纵胞藻切段再生的初步研究

作者将纵胞藻切成1.5—3mm长的切段,用PES培养液,室内漫射光进行培养,成功地得到大量纵胞藻再生植株。通过实验探讨,作者认为纵胞藻的切段再生现象可能是该种海藻营养繁殖的一种形式。     

粗枝软骨藻Chondria crassicaulis组织培养初探

在固体培养基上研究了粗枝软骨藻(Chondria crassicaulis)再生的极性,并利用三种不同的培养液和不同的温度对粗枝软骨藻进行切段培养,探索了部分外界因素对粗枝软骨藻生长的影响.发现软骨藻在人工培养条件下的再生出芽过程并无明显极性.在10℃、15℃和22℃三个温度梯度和PES、改良的ASP1和改良的ES三种培养液中,15℃改良的ES培养液中较有利于再生芽的出现.同时我们还观察了粗枝软骨藻四分孢子的发育过程,发现软骨藻具有十字型和四面锥型两种不同的四分孢子囊,软骨藻在四分孢子萌发过程中可形成四种不同的孢子苗.     

大型绿藻浒苔藻段及组织块的生长和发育特征

通过将浒苔叶状体分为基部、中部和顶端三部分分别进行切段和切碎处理,在实验室条件下,用液体浅层培养的方法,系统地研究了其组织和细胞的生长和发育特性。显微观察的结果显示：切段培养条件下,基部和中部的藻段均可在其形态学下端形成假根,在形态学上端产生类似叶状体的突起。藻段的发育具极性,但是其极性并不绝对的,在1.0 mm的基部藻段两端都观察到了假根的形成。虽然顶端的藻段和组织块全都形成和释放了孢子,未见明显的营养生长,但是在培养早期,其下端仍然具有形成假根的能力。浒苔各部位藻段和组织块释放的和滞留于孢子囊内的孢子都可以立即萌发成苗。快速生长的中基部藻段形成了气囊,致使其漂浮于培养基上。有很多藻段和组织块形成和释放了生殖细胞,释放到外界以及滞留于孢子囊内的孢子均可立即附着萌发。数据分析表明：藻段的生长具有极性,不同部位相同长度的藻段生长率差异明显,基部藻段的生长率高于中部藻段,顶部藻段无明显的营养生长。藻段的生长与其原始长度和在藻体中所处的位置有密切关系;藻段和组织块的再生与藻体的完整性及其在藻体中所处的位置有关。     

大花飞燕草的组织培养及再生体系建立

分别采用种子切段、无菌苗真叶作外植体首次成功建立了大花飞燕草的组织培养和再生体系。结果表明：大花飞燕草种子切段和无菌苗真叶大多数是通过愈伤组织途径再生,也有极少数不经过愈伤组织阶段而直接再生出小植株。在合适的培养基上,种子切段和叶片两种外植体离体培养均能高效再生,平均每个外植体能分化出１０－２０个不定芽。种子切段培养的最适通用培养基为改良ＭＳ附加ＺＴ３ｍｇＬ＾－１和ＮＡＡ ０．３ｍｇＬ＾－１,叶培     

大白菜下胚轴离体不定芽高效再生体系的研究

以大白菜的下胚轴为外植体,比较了不同浓度TDZ和6-BA两种细胞分裂素与不同浓度NAA相配合的培养基上不定芽再生的差异,并利用筛选出的高效再生培养基研究外植体苗龄、切段来源、接种方式以及品种对不定芽再生的影响。结果表明:与6-BA相比,TDZ对诱导下胚轴不定芽再生更有效,在M S+TDZ 0.3 m g.L-1+NAA0.5 m g.L-1+A gNO35 m g.L-1的培养基上,下胚轴不定芽再生频率高达87.8%,平均每下胚轴再生不定芽数也达到15.1个;3~5 d苗龄之间的下胚轴不定芽再生能力无显著差异,再生频率均达到80%以上,此后随着苗龄的增加,不定芽分化频率快速下降,苗龄为7 d时再生频率只有51.1%;下胚轴不同切段不定芽再生能力由强到弱表现为:上部切段>中部切段>下部切段;以正插(形态学下端插入培养基)方式接种的外植体不定芽再生能力显著大于反插(形态学上端插入培养基)和平放的;不同品种大白菜下胚轴的不定芽再生能力有一定差异。     

