The Role of Glucose on Flower Bud Formation in Thin-Layer Tissue 12Nicotiana tabacum L.

The effect of glucose on flower bud formation was studied inthin-layer tissue cultures of epidermal strips from flower stalksof Nicotiana tabacum L. cv. Samsun. A minimum concentration of 30 mol m^–3 glucose in the MS-mediumcontaining 1.0 mmol m^–3 of both NAA and BA was necessaryfor flower bud formation. With 150 mol m^–3 glucose a minimumstay of 10 d was required for optimal flower bud formation. Withholding glucose for a limited period at different time intervalsafter the onset of culture caused a delay in flower bud formationand did not affect previous development on glucose. The resultsindicated that competence for flower bud initiation is not restrictedto the early stage of culture. The process may start at anytime later at the appropriate glucose concentration. However,for both optimal initiation and further development of flowerbuds the presence of a metabolizable sugar is required. Incubationof the tissue on glucose is associated with higher respirationrate. Key words: Flower formation, Glucose, mannitol, Nicotiana tabacum, Respiration, tissue culture     

油茶花芽分化形态结构及内源激素变化

以普通油茶(Camellia oleifera) 4个无性系为材料,结合油茶成花的动态观察和花芽分化过程的石蜡切片形态观察,采用酶联免疫吸附分析法测定花芽中玉米素核苷(ZR)、脱落酸(ABA)、生长素(IAA)、赤霉素(GA) 4种内源激素含量,探讨油茶花芽分化与内源激素的关系。油茶花芽分化过程可分为6个时期：前分化期(10 d)、萼片形成期(20 d)、花瓣形成期(30 d)、雌雄蕊形成期(20 d)、子房与花药形成期(10 d)和雌雄蕊成熟期(20 d),历时3～4个月。油茶不同无性系的花芽分化时间略有不同。油茶花芽中ZR含量相对较低(5.102～16.412 ng·g–1 FW),ABA含量相对较高(76.815～137.648 ng·g–1 FW)。其中,粤华5号和湘林8号的ZR、ABA含量变化趋势一致,岑软3号和岑软2号含量变化趋势一致。油茶花芽中IAA含量相对较高,为49.072～135.622 ng·g–1 FW,随着花芽分化进程,IAA含量均呈先升后降再升的变化趋势。GA含量相对较低,为5.616～13.720 ng·g–1 FW,随时间变化,呈现出不断降低的趋势。其中,不同无性系的IAA、GA含量变化趋势一致,而ZR、ABA含量变化趋势有所差异。ZR有利于花器官形成;高浓度IAA促进油茶花芽分化,低浓度IAA有利于开花;花芽中IAA与ABA存在明显的颉颃作用;GA抑制花芽分化。     

Flower bud differentiation in Salix pentandra as affected by photoperiod, temperature and growth regulators

Flower bud initiation in seedlings and vegetatively propagated plants of Salix pentandra from different locations has been studied under controlled conditions. In mature plants flower bud formation was induced by 2-chloroethyltrimethylammoniumchloride (CCC) and by short day treatment. The effect of CCC was antagonized by GA₃. The critical photoperiod for flower bud formation was about 18 h for a southern clone (from 49°48'N), but cuttings of a northern ecotype (from 69°39'N) formed flower buds even at 24 h photoperiod. Generally, flower bud formation occurred simultaneously with apical growth cessation. However, apical growth cessation was not a prerequisite for floral initiation and flower buds were also found in elongating plants. Seedlings up to 60 days old did not form flower buds in growth chamber studies. The length of the juvenile phase has not been studied in detail, but cuttings taken from seedlings approximately 20 cm high and 60 days old were able to develop flower buds when treated with CCC. A gradual transition from the juvenile to the mature phase was obtained by repeated pruning of seedlings grown at 18°C and 24 h photoperiod.     

