天麻造粉质体发育的超微结构观察(简报)

天麻的造粉体最早发生在幼龄细胞内核的附近。它是由原质体转化来的。随着天麻球茎的生长发育,逐渐积累淀粉。在造粉体周围的淀粉粒小,多呈圆形,而中部的淀粉粒大,互相挤压呈多面形。在造粉体旁常有线粒体存在。造粉体消解时首先是外膜破裂,释放出的淀粉粒一部分被附近的液泡吞噬。     

香榧营养苗端细胞组织分区的超微结构观察

本文研究了榧树(Torreya grandis)成熟植株在季节生长中营养苗端的超微结构变化。各区域细胞的主要区别特征为:顶端原始细胞与亚顶端细胞相接的细胞壁较厚,液泡多分布于细胞游离面,质体中淀粉粒较小;亚顶端细胞壁较厚,液泡较大,质体中淀粉粒较大而多;周缘区细胞质体多不具淀粉粒,液泡也较小,胞间连丝丰富;肋状区细胞被大量的含淀粉质体及液泡占据了大部分空间,胞间连丝丰富。在季节变化的四个时期中,各区域细胞的亚显微结构特征亦不相同。休眠期各区细胞淀粉质体较发达,细胞壁较厚,液泡大;叶扩展期淀粉质体减少或消失;芽鳞形成期出现大量小液泡;新的顶芽形成期液泡增加,核糖体含量较高。讨论了各区域细胞核形态与其细胞活跃性的关系。     

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。     

兰科奇葩——独蒜兰

福建省武夷山自然保护区以其绮丽的森林自然景观和丰富多样的生物资源而闻名于世。在那崇山峻岭的悬崖峭壁上,生长着兰科奇葩——独蒜兰(见封三照片)。 独蒜兰(Pleionebulbocodioldes),又名一叶兰,兰科独蒜兰属植物。该属10种,我国约有6种,分布于长江流域及以南各省区。独蒜兰为附生兰,株高10—25厘米,假鳞茎紫     

蒜鳞片薄壁细胞衰退过程中酶的细胞化学定位及DNA生化分析

蒜在储藏过程中,鳞茎薄壁细胞衰退,其营养物质供给幼芽萌发生长。采用细胞化学方法,对蒜休眠进程中的鳞茎薄壁细胞进行了ATPase以及APase的细胞化学定位,结果显示在薄壁细胞的质膜、细胞壁和胞间连丝上的酶活性随着蒜自休眠至萌发的不同发育进程而呈现增强的趋势,且在萌芽期酶活性表现最为强烈,表明细胞内物质的降解、转化与输出的加强有助于细胞内含物向新生芽的彻底转移。配合采用琼脂糖凝胶电泳对衰退薄壁细胞的DNA进行了分析,实验结果表现出典型的DNA Ladder,为蒜鳞茎薄壁细胞的衰退属于受基因控制的程序性死亡范畴补充了生化证据。     

蒜鳞片薄壁细胞衰退过程中酶的细胞化学定位及DNA生化分析

蒜在储藏过程中。鳞茎薄壁细胞衰退。其营养物质供给幼芽萌发生长。采用细胞化学方法,对蒜休眠进程中的鳞茎薄壁细胞进行了ATPase以及APase的细胞化学定位,结果显示在薄壁细胞的质膜、细胞壁和胞间连丝上的酶活性随着蒜自休眠至萌发的不同发育进程而呈现增强的趋势,且在萌芽期酶活性表现最为强烈。表明细胞内物质的降解、转化与输出的加强有助于细胞内含物向新生芽的彻底转移。配合采用琼脂糖凝胶电泳对衰退薄壁细胞的DNA进行了分析,实验结果表现出典型的DNA Ladder．为蒜鳞茎薄壁细胞的衰退属于受基因控制的程序性死亡范畴补充了生化证据。     

