外源激素对风信子再生花芽发育的控制

外源激素在诱导再生花芽花器官发生和控制它们的数目中的关键作用被进一步证实。首先通过２ｍｇ／Ｌ ６－ＢＡ和０．１ｍｇ／Ｌ ２,４－Ｄ的激素组合诱导风信子Ｈｙａｃｉｎｔｈｕｓ ｏｒｉｅｎｔａｌｉｓ Ｌ．ｃｖ．Ｗｈｉｔｅ ｐｅａｒｌ）花芽从花被外植体发生,然后保持这种激素浓度,成功地控制了１００多片花被片的连续发生（自然情况下一个风信子花芽仅有６片花被片）。改变激素浓度（２ｍｇ／Ｌ ６－ＢＡ和０～０．０     

外源激素对诱导风信子（Hyacinthus orientalis L．）同一花被外植体不同部位细胞分化花芽的影响

本文研究了不同外源激素组合对诱导同一花被不同部位细胞分化花芽的影响．测定了花被上部、中部、下部切块离休培养前后的内部ＩＡＡ和Ｚ＋ＺＲ会量。结果表明,风信子同一花被不同部位细胞均能分化花芽。当ＭＳ培养基中附加２．０ｍｇ／Ｌ的ｚｅａｔｉｎ或６－ＢＡＰ时,随着外源ＩＡＡ浓度从０升高到１０．０ｍｇ／Ｌ,花芽分化部位由花被下部向上部移动。     

外源激素对诱导风信子同一花被外植体不同部位细胞分化花芽的影响

本文研究了不同外源激素组合对诱导同一花被不同部位细胞分化花芽的影响,测定了花被上部、中部、下部切块离体培养前后的内部ＩＡＡ和Ｚ＋ＺＲ含量。结果表明,风信子同一花被不同部位细胞均能分化花芽,当ＭＳ培养基中附加２．０ｍｇ／Ｌ的ｚｅａｔｉｎ或６－ＢＡＰ时,随着外源ＩＡＡ浓度从０升高到１０．０ｍｇ／Ｌ,花芽分化部位由花被下部向上部移动。     

离体条件下诱导番茄果实状结构的再生

以番茄（Ｌｙｃｏｐｅｒｓｉｃｏｎ ｅｓｃｕｌｅｎｔｕｍ Ｍｉｌｌ．）雌蕊和幼果的组织作外植体可以诱导果实状结构的再生。这种果实状结构在离体条件下能培养成熟,成熟时具红色。解剖观察表明：果实状结构由果肉和包围在外面的果皮组成,无种子和胎座。外源激素和外植体年龄的试验揭示：１．以雌蕊组织作外植体时,仅附加外源细胞分裂素就可以诱导果实状结构的再生,外源生长素似乎不是必需的,最高的诱导频率（５０．０％ ）出现在仅附加玉米素０．５ ｍ ｇ／Ｌ的组合。２．从直径４—１２ ｍ ｍ 的幼果上分离的外植体在附加外源激素的培养基上均可诱导果实状结构的再生,但只有从直径８ ｍ ｍ 的果实分离的组织块作外植体并将它们培养在６－ＢＡＰ ２ ｍ ｇ／Ｌ,ＮＡＡ０．１ ｍ ｇ／Ｌ的培养基上时,果实状结构的诱导频率最高（６２．５％ ）。为了探讨在果实状结构再生中表现出来的细胞全能性的表达,提出了植物细胞全能性的部分表达（Ｐａｒｔｉａｌｅｘｐｒｅｓｓｉｏｎ ｏｆｐｌａｎｔ ｃｅｌｌｔｏｔｉｐｏｔｅｎｃｙ）的概念并进行了讨论。     

