化学调控四季花龙眼成花座果的初步研究

不同化学试剂组合对四季花龙眼枝梢生长和成花座果研究表明,不同时期成熟的枝梢对四季花龙眼成花座果无重大的影响;乙烯利、多效唑和赤霉素三者共同作用可促进成花座果;当枝梢充分成熟时,树冠喷施乙烯利250mg·L-1+多效唑450mg·L-1,谢花3/4时再喷施赤霉素50mg·L-1,可以有效抑制四季花龙眼植株新梢的萌发,促使植株100%成花,并且花穗和果穗性状的综合表现最好。     

光周期诱导甘蔗花芽分化及成花逆转过程中生理代谢的变化

以两个在自然条件下难开花的甘蔗品种‘ROCl6’和‘ROC22’为材料,研究经光周期诱导甘蔗花芽分化和成花逆转过程中叶片碳水化合物和可溶性蛋白质含量的变化。结果表明,未分化前,两品种经光周期诱导后叶片可溶性总糖、淀粉和蛋白质含量与对照相比无明显变化;从花芽分化诱变期开始,两品种叶片可溶性总糖、淀粉和蛋白质含量迅速增加,明显高于对照（未分化）。随着花芽进一步分化,其叶片可溶性总糖、淀粉含量逐渐降低并低于对照,处在一个较低的水平,蛋白质含量始终高于对照。成花逆转植株在花芽分化前期叶片可溶性总糖、淀粉和蛋白质含量也高于对照,但低于正常抽穗开花植株;之后随着花芽分化的停止,其叶片可溶性总糖、淀粉含量一直保持较稳定的水平,仅蛋白质略有降低。说明甘蔗花芽分化期间大量的基因表达并且合成各种蛋白质的过程需要消耗大量的碳水化合物。     

高等植物成花诱导调控的分子和遗传机制

成花诱导是高等植物由营养生长向生殖生长过渡的重要环节。成花诱导过程由内因和外因两个因素决定。近年来,在对拟南芥、水稻等有花模式植物成花机制的研究中,已发现植物成花主要受春化、温敏、光周期、赤霉素、自主、成花抑制和年龄7条途径控制。文章简要综述这7条途径相关研究的最新进展,以期为今后从分子和生理水平调控植物成花诱导提供基础。     

龙眼重回缩修剪树有机营养及枝梢生长特性

测定石硖龙眼树重回缩后各次梢的长度、叶绿素含量、净光合速率、可溶性总糖和可溶性蛋白质含量,结果表明:重回缩修剪树较对照多长1次梢,梢长也极显著大于对照;叶绿素含量、可溶性蛋白质含量和对照都没有显著差异;净光合速率总体高于对照;可溶性糖含量极显著低于对照。施用PP333可以有效抑制枝梢徒长,对其它测定项目无显著影响。     

高等植物成花分子机理研究现状及展望

以拟南芥、金鱼草为例,介绍了近几年植物成花（包括成花诱导、花序分生组织的组成、花发端、花器官发生及发育）研究的一些进展,着重介绍了成花过程中基因的表达,调控与生理功能。     

光周期和外源糖对新铁炮百合生长和内源糖含量的影响

糖类和光周期是植物成花启动中的重要因素,二者相互作用,共同调节植物成花。新铁炮百合(Lilium×formolongi)具有短生育期的特性,在适宜条件下,一年内可实现从播种到开花。为此,对新铁炮百合品种‘雷山三号’实生苗进行不同光周期和外施蔗糖的处理,探究其对内源糖、海藻糖-6-磷酸含量及对成花诱导的影响。结果表明:在长日照条件下外施蔗糖可以提高抽葶率,并缩短抽葶时间和可见花蕾出现的时间;同时提高植株体内蔗糖和海藻糖-6-磷酸的含量。植株体内葡萄糖含量受光周期影响较大呈现不同变化趋势,而果糖含量在四种不同处理中未表现出明显变化趋势,并且植株体内海藻糖-6-磷酸和蔗糖含量呈现显著正相关。综合而言,光周期是新铁炮百合成花启动的主要影响因素,外施蔗糖在长日照下对成花的促进作用更为明显。     

