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     

植物的成花决定

在成花诱导结束后,植物就具备了分化花的能力,即进入了成花决定态。文中着重介绍植物获得这一能力的过程及其特征,即植物成花决定过程及成花决定态的问题。     

植物成花转变及成花逆转的研究进展

本文主要讨论了植物成花转变及成花逆转等开花研究中应用分子生物学技术所取得的一些进展,描述了成花决定态的特性,5个从拟南芥中分离获得的成花转变的基因,有关光受体的分子生物学研究和造成成花逆转的原因等。     

光温外界信号、植株状态与成花决定

植物由营养生长状态转向生殖生长状态（成花转变）是发育过程中的重要一步。经过一段时期营养生长的植株,便自动进入成花感受态,在这种状态下植株才能够对外界信号产生应答反应而启动成花过程。本文主要讨论光周期和温度对成花的作用     

光温外界信号、植株状态与成花决定

植物由营养生长状态转向生殖生长状态(成花转变)是发育过程中的重要一步。经过一段时期营养生长的植株,便自动进入成花感受态,在这种状态下植株才能够对外界信号产生应答反应而启动成花过程。本文主要讨论光周期和温度对成花的作用。     

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。     

脱落酸在植物花发育过程中的作用

植物激素脱落酸(ABA)对植物的生长发育具有多方面的调节作用,比如种子休眠、萌发,营养生长,环境胁迫反应等。大量研究显示,ABA也参与了植物的成花调控。影响植物成花调控的环境因子,包括光周期变化、春化作用、干旱等均会导致植物体内ABA代谢的变化。本文从调控植物开花的4条主要途径与植物体内ABA代谢变化之间的相互关系,花芽分化时期ABA在植物叶芽和花芽中的动态分布以及离体培养条件下ABA对花芽分化的影响等方面总结了ABA与植物花发育这一领域的最新研究进展。对ABA在植物成花诱导和花发育中的作用进行了综合分析。     

温度对植物成花的影响

温度对于植物成花的影响是多方面的,本文主要从低温、高温和昼夜温差三方面综述了温度影响成花之生理学方面的研究结果。认为温度处理的效果发生于成花启动之前和/或成花启动进程中的较早步骤,其作用可能是间接的。     

温度对植物成花的影响

温度对于植物成花的影响是多方面的 ,本文主要从低温、高温和昼夜温差三方面综述了温度影响成花之生理学方面的研究结果。认为温度处理的效果发生于成花启动之前和 /或成花启动进程中的较早步骤 ,其作用可能是间接的。     

植物的成花逆转

成花逆转是生长发发育过程中的特殊现象,与环境因素、成花决定的程度及遗传因素有关。逆转为我们从另一角度研究开花现象提供了一个枘地。文章主要介绍成花志的类型,研究成花的逆转的体系。引起成花逆转的因素以及逆转九一与成花决定之间的关系。     

大岩桐花瓣切块离体培养高频率花芽再生

该文报道了大岩桐花瓣切块离体培养再生花现象,花瓣切块再生花有两种方式：一种是仅再生花芽（命名为BF）;另一种是既再生花芽也再生营养芽（命名为BF＋V）。花芽再生的能力与光照、花芽大小及培养基中赤霉素和细胞分裂素浓度紧密相关。当培养基中含有1.0 mg/L GA3时,BA的添加会显著增加总花芽（BF＋BF＋V）的形成率,添加0.5 mg/L BA时,总花芽形成率达100%。在暗中培养时,BF达93.4%。不同大小花芽的花瓣再生花的能力不同,7 mm直径花芽的BF最高,达86.7%。同时,对花芽再生过程中花瓣切块的组织结构形态变化也进行了观察。     

Effect of ABA on the in Vitro Induction of Floral Buds of Dendrobium candidu Wall.ex Lindl.