蓝藻球形体的分离,培养及再生

在高渗溶液中,用0.05%溶菌酶和2—5mmol·1~(-1)EDTA 处理蓝藻柱孢鱼腥藻、多变鱼腥藻和组囊藻细胞。5—8h 后,70—90%的细胞转为对渗透压敏感的球形体(Spheroplast),又称原生质球。研究了藻的不同培养条件对球形体形成率的影响。测定了 EDTA 处理藻纽胞后外膜脂多糖的释放量。在高渗溶液中,藻细胞和经酶处理获得的球形体的光合放氧活性明显下降,固氮种类的固氮活性失去。饲养层法、固体混合法和含有0.5mg·1~(-1)BA 的液体悬滴培养的柱孢鱼腥藻的球形体,9天后出现再生藻落;在固体混合法培养中获得了组囊藻球形体的再生藻落。在第4天的悬滴培养物中,可以看到球形体发生第一次细胞分裂。再生藻细胞和酶处理物中残留细胞的抗溶菌酶特性有差异。     

我国淡水红藻一新记录种

温州师范学院生物系于1984年10月间,从浙江泰顺乌岩岭国家重点自然保护区的山涧溪流中采得了一些藻类标本,作者对其中的红藻标本进行了鉴定,发现一个新记录种,即角毛藻科(Gooiotrichaceae)星胞藻属(Asterocytis)星胞藻(A.smaragdina(Reinsch)Forti)1-5。       

胞壁钙在红光抑制绿豆下胚轴伸长中的作用

研究了胞壁钙在红光抑制黄化绿豆（ＰｈａｓｅｏｌｕｓｒａｄｉａｔｕｓＬ．）下胚轴切段伸长生长中的作用。培养在有Ｃａ２＋介质中的切段胞壁钙含量比无Ｃａ２＋介质中的高３倍多,但不论介质中有无外源Ｃａ２＋,红光对下胚轴伸长的抑制程度都为２０％～２５％。乙醇双乙胺醚Ｎ,Ｎ,Ｎ′,Ｎ′四乙酸（ＥＧＴＡ）减少胞壁钙含量,相应地抵消红光对伸长的抑制;ｖｅｒａｐａｍｉｌ、Ｌａ３＋处理的切段胞壁钙含量与黑暗对照接近,但削弱红光的抑制作用;Ａ２３１８７减少胞壁钙,相应地抵消红光作用,甚至促进伸长生长。此外,氯丙嗪不影响胞壁钙含量,却阻止红光抑制伸长。表明红光无需外源Ｃａ２＋也能抑制切段伸长生长,但并非完全不需要Ｃａ２＋,可能胞壁自身的Ｃａ２＋基本能满足伸长生长所需。胞壁Ｃａ２＋的作用很复杂,它既可作为钙库起内流Ｃａ２＋信号的作用,也可在壁区起生长调节作用。     

浒苔Enteromorpha prolifera组织培养初步研究

通过将大型绿藻--浒苔切成一定大小的藻体片段,在实验室条件下用液体和固体平板组织培养的方法,系统地研究了在藻体切段条件下,浒苔组织块中细胞的发育路径和趋势.在培养的过程中发现叶状体中细胞的发育能力和方向都具有明显的极性,且浒苔组织块中细胞的发育速度和规模与组织块大小和其组织块中的位置有关.在切段培养的条件下,浒苔细胞有5种发育途径:1.分化为孢子囊,2.细胞极化下端延伸形成类似于假根的结构,3.分裂成细胞团并在后续的发育过程中成苗,4.细胞进一步极化形成带假根的单细胞苗,5.维持一定状态不再分化.而切段培养条件下,藻段中的不同细胞可能发生不同的发育情况.     

满江红鱼腥藻(Anabaena azollae)和柱孢鱼腥藻(A.cylindrica)营养细胞和异形胞色素的种类

满江红鱼腥藻和柱孢鱼腥藻营养细胞和异形胞的液氮低温吸收光谱表明两种细胞含有叶绿素a、藻蓝素和β-胡萝卜素。液氮低温荧光发射光谱表明:柱孢鱼腥藻营养细胞存在藻蓝素、别藻蓝素和两个光系统的叶绿素a,柱孢鱼腥藻异形胞存在藻蓝素和系统Ⅰ叶绿素a。荧光发射光谱的685nm荧光发射仅为微弱突起。满江红鱼腥藻异形胞亦存在藻蓝素和系统Ⅰ叶绿素a,缺少系统Ⅱ叶绿素a。推断满江红鱼腥藻和桩孢鱼腥藻营养细胞分化为异形胞时,伴随光系统Ⅱ的改组。系统Ⅱ叶绿素a消退和藻胆色素含量显著减少。     

GROWTH AND DEVELOPMENT OF THE RETICULATE THALLUS IN THE LICHEN RAMALINA MENZIESII

The thallus of the lichen Ramalina menziesii Tayl. is comprised of subunits which resemble planar nets. The nets arise upon older nets as buds which develop perforations and expand. Microphotographic study of thallus development in the field shows several features which differ from a recently proposed model of development for this species. New perforations develop continually in new tissue produced at the apical margin of the net. The apical margin is inrolled, and may furcate. This type of branching is developmentally distinct from the formation of new nets from buds borne upon expanded parts of the net. Anatomical study of net apices appears to support assertions that programmed tissue necrosis contributes to perforation formation at sites where gaps are present in the algal layer.     

