Differences in the location of subcotyledonary buds among Epilobium angustifolium L., E. dodonaei Vill. and E. fleischeri Hochst. (Onagraceae) and effects on architecture and population structure

STÖCKLIN, J., 1992. Differences in the location of subcotyledonary buds among Epilobium angustifolium L., E. dodonaei Vill. and E. fleischeri Hochst. (Onagraceae) and effects on architecture and population structure . Morphological and architectural features in the two closely related pioneer plant species Epilobium dodonaei and E. fleischeri are examined in cultivation and in the field and compared with E. angustifolium. In E. angustifolium , the aerial shoot system is renewed every year from buds on horizontal roots and results in a horizontal spread and a clonal growth form. In E. dodonaei , bud formation is restricted to the hypocotyl and in larger plants to the transitional region between root and shoot. Consequently this species shows no vegetative mobility and develops a shrub-like habit. The alpine E. fleischeri combines the habit of E. angustifolium and E. dodonaei and may either develop successive generations of shoots from the transitional region between root and shoot and/or exploit new areas by horizontal roots and the formation of shoots from root buds. The simple difference in the location of renewal buds is accentuated by cumulative growth. The study shows that E. dodonaei and E. fleischeri , which often are considered as subspecies, are separated by fundamental differences in their architectural models. The ecological and demographic implications of these differences are discussed.     

Ca2+、pH在花粉及萌发花粉管生长中的作用研究进展

花粉正常萌发并生长是精细胞顺利到达胚囊并实现受精作用的前提,因而是高等植物有性生殖的一个关键环节。花粉管生长涉及一系列过程,而花粉(或花粉管)内外的Ca^2 和pH的变化与花粉萌发、花粉管生长有着密切的关系。比较详细地论述了Ca^2 和pH在花粉萌发、花粉管生长过程中的分布特点、生理功能及分子机制。     

Isolation and Artificial Germination of De-exined Pollen in Brassica

In view of the fact that pollen deprived of exine has been shown by electroporation to be a superior receptor of foreign genes in tobacco, the authors developed a technique to isolate and artificially germinate the de-exined pollen in Brassica. Pollen grains of B. chinens/s and B. campestris var. purpurea were first hydrated at 4 ℃ in a medium containing Roberts' salts, 24% sucrose, 7.3% mannitol, 0.05% lactoalbumin hydrolysate (pH 8.5) for 18 h, followed by heat shock at 34 ℃ for 40～60 min and osmotic shock for 20 min subsequently. Through this three-step procedure the exine could dehisce along the germination furrows and completely detached off, resulting in the release of pollen coated with naked intine with an isolation rate as high, as over 60%. The de-exined pollen were germinated in a modified medium containing 15%～20% polyethylene glycol (MW 6000), 5% sucrose, 0.05% lactoalbumin hydrolysate and Roberts' salts (pH 8.5) with a rate of 41% in B. chinensis and 33% in the other species. However, in sharp contrast with the behavior of the intact pollen, the de-exined pollen did not germinate in the carbon and nitrogen sources free media. Scanning electron microscopic and light microscopic observations on the processes of isolation and germination of de-exined pollen were carried out. The phenomenon of exine detachment in a few plant species is reviewed. There might be some corresponding association between pollen wall characteristics and methods of isolation. The de-exined pollen may be a useful experimental system not only for introducing and transferring foreign genes, but also for investigating the role of exine in pollen germination and in sporophytic self-incom- patibility.     

桃花粉离体萌发和花粉管生长特性研究

采用花粉离体萌发法研究不同培养基组分和培养条件对桃花粉萌发和花粉管生长的影响,同时对不同贮藏温度下的桃花粉寿命进行研究.结果表明:固体培养基与液体培养基对桃的花粉萌发率和花粉管长度影响差异不显著;10%蔗糖是大多数桃品种花粉的最适萌发条件;硼能提高桃花粉的萌发率,但对花粉管的生长没有促进作用;桃花粉在20℃～25℃的培养温度下萌发率最高,花粉管最长;桃花粉萌发率和花粉管长度在培养前3 h内上升最快,3～5 h上升趋势减弱,5 h后基本停止;随着贮藏温度的升高和贮藏时间的延长,花粉生活力呈降低的趋势.     