不同温度对独蒜兰开花和生长的影响

该研究采用人工温室于3种培养温度(20℃/15℃、15℃/10℃、10℃/5℃)条件下,分析独蒜兰生长开花进程以及假鳞茎中有机物质含量的动态变化。结果表明:(1)于20℃/15℃(模拟原生地开花期自然温度)处理下,独蒜兰进入初花期的时间比15℃/10℃、10℃/5℃处理下分别提前24d和53d,花期分别延长了4d和6d。(2)独蒜兰的花色以10℃/5℃处理较深,但该处理中有哑蕾出现。(3)老假鳞茎生长开花过程中,20℃/15℃处理的淀粉含量呈升高趋势,15℃/10℃和10℃/5℃处理先升高后降低;3种温度处理下,可溶性糖均在花期含量最高,且10℃/5℃处理下可溶性糖含量、可溶性蛋白含量均保持较高水平。研究认为,20℃/15℃和15℃/10℃培养温度均有利于独蒜兰的生长和开花;独蒜兰休眠的假鳞茎不需要经过低温诱导解除休眠,随着温度上升,相应的生长发育进程就会启动。     

文冠果果实韧皮部及其周围薄壁细胞的超微结构观察及功能分析

该研究应用透射电镜技术,对生长发育过程中的文冠果果实的韧皮部及其周围薄壁细胞的超微结构进行了观察,以探讨文冠果果实同化物韧皮部卸载的细胞学路径及其机理。结果显示:(1)文冠果果实发育过程中,筛分子细胞胞腔较空,几乎没有细胞器,但有类似于囊泡的丝状不定型物存在;伴胞胞质浓密且细胞器丰富,液泡化程度不一,大多数存在多个小液泡;薄壁细胞具有中央大液泡,发育中期富含线粒体、高尔基体、内质网等细胞器,并存在囊泡运输现象,发育后期细胞器发生降解,说明随着果实生长发育,果实内物质代谢和转运活跃程度逐渐下降。(2)果实发育过程中筛分子和伴胞之间始终有胞间连丝,薄壁细胞之间也一直存在大量的胞间连丝,而筛分子-伴胞复合体与薄壁细胞之间只有在果实发育前期和后期存在一定数量的胞间连丝,发育中期却几乎没有胞间连丝。研究结果表明,文冠果果实发育过程中同化物韧皮部卸载路径可能发生了共质体途径-质外体途径-共质体途径的转变。     

15种独蒜兰属植物叶表皮微形态特征及分类学意义研究

为解决兰科(Orchidaceae)独蒜兰属(Pleione D. Don)植物分类学问题并探索叶片超微结构在分类学中的意义,该研究利用扫描电子显微镜,对独蒜兰属15种植物成熟叶片的细胞界限、角质层纹理、气孔器分布等15个叶表皮超微特征进行观测分析,以明确它们的分类学意义。结果表明：(1)细胞界限、表皮细胞蜡质量、角质层纹理、气孔器分布、气孔器周围蜡质、气孔器外拱盖内缘、角化现象、气孔器相对高度、表皮细胞长度、表皮细胞面积、保卫细胞长度和保卫细胞面积这9个指标对于该属分类具有重要价值和意义。(2)利用上述特征可以对春花独蒜兰组(S. Humiles)、独蒜兰组(S. Pleione)和独蒜兰复合体(P. bulbocodioides complex)的组内区分进一步细化。(3)聚类分析将15种独蒜兰属植物聚类为4个分支,与传统分类学和分子系统学分类结果基本一致。研究认为,大理独蒜兰(P. × taliensis P. J. Cribb & Butterfield)与云南独蒜兰［P. yunnanensis (Rolfe) Rolfe］、黄花独蒜兰(P. forrestii Schltr.)在多个叶片微观特征方面表现出高度的一致性,大理独蒜兰的亲本有待于进一步研究确认。     

