamia pumila L. root apices was studied during light-induced nodulation. Dark-grown roots had an apical organization identical to that of other cycads and similar to that of other gymnosperms. A distinct protoderm was not observed in these roots, which had a large open meristem and a root cap with a well-defined columella. During nodulation, the meristem became reduced in size, and its constituent cells became vacuolate until all but a few resembled ground tissue. The root cap senesced during nodulation, and a recognizable root cap was absent from mature nodules. A file of densely cytoplasmic cells with centrally positioned nuclei developed in the nodule cortex. This layer was continuous across the nodule apex, and was identical to the presumptive algal-zone described previously by other authors. Light-induced nodules branched dichotomously and were identical to algal-free nodules described by other authors. In dichotomously branched nodules, each lobe was covered by a parenchymatous mantle analogous to a root cap. A unicellular layer similar to the presumptive algal zone spanned the gap between opposite nodule lobes, and extended beneath each lobe before terminating in the cortex. Typical meristematic regions were not observed in these nodules. Based on cell sizes and patterns, a meristematic zone was thought to exist between the mantle and the inner cortex.     

DIFFERENTIAL OXIDATION OF MANGROVE SUBSTRATE BY AVICENNIA GERMINANS AND RHIZOPHORA MANGLE

Both Avicennia germinans (black mangrove) and Rhizophora mangle (red mangrove) are commonly found in anaerobic substrate. Black mangrove roots create oxidized rhizospheres substantially larger than those described for other plant species. When air cannot enter the root system through the pneumatophores, the rhizospheres become as reduced as nearby un vegetated soil. The presence of red mangrove, in contrast, appears to have no effect on the oxidation state of surrounding anaerobic soils. It is likely that these data help to explain the distributions of both species in intertidal associations.     

Diversity of endophytic fungi in the roots of mangrove species on the west coast of India

Because mangrove plant species are a valuable source of useful metabolites, their endophytes have gained more importance. Randomly sampled surface-sterilized whole root segments of four mangrove plant species, Acanthus ilicifolius, Avicennia officinalis, Rhizophora mucronata, and Sonneratia caseolaris from the mangroves of Udyavara (Karnataka) on the west coast of India, were characterized for fungal communities by direct plating, damp chamber, and bubbling chamber incubation methods. The richness of endophytic fungal species from whole root segments after direct plating and damp chamber incubation was greatest for R. mucronata than for other plants (18 vs. 8-13). Incubation of whole root segments in bubbling chambers yielded conidia of two freshwater hyphomycetes: Mycocentrospora acerina (in Avicennia officinalis) and Triscelophorus acuminatus (in R. mucronata and in S. caseolaris). Surface-sterilized whole root and root bark segments of R. mucronata sampled from the mid-tide level on direct plating yielded more fungi than that of the root segments sampled from low-tide and high-tide levels. The greatest number of isolates, species richness, and diversity of fungi were shown by the whole root segments of R. mucronata from the mid-tide level. Rarefaction indices also revealed the highest expected number of species out of 150 random isolations from the mid-tide level samples of whole root and root bark segments of R. mucronata. The present study showed that fungi in mangrove roots are composed of a consortium of soil, marine, and freshwater fungi.