长日照处理对牵牛开花抑制作用研究 Ⅱ.光周期处理与牵牛花芽分化及基因活动的关系

单个光周期暗期长度短于12h时,牵牛植株营养生长旺盛,开花受到抑制,并且出现了诱导光周期处理（ISD）子叶中没有的二种蛋白质或多肽（pI4.1,MW16.5kD;pI4.2,MW16．5kD）。连续光照处理（ICL）子叶内出现了短日照处理（ISD）子叶内没有的体外翻译蛋白质分子量为17．4kD的Poly（A~ ）mRNA。牵牛子叶内的这些变化可能与抑制牵牛花芽分化有一定的关系。     

多胺及其合成抑制剂MGBC对稀脉萍成花反应的影响

腐胺、亚精胺和精胺对稀脉萍的成花均有一定的抑制作用,这种作用随多肢的浓度增加而增强。多胺合成抑制剂MGBG强烈抑制稀脉萍群体的增殖速率,并使稀脉萍群体在非诱导光周期下开花。这种由MGBG引起的增殖速率的降低及成花诱导作用均可被多胺逆转。稀脉萍成花诱导过程中,内源腐胺含量显著升高,亚精胺则下降。     

NAA与PP_(333)对茉莉新梢部分生理生化作用的影响

在茉莉开花前期分别使用不同浓度NAA(20、50、100mg/L)与PP333(100、300、500mg/L)溶液均匀喷施于植株茎、叶片等生长部位,研究其对茉莉开花的影响,分析测定植株新梢生长部位的可溶性蛋白质、游离氨基酸含量以及保护酶活性等生理生化指标。结果表明:NAA处理使新梢徒长;PP333处理的茉莉,花蕾盛开期比对照提早4d,浓度以300mg/L为宜,其产量比对照增加12.95%,明显提高花蕾产量。茉莉经PP333处理后,新梢可溶性蛋白质和游离氨基酸含量在整个花芽生长过程中趋于相对稳定,而NAA处理后则使可溶性蛋白质和游离氨基酸含量变化幅度大。NAA与PP333处理后新梢中POD活性在花芽生长过程中稍有下降,NAA处理高于对照,而SOD活性则有上升趋势。经NAA和PP333处理后,其效应各不相同,而适宜浓度的PP333处理可以提高茉莉花蕾产量。     

光皮树花芽分化过程中内源激素含量变化的研究

以4年生光皮树嫁接苗为材料,采用酶联免疫吸附法（ELISA）测定同龄开花光皮树与不开花光皮树叶内4种内源激素生长素（IAA）、赤霉素（GA3）、玉米核苷素（ZR）、脱落酸（ABA）含量的动态变化,研究成花过程中叶片内源激素含量的变化与成花的关系。研究结果表明：在芽分化时期开花光皮树和未开花光皮树叶内4种内源激素含量动态变化存在显著差异。有花芽分化的光皮树保持相对较低和稳定IAA、GA3含量,ABA含量高且变化幅度较大,ZR含量相对较低,但随着花的形成含量逐渐升高;而在相同的生长季内,无花光皮树IAA、GA3含量先升高后降低,ABA含量先逐渐升高,然后下降,而ZR含量呈现出先逐渐升高然后降低,再升高再下降的变化趋势。因此,4种内源激素含量的动态变化影响光皮树的成花过程。     

Endogenous gibberellins and inhibitors in relation to flower induction and inflorescence development in the olive

Comparative analyses of reproductive and vegetative tissues of the olive (Olea europaea L. cv. Manzanillo) for endogenous hormones, particularly inhibitors and gibberellin like substances, were made to study the relation between such hormones and thermoinduction of flowering. Qualitative and quantitative changes in gibberellin-like subtance(s) were observed in lateral buds (potential flower buds) but not in leaves or terminal buds (potential vegetative buds) sampled from orchard trees at intervals during the winter and spring. At least two types of gibberellin-like substances were found in extracts of lateral buds; their levels increased progressively during the low temperature induction period, reaching a maximum shortly before floral initiation. Two types of inhibitors were extracted from buds and leaves. A nonacidic type did not change during the induction stage but decreased considerably during the initiation period. An acidic inhibitor, which was identified as an abscisic acid-like substance, was present at a relatively lower level in lateral (flower) buds than in terminal (vegetative) buds during the induction period.     