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。     

Role of hormones on flower bud formation in thin-layer expiants of tobacco

Flower bud formation was studied in thin-layer tissue expiants of epidermis plus subepidermal cortex from the inflorescence ramifications ofNicotiana tabacum cv. Samsun. With appropriate hormone concentrations of BA and NAA expiants from flowerv and fruitbearing stalks regenerate flower buds only, while those from the internodes of the inflorescence ramifications produce generative as well as vegetative buds. In both types of expiants the number of buds formed depend mainly on the hormone concentrations but, in addition, the age of stalks and internodes from which expiants are taken also affects bud formation. Both ABA and JA inhibit flower bud formation in expiants of flower stalks. JA was shown to particularly inhibit bud initiation.     

Changes in IAA,Phenolic Compounds,Peroxidase, IAA Oxidase,and Polyphenol Oxidase in Relation to Flower Formation in Crocus sativus

Changes in levels of IAA, phenolic compounds, peroxidase, polyphenol oxidase, and IAA oxidase activities in the corm and the apical bud of Crocus sativusL. during bud growth and development, with special emphasis on the flowering stage, were studied. In the bud, flower formation was accompanied by enhanced activities of peroxidase, polyphenol oxidase, IAA oxidase, and higher contents of phenolic compounds as well as lower levels of IAA. In the corm, during the flower formation, these enzymes showed an opposite behavior. Moreover, the contents of phenolics and IAA in the corm tissues during flower formation and growth were higher than at the other developmental stages. It may be concluded that the transition of saffron plants to flowering is correlated with peroxidase, polyphenol oxidase, and IAA oxidase. Furthermore, these enzymes might exert their roles in the regulation of flowering through their participation in IAA catabolism. The hypothesis of regulation of bud development by an interaction between phenolics and the enzymes involved in IAA catabolism is discussed.     

Floral morphogenesis in thin-layer tissue cultures of Nicotiana tabacum

The morphological changes in thin-layer tissues of Nicotiana labacum L. cv. Samsun, cultured on Murashige and Skoog medium with 1 μ M each of naphthalene acetic acid (NAA) and benzyladenine (BA), were studied during the first 8 days of culture with light and scanning electron microscopy. The first three days of culture arc characterized by enlargement of all cells and cell divisions starling in the cortical parenchyma cells adjacent to the medium. Between days 3 and 6, epidermal and/or subepidermal cells start to divide, resulting in division centers, which lead to flower bud formation. The hormones NAA and BA in different concentrations affect the formation and distribution of flower buds, bud morphology and callus formation. BA influences particularly bud formation and bud morphology, while NAA affects callus formation in particular. In addition, polarity may occur in the formation of both callus and flower buds, the degree of which depends upon the hormone concentrations.     

苹果花芽孕育机理的探讨

花芽孕育期,以环剥、多效唑＋环剥和ＧＡ３处理“红富士”苹果树,成花效应以多效唑＋环剥处理为最高（＋６８４％）。花芽孕育起动时,促花处理的短枝顶芽内ＩＡＡ、ＺＲ含量和ＩＡＡ／ＧＡｓ、ＺＲ／ＧＡｓ的比值均明显提高。在花芽孕育完成过程中,促花处理的短枝叶内淀粉含量、Ｃ／Ｎ比,芽内ＺＲ、ＩＡＡ含量和ＺＲ／ＧＡｓ明显提高,ＧＡｓ则明显下降。     

In vitro flower bud formation in tobacco: interaction of hormones

External application of auxin and cytokinin is required for the formation of flower buds on thin-layer tissue explants of Nicotiana tabacum cv Samsun. Interaction between both plant growth regulators during this regenerative process has been demonstrated with respect to speed of flower bud initiation and the number of flower buds formed. Separation in time of the hormone application during culture revealed that the cytokinin benzyladenine plays a key role in flower bud initiation whereas auxin (indoleacetic acid) stimulates in particular the differentiation of flower buds. The uptake of each hormone was proportional to the concentration supplied in the medium, and the uptake of either hormone appeared independently of the presence of the other. Metabolism studies showed the conversion of indoleacetic acid by the tissue to at least 13 metabolites after 24 h of culture. In addition, indoleacetic acid metabolism was demonstrated not to be influenced by the uptake and metabolism of benzyladenine. Taken together the results indicate that the interaction of auxin and cytokinin with respect to in vitro flower bud formation is indirect, i.e. does not take place at the level of hormone uptake or metabolism but at some step in the cascade of processes they initiate.     

