长白山区几种观赏鸢尾

鸢尾,花姿优美,色彩典雅、庄重,是优美的庭院绿化观赏植物。据我们长白山野生花卉课题组调查,从海拔400米到2500米的岳桦林下均有分布。据不完全统计有如下7种:燕子花、玉蝉花、山鸢尾、溪荪、马蔺、野鸢尾、单花鸢尾。其中前5种,我们在海拔720米试验地中进行繁殖栽培,现长势良好,形成群体观赏效应,每年5—7月竞相开放,花期持续衔接,美丽无比,可用其妆点园林、美化庭院。     

药用植物种子生物学特性的多样性(摘要)

本文对药用植物种子形态结构多样性、休眠习性的多样性、萌发习性的多样性进行了研究。1　药用植物种子形态和结构的多样性(1 )种子外部形态的多样性 ;(2 )种子内部结构的多样性 :①种皮结构的多样性 ;②胚的结构多样性 ;③胚乳的多样性。2　药用植物种子休眠习性的多样性(1 )种皮休眠 ;(2 )胚休眠 :①胚未完全分化引起的休眠 ;②生理休眠。3　药用植物种子萌发习性的多样性(1 )低温型种子 ,萌发最适温度 1 5℃左右。(2 )中温型种子 ,萌发最适温度 2 0～ 2 5℃。(3 )高温型种子 ,萌发最适温度 3 0℃。(4)变温型种子 ,萌发要求有昼夜一定变化…     

珍稀濒危植物金丝李种子的休眠机理

珍稀濒危植物金丝李(Garcinia paucinervis)种子的萌发十分缓慢,探讨其休眠机理,可为该物种的种质资源保育与可持续利用提供理论依据。本文对金丝李种子种皮结构及其透水性,剔除部分种皮和胚乳后种子的萌发情况,胚乳和胚等粗提物的活性,储藏、层积和不同温度下种子萌发情况,萌发过程中内源激素含量等进行了研究。结果表明:金丝李种皮无栅栏细胞层,下表面的角质层较薄;种皮对种子的吸胀阻碍小;随着种孔端剔除种皮和胚乳程度的加深,金丝李种子的萌发进程逐渐延长,甚至降低其萌发率,种脐端削除处理对种子萌发影响不大;内果皮、种皮、胚乳和胚中可能存在抑制金丝李种子萌发和生长的内源抑制物;新鲜种子胚率达86.12%,低温层积后胚率无显著变化;低温层积处理延缓其萌发进程,对萌发率无显著影响,4℃低温层积是储藏金丝李种子的较好方法;种子萌发对温度敏感,在32℃培养下可打破种子休眠,萌发速度显著加快。种子萌发过程中ABA含量降低,GA与ABA、IAA与ABA的比值随种子萌发显著升高,萌发促进与抑制物比例逐渐趋于提高。因此,金丝李种子存在内源抑制物,同时缺乏萌发促进物质,导致生理休眠。该种子休眠特性使其幼苗生长能应对生境的季节变化,种群在风险环境中得以延续,避免大量幼苗竞争。植被破坏导致种子萌发阶段受阻是造成金丝李濒危的原因之一。     

桃儿七种子解剖结构及其萌发生长期形态特征

为探明种皮和胚乳是否是限制桃儿七种子萌发的主要因素,利用组织切片和显微技术,对桃儿七种子及其不同萌发期（1、7、14、21、28 d）解剖结构和播种后一定时期内（7~210 d）的植株生长形态进行观察。桃儿七种子由种皮、胚乳和胚构成。种皮包括外种皮和内种皮,外种皮致密规整,由外至内分别为栅状石细胞和表皮层细胞,内种皮由5~6层海绵细胞组成。胚乳占种子体积的绝大部分,包括珠孔胚乳和外胚乳。胚由胚根、胚轴和子叶组成,被致密种皮、多层珠孔胚乳和外胚乳包围。萌发期1~7 d胚根和胚轴开始伸长,7~14 d两片子叶分离,14~21 d胚根突破珠孔胚乳和种皮,21~28 d胚根、胚轴和子叶继续扩张伸长。种子播种210 d后可平均形成3片功能真叶和5条不定根。致密种皮（物理休眠）和多层胚乳（机械休眠）是限制桃儿七种子萌发的两个主要因素。     