果梅花粉离体萌发及花粉管生长特性研究

研究了果梅(Prunus mumeSieb.1et Zucc.)花粉在不同培养基组分、花粉不同培养密度和不同温度及培养时间的离体萌发和花粉管生长特性.结果表明:细叶青花粉萌发及花粉管生长最适宜的液体培养基为30mmol/L MES(pH 6.5)缓冲液中含20%蔗糖,0.01%硼酸,20%PEG-4000,0.03?(NO3)2?4H2O,0.02%Mg-SO4?7H2O;萌发率达45.03%,花粉管长度达597.2μm.适宜于果梅花粉萌发和花粉管生长的花粉粒密度为20~80粒/μL.培养温度过高或过低都不利于果梅花粉的萌发和生长,25℃时花粉萌发和花粉管生长最好.细叶青"、月世界"、莺宿"3个品种的平均萌发率为48.6%,平均花粉管长度为762.3μm.果梅花粉在不同培养温度下,萌发及生长不同,在25℃条件下花粉管生长速度最快,集中在0~12 h内,3个品种花粉管平均生长速度为58.5μm/h.     

钙调素对花粉萌发和花粉管生长的效应

牛脑和玉米胚ＣａＭ能显著促进花粉萌发和花粉管生长（图１）,而ＣａＭ抑制剂ＴＦＰ、ＣＰＺ及另外两个专一性更强的抑制剂Ｃｏｍｐｏｕｎｄ４８／８０和Ｗ７均严重抑制甚至阻止花粉的萌发（图２,３）。用对ＣａＭ亲和性较低的Ｗ７同系物Ｗ５,在与Ｗ７同样浓度下,对花粉萌发和花粉管生长无明显影响。此外,Ｗ７对花粉萌发和花粉管生长的抑制效应可被外源ＣａＭ所消除（图４）。在花粉萌发过程中,其内源ＣａＭ含量显著上升,在花粉萌发率接近最大值时,花粉ＣａＭ含量达最高水平（图５）。上述结果表明ＣａＭ对花粉萌发和花粉管生长的调控起重要作用。     

GA_3对含笑花粉萌发及花粉管生长的影响

以含笑（Michelia figo）花粉为试材,采用花粉离体培养法,研究GA3对含笑花粉萌发和花粉管生长的影响。结果表明,GA3可以促进含笑花粉提早萌发,20～200 mg/L GA3对含笑花粉萌发和花粉管生长起促进作用,浓度超过200 mg/L花粉萌发和花粉管生长均受到抑制。以GA3200 mg/L的促进作用最好。     

Variation Patterns and Systematics of the Widespread Species Epilobium angustifolium L.(Onagraceae) in China

Cytological, morphological, and geographical studies of Epilobium angustifolium in China reveal two partly distinct, partly overlapping entities that are best treated as subspecies. The diploid (n=18) subsp. angustifolium has smaller, triporate pollen grains, typically glabrous stems and leaves, and smaller leaves and flowers, and occurs in colder, more northern areas, and at higher elevations in overlap zones. The tetraploid (n=36) subsp. circumvagum has larger pollen with a mixture of quadriporate pollen grains, pubescent stems and leaves, and larger leaves and flowers, and occurs in warmer parts of southern China and at lower elevations. We report 11 chromosome counts, six diploid and five tetraploid, includingthe first reported tetraploids in Asia.     

