PROLIFERATION AND PLANT REGENERATION FROM THE NODAL REGION OF ZEA MAYS L. (MAIZE,GRAMINEAE) EMBRYOS

Immature embryos of Zea mays L. (maize), cultured on Murashige and Skoog's medium containing 2,4-dichlorophenoxyacetic acid (2,4-D, 0.25–1.0 mg/l) and sucrose (3, 6 and 12%), produced a narrow ridge of tissue in the nodal region of the embryo axis, opposite the scutellum. Only those embryos which were placed with the scutellum in contact with medium showed such a response. The ridge of tissue further proliferated and formed a compact and opaque callus that appeared similar to the scutellar callus. Morphogenesis took place on media containing low concentrations of both 2,4-D and sucrose. Plant regeneration was achieved and is interpreted to take place by the precocious germination of somatic embryos. It is suggested that the ridge of tissue formed at the node may represent an evolutionarily extinct epiblast of the maize embryo and may be cotyledonary in nature.     

玉米原生质体的植株再生

以玉米花粉诱导产生的胚性愈伤组织,在 N6基本培养基附加激动素2 mg/l,6-苄基氨基嘌呤1mg/l,2,4-D 0.3 mg/l,水解酪蛋白500 mg*l 及谷酰胺250 mg/l 的培养基上进行转代培养。用转代培养一年半后的胚性愈伤组织分离原生质体,原生质体培养在附加激动素0.2 mg/l,6-苄基氨基嘌呤0.1 mg/l,2,4-D 0.5 mg/1,水解酪蛋白200 mg/l,谷酰胺100 mg/l及椰乳296的原生质体培养基 Z_2中。培养4—6天后,原生质体的再生细胞进行第一次分裂;培养3星期后发育成肉眼可见的小愈伤组织。此后,需添加降低糖浓度的同样原生质体培养基 Z_2共两次。待再生愈伤组织长到直径2—4 mm 大小时,把它们先后转经第一及第二(即Z_3及 Z_4)分化培养基上诱导器官分化。最后在 Z_4分化培养基上同时有胚状体的发生及植株的分化。     

红龙利离体培养的植株再生研究(简报)

PLANTREGENERATIONFROMINFITROCULTUREOFPHLLODENDRONERUBESCENSZhangPeng;HuangXiangli;XuXinlan;LingDinghou(SouthChinaInstituteofBotany.AcademiaSinica,Guangzhou510650)(SortthChinaBotanicalGarden,AcademiaSinica.Guangzhou510520)红龙利是华南地区新引进的名贵热带观叶植物,属天南星科,喜林芋属。其株体茎攀援,茎叶呈紫红色,叶片正面具光泽,为适于室内栽培的优良观叶花卉。红龙利采用常规分株繁殖,因此存在繁殖速度慢、系数低等问题。植物组织培养技术在促进园艺植物事业的发展上取得了引…     

CORTICAL ONTOGENY IN ROOTS. I. ZEA MAYS

Serial growth stages of young Zea mays primary roots were analyzed for patterns of ground meristem ontogeny. The number of cell layers in the cortex decreases from approximately 15 to 11 during early root growth. The cortex arises mostly by periclinal divisions in the outer portions of the ground meristem at levels 50–150 μm from the meristem tip, although some layers of outer cortex arise beyond 150 μm. The proendodermis contributes 3–5 cell layers to the cortex, but this contribution diminishes during early seedling growth as anticlinal divisions occur in the proendodermis. The relationship between the ground meristem and protoderm changes at the tip of the meristem during root elongation.     

沙葱(Allium mongolicum Regel)离体培养再生可育植株

以沙葱（Allium mongolicum Regel)的叶基切段作外植体,成功地诱导出愈伤组织和再生植株。诱导愈僵组织的培养基为附加2mgL^-22,4-D和0.2mgL^-1KT的MS培养基。愈伤组织转移到附加2mgL^-16BA和0.4mgL^-1NAA的MS培养基后分化出大量的苗;分化苗在含有IBA1mgL^-1的1/2MS培养基上生根最佳。再生植株移栽成活率在95%以上。移栽到田间的植株第二年以后可正常开花结实。     

影响小麦成熟胚再生频率因素的研究(简报)

以小麦成熟胚为外植体,研究了基本培养基、预处理类型、接种方式、植物激素的浓度和不同组合以及分化培养基中是否添加抗生素对愈伤组织诱导和分化的影响．在此基础上建立了一套高效的小麦成熟胚植株再生系统。经过试验,我们选择在MS培养基上接种经无菌水预处理的纵切成熟胚作为起始的试验条件。在含2mg／L2,4-D的MS培养基上．初级愈伤组织的诱导频率可达80％以上．在继代培养基中添加0．5mg／L6-BA和0．2mg／LNAA可以显著提高胚性愈伤组织的产生。而在再生培养基中加入适当浓度的头孢霉素可以有效提高胚性愈伤组织再生出小植株的比例。利用该再生系统,我们从5个小麦优良主栽品种的成熟胚再生出了可育的植株,再生频率达15．3％-34．5％。     