枸杞花药发育过程中脂滴和淀粉粒的分布特征

宁夏枸杞(Lycium barbarurn L．)花药发育过程中,淀粉粒和脂滴两种营养物质的积累和分布具有一定的特点：在造孢细胞时期,药隔薄壁细胞,表皮和药室内壁细胞中开始积累淀粉粒,而造孢细胞、绒毡层细胞和中层细胞中则没有淀粉粒。在四分体时期,绒毡层细胞开始积累脂滴并且数量逐渐增加。到小孢子晚期,绒毡层细胞降解,内含脂滴流入药室中。在小孢子发育过程中既没有淀粉粒也没有脂滴积累,直到二胞花粉的大液泡消失后花粉粒中才开始积累脂滴,然后又开始出现淀粉粒。枸杞成熟花粉中的营养储存物是脂滴和淀粉粒。     

ROLE OF PSEUDOBULBS IN GROWTH AND FLOWERING OF CATASETUM VIRIDIFLAVUM (ORCHIDACEAE)

In Catasetum viridiflavum Hook., a drought-deciduous orchid from central Panama that produces unisexual flowers, plants possess up to nine annually-produced pseudobulbs. I investigated the role of these structures in plant growth and flowering by 1) relating annual shoot size and flower production to the size and number of pseudobulbs possessed by plants, 2) experimentally severing connections between young and old pseudobulbs when plants were dormant and monitoring their subsequent vegetative growth and flowering, and 3) determining the seasonal variation in water content, total nonstructural carbohydrates, nitrogen, and phosphorus in pseudobulbs. In small plants (1 to 3 pseudobulbs) pseudobulb stores appeared important to both vegetative growth and flowering. In larger (= older) plants, pseudobulb number was not related to vegetative growth and experimental separations of young from old pseudobulbs did not affect growth. However, flower production by experimental plants was significantly reduced relative to controls. Male plants were usually smaller than female plants in the areas studied; however, experimental reductions of pseudobulb number did not affect the sex expression of plants. All measured nutritional components of pseudobulbs exhibited significant seasonal variation. Carbohydrates appeared most important for supporting growth immediately following dormancy. Nitrogen and phosphorus were less important for this role and may have been more important for determining the number of flowers produced by plants.     

Morphological development of anthers induced by the dimorphic smut fungus<Emphasis Type="Italic"> Microbotryum violaceum</Emphasis> in female flowers of the dioecious plant<Emphasis Type="Italic"> Silene latifolia</Emphasis>

When inoculated with the dimorphic smut fungus Microbotryum violaceum (Pers.) G. Deml and Oberwinkler, the female flower of the dioecious plant Silene latifolia (Miller) E.H.L. Krause develops anther-like structures filled with spores instead of pollen grains. Using natural scanning electron microscopy, Nomarski interference microscopy, and fluorescence microscopy, we investigated the morphological modifications of the host plant resulting from this parasitism and the localization of smut hyphae in the flower bud. Flowers of infected plants lasted significantly longer than those of healthy plants, probably because the infection strengthened floral organs, such as the flower base and the anther filaments. Smut hyphae were observed throughout all organs of the young flower buds of infected plants, including sepals, petals, stamens, and pistil primordia. In healthy female flowers, anthers initiated sporogenous cell formation, but lacked parietal cell layers. By contrast, the parietal cell layers of infected female flowers differentiated into tapetal tissue, middle cell layers, and endothecial layers, as in the anthers of healthy male flowers. Smut spore formation in the infected anther was initiated in intercellular regions between the sporogenous cells, resulting in degeneration of premature sporogenous cells, tapetal tissue, and middle cell layers. The development of the endothecial layers and epidermis in the infected anther were morphologically normal.Abbreviations DAPI 4,6-diamidino-2-phenylidole - i infected - PMC pollen mother cell     