伊乐藻和黑藻断枝根和芽的发生及生长研究

为了解外来种伊乐藻的无性繁殖力、评价其生态安全性,采用插植方式比较研究了伊乐藻(Elodea nuttallii)和本土种黑藻(Hydrilla verticillata)两种沉水植物不同节数(1至4节)和不同节位断枝的不定根和新芽的发生及生长情况。通过室内4周的3次平行实验,结果表明:两者顶芽段均有形成不定根继而形成新植株的能力,而顶芽以下茎段只有本身具有腋芽的断枝才有形成新芽和不定根的能力。两者具相同节数的断枝形成不定根的百分率及根、芽长度,以具顶芽断枝的均明显高于不具顶芽断枝的,具顶芽四节断枝的不定根生成率最高达到90%以上。不具顶芽断枝形成新芽和不定根的百分率及长度随着断枝节数的增加均呈显著递增趋势,每类断枝的发芽率显著大于其生根率;伊乐藻和黑藻枝条一般分别每7节和5节具有一个腋芽,只有具腋芽断枝才能存活,因此,对不具顶芽断枝,7节和5节分别是其形成新苗所需的最短断枝长度。根和芽的长度随节位的下降大致呈递增的趋势。但是节数对形成根、芽的影响显著大于节位的影响。具顶芽断枝的顶芽的增长量和具顶芽4节断枝的生物量增量伊乐藻的高于黑藻,其余指标伊乐藻均显著低于黑藻。伊乐藻断枝的繁殖力总体上低于黑藻。       

25 Proposal of a new red algal genus in the ceramieae (ceramiaceae, ceramiales)

A new genus is proposed to accommodate four species belonging in the Ceramium flaccidum complex based on comparative vegetative morphology and rbc L sequence analysis: C. flaccidum (Harvey ex Kuetzing) Ardissone (1871), C. gracillimum, C. Agardh (1824), C. fimbriatum S. & G. (1924) and C. rectocorticum Dawson 1950. Comparative rbcL sequence analysis indicates that this complex forms a distinct monophyletic clade separate from other Ceramium species. Although C. flaccidum has been placed in Hormoseras Kuetzing 1841 (as H. flaccidum Harvey ex Kuetzing 1862), the type species of Hormoceras is Ceramium diaphanum . The new genus is characterized by alternate branching, incomplete cortication, production of three cortical filament initials of which the basipetal initial divides horizontally, and unicellular rhizoids terminating in pad-like structures produced from periaxial cells. Cortical filament development is discussed for related genera in the tribe Ceramieae ( Campylaephora, Carpoblepharis, Centroceras, Ceramium, Corallophila, Herpochondria, Microcladia, Reinboldiella ). Rbc L-based phylogenies indicate that the new genus is sister to Centroceras , a genus possessing three cortical filament initials. The phylogenetic relationships within the tribe may correlate with cortication patterns that characterize each genus     

The Structure and Development of the Thallus in the British Species of Gelidium and Pterocladia

The apical structure and the development of the thalli of allthe British species of Gelidium and Pterocladia have been investigated;the development of G. pulchellum is described in detail. Eachaxis is terminated by one or more apical cells, which by theirsegmentation form the tissues of the thallus. An axial filamentis distinct for a short distance behind each apical cell, butsecondary pit-connexions develop rapidly so that in sectionthe mature axis has the appearance of a multi-axial structure. Lateral branches of the frond develop by the segmentation ofthe lateral branch apical cells, which are formed by the transformationof superficial cortical cells, either in the meristematic ormature parts of the axes. The extreme variability of externalappearance is due principally to the indeterminate origin ofall lateral branches. The thallus in the British species of Gelidium and Pterocladiaconsists of erect fronds borne on creeping axes. The relativeproportions of the frond and creeping axes in various speciesand their survival through adverse conditions are discussed.     