An in vitro flowering system of Dendrobium candidurn Wall. ex Lindl., a wild species of orchid, was established. Callus was induced from seeds and protocorms formed on MS agar medium supplemented with 0.3 mg/L NAA under diffused light. Floral buds were induced when protocorms were cultured on MS agar medium supplemented with 2 mg/L 6-BA and 0.5 mg/L NAA, the frequency of floral bud induction being 27.0%. When protocorms were precultured on MS medium supplemented with 0. 5 mg/L ABA for 15 days and then transfered onto MS medium supplemented with 2 mg/L 6-BA, the frequency of floral bud induction increased greatly reach 84.0 % during a period of 5 months. Meanwhile the number of branches and floral buds also increased and in some instances inflorescence appeared. Never the less, no floral bud was formed if protocorms continued to be cultured on the ABA-containing MS medium.     

石斛离体培养中ABA对诱导花芽形成的影响

由兰科植物铁皮石斛（Ｄｅｎｄｒｏｂｉｕｍ ｃａｎｄｉｄｕｍ Ｗａｌｌ．ｅｘ Ｌｉｎｄｌ．）种子诱导形成的愈伤组织,在光照下置于ＭＳ附加０．３ ｍ ｇ／ＬＮＡＡ 的培养基上繁殖,可以形成原球茎。将原球茎转入ＭＳ含２ ｍ ｇ／Ｌ ６－ＢＡ 和０．５ ｍ ｇ／ＬＮＡＡ 的培养基上,花芽形成频率为２７．０％ 。原球茎先在０．５ ｍ ｇ／ＬＡＢＡ的培养基上预培养１５ ｄ,再转入含２ ｍ ｇ／Ｌ６－ＢＡ 的ＭＳ培养基上培养,花芽形成频率明显提高,可达８４．４％ ,而且每株植株花的数目增加;但是在仅有ＡＢＡ 的ＭＳ培养基上培养的原球茎再生的植株未见花芽形成     

大果良种沙棘愈伤组织诱导及植株再生的研究

大果良种沙棘的幼嫩茎尖,茎段外植体接种在MS,1／2MS附加不同浓度配比的IAA,IBA,BA,NAA培养基上可诱导茎尖及腋芽生长,将诱导产生的无性系芽接种在MS或1／2MS附加BA0．3－0．5mg/L,NAA0．05mg/L的培养基上可形成丛生芽,同时在小叶片和嫩茎上诱导产生愈伤组织,继续培养愈伤组织表面形成大量的绿色突起,进一步分化成不定芽,在相同培养基上,不定芽上可直接产生不定芽,从而形成多达数百个的不定芽族,不定芽长至3cm时切下转至1／2MS附加IAA或IBA 0．2mg/L的培养基上可生根而形成完整 的再生植株。     

Synergistic promotion of gibberellin and cytokinin on direct regeneration of floral buds from in vitro cultures of sepal segments in sinningia speciosa hiern

Summary This study reports the direct regeneration of flower buds from cultured sepal segments of Sinningia speciosa Hiern. Two types of floral bud regeneration were observed: regeneration of floral buds only (designed as B^F) and regeneration of both floral and vegetative buds (designed as B^F+V). The capacity of B^F regeneration was closely related to the location of sepal segments and the concentration of exogenous gibberellin (GA₃) and cytokinin in the medium. On the medium containing 1.0mgl^−1 GA₃, the addition of 6-benzyladenine (BA) significantly increased the frequency of total flower bud (B^F+B^F+V) formation, with the frequency up to 91.5% in the presence of 0.4mgl^−1 BA. On the medium containing 0.1mgl^−1 BA, the addition of GA₃ also increased the frequency of total flower bud regeneration, with the frequency up to 74.3% in the presence of 1.0mgl^−1 GA₃, but no further increase in regeneration was observed when the GA₃ concentration was higher than 1.0mgl^−1. The capacity of B^F regeneration from different locations of sepal segments was differential. The adaxial part of sepal segments gave rise to the highest frequency of 56.7 and 84.3% for B^F and B^F+B^F+V, respectively.     