附生植物石斛的株丛生长及营养繁殖特征

石斛(Dendrobium nobile Lindl.)为兰科多年生附生性草本植物,特化的假鳞茎是其营养贮藏器官,通过假鳞茎可实现克隆生长。该研究以野外调查发现的石斛株丛为研究材料,比较不同等级株丛假鳞茎合轴生长和高位腋芽的差异,分析高位株丛的定植方式,探讨石斛株丛生长及营养繁殖对附生环境的适应策略。结果显示:(1)石斛株丛的生长和扩大通过合轴生长的营养繁殖方式进行,假鳞茎基部具有2~3个储备芽,每年萌发1~2个新芽,随着生长年限的增加,形成大小不一的株丛。(2)株丛具有典型的高位腋芽营养繁殖特性,且主要形成于假鳞茎密集和老根密布的大株丛。(3)高位株丛母茎一端附着于附主树种上,在母茎软化和高位株丛的重力作用下,缩短了高位株丛与附主的距离,使其根系能够触及附主,完成高位株丛的定植。研究表明,附生植物石斛通过假鳞茎合轴生长的营养繁殖方式来增强并延续株丛寿命,高位腋芽的频发是株丛假鳞茎对拥挤等逆境的响应,高位株丛的定植依赖于母茎,这也是石斛对附生环境的一种生态适应策略。     

The Roles of Auxin in Regulating “Shoot Branching” of Cremastra appendiculata

Cremastra appendiculata (D. Don) Makino is a mainly vegetative propagation terrestrial orchid that is a typical representative of the warm-temperate vegetation in China. In this experiment, we investigated the growth and development process of C. appendiculata leaf buds and examined their biochemical components (proteins, auxin, and cytokinin) to gain insight into the “shoot branching” of C. appendiculata pseudobulb string. The results showed that the metabolic activity of C. appendiculata pseudobulbs became lower with the increase of pseudobulb age. However, biennial and triennial pseudobulbs have higher auxin levels than annual pseudobulbs in the intact plant (P < 0.05). After decapitation, the auxin rapidly reduces in biennials. The reduction of auxin level promotes cytokinin biosynthesis, which makes the biennial dormant buds start to germinate 18 days after decapitation. These data and phenomena suggested that auxin plays important roles in regulating shoot branching of C. appendiculata, although further studies are needed to consolidate this viewpoint. Our data indirectly support the classical apical dominance theory whereby biennial pseudobulbs are strongly dependent on reduced auxin to initiate leaf bud outgrowth.

     

广西凭祥口岸首次截获有害生物台湾坡天牛Pterolophia formosana

台湾坡天牛一般随着木制品及包装制品进行远距离传播入境。目前我国台湾地区和日本有分布,在我国大陆地区尚未见该虫的发生报道。2019年5月凭祥口岸从来自越南的相思木板上截获了台湾坡天牛,为我国大陆首次截获。通过显微形态特征的观察和测量进行台湾坡天牛种类鉴定。台湾坡天牛与近似种的主要区别:其鞘翅基部具明显的黑褐色宽横带。通过入侵可能性分析,来自我国台湾地区、日本的台湾坡天牛入侵我国大陆地区的可能性很大。台湾坡天牛在我国广东、广西、福建等地区定殖和扩散风险很大。一旦传入我国,将对我国的农林安全造成巨大威胁,各口岸应对进境的木制品及包装加强检验检疫。     

Comparative anatomy and systematics of Catasetinae (Orchidaceae)

Catasetinae consist of five genera of pseudobulbous Orchidaceae of the Neotropics. Anatomy is characterized by sunken, three-celled foliar hairs, mostly tetracytic stomatal apparatuses, superficial stomata, homogeneous mesophyll, foliar fibre bundles, collateral vascular bundles in a single row, xylem and phloem sclerenchyma associated with vascular bundles in leaves, conical, and rough-surfaced silica bodies adjacent to vascular bundle sclerenchyma; epidermal cells of pseudobulbs with heavily thickened outer walls, pseudobulb ground tissue of assimilatory and water-storage cells, scattered vascular bundles in pseudobulbs, and sclerenchyma and stegmata associated only with phloem of pseudobulbs; roots with thin-walled velamen cells and tenuous spirals of cell wall material, distinctive epivelamen cells, thin-walled exodermal cells and vascular tissue embedded in parenchyma. Except for mucilaginous idioblasts that occur in Mormodes and Cycnoches , there are few outstanding anatomical differences among the five genera. Thus, there are few anatomical characteristics of phylogenetic value. The monophyly of Catasetinae is supported by the presence of sunken foliar hairs. Our results support a close relationship between Clowesia and Catasetum , and between Mormodes and Cycnoches. Among the outgroups Pteroglossaspis is especially distinctive.     