绞股蓝种子休眠机理及其破除方法研究

以采自广西金秀县的绞股蓝种子为研究材料,对其休眠原因、休眠类型及其破眠方法进行了研究,为绞股蓝种子繁殖提供理论依据和技术支持。结果表明:(1)绞股蓝新采收成熟种子的生活力达91%,在10℃~35℃恒温和15℃/25℃变温中的发芽率均低于10%,新种子的生活力极显著大于发芽率,具有显著的休眠现象。(2)绞股蓝种皮不限制吸水,胚分化发育完全,离体胚发芽率为(78.0±4.8)%,且能够长成正常幼苗,说明绞股蓝种子的胚在离体条件下无休眠现象。(3)绞股蓝完整种子及其粉碎种子的水提液对白菜种子的萌发率、苗高及根长均有抑制作用,随水提液浓度增加抑制作用均显著增强,且粉碎种子的抑制作用较强;当粉碎种子的水提液浓度为5%时白菜种子萌发率、苗高、根长分别为18.0%、0.1cm、0.1cm,分别显著低于对照77.1%、97.3%、95.8%,说明绞股蓝种子的种皮和胚乳中存在水溶性萌发抑制物质,是绞股蓝种子休眠的主要原因。(4)GA3和6-BA不能促进绞股蓝种子萌发,低温层积对绞股蓝种子休眠的解除具有促进作用;绞股蓝种子的休眠属于生理休眠类型,休眠水平属于中间型。(5)低温干藏能够打破绞股蓝种子休眠,是绞股蓝种子破除休眠及种子保存较为理想的方式。     

曼陀罗种子休眠机理与破眠方法研究

通过对曼陀罗种子生活力测定、发芽试验、吸水率测定及种子萌发抑制物研究,揭示曼陀罗种子休眠机理,并利用物理、化学法处理曼陀罗种子,以探寻打破曼陀罗种子休眠的最佳方法.结果表明:(1)新采收的曼陀罗种子为综合休眠,休眠原因包括:种皮障碍、缺少萌发所需激素以及种皮和种仁中存在萌发抑制物,其中种皮障碍是限制种子萌发的首要因素.(2)室温存储6个月可解除曼陀罗种子种仁的休眠,但种皮障碍始终是其种子萌发的限制因素.(3)机械摩擦、浓H2SO4处理和NaOH处理均可打破除曼陀罗种皮的休眠障碍,促进种子萌发,其中用10% NaOH处理90 min为破除曼陀罗种皮休眠障碍的最佳方法,且发芽率比对照提高了83%.     

离体条件下TDZ对解除北五味子种子休眠的影响

以深度休眠的北五味子种子为材料,研究了离体条件下,种皮、胚乳因素对北五味子种子休眠的影响;建立了离体条件下,使用TDZ有效解除北五味子种子休眠的方法;并对北五味子种子解除休眠过程中过氧化物酶和过氧化氢酶活性变化规律进行分析.结果表明,(1)种皮和胚乳因素是引起北五味子种子休眠的主要因素,种皮和胚乳对北五味子种子的萌发具有不同程度的抑制作用;(2)MS培养基中添加0.02 mg·L-1 TDZ能有效解除北五味子种子休眠,可使第30天的发芽率达到90.0%,显著缩短北五味子种子休眠时间;(3)随着北五味子种子休眠被解除,过氧化物酶和过氧化氢酶活性均呈明显的增加趋势.     

鸢尾属植物种子休眠研究进展

鸢尾属(Iris L.)花卉具有较高的观赏性,极具开发利用价值,且主要以种子繁殖后代;但多数种子具有休眠特性,给育种工作带来了困难。其休眠原因包括种皮机械阻碍和种子中萌发抑制物存在等内外多重因素,单一或交互作用影响种子萌发。种子休眠解除的方法主要有环境条件处理、机械处理、化学试剂或激素处理等。本文对鸢尾属植物种子休眠原因、休眠解除方法及其机理等作了系统概述,旨在为鸢尾属花卉资源的合理开发利用及种质创新提供理论依据。     