Timing of reproductive and vegetative development in Saxifraga oppositifolia in an alpine and a subnival climate

Morphogenesis of floral structures, dynamics of reproductive development from floral initiation until fruit maturation, and leaf turnover in vegetative short-stem shoots of Saxifraga oppositifolia were studied in three consecutive years at an alpine site (2300 m) and at an early- and late-thawing subnival site (2650 m) in the Austrian Alps. Marked differences in the timing and progression of reproductive and vegetative development occurred: individuals of the alpine population required a four-month growing season to complete reproductive development and initiate new flower buds, whereas later thawing individuals from the subnival sites attained the same structural and functional state within only two and a half months. Reproductive and vegetative development were not strictly correlated because timing of flowering, seed development, and shoot growth depended mainly on the date of snowmelt, whereas the initiation of flower primordia was evidently controlled by photoperiod. Floral induction occurred during June and July, from which a critical day length for primary floral induction of about 15 h could be inferred. Preformed flower buds overwinter in a pre-meiotic state and meiosis starts immediately after snowmelt in spring. Vegetative short-stem shoots performed a full leaf turnover within a growing season: 16 (+/-0.8 SE) new leaves per shoot developed in alpine and early-thawing subnival individuals and 12 (+/-1.2 SE) leaves in late-thawing subnival individuals. New leaf primordia emerged continuously from snowmelt until late autumn, even when plants were temporarily covered with snow. Differences in the developmental dynamics between the alpine and subnival population were independent of site temperatures, and are probably the result of ecotypic adaptation to differences in growing season length.     

菊苣薄层培养花芽,营养芽分化中内源激素的动态变化

菊苣（Ｃｉｃｈｏｒｉｕｍ ｉｎｔｙｂｕｓＬ．）花梗薄层细胞培养于ＭＳ附加ＮＡＡ 和ＢＡ 或ＩＡＡ 和ＢＡ 的ＭＳ培养基上有花芽或营养芽分化． 花芽分化中内源ＩＡＡ、ＤＨＺ＋ ＤＨＺＲ、ｉＰＡ 含量明显增加,而Ｚ＋ ＺＲ变化不明显．营养芽分化中内源细胞分裂素含量增加明显,而ＩＡＡ 在培养前７ ｄ 含量下降,随后有所增加,在原基形成时含量达原初水平的２／３． 可见,花芽分化比营养芽分化所需内源ＩＡＡ／ＣＴＫ 比值要高     

穗花牡荆花芽分化过程中形态和生理指标变化

以穗花牡荆为研究材料,通过探究其花芽分化进程和生理特性,为花期调控技术提供成花机理。采用物候期观察和石蜡切片相结合的方法并测定花芽分化过程中相关生理指标,研究花发育过程中的形态和生理变化。结果表明,穗花牡荆花芽分化为一年多次分化型,其进程可划分为七个时期：未分化期、总轴花序原基分化期、初级分轴花序原基分化期、次级分轴花序原基分化期、小花原基分化期、花器官分化前期和花器官分化后期。同一植株不同位置花芽及同一花序中不同单花分化的进程不同,第一季花期后各阶段的花芽分化形态常存在重叠。花芽分化过程中不同时期叶片和花芽的可溶性糖和可溶性蛋白质含量均有上升下降的变化,总体上叶片中营养物质含量高于花芽保证营养供应。花芽分化过程中,IAA、ABA、CTK和GA3整体水平上先升后降有利于花芽分化进行。研究认为,花芽中大量的可溶性糖和蛋白质积累及较高的碳氮比,有利于穗花牡荆花芽形态分化顺利完成。低水平的GA3/ABA和IAA/CTK有利于花序的形成,ABA/CTK和ABA/IAA比值升高促进小花原基和小花萼片原基的分化, GA3/CTK、GA3/ABA和GA3/IAA比值升高促进花瓣原基、雄雌蕊原基发育。     

Changes of Endogenous Hormone Contents During Floral Bud and Vegetative Bud Differentiation in Thin Cell Layer Culture of Cichorium intybus L. Explant

The sectioned thin cell layers (TCL) of flower stalk of Cichorium intybus L. were cultured in MS medium supplemented with NAA and BA or IAA and BA where floral and vegetative buds were developed from the explant. Endogenous IAA, DHZ+DHZR, iPA increased significantly during the floral bud formation, while Z+ZR remained changed. The levels of cytokinins, DHZ +DHZR, iPA, and Z-f-ZR all increased significantly during the vegetative bud formation, however IAA level was reduced during the first 7 days of culture and increased to two-thirds of initial values on the day when the bud primordia were formed. The results suggested that the initiation of floral buds was associated with a high IAA/CTK ratio, whereas the induction of vegetative bud differentiation was related to a low IAA/CTK ratio.     