单芽狗脊营养器官的解剖学研究

采用离析法和石蜡切片法对单芽狗脊营养器官进行形态解剖研究。结果表明：单芽狗脊叶为异面叶,上、下表皮细胞均为不规则型,仅下表皮有气孔器分布;叶柄维管束有2~6个,自叶柄基部向上至叶轴仅有2个较大的维管束;根状茎薄壁细胞之间有多个维管束散生分布,且富含丰富的淀粉粒;皮层在根的横切结构中占比较大,木质部的发育方式为外始式;单芽狗脊珠芽的发育过程分为三个阶段,珠芽原基的形成期、珠芽原基的分化期、成熟期。     

Role of auxin in regulating Arabidopsis flower development

To elucidate the role of auxin in flower morphogenesis, its distribution patterns were studied during flower development in Arabidopsis thaliana (L.) Heynh. Expression of DR5::GUS was regarded to reflect sites of free auxin, while immunolocalization with auxin polyclonal antibodies visualized conjugated auxin distribution. The youngest flower bud was loaded with conjugated auxin. During development, the apparent concentration of free auxin increased in gradual patterns starting at the floral-organ tip. Anthers are major sites of high concentrations of free auxin that retard the development of neighboring floral organs in both the acropetal and basipetal directions. The IAA-producing anthers synchronize flower development by retarding petal development and nectary gland activity almost up to anthesis. Tapetum cells of young anthers contain free IAA which accumulates in pollen grains, suggesting that auxin promotes pollen-tube growth towards the ovules. High amounts of free auxin in the stigma induce a wide xylem fan immediately beneath it. After fertilization, the developing embryos and seeds show elevated concentrations of auxin, which establish their axial polarity. This developmental pattern of auxin production during floral-bud development suggests that young organs which produce high concentrations of free IAA inhibit or retard organ-primordium initiation and development at the shoot tip. Electronic Supplementary Material Supplementary material is available for this article at This paper is dedicated to Orna Aloni for continuous support and management over many years.     

Sustainable harvesting and conservation of Laelia furfuracea,a rare epiphytic orchid from Oaxaca,Mexico

Many epiphytic orchids are harvested in Mexico for different purposes. Laelia furfuracea is one of the most intensively traded species. Its inflorescences are used as ornaments during the December festivities. We investigated the effect of severing the flowering pseudobulb. This is the traditional technique frequently used by collectors at the study area. We wished to investigate its effects on the production of new pseudobulbs, as well as on their size and flowering probability. Also, we examined the survival probability and growth of individuals that had fallen on the ground to evaluate their potential as trading resources. Inflorescence collection did not affect the production of new pseudobulbs the following season. However, it affected the size of these pseudobulbs, as well as their flowering probability. Yet, the direction of this effect was not consistent between years. Nearly six percent of all L. furfuracea plants at the study site were found on the ground. Over 80 percent of them survived for at least two years, although most of them showed pseudobulb loss over that period of time. We conclude that harvesting of flowering pseudobulbs may be sustainable in terms of its effects on plant performance, at least in the short term. The active management of plants that have fallen on the ground may reduce the harvesting pressure on natural populations. Harvesting of flowering pseudobulbs may diminish some aspects of plant performance, but its effects need to be evaluated with complete life cycle data and take into account interannual variation in vital rates. Abstract in Spanish is available with online material