珍稀药用植物云南萝芙木种子休眠与萌发特性

研究了云南萝芙木（Rauvolfia yunnanensis）种子吸水及内源萌发抑制物特性,探讨了赤霉素浓度、温度和光照对种子萌发的影响。结果表明：云南萝芙木新鲜饱满种子28℃和31℃／22℃光照或黑暗下1个月内不萌发,种子胚已分化发育完全,种皮透水,种仁含有萌发抑制物,GA可促进种子萌发,说明云南萝芙木种子具有浅度生理休眠。400-1800mg·L-1是打破云南萝芙木种子休眠的适宜GA处理浓度范围。云南萝芙木种子的适宜萌发温度范围为22～2822和31℃／22℃变温,28％发芽指数最高,1023种子不萌发。云南萝芙木种子在周期性光照和全黑暗下均可萌发,但31℃和31℃／22℃下周期性光照促进种子萌发。     

云南红豆杉新采收种子的形态与离体胚的萌发特性

通过云南红豆杉新采收种子形态观察、透水性测定、种子大小以及所带胚乳多少对离体胚萌发率的影响等试验,探讨云南红豆杉种子的休眠与萌发机理。结果表明,云南红豆杉种子呈倒卵形和三棱形;胚酒瓶形,白色;胚乳淡黄色,油质。种子千粒重为72.934g;种皮、种仁和种胚分别占种子鲜重的50.56%、40.45%和8.99%;胚与种子的体积比(E∶S)为0.074。胚的体积为0.156—1.012mm~3,种子为51.658—109.649mm~3,两者呈显著正相关(P0.05,r=0.810)。完整种子的吸水率明显低于破裂种皮、酸蚀40min和酸蚀20min的种子,但差异随着浸泡时间延长而缩小;种子含水量饱和时,完整种子、破皮种子与酸蚀种子的吸水率无显著差异(前者为23.7%,后两者约28.0%)。不同大小种子离体胚的萌发率差异显著(P0.05),特大、大、中、小和特小种子的离体胚的萌发率为80%、77.8%、67.5%、62.0%和44.0%。胚乳抑制离体胚的萌发,不带胚乳离体胚的萌发率为41.3%,显著高于带胚乳的萌发率(P0.05),带部分胚乳的胚为9.7%—13.3%,带全胚乳的胚为0。同时离体胚培养过程中所用种胚的新鲜程度也严重影响胚的萌发率。云南红豆杉种子休眠属于中度生理休眠类型,种子中的抑制物质含量随时间的动态变化和胚乳中抑制物质含量的多少对胚萌发率的影响是以后云南红豆杉休眠研究的重点。     

Foreign exploration for Scirtothrips perseae Nakahara (Thysanoptera: Thripidae) and associated natural enemies on avocado (Persea americana Miller)

Scirtothrips perseae Nakahara was discovered attacking avocados in California, USA, in 1996. Host plant surveys in California indicated that S. perseae has a highly restricted host range with larvae being found only on avocados, while adults were collected from 11 different plant species. As part of a management program for this pest, a “classical” biological control program was initiated and foreign exploration was conducted to delineate the home range of S. perseae, to survey for associated natural enemies and inventory other species of phytophagous thrips on avocados grown in Mexico, Guatemala, Costa Rica, the Dominican Republic, Trinidad, and Brazil. Foreign exploration efforts indicate that S. perseae occurs on avocados grown at high altitudes (>1500 m) from Uruapan in Mexico south to areas around Guatemala City in Guatemala. In Costa Rica, S. perseae is replaced by an undescribed congener as the dominant phytophagous thrips on avocados grown at high altitudes (>1300 m). No species of Scirtothrips were found on avocados in the Dominican Republic, Trinidad, or Brazil. In total, 2136 phytophagous thrips were collected and identified, representing over 47 identified species from at least 19 genera. The significance of these species records is discussed. Of collected material 4% were potential thrips biological control agents. Natural enemies were dominated by six genera of predatory thrips (Aeolothrips, Aleurodothrips, Franklinothrips, Leptothrips, Scolothrips, and Karnyothrips). One genus each of parasitoid (Ceranisus) and predatory mite (Balaustium) were found. Based on the results of our sampling techniques, prospects for the importation of thrips natural enemies for use in a “classical” biological control program in California against S. perseae are not promising.     