Fruit Regulates Bud Sprouting and Vegetative Growth in Field-Grown Loquat Trees (Eriobotrya japonica Lindl.): Nutritional and Hormonal Changes

The effects of fruit on bud sprouting and vegetative growth were compared on fruiting and defruited loquat trees from fruit set onward. Carbohydrate and nitrogen content in leaves and bark tissues and hormone concentrations were studied during the fruit development and vegetative growth periods. On defruited trees, a significant proportion of buds sprouted in winter, whereas buds from fruiting trees sprouted only in the spring when fruit reached its final size. Furthermore, when panicles were completely removed in autumn, the buds also sprouted. In addition, fruit directly affected vegetative growth by reducing shoot length. An effect of sink removal (flower or fruit) promoting bud sprouting, regardless of the season, was then demonstrated. Neither soluble sugar concentration nor nitrogen fraction concentration in leaves or bark tissues was related to bud sprouting, but a certain nutritional imbalance was observed during the most active period of fruit development. Moreover, fruit sink activity significantly modified hormone content by increasing indole-3-acetic acid (IAA) and reducing zeatin concentrations, resulting in a higher IAA/zeatin ratio parallel to the lower bud sprouting intensity. Therefore, these changes caused by fruit removal are all related to vegetative growth, but there is no evidence that they are responsible for bud burst.     

黄瓜离体子叶节花芽和营养芽分化中CFL基因的表达

CFL基因是从黄瓜中克隆到的拟南芥LEAFY(LFY)同源基因.以离体黄瓜子叶培养物成花为实验体系,利用mRNA原位杂交技术对CFL基因在花芽和营养芽分化过程中的时空表达进行了分析.结果如下:在花芽分化过程中,CFL基因在花原基形成、花器官原基分化及各轮花器官形成之初强表达,在花器官形成以后表达减弱或不表达;在营养芽分化过程中,CFL基因在分生组织、叶原基和幼叶中有明显表达,在成熟组织中不表达.结果说明CFL基因的表达在黄瓜子叶节花芽和营养芽分化中原基的分化形成是必需的.结果提示CFL基因可能参与细胞分裂调控和启动、营养性分生组织向花分生组织转变等过程.     

Further experiments on spermidine-mediated floral-bud formation in thin-layer explants of Wisconsin 38 tobacco

We studied the effects of various polyamines on bud regeneration in thin-layer tissue explants of vegetative and floweringNicotiana tabacum L. cv. Wisconsin 38, in which application of exogenous spermidine (Spd) to vegetative cultures causes the initiation and development of some flower buds (Kaur-Sawhney et al. 1988 Planta173, 282). We now show that this effect is dependent on the time and duration of application, Spd being required from the start of the cultures for about three weeks. Neither putrescine nor spermine is effective in the concentration range tested. Spermidine cannot replace kinetin (N⁶-furfurylaminopurine) in cultures at the time of floral bud formation, but once the buds are initiated in the presence of kinetin, addition of Spd to the medium greatly increases the number of floral buds that develop into normal flowers. Addition of Spd to similar cultures derived from young, non-flowering plants did not cause the appearance of floral buds but rather induced a profusion of vegetative buds. These results indicate a morphogenetic role of Spd in bud differentiation. Dedicated to Professor Hans Mohr on the occasion of his 60th birthday     

矮牵牛(Petunia hybrida)开花过程中的可溶性蛋白质分析

在进行矮牵牛(Petunia hybrida)光周期诱导开花的过程中,对叶子中的可溶性蛋白质进行了分析,其中有4条与开花有关的特异蛋白,分子量分别为49.45 kD(a)、35.45 kD(b)、17.98 kD(c)和11.74 kD(d).在不开放的花苞中不含有蛋白质a和d,只有这4种蛋白质全出现时,才能形成花苞并且开放.花开了以后,蛋白质c和d就消失.即使在开花的植株中,各组织中的蛋白质也是不同的.茎中完全不含有蛋白质c和d,叶子和花中的蛋白质组成也是不同的.     

赤霉素对大岩桐花蕾离体培养直接再生花芽的影响(简报)

植物经过一定时期的营养生长(或感受外界信号)后,就能产生成花刺激物。成花刺激物被运输到茎尖,诱导发生一系列的反应。随后其分生组织在一定时期内处于一个相对稳定的状态,即成花决定态。植物成花决定态建立的过程称为成花决定。对