GA3对含笑花粉萌发及花粉管生长的影响

以含笑(Michelia figo)花粉为试材,采用花粉离体培养法,研究GA3对含笑花粉萌发和花粉管生长的影响。结果表明,GA3可以促进含笑花粉提早萌发,20～200 mg/L GA3对含笑花粉萌发和花粉管生长起促进作用,浓度超过200 mg/L花粉萌发和花粉管生长均受到抑制。以GA3200 mg/L的促进作用最好。     

Changes in volume,surface area,and frequency of nuclear pores on the vegetative nucleus of tobacco pollen in fresh,hydrated, and activated conditions

The vegetative nucleus (VN) of Nicotiana tabacum L. has been qualitatively and quantitatively studied in fresh, hydrated, and activated pollen. Techniques included the use of optical sectioning by confocal scanning laser microscopy to obtain volume and surface area measurements, and stereoscopic pairs; and freeze-etch electron microscopy to estimate the frequency of nuclear pores per m² in the vegetative nucleus. Several morphological changes were observed to occur in pollen grain nuclei during the early processes of tube growth. In freshly dehisced pollen grain, the vegetative and generative nuclei were side by side, but following hydration and activation of the grain, the elongated generative nucleus became partially surrounded by the vegetative nucleus. It was found that during hydration, the surface area of the vegetative nucleus increased and there was a decrease in the frequency of nuclear pores. The calculated total number of pores remained similar. After activation and pollen-tube growth, the vegetative nucleus retained the same surface area as in the hydrated state but the frequency of nuclear pores decreased; therefore, the calculated total number of pores was significantly lowered. When considered alongside complementary biochemical data, these morphological results indicate that RNA production in the vegetative nucleus decreases following germination.Abbreviations VN vegetative nucleus (nuclei) - GN generativenucleus - GC generative cell - CSLM confocal scanning laser microscope We acknowledge research support by the Biotechnology Action Programm of the Commission of European Communities, and CNR for the fellowship awarded to Dr. Wagner. We would also like to thank Mrs. C. Faleri for the expert technical help.     

The Effect of Concanavalin A on Membrane Potential and Intracellular pH during Activation In Vitro of Tobacco Pollen Grains

We studied the effects of short-term (5–10 min) treatment of Nicotiana tabacum L. pollen grains with concanavalin A (ConA) on their activation (changes in the membrane potential and intracellular pH) and germination in vitro. ConA (10–1000 g/ml) induced plasma membrane hyperpolarization in the vegetative cell and enhanced pollen grain germination. These effects depended on ConA concentration and were interrelated: the value of the membrane potential was negatively correlated with the number of pollen grains germinated for 1 h of their incubation (r = –0.96). In addition, ConA (100 g/ml) increased the intracellular pH value by 0.3 unit. All these effects of ConA are determined by its specific interaction with carbohydrate determinants because a competitive sugar methyl--mannopyranoside (0.1 M) completely blocked ConA effects. The data obtained presume that the specific receptors are present on the surface of pollen grains, evidently on their plasma membrane, and their interaction with lectins has a functional significance for pollen grain activation and germination.     

凯特杏花粉的离体培养及影响因子分析

采用离体培养法,在不同培养基组分含量、pH值、温度及植物生长调节物质的培养条件下,对凯特杏(Prunus armeniacaL.cv Katy)花粉的离体萌发和花粉管生长状况进行观察研究。结果表明:(1)凯特杏花粉离体萌发及花粉管生长的适宜培养基为20%蔗糖 0.04%硼酸 0.01?Cl2,最适pH为6.0,最适温度为20℃,培养20 h后,花粉的萌发率达68.76%,花粉管长度达1 083.53μm。(2)不同植物生长调节物质对花粉萌发和花粉管生长作用不同,赤霉素浓度为5~8 mg/L、矮壮素浓度为10~150 mg/L、多效唑浓度为5~10 mg/L时对凯特杏花粉萌发和花粉管生长都有促进作用,但国光丁酰肼对凯特杏花粉萌发和花粉管生长均有抑制作用。     