亚麻原生质体培养及植株再生

试验分别采用四个纤维用亚麻(Linumusitatissimum)品种7309,948,Belinka和Viking的无菌苗的茎尖为材料游离原生质体。以萌发10天的无菌苗茎尖游离获得的原生质体得率和活性最高,分别达到1．8×106／gFW和85．5％。以V-KM为培养基,采用琼脂岛法培养的原生质体,可在培养3天后发生第一次分裂,10天后统计细胞分裂频率为36％,20天后统计植板率达到5．2％。品种7309和Belinka再生的愈伤组织接种在均附加o．6mg/L6-BA和0．1mg／LNAA的B5-1和MS3固体培养基上,都有芽苗分化,并分别获得再生植株。品种Viking和948分别仅分化获得了不定根或叶状体。     

从石刁柏原生质体培养再生植株

石刁柏,又名芦笋(Asparagus officinalisL.)是百合科天门冬属植物。其栽培品种含有丰富的维生素类及蛋白质。同时,石刁柏对于某些疾病有一定的药效,因此它已成为人们所喜爱的一种高级营养蔬菜。国外已有不少关于石刁柏试管苗繁殖的报告,但至今只有Bui Dang Ha等从石刁柏枝状叶分离的原生质体得到愈伤组织,并由此愈伤组织诱导获得了再生植株。此后,未见在石刁柏的原生质体培养方面再有新的工作。在本文中,我们利     

花生体细胞胚的诱导及其植株再生

采用不同成熟度的花生胚轴为外植体进行体细胞胚诱导及植株再生研究,结果表明,成熟胚轴在高浓度2,4－D的MS培养基中,经过30d左右的培养,可直接诱导产生出大量的体细胞胚,含40mgL~－12,4－D的培养基中体细胞胚的诱导率达100％,平均每个外植体产生11．58个体细胞胚．体细胞胚的继代培养需降低2,4－D的浓度（1－20mgL~－1）．未成熟胚轴的体细胞胚诱导及继代培养的2,4－D浓度宜为10mgL~－1．将诱导的体细胞胚转接到合5－10mgL~－1BA的MS培养基中,体细胞胚能够萌发再生成无根小植株,将其转接到生根培养基中可获得完整小植株．     

大豆未成熟胚培养中高浓度植物生长素的作用及其植株再生

用大豆(Glycine max(L.)Merr.)未成熟胚为外植体,在含高浓度 NAA 或2,4-D 的培养基上可诱导绿色结构体和体细胞胚状体。叶状、花状和喇叭形状的绿色结构体在含30mg/l2,4-D 的 MS-1培养基上可重新愈伤组织化。这种由高浓度2,4-D 诱发并保持的愈伤组织,转到低激素水平的培养基上后,能诱导出大量的同类形状的新结构体。绿色结构体可以进一步发育成叶丛状,但顶端不伸长。使用含2m g/l GA,和0.1mg/l IBA 的培养基,能促进顶端伸长和根的发育,获得正常植株。由未成熟胚的子叶(其时种子长度约4—6mm)诱导的愈伤组织具有再生能力。在含高浓度2,4-D(5-30mg/l)的培养基上诱导出的愈伤组织具有较高的产生绿色结构的潜力。而高浓度 NAA(10mg/l)培养基产生的愈伤组织具有较强的产生根状体的潜力。培养的外植体或愈伤组织在含5mg/l 2,4-D 的培养基上,不需要经常的继代培养,即可长期保存。     

花叶芋的组织培养和植株再生

双色花叶芋(Caladium bieolor)和亮白花叶芋(C.hortulanum)的叶及花序外植体在加有2,4-D 和激动素或只加有2,4-D 的培养基上产生了愈伤组织,它们在转移到无激素或含激动素和低浓度生长素的培养基上以后分化出大量胚状体,并进一步长成小植株。本工作为花叶芋的快速繁殖提供了方法。     

ADVENTITIOUS ROOT DEVELOPMENT FROM THE COLEOPTILAR NODE IN ZEA MAYS L.

Department of Botany and Bacteriology, University of Arkansas, Fayetteville, Arkansas 72701 Zea mays L. root development from the coleoptilar node was observed by light and electron microscopy. Roots developed opposite collateral vascular bundles in the coleoptilar nodal region. Three distinct histogens (stelar, cortical-protoderm, and root cap) became evident in early development. In median sections of the young roots, root cap and cortical regions formed a “hat” configuration over the stelar region. As the root matured, this “hat” developed centripetally to encapsulate the stelar region. Central core cells of the root cap were characterized by having numerous dictyosomes, amyloplasts, vacuoles, and thin cell walls. As these cells matured into outer or peripheral cap cells, the Golgi vesicles became hypertrophied. These hypertrophied vesicles contained a granular PAS-positive material which accumulated between the plasma membrane and the cell wall and formed a thick layer. As the PAS-positive material passed through the cell wall, it changed to a fibrillar texture. A PAS-positive material similar to that in the outer root cap cells was found adjacent to the outer walls of the protodermal cells. In median sections, PAS-positive material was not present in the promeristem region. Root cap cells as well as parent cortical cells were crushed as the young root forced its way through the parent tissue.     