风信子花被外植体年龄对花器官分化的影响

离体培养风信子（ＨｙａｃｉｎｔｈｕｓｏｒｉｅｎｔａｌｉｓＬ．）不同年龄的花被外植体诱导花器官直接再生的实验表明：１．在ＭＳ附加６ＢＡ２ｍｇ／Ｌ、２,４Ｄ０．１ｍｇ／Ｌ的培养基上,年龄Ｖ的外植体大量衰老,基本丧失器官再生能力,处于年龄段ＩＩ～ＩＶ的外植体可发生玻璃化反应。２．玻璃化反应的外植体转移至ＭＳ附加６ＢＡ０．２ｍｇ／Ｌ、ＮＡＡ０．００５ｍｇ／Ｌ的培养基上继续培养３０ｄ后可再生正常的花被片,表明降低培养基中外源激素浓度能够阻止玻璃化反应继续发生。３．在ＭＳ附加６ＢＡ２ｍｇ／Ｌ、２,４Ｄ０．１ｍｇ／Ｌ的培养基上,外植体形态学下部可再生雌蕊状早期结构。平均每块外植体分化雌蕊状早期结构数以年龄Ⅲ的外植体最多     

在1／3海水培养基上筛选豆瓣菜耐盐变异体

系统地研究了豆瓣菜（ＮａｓｔｕｒｔｉｕｍｏｆｆｉｃａｉｎａｌｅＲ．Ｂｒ）茎段外植体对６－ＢＡ,ＮＡＡ和２,４－Ｄ的反应,确定了ＭＳ培养基附加６－ＢＡ２．０ｍｇ／Ｌ,２,４－Ｄ０．２ｍｇ／Ｌ为豆瓣菜愈伤组织诱导,继代培养基;ＭＳ培养基附加６－ＢＡ４．０ｍｇ／Ｌ为芽再生培养基;ＭＳ基本培养基为植株的生根的扦插繁殖培养基,将３２５个豆瓣菜茎切段外植体接种到含１／３海水的愈伤组织诱导培养基上,１７块外植体     

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     

马尾松成熟合子胚的体细胞胚胎发生和植株再生

采用马尾松（Ｐｉｎｕｓｍ ａｓｓｏｎｉａｎａ Ｌａｍ ｂ．）成熟合子胚为起始外植体,在含２,４－Ｄ １０ ｍ ｇ／Ｌ,ＫＴ和ＢＡ 各４ ｍ ｇ／Ｌ的ＤＣＲ培养基上得到胚发生培养物。将白色半透明的愈伤组织（含早期原胚）在含２,４－Ｄ１．０ ｍ ｇ／Ｌ,ＫＴ和ＢＡ 各０．４ ｍ ｇ／Ｌ的ＤＣＲ培养基上保持并增殖。在附加９０００ ｍ ｇ／Ｌ肌醇的ＤＣＲ高渗培养基上得到粗壮的后期原胚。ＡＢＡ 和活性炭同时使用能促进子叶胚的形成,最高频率为３５．１％ 。在无激素培养基上,成熟体细胞胚萌发并进一步形成完整小植株     

云南红豆杉愈伤组织诱导和组织培养

云南红豆杉愈伤组织的诱导频率为Ｗｈｉｔｅ〉ＭＳ〉Ｂ５,其中最高达８０％,叶片和种子之间差异不大,但不同时期的叶片差异较大,以嫩叶诱导为佳,激素配比以２,４－Ｄ２．０－３．０ｍｇ／Ｌ,ＢＡＰ０．５－１．０ｍｇ／Ｌ为宜,在继代培养阶段,Ｂ５比Ｗｈｉｔｅ和ＭＳ更适合细胞的快速生长、繁殖,并且有利于克服组织的褐化,适合于细胞生长的激素配比也以２,４－Ｄ２．０－３．０ｍｇ／Ｌ,ＢＡＰ０．５－１．０ｍｇ／Ｌｏ     