Artificial Germination of Gossypium Pollen and Its utilization in Interspecific Fertilization In Vitro

The effects of different media and cultural methods on cotton pollen germination were compared. Pollen germination was successful on the improved Taylor solid medium in which the extracts of the stigmata and petals of the original species, and the comprehensive amino acids were added, respectively. The germinating pollens were viable, and active protoplasmic streaming was observed within the pollen tube. It was found that low temperature pretreatment could increase the pollen germination rate. The reasons that low temperature pretreatment stimulated pollen germination and castor oil caused abortive germination of cotton pollens were discussed. In vitro fertilization between two species of Gossypium can be promoted by smearing the stigmata with the improved Taylor medium.     

温度、蔗糖和硼酸对含笑花粉离体萌发的影响

以含笑(Michelia figo)花粉为试验材料,采用花粉人工培养法研究了含笑花粉离体萌发的最适条件。结果表明:蔗糖、硼酸在一定浓度范围内能促进花粉萌发,含笑花粉萌发的最适蔗糖和硼酸分别为50 mg.L-1和5mg.L-1,萌发率分别为21.51%和44.14%;花粉最佳萌发温度为25℃,萌发率达53.33%。正交试验设计结果表明,花粉萌发的最佳组合为70 mg.L-1蔗糖+5 mg.L-1硼酸+28℃,萌发率可达65.33%。     

Pollen morphology and structure of Tropical and Subtropical American genera of the Piptadenia -group (Leguminosae: Mimosoideae)

A survey of the pollen morphology of the American taxa of the Piptadenia -group (Mimoseae) was done including all together 384 species of the following genera: Piptadenia , Parapiptadenia , Pseudopiptadenia , Piptadeniopsis , Microlobius (= Goldmania ), Stryphnodendron , Adenopodia , Anadenanthera and Mimosa . Because of a high morphological and structural variation the definition and characterization of pollen types turned out to be very difficult. Nevertheless the presence and durability of some pollen characters allow a provisional grouping: (1) always tetrads or polyads, (2) small size 6 (20) 40 mum, (3) unstable shape but currently ovoidal and, if biconvex, ellipsoidal in the outline, (4) number of pollen grains of the polyads very variable and unstable; the most frequent numbers are 8-12-16, (5) pollen grains irregularly united in polyads, with homomorphous exine and, (6) pores always located in the angles of the pollen grains in distal-subdistal position, rarely subdistal, (7) without or with pseudocolpi or subpseudocolpi (never colpi) in the distal face, (8) endexine forming an annulus around the endoaperture with ends of free lamellae with a central white line, (9) the tectal stratum above the pores forming a small vestibular space (except in Anadenanthera ). These palynological characters or most of them confirm the affinity among genera in the Piptadenia -group and its distinction from other taxa of the subfamily Misosoideae with tetrads or polyads.     

培养基组分及pH值对梨花粉萌发和花粉管生长的影响

采用花粉液体培养法研究不同培养基组分和pH值对梨花粉萌发和花粉管生长影响.结果表明:培养基内硼酸、氯化钙、PEG-4000、蔗糖、葡萄糖、麦芽糖、山梨醇、果糖在一定浓度范围内,对花粉萌发及花粉管生长起促进作用,但超过一定浓度时起抑制作用;最适的培养基组分为:30mmol/LMES、0.01%硼酸、0.03%CaCl2·2H2O、15%PEG-4000、5%果糖 或5%山梨醇、10%蔗糖 ,最适的pH值为6.5.在该培养基内梨花粉萌发率约为59.2%,花粉管生长长度为966.3μm.     