多胺在植物花发育中的作用

多胺是植物体内一类生理活性物质,其代谢变化与高等植物的花芽形成和发育关系密切。该论文综述了多胺在植物体内的形态和分布,以及成花诱导、花芽形成,尤其是雄性育性的发生和性别分化过程中的作用,并对今后的研究方向进行了讨论。     

Latitudinal variation in suppression of flower bud formation at high temperature in four native dandelions (Taraxacum spp.) with different distributions and genetic structures in Japan

The control of the response of flowering to temperature plays a key role in successful range‐expansion of plants. A previous study showed that the suppression of flower‐bud formation at high temperature in Taraxacum officinale decreases genetically with latitude from north to south in Japan. The present study investigated whether similar trait variation occurs among populations of native Taraxacum species in Japan. Seedlings of T. albidum (a low‐ and mid‐latitude allopolyploid), T. japonicum (a mid‐latitude diploid) and T. venustum (a high‐latitude autopolyploid) were grown at three temperatures. Time to flower‐bud appearance increased with temperature in T. japonicum and T. venustum, but did not increase in T. albidum. Time to flower‐bud appearance did not differ significantly among the three species at 14°C, but it was shorter in T. albidum than in the other two species at 19°C and 24°C. The early appearance of buds of T. albidum was confirmed by another experiment in which plants of 18 populations from the three species and T. platycarpum (a mid‐latitude diploid) grown at 19°C were used. The results clearly indicate that high‐temperature suppression of flower‐bud formation was lower in low‐latitude species than in high‐latitude species. This interspecific variation is analogous to the intraspecific variation in T. officinale. Time to bud appearance of five populations in T. albidum was homogeneous within and between the populations. The results suggest that the five populations are monoclonal and lack the sensitivity of suppression of flower‐bud formation to high temperature.     

2个果梅品种雌蕊分化进程及相关生化指标分析

为了解果梅(Prunus mume Sieb.et Zucc.)雌蕊分化进程及其败育机制,采用石蜡切片法观察了不同时期果梅品种‘龙眼’(‘Longyan’)和‘大嵌蒂’(‘Daqiandi’)花芽纵切面的解剖结构,并对2个品种不同时期花器官发育状况、花芽百分率、花芽纵径和横径以及花芽中的可溶性糖、可溶性蛋白质和淀粉含量进行了测定分析.结果显示:雌蕊分化期、雌蕊分化末期及盛花期,品种‘龙眼’的不完全花比例均显著小于品种‘大嵌蒂’,其中,盛花期‘龙眼’不完全花比例仅为5.0％,而‘大嵌蒂’不完全花比例高达76.3％.品种‘龙眼’雌蕊分化过程经历未分化期、分化初期、分化期及分化末期4个阶段,且最终有95.0％的花芽在分化末期能顺利形成完全花;品种‘大嵌蒂’雌蕊分化过程则包含未分化期、分化初期、分化期、解体期、解体后修复期和分化末期6个阶段,且仅有23.7％的花芽能形成完全花.雌蕊分化的不同阶段2个品种花芽纵径和横径的变化与其分化进程基本一致.品种‘龙眼’完全花的可溶性糖和可溶性蛋白质含量均高于品种‘大嵌蒂’的完全花和不完全花、淀粉含量则低于后两者;品种‘大嵌蒂’不完全花的可溶性糖和可溶性蛋白质含量最低、淀粉含量则最高,与2个品种的完全花有显著差异.综合分析结果表明:品种‘大嵌蒂’的花芽在12月中上旬停止伸长生长、雌蕊分化停滞直至逐渐解体,这一时期即为品种‘大嵌蒂’雌蕊败育的关键时期;导致果梅雌蕊选择性败育的原因可能与花芽中大分子营养物质的分解代谢有关.     