Phylogeny of cardinalfishes (Teleostei: Gobiiformes: Apogonidae) and the evolution of visceral bioluminescence

The cardinalfishes (Apogonidae) are a diverse clade of small, mostly reef-dwelling fishes, for which a variety of morphological data have not yielded a consistent phylogeny. We use DNA sequence to hypothesize phylogenetic relationships within Apogonidae and among apogonids and other acanthomorph families, to examine patterns of evolution including the distribution of a visceral bioluminescence system. In conformance with previous studies, Apogonidae is placed in a clade with Pempheridae, Kurtidae, Leiognathidae, and Gobioidei. The apogonid genus Pseudamia is recovered outside the remainder of the family, not as sister to the superficially similar genus Gymnapogon. Species sampled from the Caribbean and Western Atlantic (Phaeoptyx, Astrapogon, and some Apogon species) form a clade, as do the larger-bodied Glossamia and Cheilodipterus. Incidence of visceral bioluminescence is found scattered throughout the phylogeny, independently for each group in which it is present. Examination of the fine structure of the visceral bioluminescence system through histology shows that light organs exhibit a range of morphologies, with some composed of complex masses of tubules (Siphamia, Pempheris, Parapriacanthus) and others lacking tubules but containing chambers formed by folds of the visceral epithelium (Acropoma, Archamia, Jaydia, and Rhabdamia). Light organs in Siphamia, Acropoma, Pempheris and Parapriacanthus are distinct from but connected to the gut; those in Archamia, Jaydia, and Rhabdamia are simply portions of the intestinal tract, and are little differentiated from the surrounding tissues. The presence or absence of symbiotic luminescent bacteria does not correlate with light organ structure; the tubular light organs of Siphamia and chambered tubes of Acropoma house bacteria, those in Pempheridae and the other Apogonidae do not.     

Molecular phylogeny of Phebalium (Rutaceae: Boronieae) and related genera based on the nrDNA regions ITS 1+2

Parsimony analyses of the internal transcribed spacer regions of nuclear ribosomal DNA (ITS 1 & ITS 2) for 38 taxa sampled from the Phebalium group (Rutaceae: Boronieae) and two outgroups confirm that, with the exception of Phebalium sensu stricto and Rhadinothamnus, six of the currently recognised genera within the group are monophyletic. The data indicate that Phebaliums. str. is paraphyletic with respect to Microcybe, and Rhadinothamnus is paraphyletic with respect to Chorilaena. Rhadinothamnus and Chorilaena together are the sister group to Nematolepis. Drummondita, included as an outgroup taxon, clustered within the ingroup as sister to Muiriantha and related to Asterolasia.The phylogeny suggests that the evolution of major clades within a number of these genera (e.g. Phebalium) relates to vicariance events between eastern and south-western Australia. Leionema is an eastern genus, with the most basal taxon being the morphologically distinct Leionema ellipticum from northern Queensland. Leionema also includes one species from New Zealand, but this species (as with some others) proved difficult to sequence and its phylogenetic position remains unknown. Taxonomic changes at the generic level are recommended.The authors wish to thank Paul G.Wilson, PERTH, for advice and discussion, and Paul Forster, BRI, for collecting and providing material of Leionema ellipticum. The project was supported by a Melbourne University Postgraduate Award (to BM), the Australian Biological Resources Study (ABRS), Australian Systematic Botany Society and Wolf Den (Australia) Investments.     

Biological control of three floating water weeds,<Emphasis Type="Italic">Eichhornia crassipes,Pistia stratiotes</Emphasis>, and <Emphasis Type="Italic">Salviniamolesta</Emphasis> in the Republic of Congo

Since 1999, four specific weevils (Coleoptera, Curculionidae) were released in the Republic of Congo against three exotic floating water weeds: Neochetina eichhorniae Warner and N. bruchi Hustache against water hyacinth, Neohydronomus affinis Hustache against water lettuce, and Cyrtobagous salviniae Calder and Sands against water fern. Recoveries of exotic weevils were made from all 24 release sites except one, and all four species have established and spread (up to 800 km for water hyacinth weevils). Within a few years of releases, control of water fern and water lettuce was such that fishing and navigation could be resumed, while reductions of water hyacinth populations were only beginning.     

New species and new combinations in Peruvian Orchidaceae

seventeen new species and combinations are proposed in the generaChondrorhyncha, Cischweinfia, Cochlioda, Eloyella, Encyclia, Kefersteinia, Koellensteinia, Macroclinium, Rodriguezia, Solenidiopsis, andStenia. All new species are illustrated. A key is provided for 2-flowered species ofMacroclinium, PeruvianSigmatostalix, and PeruvianStenia. Solenidium (Solenidiopsis) peruvianum Schltr. is lectotypified.     