Sucrose treatment alters floral induction and development in vitro in gloxinia

Previous studies have shown that Cucumber-FLO-LFY (CFL) overexpression significantly promotes early flowering without a gibberellin (GA₃) supplement in gloxinia (Sinningia speciosa), suggesting that CFL can serve functionally as a LEAFY homolog. In the present study, different sucrose concentrations were applied to the culture medium to investigate the effects of sucrose on the development of excised flower buds and the regeneration of floral buds from sepals in wild-type and 35S::CFL gloxinia lines. The results showed that floral buds were formed directly from sepal explants without prior formation of shoots and leaves in 35S::CFL gloxinia lines when 2% w/v sucrose was added. Conversely, 0% or 5% w/v sucrose inhibited the generation of flower buds from sepals and the opening of flowers. Semi-quantitative PCR also showed that a medium with 5% w/v sucrose significantly inhibited MADS-box gene expression in wild type and much less significantly in 35S::CFL gloxinia. These data indicate that sucrose, as the main carbohydrate transported in floral organs, is a significant promoter of flower induction and maturity.     

无融合生殖油菜AMR—1花托离体培养的研究

报道了不同激素浓度对无融合生殖没菜花托器官分化效果的研究,结果显示：（１）以ＭＳ为基本培养基,以带有子房和花柄的花托为外植体离体培养,花托、花柄切口部位直接芽诱导的最佳激素配比为４．０ｍｇ／Ｌ６－ＢＡ＋０．０１ｍｇ／Ｌ ＮＡＡ,频率为５８．８２％,花托、花柄部位先形成愈伤组织,继而分化出丛生芽的最佳激素配比为５．０ｍｇ／Ｌ ６－ＢＡ＋０．５ｍｇ／Ｌ ＮＡＡ,频率为８４．００％;（２）腋芽增殖的最佳     

花叶千年木花序梗愈伤组织直接再生花芽的初步研究

在离体条件下,诱导愈伤组织或外植体直接再生花芽已经在许多草本植物上取得成功［１～７］,而就木本植物来说,迄今尚未见到成功的报导。诱导愈伤组织或外植体直接再生花芽所形成的离体培养实验系统将十分有利于研究雌、雄性器官分化和发育所必需的条件［８］和找到所需...     

Isolation of <Emphasis Type="Italic">HAG1</Emphasis> and its regulation by plant hormones during in vitro floral organogenesis in <Emphasis Type="Italic">Hyacinthus orientalis</Emphasis> L.

Floral organs have been successfully induced from the regenerated floral buds of Hyacinthus orientalis L. by precisely controlling exogenous hormones in the medium. Under high concentrations of cytokinin and auxin, the regenerated floral bud produces only tepals. However, at reduced levels of the hormones, the regenerated floral bud can produce stamens and/or carpels with ovules. To understand the molecular mechanism of hormone-regulated flower development, a MADS-box gene, HAG1, which is homologous to AGAMOUS (AG) in Arabidopsis, was isolated from the floral tissues of Hyacinthus. Overexpression of HAG1 in Arabidopsis created flower phenotypes resembling those of the apetala2 mutant and AG transgenic Arabidopsis plants. Furthermore, the HAG1 expression pattern was similar to that of AG, confirming that HAG1 is the ortholog of AG in Hyacinthus. HAG1 mRNA was first detected in cultured explants at day 5 in the medium containing high levels of cytokinin and auxin, which could induce floral regeneration in vitro. However, no HAG1 mRNA was detected in the cultured explants until day 10 in media with low or no hormones. Further, HAG1 mRNA was detected in the stamens and carpels of regenerated floral buds, but not in the tepals. Our data support the hypothesis that hormone-regulated HAG1 activity is required for the induction of floral buds and the determination of floral organ types during the regeneration of floral buds.