中国水仙花芽分化观察及储藏条件对花芽数的影响研究

以三年生中国水仙‘金盏银台’为材料,采用石蜡切片法观察其花芽形态分化过程。结果表明：中国水仙的花芽分化从7月上旬开始,到9月中旬形成雌蕊结束。其过程可分为叶芽时期、花序原基形成期、佛焰状总苞形成期、花原基形成期、花冠形成期、雄蕊形成期、雌蕊形成期7个时期。其中花冠形成期较长,20 d左右。花芽的外部形态变化上,分化后期芽的生长速度明显快于前期。对鳞茎球内花序数量的统计结果显示,高温储藏及烟熏法共同使用对中国水仙花序的形成具有很好的促进作用。     

无花果花芽分化与内源激素含量的关系

在‘布兰瑞克’无花果花芽分化形态学研究的基础上,对花芽分化期无花果新梢第7或第8节位花芽中的玉米素核苷(ZRs)、脱落酸(ABA)、赤霉素(GA1 3)、生长素(IAA)4种内源激素含量的变化进行了探讨。结果表明,在无花果花芽分化阶段,GA1 3和IAA初期含量较高,后快速下降,后期稳定在较低水平;ZRs和ABA在初期含量较低,后大幅提高,后期稳定在较高水平。可见,较高水平的内源ZRs、ABA和较低水平的内源GA1 3、IAA,以及较高的ABA/IAA、ABA/GA1 3、ZRs/GA1 3和ZRs/IAA比值有利于无花果花芽分化。     

Induction of Continuous Tepal Differentiation from in Vitro Regenerated Flower Buds of Hyacinthus orientalis

Continuous differentiation of tepals was successively induced from regenerated flower buds in Hyacinthus orientalis L. cv. White Pearl by controlling the exogenous hormones and explant ages. In 250 days of subculture, each flower bud differentiated an average of more than 70 tepals, with a maximum of over 140 tepals. Studies on the morphogenesis and characteristics of growth and development of the flower buds indicate that the first whorled organ of the flower bud was perianth which consisted of perianth tube and tepals grown at the top of the perianth tube, which is the same as the flower bud of the wild type in H. orentalis. The second and third whorls of the flower bud, which should be stamen and pistil in the wild type, but remained as the tepals in the regenerated flower bud. Growth of the regenerated flower bud was faster in the first several months of culture, then slowed down gradually with time. After 150 days in culture the flower bud growth and organ differentiation became very slow. Other than the tepal differentiation the regenerated flower buds also differentiated at random positions some small flower buds that also differentiated the tepals only. Histological observation revealed that the origin of the regenerated flower buds was jointly participated by some cells in the epidermal and subepidermal layers at the inner surface of the perianth explant, and the inner small flower buds were originated from the meristem which was formed by the transformation of the parenchyma at the base of the very young tepal. The authors also compared and discussed the similarities and differences of the phenotypes between the regenerated flower bud in Hyacinthus and agamous flower in Arabidopsis, from which, they have hypothesized on the role of the hormones in the promotion and termination of the gene expressions by an order of development in plant.     

喷施烯效唑对苹果顶芽激素水平和花芽分化的影响

用烯效唑(uniconazol,S3307)1 g/L喷洒“红富士“苹果树降低了顶芽IAA、GA1,3,4,7含量,提高了ZR、ABA含量,从而提高了ZR/IAA、ZR/GA1,3,4,7、ABA/IAA和ABA/GA1,3,4,7比值.烯效唑处理增加了花芽形成百分率,加速了花芽分化的进程,缩短了花芽形成的延续时期,但对花芽生理孕育临界时期长短没有影响.烯效唑处理对花芽的节位数没有影响,但使叶芽节位数增加了1节.     

蝴蝶兰成花过程中叶片内源激素与多胺含量的变化动态

以苗龄18~20个月的蝴蝶兰(Phalaenopsis)成熟苗为试材,通过夜温17℃/日温27℃处理诱导其成花,并研究蝴蝶兰成花过程中,叶片内源激素及多胺含量的变化动态。结果显示:低温诱导蝴蝶兰成花的临界期为第15d,芽重、内源激素和多胺含量均在第15d出现明显的消长规律;较低含量GA₃、ABA,高含量ZR、Spd,高比值ZR/GA₃、ZR/ABA和Spd/Put状态有利于成花;相对高含量的内源ZR是成花的关键因素;内源多胺与激素含量动态具有关联效应。     