鹧鸪菜生殖器官发育的研究

鹧鸪菜[Caloglossa leprieurii(Mont)J.Ag.]细胞含多核。在生殖季节,孢子体、雌、雄配子体在外形上有明显的差异:四分孢子体大而平展,分枝的上部肉眼可见有红色小斑点,即为四分孢子囊群。雌配子体顶部略蜷曲,分枝密,囊果呈球状,多位于分枝上部分枝点的腹面。雄配子体个体较小,枝顶蜷曲,颜色淡,特别生有精子囊的部分更淡。每种藻体的营养细胞的纹孔连结非常发达,每个细胞都具有4-5条,多者达7-8条。果胞枝由四个细胞组成,一般由围轴细胞分裂形成,果胞受精后,由支持细胞分裂形成辅助细胞,一个生育小枝上,可以连续形成5-7个甚至10个以上幼果胞系,但多数仅有一个果胞受精发育成囊果。当一个果胞受精时,其他果胞系就停止发育。精于囊位于分枝上部中肋的两侧,背腹面均有分布。一个营养细胞沿着叶面平行方向平周分裂成三个细胞,在两个外侧细胞各形成3-4个精子囊母细胞,每个精子囊母细胞斜壁分裂产生2-4个精子囊,放散后,余下的精子囊母细胞仍留在中间盘状细胞上。     

Reiterative production and deformation of cell walls in expanding thallus nets of the lichen ramalina menziesii (Lecanorales,Ascomycetes)

The thallus of the lichen Ramalina menziesii Tayl. is composed of net-like units that develop by diffuse expansion of perforated tissue produced at the net apex. Study of net tissue with transmission electron microscopy reveals that the cortical cells are surrounded by a succession of cell walls alternating with layers of an electron-transparent matrix substance. In the course of thallus growth the cortical cell walls are continually deformed and new ones constructed. The deposition of new walls and matrix layers displaces the older walls centrifugally from the cell. Electron-dense boundaries develop at the interfaces among cells where the remains of the oldest walls are compressed against those of neighboring cells. As new branch cells are inserted through the concentric accumulations, the dense boundaries appear to enclose fascicles of cells, visible in cross section with light microscopy. Cortical organization in Ramalina menziesii is contrasted with that reported in other lichens, and a functional relationship to diffuse growth of the thallus is suggested.     

Effect of gibberellin and kinetin on the regeneration ability ofFucus vesiculosus L.

The influence of gibberellic acid (GA³) and kinetin (6-furfurylaminopurine) on the regeneration ability of the basal and apical thallus fragments ofFucus vesiculosus L. was examined. The naturally occurring gibberellin and kinetin-like substances in these thallus fragments were also studied. It was found that exogenously applied GA³ markedly increased the number of adventitious branches formed on the cut surface of the thallus fragments taken from the apical parts of plants. The concentration of 0.001 mg GA³ I-1 proved to be the most effective. The growth promoting effect of GA³ was increased by simultaneous action with kinetin. In experiments in which the fragments of the basal parts of the thallus were treated with GA³, as a rule a slight growth inhibition was observed. The growth responses of the investigated plant tissues to gibberellin and kinetin varied according to season. Usually their susceptibility to the applied plant hormones was greater in spring than is summer. The shifts in growth reaction were related to the seasonal changes in the content of endogenous gibberellin and kinetin-like substances in the investigated parts of the thallus. It is suggested that growth regulators of the gibberellin and cytokinin type are involved in the regeneration processes inFucus.     

Organismic determinants and their effect on growth and regeneration in Gracilaria gracilis

The growth of Gracilaria gracilis (Stackhouse) Steentoft, Irvine et Farnham was examined by studying the effect of organismic determinants such as thallus length, position along the thallus and branching. Knowledge of these factors is essential in order to increase production from suspended seaweed rafts seeded with vegetative G. gracilis fragments. Seeding netlons with seaweed material freshly collected from subtidal populations provided up to 30% higher relative growth rates than seaweed maintained on the netlons for successive months. Initial seedstock length greatly affected growth rates and yields such that 30-cm thalli fragments resulted in growth rates 14% higher than for 10-cm fragments. This difference is suggested to be due to the higher contribution to overall biomass by growth of lateral branches. Comparisons of the growth of apical and basal fragments suggest that growth takes place over the entire length of the thallus, but that the apex contributes more to overall elongation than does the proximal part. The removal of apical meristems resulted in an enhanced branching frequency with production of four times as many branches as intact fragments. Evidence is also provided for extensive morphological differentiation following long periods of rapid growth. These thalli have very high frequency of branching, are hollow due to the disintegration of medullary cells and are considered to be completely senescent. These factors have implications for the successful cultivation of G. gracilis on commercial mariculture systems. This revised version was published online in July 2006 with corrections to the Cover Date.