中麻黄悬浮培养体系的建立

本文用中麻黄无菌苗为外植体,其切段培养在附加２ｍｇ／Ｌ２,４－Ｄ和０．５ｍｇ／Ｌ　６　ＢＡ的ＭＳ培养基上,全部脱分化形成白色疏松愈伤组织。愈伤组织继代培养于ＭＳ＋０．５ｍｇ／Ｌ２,４－Ｄ＋０．２ｍｇ／Ｌ６ＢＡ＋０．２ｍｇ／Ｌ　ＮＡＡ＋４％蔗糖的培养某上。以继代培养愈伤组织为材料进行悬浮培养,培养基为附加０．２ｍｇ／Ｌ２,４－Ｄ＋０．１ｍｇ／Ｌ６ＢＡ＋０．１ｍｇ／ＬＮＡＡ＋２％蔗糖的ＭＳ液体培养基,得到分散性好,细胞形状接近圆形,细胞大小均一,细胞团多由２－３０个细胞组成的悬浮培养体系。第三代悬浮培养细胞增长率为０．３５ｇ·ｆｗ／２０ｍｌ·ｄ,细胞有丝分裂指数为１１．２％。条件培养和高密度接种可缩短延迟期,条件培养不能提高分裂指数,１ｇ／１０ｍｌ接种密度可使分裂指数提高至２１．２％。     

Role of Exogenous Hormones in Inducing Cells in different Positions of Perianth Explants to Regenerate Flower Buds in Hyacinthus orientalis

Role of the exogenous hormone in inducing different position cells of perianth explants of hyacinth to regenerate flower buds was studied. Experiments showed that (1) Exogenous hormones are necessary for inducing cells of the perianth explant to regenerate the flower buds; (2) Only cytokinine alone could induce the regeneration of the flower buds, the auxin was not necessary; (3) Exogenous hormones in different concentrations could induce cells in the different parts of the perianth explants to differentiate the flower buds: 6-BAP or zeatin 2 mg/L alone could induce cells located at the lower part of the perianth to differentiate flower buds. Combination of 6-BAP or zeatin 2 mg/L and 2, 4-D 0.1 mg/L was advantageous to cells located middle part of the perianth to regenerate the flower buds. Combination of 6-BAP or zeatin 2 mg/L and 2, 4-D 1.0 mg/L could promote cells located at the upper part of the perianth to differentiate flower buds.     

软枣猕猴桃试管苗叶片和茎段的愈伤组织诱导及植株再生

从软枣猕猴桃试管苗茎段和叶片诱导出愈伤组织并得到再生植株。茎段外植体容易愈伤化,但其愈伤组织难以分化,叶片外植体不易愈伤化,但其愈伤组织容易分化。ＭＳ培养基分别附加ＢＡＰ、Ｋｉｎ、ＴＤＺ或ＣＰＰＵ都不能诱导芽的分化,而ＭＳ附加玉米素能有效地诱导芽分化,其中以２．０ｍｇ／Ｌ玉米素效果最好。     

Regeneration of tepals,stamens and ovules in explants from perianth of Hyacinthus orientalis L. importance of explant age and exogenous hormones

Regeneration of tepals, stamens and ovules from perianth explants of Hyacinthus orientalis L. in different developmental stages could be controlled by means of exogenous hormones. Perianth explants in a relatively early stage of development were competent for differentiation of tepals on Murashige and Skoog (MS) medium supplemented with 2 mg·1^-1 N⁶-benzylaminopurine (BAP) or zeatin and 0.1 mg·1^-1 2,4-dichlorophenoxyacetic acid (2,4-D). Perianth explants in a later stage of development regenerated stamens and ovules, and marked difference was observed in the activity of BAP and zeatin in this regard. Zeatin stimulated more strongly stamen formation, while BAP enhanced ovule formation. Thus, stamens were formed when the explants were cultured for four months on medium with 2 mg·1^-1 BAP and 0.1 mg·1^-1 2,4-D and then transferred to medium with 0.2 mg·1^-1 zeatin and 0.005 mg·1^-1 1-naphthaleneacetic acid. On the other hand, differentiation of ovules occured in explants cultured for two weeks on the former medium and then transferred to medium with 0.1 mg·1^-1 BAP and 0.01 mg·1^-1 2,4-D. Although ovule formation could also be obtained with 2 mg·1^-1 BAP alone, it was substantially enhanced by the presence of 0.1 mg·1^-1 2,4-D in the medium in the early stages of culture. The results demonstrate the importance of both the developmental stage of the source organ from which explants are excised and of the hormone composition of the medium for the regeneration of different floral organs by perianth explants of Hyacinthus.Abbreviations BAP N⁶-benzylaminopurine - 2,4-D dichlorophenoxyacetic acid - NAA 1-naphthaleneacetic acid     

In Vitro Induction of Regeneration of Fruit-Like Structure in Lycopersicon esculentum Mill.