Taxonomic status of the species of the green algal genusNeochloris

Komárek has recently reviewed the various species assigned to the green algal genusNeochloris Starr (Chlorococcales, Chlorococcaceae) and removed those with uninucleate vegetative cells to a new genus,Ettlia. Watanabe & Floyd, unaware ofKomárek's work, also reviewed the species ofNeochloris and distributed them among three genera—Neochloris, Chlorococcopsis gen. nov., andParietochloris gen. nov.—on the basis of details of the covering of the zoospore and the arrangement of the basal bodies of the flagellar apparatus. This paper reconciles these two treatments and makes additional recommendations at the ranks of genus, family, order, and class.     

A molecular phylogeny of Hebeloma species from Europe

In order to widen the scope of existing phylogenies of the ectomycorrhizal agaric genus Hebeloma a total of 53 new rDNA ITS sequences from that genus was generated, augmented by sequences retrieved from GenBank, and analysed using Bayesian, strict consensus and neighbour joining methods. The lignicolous Hebelomina neerlandica, Gymnopilus penetrans, and two species of Galerina served as outgroup taxa. Anamika indica, as well as representatives of the genera Hymenogaster and Naucoria, were included to test the monophyly of Hebeloma, which is confirmed by the results. Hebeloma, Naucoria, Hymenogaster and Anamika indica cluster in a strongly supported monophyletic hebelomatoid clade. All trees largely reflect the current infrageneric classification within Hebeloma, and divide the genus into mostly well-supported monophyletic groups surrounding H. crustuliniforme, H. velutipes, H. sacchariolens, H. sinapizans, and H. radicosum, with H. sarcophyllum being shown at an independent position; however this is not well supported. The section Indusiata divides with strong support into three groups, the position of the pleurocystidiate Hebeloma cistophilum suggests the possible existence of a third subsection within sect. Indusiata. Subsection Sacchariolentia is raised to the rank of section.     

Die GattungKarschia — Bindeglied zwischen bitunicaten Ascomyceten und lecanoralen Flechtenpilzen?

The genusKarschia, in the earlier sense, including saprophytes and parasites on lichens, has been thought to be a non-lichenized parallel genus of the lichen genusBuellia. Modern workers included it on the one hand inBuellia, on the other hand combined it with bitunicate ascomycetes. It is now proved thatKarschia is heterogeneous and contains but superficially similar members both of the genusBuellia of theLecanorales and of typical or masked bitunicateAscomycetes. Therefore, it can not be regarded as a link betweenLecanorales andDothideales. The type species ofKarschia belongs to theDothideales.

     

Entwicklungsgeschichte und Ultrastruktur von Pollenkitt und Exine bei nahe verwandten entomophilen und anemophilen Angiospermensippen derAlismataceae,Liliaceae, Juncaceae,Cyperaceae, Poaceae undAraceae

Some closely related members of the monocotyledonous familiesAlismataceae, Liliaceae, Juncaceae, Cyperaceae, Poaceae andAraceae with variable modes of pollination (insect- and wind-pollination) were studied in relation to the ultrastructure of pollenkitt and exine (amount, consistency and distribution of pollenkitt on the surface of pollen grains). The character syndromes of pollen cementing in entomophilous, anemophilous and intermediate (ambophilous or amphiphilous) monocotyledons are the same in principal as in dicotyledons. Comparing present with former results one can summarize: 1) The pollenkitt is always produced in the same manner by the anther tapetum in all angiosperm sub-classes. 2) The variable stickiness of entomophilous and anemophilous pollen always depends on the particular distribution and consistency of the pollenkitt, but not its amount on the pollen surface. 3) The mostly dry and powdery pollen of anemophilous plants always contains a variable amount of inactive pollenkitt in its exine cavities. 4) A step-by step change of the pollen cementing syndrome can be observed from entomophily towards anemophily. 5) From the omnipresence of pollenkitt in all wind-pollinated angiosperms studied one can conclude that the ancestors of anemophilous angiosperms probably have been zoophilous (i.e. entomophilous) throughout.