玉米花粉体外萌发方法改进及其对花粉介导转基因的作用

超声波处理花粉介导植物基因转化方法由山西省农业科学院生物技术研究中心发明, 已被国家知识产权局授予发明专利(专利号ZL 99121152.9)。在该专利的基础上, 针对玉米(Zea mays)花粉取样、保存和处理条件等因素对其体外萌发的影响进行深入研究, 提出了改进玉米花粉体外萌发实验的方法。研究结果表明, 在不同时期对开花的玉米进行花粉培养时所需蔗糖溶液的浓度不同; 确定了玉米花粉的保存时间、条件及其对超声波处理后花粉萌发率的影响, 以提高该转化方法中花粉的活力, 并进一步验证了该转基因方法的可靠性; 讨论了玉米花粉体外萌发的操作技巧和各因子的参数, 对提高花粉介导植物基因转化效率有一定的参考价值。     

银杏胚珠贮粉室的早期发育

对银杏 (GinkgobilobaL .)胚珠贮粉室的早期发育过程以及珠心细胞死亡的细胞学机制进行了研究。DNA电泳出现DNAladder和TUNEL标记说明参与形成贮粉室的珠心细胞死亡是程序性死亡 (PCD)过程 ,并且显示出在贮粉室形成中 ,PCD的发生有一定的空间分布式样。结合扫描电镜观察 ,贮粉室的早期发育可分为 4个阶段 :起始事件是位于珠孔端的 3至 4层珠心细胞纵向伸长 ;接着 ,位于珠心组织最上部 (珠孔端 )的珠心细胞启始死亡 ;然后 ,这些已经纵向伸长的珠心细胞向基地和侧向地逐渐死亡 ,形成一个空腔 ;最后 ,珠孔端珠心表皮细胞以开裂的方式与其余表皮细胞脱离而形成贮粉室的开口。大孢子母细胞时期 ,贮粉室尚未发生 ;四分体阶段 ,贮粉室已经开始形成 ;到雌配子体发育时期 ,贮粉室已经完全产生。反映大孢子发育和贮粉室发生的同步性。     

肌醇磷脂信号途径参与胞外钙调素启动花粉萌发和花粉管伸长

高等植物有性生殖是植物发育生物学研究的重要内容之一,而作为雄配子体的花粉在雌蕊柱头上萌发及花粉管在花柱内的持续生长是有性生殖实现的关键。已有许多研究表明Ca2 在花粉萌发和花粉管生长过程中起重要作用。最近,我室在多年细胞外钙调素（calinodulin,CaM）存在。性质及生物学功能研究（孙大业等1995;Sun等1994,1995;Tang等1996）的基础上,通过不过膜的大分子CaM拈抗剂或抗体并结合恢复实验证实细胞外CaM对花粉的萌发和花粉管的伸长具有启动作用（马力耕和孙大业1996）,并发现G蛋白、质膜Caz”通道及胞内依赖Caz”的蛋白…     

不同贮藏条件及生长调节剂对欧李花粉生活力的影响

以2年生欧李植株为试材,采用液体培养法研究了不同采集时间、贮藏时间、贮藏条件以及不同生长调节剂对欧李花粉萌发和花粉管生长的影响。结果表明:(1)欧李花粉在大花苞期至初花期的生活力和发芽力最强,是花粉适宜的采集时期。(2)贮藏条件对花粉的贮藏时间起决定作用,在干燥条件下,花粉的生活力迅速降低,在自然湿度条件下,欧李花粉的贮藏时间随温度的降低而延长,-89℃超低温是欧李花粉贮藏的适合条件。(3)6-BA对花粉的萌发有抑制作用,但适宜的浓度(15mg·L-1)可以促进花粉管的生长,反之则抑制花粉管的生长;所有浓度的2,4-D均能促进花粉管的生长,但浓度对花粉萌芽率的影响极大;低浓度NAA(<20mg·L-1)或GA3(<50mg·L-1)对欧李花粉的萌发和花粉管的生长均影响不大;当NAA≥20mg·L-1时,对花粉的萌发有抑制作用,对花粉管的生长有促进作用;当GA3≥50mg·L-1时对花粉萌发和花粉管生长均具有一定的抑制作用。