It is possible to induce in vitro regeneration of fruit-like structures from tissue pieces excised from young pistil and young fruit of Lycopersicon esculenturn Mill. These fruit-like structures could be cultured in vitro to maturation, meanwhile they became red coloured. Under dissection it was observed that the fruit-like structure consists of fruit flesh and fruit coats without seeds and plancentae. Tests of exogenous hormones and explant ages revealed: 1. Supplement with exogenous cytokinins alone could induce the explants excised from the pistils to regenerate the fruit-like structures, and the highest induced frequency (50%) was obtained when 0. 5 mg/L zeatin was supplemented. Exogenous auxin seems unnecessary. 2. When tissues of young fruit were used as explants, all explants excised from 4—12 mm (diameter) young fruits could be induced to differentiate the fruit-like structures on medium supplemented with exogenous hormones. However, the hightest frequency of induction (62.5%) was obtained only in tissues of explants excised from 8 mm (diameter) sized fruit and cultured on medium supplemented with 2 mg/L of 6-BAP and 1 mg/L of NAA where regermination of the fruit-like structures took place. In order to investigate the expression of cell totipotency arisen in the regeneration of the fruit-like structure a concept of partial expression of plant cell totipotency was proposed and discussed.     

离体培养下番红花花柱—柱头状物再生的研究

番红花(Crocus sativus L.)幼花被和幼花柱可以诱导花柱-柱头状物的再生,长度为24mm 的花芽上分离的花被具有最高的诱导频率(37.5%);花被外植体附加 K5 mg/L 和NAA 4mg/L 有利于再生花柱-柱头状物,频率达到35.3%;附加6-BAP 7 mg/L 和 NAA9mg/L 则有利于柱头状物的大量形成。     

The Exogenous Hormornal Control of the Development of Regenerated Flower Buds in Hyacinthus orientalis

The critical role of exogenous hormone on inducing the initiation of different floral organs in the regenerated flower bud and controlling their numbers was further evidenced. The initiation of the flower buds was first induced from the perianth explants of Hyacinthus orientalis L. cv. White pearl by a combination of 2 mg/L 6-BA and 0.1 mg/L 2,4-D, and then a continuous initiation of over 100 tepals (a flower bud of H. orientalis in situ has only 6 tepals) was successfully controlled by maintenance of such a hormone concentration. However, a change of hormonal concentration (2 mg/L 6-BA and 0-0.000 1 mg/L 2,4-D) caused cessation of continuous initiation of the tepals but gave rise to induction of stamen initiation. Keeping the changed hormone concentrations could successfully control the continuous initiation of over 20 stamens (a flower bud of H. orientalis in situ has only 6 stamens). The experiment showed that the number of identical floral organs in the regenerated flower buds can be controlled by certain defined concentrations of the exogenous hormones, and the amount of the induced identical floral organs has no effect on the differentiation sequence of the different floral organs in the regenerated flower bud. Based on a systematic research on controlling the differentiation of the floral organs from both the perianth explants and the regenerated flower buds by the exogenous hormones in H. orientalis over the past decade, the authors put forward here a new idea on the role of phytohormone in controlling the automatic and sequential differentiation of the different floral organs in flower development. The main points are as follows: 1. the development of flower bud in plant is a process in which all of the floral organs are automatically and sequentially differentiated from the flower meristem. 2. Experiments in vitro showed that the effect of exogenous hormones in controlling the initiation of different floral organs is strictly concentration dependent, i.e., one kind of the floral organ can continuously and repeatedly initiate from the flower meristem as long as it is maintained in that specific concentration of the exogenous hormone which is suitable for the initiation of that particular kind of floral organ. 3. It shows that the flower buds in situ must be automatically able to adjust the endogenous hormonal concentrations just after the completion of the differentiation of one whorl of floral organ to suit the differentiation of the next whorl. Thus, the phytohormone in different concentrations takes after many change-over switches of the organ differentiation and plays a connective and regulatory role between the differentiation of every two whorls of the floral organ. In other words, these change-over switches play the roles of inhibiting the expression of the genes which control the initiation of the floral organs in the first whorl, meanwhile, activating the expression of the genes which control the initiation of the floral organs in the second whorl during the successive initiation of the different floral organs from the flower bud. It results in the automatic and sequential initiation of the various floral organs from the floral meristem.      

