花叶千年木单个生殖器官和营养器官的体外直接再生的控制——单个器官直接再生的规律性

花叶千年木(Dracaena fragrans cv.massangeana Hort．)的各种单个器官(花被片、花芽、花序分枝、花序、成年态营养芽和幼态营养芽)在离体培养中被愈伤组织直接再生了。在这些单个器官的再生期间,一些规律性现象被观察到了。首先,单个再生器官种类的范围与分离外植体的器官在植物个体发育中被分化的时期有密切关系。从植株个体发育某个时期(时期A)分化的地上部分器官上分离的外植体能够分别再生下面这些地上部分器官：稍晚于时期A分化的器官,与时期A同期分化的器官和早于时期A分化的所有器官。其次,在这个范围内,究竟再生哪一种器官被再生取决于培养基中外源生长素的浓度。随着2,4-D浓度从0．005mg／L逐渐升高到0．5mg／L,单个再生器官的种类将按如下的次序变化：营养芽,花序,花序分枝,花芽,花被片。这些规律性现象将被用于诱导一个给定的被子植物地上部分器官的直接再生。     

花叶千年木愈伤组织直接再生花序

以花叶千年木(Dracaena fragrans cv. Massangeana Hort.)的花被筒、花序分枝轴和花序轴为外植体成功地诱导了花序的直接再生. 3种外植体首先在MS附加1.0 mg/L 6-BA和0.5-0.8mg/L 2,4-D的培养基上诱导形成愈伤组织,然后转移到MS附加0.5 mg/L 6-BA和0.005～0.5 mg/L 2,4-D的培养基上分别诱导了花序的直接再生.观察了愈伤组织形成和花序分化的形态学过程.     

花叶千年木愈伤组织直接再生花序

以花叶千年木（Dracaena fragrans cv.Massangeana Hort.)的花被筒，花序分枝轴和花序轴为外植体成功地诱导了花序的直接再生，3种外植体首先在MS附加1.0mg/L6-BA和0.5-0.8mg/L2,4-D的培养基上诱导形成愈伤组织，然后转移到MS附加0.5mg/L6-BA和0.005-0.5mg/L,2,4-D的培养基上分别诱导了花序的直接再生，观察了愈伤组织形成和花序分化的形态学过程。     

诱导风信子再生花芽不断分化花被片的研究

通过外源激素及外植体年龄的控制,诱导风信子再生花芽不断分化花被片已经获得成功。在２５０ｄ的继代培养中平均每个花芽可分化７０多片花被片,最多的可分化１４０多片。对这种花芽不断分化花被片的形态发生过程以及生长发育特点的观察表明,花芽的第１轮器官与风信子野生型花基本相同,查花被,它由花被筒及其上部的裂片－花被片组成。     

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     

小麦幼胚培养再生单性雌花的研究

通过45个基因型的小麦(Triticum aestivum L.)幼胚培养,发现有11.1%的基因型从靠近再生芽基部的愈伤组织上分化形成花器官.再生花芽呈裸露的、多子房丛生的、具有茂盛羽毛状柱头而缺乏雄蕊、外稃、内稃和颖片的单性雌花. 组织切片观察发现,其雌蕊起源于再生芽附近的分生组织细胞,并通过次生雌蕊再生的方式形成丛生状,其羽毛状结构的发育先于子房中胚珠的分化. 除正常的单胚珠外,还发现双生胚珠分化.χ2独立性检验结果显示,花芽再生率存在强烈的基因型效应.小麦品种YA-1 表现突出(44.4%),其花芽再生潜力能在不同年份间较好地再现,说明YA-1的花芽再生能力具有相对稳定性.与脱分化培养基的效应相比,YA-1的花芽再生效率主要受继代培养基成分的影响. 其中,6-BA、NAA和加倍无机铁盐的配比较2,4-D和正常浓度无机铁盐的配比更有利于YA-1的幼胚培养再生花芽.同时,外植体实验表明,YA-1的幼穗和成熟胚培养无任何成花反应,而其幼胚外植体具有特异的花芽再生能力.据此认为,YA-1的幼胚培养有助于为小麦花发育机理研究建立理想的实验系统.     