补光对大棚火龙果冬季促花的影响

为探讨夜间补充光照对大棚火龙果冬季植株促花的效应,以2年生‘短芯’红肉(心)火龙果植株为试材,每天夜间补光6 h,以不补光为对照,观测火龙果枝条抽蕾状况。结果显示,在平均光强500 lx、每天补充光照6 h、连续补光45 d条件下,第一批次植株抽生花蕾率达83.3%,老枝(枝龄≥12个月)抽生花蕾率为15.2%,青枝(枝龄＜12个月)抽生花蕾率为28.0%,抽生花蕾枝条占植株总枝条数的21.4%;枝条花蕾数占枝条上芽点数的比率,老枝为2.7%、青枝为2.9%。而对照植株没有抽生花蕾,抽蕾率为0。表明夜间补充光照可有效地促进大棚火龙果冬季植株抽花。     

罗汉果花芽分化过程中形态及其激素水平变化特征

采用石蜡切片和酶联免疫法(ELISA)对罗汉果雄性、雌性、两性花芽分化过程的形态和激素水平变化进行观测,为罗汉果开花调控和品种选育提供科学依据。结果表明:(1)罗汉果雄性、雌性、两性花的花芽分化过程均可分为花芽未分化期、花芽分化初期、花序分化期、萼片原基分化期、花瓣原基分化期、雄蕊原基分化期和雌蕊原基分化期7个阶段。雄蕊原基分化期前,3种花芽分化过程无明显差异,各时期形态特征均依次为:茎端呈圆锥状(花芽未分化期)→茎端经半球形变成扁平状(花芽分化初期)→距茎端5~7节位处分化出穗状花序(花序分化期)→小花原基周围形成5个萼片原基(萼片原基分化期)→萼片原基内侧形成5个花瓣原基(花瓣原基分化期)。雄蕊和雌蕊原基分化期,3种花芽分化过程存在明显差异,雄蕊原基内侧出现雌蕊原基后,雄花芽雄蕊原基继续发育成雄蕊,雌蕊原基停滞生长,退为一个小突起;雌花芽雌蕊原基继续发育成雌蕊,雄蕊原基生长缓慢,退化为小花丝;两性花芽雌蕊和雄蕊原基均继续发育,形成外观正常的雌蕊和雄蕊。(2)内源激素脱落酸(ABA)、赤霉素(GAs)和玉米素核苷(ZR)含量在3种花芽分化过程中变化规律相似,即ABA含量在花芽生理分化期降低,花芽形态分化期升高,而GAs和ZR含量则基本保持不变;吲哚乙酸(IAA)含量在3种花芽分化过程中变化存在明显差异,雌花芽IAA含量在花芽生理分化期升高,花芽形态分化期逐渐降低,而雄性和两性花芽的IAA含量则基本保持不变。ABA/GAs、ABA/IAA、ZR/IAA和ZR/GAs激素含量比值在3种花芽分化过程中变化规律相似,ABA/GAs在花芽生理分化期降低,花芽形态分化期升高,而BA/IAA、ZR/IAA和ZR/GAs则基本保持不变。研究认为,罗汉果花芽分化过程经历一个"两性期",高ABA含量和ABA/GAs比值有利于罗汉果花芽分化,IAA可能对罗汉果花性分化具有重要作用。     

‘神马’菊花花芽分化与内源多胺的关系

用薄层层析-荧光法测定菊花'神马'花芽分化期间顶芽和叶片中多胺的动态变化,分析了菊花花芽分化与多胺的关系.结果表明,花芽分化起始期顶芽中的腐胺(Put)含量急剧下降,此后在低水平上波动;叶片内Put则于总苞鳞片分化初期大幅上升,其后各阶段处于较低的水平.顶芽中精胺(Spm)与亚精胺(Spd)含量呈平行波动上升趋势,顶芽中Spin在小花原基分化初期直到花冠分化中期处于优势地位,而顶芽中Spd并无明显变化.顶芽、叶片中的Spin变化趋势相反,顶芽中Spm、Spd的含量变化趋势十分相似,但叶片中却呈交替性变化.结果显示,菊花花芽分化过程中,Put含量的降低有利于启动菊花花芽分化,后期Spm的增加有利于小花的分化,叶片可能向顶芽提供Spm,顶芽和叶片中的Spd与小花原基分化有密切关系.