小麦外稃和内稃愈伤组织直接再生小穗和雌蕊状结构的研究

以小麦稃片为外植体,在MS附加不同外源激素的培养基上,成功地从愈伤组织上直接诱导了小穗和雌蕊状结构的再生。实验表明,附加2,4-D 2mg/L和6-BAP 0.1mg/L有利于外植体形成愈伤组织;附加2,4-D 1.0mg/L和6-BAP 2mg/L有利于外稃和内稃愈伤组织直接再生小穗;附加2,4-D 0.01mg/L和6-BAP 1.0mg/L有利于内稃愈伤组织直接再生雌蕊状结构。本文还观察了小穗和雌蕊状结构再生过程的形态学变化,并对诱导花芽和性器官再生的某些要点进行了讨论。     

风信子花被外植体年龄对花器官分化的影响

离体培养风信子(Hyacinthus orientalis L．)不同年龄的花被外植体诱导花器官直接再生的实验表明;1．在MS附加6-BA 2 mg／L,2,4-D 0.1 mg／L的培养基上,年龄V的外植体大量衰老,基本丧失器官再生能力,处于年龄段Ⅱ～Ⅳ的外植体可发生玻璃化反应。2．玻璃化反应的外植体转移至MS附加6-BA 0.2 mg／L、NAA 0.005 mg／L的培养基上继续培养30 d后可再生正常的花被片,表明降低培养基中外源激素浓度能够阻止玻璃化反应继续发生。3．在MS附加6-BA 2 mg／L．2,4-D 0.1 mg／L的培养基上,外植体形态学下部可再生雌蕊状早期结构。平均每块外植体分化雌蕊状早期结构数以年龄Ⅲ的外植体最多。     

盾叶薯蓣离体成花的影响因素及组织学观察

研究了居群、外植体类型、激素、铁盐对盾叶薯蓣（Dioscorea zingberensis C．H．Wright）离体成花的影响,建立了从花序切段高效直接再生花序和小花的实验体系。以不同的培养基对5个居群盾叶薯蓣的花序进行离体培养,利用石蜡切片技术观察再生花序的发生。结果表明5个居群的盾叶薯蓣都能直接再生花序,与花器官相关组织的外植体均具有不同程度的花序再生能力。培养基的组成对离体花序诱导率有很大影响,BA促进形成花序,KT与高浓度的铁盐促进形成营养芽。其中,MS＋2．0mg／LBA＋0．2mg／LNAA最有利于花序再生及发育。切片观察表明,离体再生的花序主要发生于花序轴与花蕾交界处的苞片以及小花的花被片表层细胞。     

An efficient mass propagation system for cassava (Manihot esculenta Crantz) based on nodal explants and axillary bud-derived meristems

Nodes from 3- to 5-week-old in vitro plants of different cassava cultivars were cultured for 2–3 days on solid Murashige and Skoog basal medium supplemented with cytokinin to induce the enlargement of axillary buds. Subculture of these buds on the same medium resulted in multiple shoot formation within 4–6 weeks. Of the four cytokinins tested (6-benzylaminopurine (BAP), thidiazuron (TDZ), zeatin, and kinetin), BAP induced shoot development most efficiently. The best results were obtained with cultivar TMS 30555, in which 63% of the explants each produced at least 25 shoots on medium with 10 mg/l BAP. In cultivars that did not produce shoots, the addition of the surfactant Pluronic F-68 (2% wt/vol) raised the percentage of explants forming at least 5 shoots from 0 to 20–60%. Axillary buds were also used to dissect meristems and test their ability to regenerate into shoots. Shoot formation from meristems of six different cultivars was observed after preculture on medium with 5 mg/l BAP followed by transfer to 10 mg/l BAP.Abbreviations MS Murashige and Skoog - BAP 6-Benzylaminopurine - TDZ Thidiazuron