小麦幼胚培养再生单性雌花的研究

通过45个基因型的小麦（Triticum aestivumL.)幼胚培养,发现有11.1%的基因型从靠近再生芽基部的愈伤组织上分化形成花器官,再生花芽呈裸露的,多子房丛生的,具有藏盛羽毛状柱头而缺乏雄蕊,外稃,内稃和颖片的单性雄花。组织切片观察发现,其雌蕊起源于再生芽附近的分生组织细胞,并通过次生雌蕊再生的方式形成从生状,其羽毛状结构的发育先于子房中胚珠的分化,除正常的单胚珠外,还发现双生胚珠分化。X^2独立性检验结果显示,花芽再生率存在强烈的基因型效应,小麦品种YA-1表现突出（44.4%)。其花芽再生潜力能在不同年份间较好地再现,说明YA-1的花芽再生能力具有相对稳定性,与脱分化培养基的效应相比,YA-1的花芽再生效率主要受继代培养基成分的影响,其中,6-BA,NAA和加倍无机铁盐的配比较2,4,-D和正常浓度无机铁盐的配比更有利于YA-1的幼胚培养再生花芽,同时,外植体实验表明,YA-1的幼穗和成熟胚培养无任何成花反应,而其幼胚外植体具有特异的花芽再生能力。据此认为,YA-1的幼胚培养有助于为小麦花发育机理研究建立理想的实验系统。     

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...     

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。     

外源激素在诱导风信子花被外植体不同部位细胞再生花芽中的作用

外源激素诱导风信子（Ｈｙａｃｉｎｔｈｕｓ ｏｒｉｅｎｔａｌｉｓＬ．）同一发育时期花被外植体不同部位细胞再生花芽的实验表明∶１． 诱导花被外植体细胞再生花芽,外源激素是必需的;２． 仅有细胞分裂素就可以诱导花芽再生,生长素并不是必需的;３． 花被外植体上的不同部位的细胞再生花芽时,需要不同浓度的外源激素． 单独加６－ＢＡＰ或玉米素２ ｍ ｇ／Ｌ可以诱导花被下部的细胞再生花芽;６－ＢＡＰ或玉米素２ ｍ ｇ／Ｌ和２,４－Ｄ ０．１ ｍ ｇ／Ｌ的组合有利于花被中部的细胞再生花芽;６－ＢＡＰ或玉米素２ ｍ ｇ／Ｌ和２,４－Ｄ １．０ ｍ ｇ／Ｌ的组合能促进花被上部的细胞分化花芽     

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.     

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.      

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。     

A Preliminary Study on Direct Regeneration of Flower Buds from Peduncle Calli in Dracaena fragrans cv. massangeana

Flower buds were directly regenerated from calli in vitro in the woody plant Dracaena fragrans cv. massangeana Hort. On modified MS medium supplemented with 1.0 mg/L 6-BA and 1.0 mg/L IBA, two kinds of calli, A and B, were formed from the peduncle explants cultured for 5 months. Calli A were loose and on their surface there were many irregular granule-like structures (GLC); Calli B were compact and had bigger tumor-like structures (TLC) on their surface. When the GLC and TLC were transferred onto the medium respectively with 0.4 mg/L 6-BA and 1.0 mg/L IBA, flower buds were differentiated directly from the GLC but only vegetative buds and roots were differentiated from the TLC after culturing for 4 weeks. The GLC could be partly transformed into TLC in the continuous passage culture. Assays on hormones revealed that at a fixed IBA concentration of 0.4 mg/L the defferentiation frequency of flower budding was increased as the 6-BA concentration was decreased from 2.0 mg/L to 10 mg/L. Alternatively, at a fixed 6-BA concentration of 2.0 mg/L, the flower budding frequency was increased when the IBA concentration was changed from 0.4 mg/L to 1.0 mg/L. Moreover, the addition of 2.0 mg/L zeatin to the culture medium containing 2.0 mg/L 6-BA and 0.4 mg/L IBA was favorable to the regeneration of the flower buds. Nevertheless supplementing 1.0 mg/L GA3 into the medium on which the calli had differentiated into flower buds, the flower buds would gradually wither after 2 weeks in culture.     