火炬松成熟合子胚培养直接器官发生和植株再生

基因型Ｈｂ,Ｍａ和Ｍｃ的火炬松成熟合子胚在附加１．０ｍｇ／ＬＮＡＡ,４．０ｍｇ／ＬＢＡ,５００ｍｇ／ＬＬＨ和５００ｍｇ／Ｌ谷氨酰胺的ＴＥ培养基上培养１２周后,在子叶和胚轴部位形成不定芽原基。然后将合子胚转移到附加０．５ｍｇ／／ＬＮＡＡ,０．０５ｍｇ／ＬＩＢＡ,２ｍｇ／ＬＢＡ,５００ｍｇ／ＬＬＨ和５００ｍｇ／Ｌ谷氨酰胺的ＴＥ不定芽分化培养基上,６周后分化产生大量不定芽,３种基因型中,Ｈｂ的直接不定芽     

THE ISOLATION AND CULTURE IN VITRO OF THE QUIESCENT CENTER OF ZEA MAYS

Using 3-day-old seedling roots of Zea mays L., cv. Kelvedon 33, it was possible to remove the root cap by a simple surgical manipulation without damage to the root proper. By a further small cut, the quiescent center (QC) itself was isolated. This double-convex lens-shaped tissue piece 100 X 250 μm is composed of 1000–1500 cells representing only 0.25 mm³ in volume. The explant was demonstrated unequivocally by ³H-thymidine incorporation before excision and then by autoradiography to be composed of the specific cells usually designated the quiescent center. Using sterile techniques, the QC's were placed on nutrient agar slants and allowed to grow in culture. Of a number of nutrient media tested, only a medium supplemented with organic nitrogen components, indoleacetic acid, kinetin and inorganic nutrients plus sucrose (S2M + K -2,4-D) was effective in eliciting development. Thirty to 40 percent of the 150 isolated QC's grown on this medium formed elongated roots, up to 2 cm in length in 3–4 weeks. Roots developing on agar medium showed in their proximal portion a vascular pattern with 5–6 metaxylem elements or variations of this pattern, but as the root elongated, the vascular pattern was progressively reduced in complexity at the more distal end to a small central group of metaxylem elements. When agar-grown roots were transferred after one week in culture to a liquid nutrient medium of the same composition, the initially reduced vascular pattern evident in the proximal tissues became progressively more complex in the distal portion of the root and after 2 cm of elongation, showed an essentially normal primary vascular tissue pattern characteristic of the seedling root.     

提高木薯循环培养的次生体胚再生植株频率研究

用木薯成熟体胚子叶作外植体诱导次生体胚,接种7d或15d后分别在诱导培养基或成熟培养基中加入AgNO3,可明显提高植株再生频率。前者可使体胚再生植株频率由对照的40．5％提高到58．1％;后者可使植株再生频率由对照的36．1％提高到61．3％。用ABA进行上述处理,效果更加显著。诱导期处理,可使植株再生频率由对照的40．5％提高到72．6％;成熟期处理,植株再生频率由对照的36．1％提高到81．3％。若诱导7d后,将2,4－D浓度由4．0mgL-1降至2．0mgL-1,并加AgNO3,继续诱导15d,转到附加0．25mgL-1ABA的成熟培养基中培养至30d,能极显著地促进体胚的发育和成熟,使植株再生频率达到一个相当高的水平,最高达95％,平均每个外植体产生的植株数达39．6个,分别相当于对照的2．38倍和2．46倍。     

西瓜不同发育时期的助细胞超微结构的变化

被子植物胚囊的“雌性生殖单位”,已在多种植物上进行了超微结构的观察,但大多都以卵细胞受精前后的结构变化为主要研究内容。对于“雌性生殖单位”中的另一重要成员——助细胞,在不同发育状态下其结构变化的详细资料不多,尤其是助细胞退化后的物质去向,少见报道。本研究主要观察了西瓜不同发育时期(受精前后)、不同发育状态(柱头授粉和未授粉)的助细胞超微结构,以期为研究助细胞在双受精中所起作用提供新的资     

芦笋皮层组织培养植株再生

报道了芦笋皮层组织培养再生植株的方法。表明：皮层在ＭＳ＋１ｍｇ／Ｌ２,４—Ｄ＋２ｍｇ／Ｌ６—ＢＡ培养基上形成无色或淡绿色疏松型愈伤组织,而ＭＳ＋２ｍｇ／Ｌ６—ＢＡ＋０．１ｍｇ／ＬＩＡＡ培养基则对芽的分化有利;试管苗的生很壮苗以无激素的ＭＳ为最佳培养基。此外,本试验还研究了不同碳源、不同激素组合对芦笋皮层离体培养再生植株的影响。