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     

麝香石竹花芽离体发育的阶段控制

在离体条件下,利用不同的培养基对麝香石竹顶芽外植体的花芽发育进行了阶段控制的研究.结果表明,麝香石竹的顶芽外植体在MS+KT1.0mg/L+IAA1.0mg/L+蔗糖3.0%+琼脂0.8%的Ⅰ级培养基上能被诱导花芽发育的启动;然后,将已诱导花芽发育启动的顶芽外植体,转接到MS+KT1.0mg/L+IAA0.5mg/L+蔗糖1.5%+葡萄糖1.5%+琼脂0.8%的Ⅱ级培养基上能进行花芽的进一步发育形成花蕾,且能从一个花蕾继续分化发育重新产生2—3个花蕾;把花蕾再转接到改良的MS+BA2.0mg/L+NAA0.2mg/L+蔗糖1.5%+葡萄糖1.5%+琼脂0.8%的Ⅲ级培养基上,培养一周后花蕾的花瓣张开,花朵全部开放.不同麝香石竹品种,诱导花芽发育启动的效果不同,Scania品种诱导效果最好.花芽发育初期可溶性蛋白含量较高,但随着花芽发育的进程而迅速下降,不同花芽发育时期的过氧化物酶活性均强于营养器官.本文为花芽分化发育机理的研究创造了条件,也为鲜花生产探索了新路子.     

Organs and Plantlets Regeneration of Gladiolus through Tissue Culture

Explants from inflorescence stalks of Gladiolus when culturedin vitro regenerated new plantlets within 6–7 weeks. Regenerationwas started by the formation on the basal end of a thin layerof callus and root primordia. This was followed by formationof buds and cormlets, on the distal end. The regeneration ofthe various organs from the explants was found to be polarizedand depended on the levels of growth substances added to thebasal medium, best combination for organ initiation being 10ppm naphthalene-acetic acid and 0.5 ppm of kinetin.     

The effect of photoperiod on flower formation in vitro in a quantitative short-day cultivar of Nicotiana tabacum

Superficial cell layers of a quantitative short-day tobacco plant ( Nicotiana tabacum L. cv. White Burley) were excised from different parts of the inflorescence (i.e. pedicels, branch internodes, rachises), and cultured in continuous darkness, continuous light or 8 h light/16 h dark daily. The flowering response in vitro of the different types of explants was investigated with respect to the effect of light on the post-evocation phases of the flowering process and explant commitment. Treatment effect was qualitatively and quantitatively influenced by explant origin. Three morphogenic features were observed: flower neoformation, caulogenesis and rhizogenesis (the latter on rachis explants only). Under all treatments, the highest flowering potential was shown by pedicels, while the highest vegetative potential was shown by rachises. Branch internodes showed an intermediate response, but with a tendency towards caulogenesis, which probably reflects their phylogenetic origin. Thus, opposite gradients of the neoformation of flowering and vegetative buds on explants were observed under all treatments. Pedicels formed new single flowers rather than inflorescences, while rachises regenerated mainly inflorescences. In darkness, flowering was limited mostly to pedicels. Vegetative bud formation was higher than floral bud regeneration in all types of explant. Continuous light enhanced the flowering response mostly in pedicel and branch internode explants. Short days enhanced flower bud formation in vitro on all types of explant. Results with respect to microsporogenesis, flower and inflorescence anomalies observed under darkness also seem to support the existence of a quantitative photoperiodic control on floral neoformation in vitro in this plant. These results suggest that in Nicotiana tabacum cv. White Burley in vivo floral induction, initiation and development are governed by the same photoperiodic requirements.