PP333对分蘖洋葱试管苗增殖和生根的影响

以MS 0.1 mg·L-1NAA 0.4 mg·L-1 6-BA为增殖培养基,1/2MS 1.5 mg·L-1IBA 0.01 mg·L-1NAA为生根培养基,添加不同浓度PP333的结果表明:增殖培养基中添加1.0 mg·L-1PP333对分蘖洋葱试管苗增殖生长有促进作用,减少超度含水态苗的发生;生根培养基中添加0.1 mg·L-1PP333对分蘖洋葱试管苗生根壮苗有良好效应.     

槐树试管正常苗与超度含水态苗茎叶的比较形态学研究

槐树(Sophora japonica L.)子叶经培养获得了大量的试管苗,依其形态正常与否可将其分为正常苗、超度含水态苗和介于二者之间的过度含水态苗。其自由水含量明显不同,正常苗低于50％,超度含水态苗高于79％,而过度含水态苗约为70％。以扫描电镜对其茎、叶的形态学结构进行了比较研究,结果表明:正常苗茎、叶表皮结构基本类似于实生苗,而过度及超度含水态苗的茎、叶表皮层结构变异较大。主要表现在其表面凹凸不平,表皮层外稀有或无蜡质存在,表皮细胞形状及排列不规则,叶片近、远轴两面气孔器密度、大小及开度均较正常苗显著增大;保卫细胞形态、结构异常。上述特征,均显示出槐树试管过度及超度含水态苗易失水干化,这可能是其在移栽过程中难以成活的主要原因之一。     

组织培养中畸形胚状体及超度含水态苗的研究

畸形胚状和超度含水态苗是组织培养中常见的2种形态、生理异常现象,由于其难以发育成苗或很难移栽成活而严重影响组织培养的成功率。概述了这2种畸形现象的的形态特征及防止方法等,并讨论了应进一步研究的问题。     

霍霍巴的组织培养与快速繁殖

从组织培养植株再生的途径,影响快速繁殖的因素,褐化、超度含水态出现的原因,对霍霍巴组织培养与快速繁殖的研究进展进行了介绍。     

大苞鞘石斛的离体培养与快速繁殖

1植物名称大苞鞘石斛(Dendrobium wardianumWarner). 2 材料类别种子(授粉6个月). 3培养条件萌发培养基:(1)1/2MS 6-BA0.2mg·L-1(单位下同) NAA 0.2.继代增殖与分化培养基:(2)1/2MS;(3)1,2MS 6-BA 0.2 NAA 0.5:(4)1/2MS 6-BA 0.5;(5)CHB 6-BA 0.5;(6)1/2MS NAA 0.5.生根壮苗培养基:(7)CHB IBA 1.0;(8)花宝1号3g·L-1 蛋白胨2 g-L-1 IBA 1.0:(9)B5.以上萌发培养基和继代增殖与分化培养基均附加2.0%蔗糖,生根壮苗培养基附加3.0%蔗糖,椰乳均为100 mL·L-1,7.6 g·L-1琼脂固化,pH 5.4～5.6.培养温度为(23±1)℃,光照强度30～40μmol·m2·s-1,光照时间16h·d-1.     

槐树组织细胞培养的研究

系统研究了槐树叶片、子叶及花药的培养方法和植株再生,获得了大量的试管苗,建立了槐树二倍体和单倍体植株快速繁殖的培养程序。实验表明在MS附加高浓度比值BA／IBA或2,4-D的培养基中可诱导各种外植体在短期内产生大量的不定芽和试管苗,但同时,又诱导产生了许多超度含水态苗。在培养过程中,BA浓度先高后低,既可获得大量的试管苗,又相对降低了超度含水态苗的比率,是槐树快速繁殖程序中的重要一环。组织学观察显示,槐树子叶切块培养中形成的胚状体来自于子叶的表皮及叶肉细胞,通过单细胞起源和多细胞出芽两种方式产生。     

乌桕不同外植体高效再生探索

以乌桕的成熟胚、胚乳、叶片和茎段为外植体,建立高效、稳定的组培快繁再生体系,并成功获得其再生苗.结果表明:(1)全胚乳带胚的愈伤组织诱导率达90%,其愈伤组织继续在MS+1.0 mg·L-1 NAA+1.0 mg·L-1 6-BA培养基上培养,不定芽最多达15个/外植体.(2)去胚乳的胚不加调节剂则胚直接萌动成苗,萌动率和成苗率可达100%;去胚乳的胚在MS+0.05 mg·L-1 NAA+0.3 mg·L-1 6-BA最佳培养基中培养,其胚轴处可直接诱导不定芽,最多达6个/外植体.(3)无菌苗叶片在MS+0.5 mg·L-1 NAA+0.5 mg·L-1 6-BA培养基中诱导的有效不定芽数最高达18个/外植体,诱导率达90%.(4)茎段在MS+0.05 mg·L-1 NAA+0.1~0.3 mg·L-1 6-BA培养基上不定芽的诱导率较高(100%),直接诱导的不定芽数最多达17个/外植体.(5)芽苗在1/2MS+0.5 mg·L-1 IBA上生根率达到100%,但根系较细弱,而在MS+1.0 mg·L-1镧稀土中的生根率达100%,且根系粗壮;生根的小苗练苗移栽后温室内成活率为89.2%,移栽到室外沙质土壤中的成活率为68.9%.     

东北天南星的离体培养与快速繁殖

1 植物名称东北天南星(Arisaema amurense Maxim.). 2 材料类别新萌发的嫩叶. 3 培养条件基本培养基为MS.(1)嫩叶愈伤组织诱导培养基:1/2MS 6-BA 2.0 mg·L-1(单位下同) 2,4-D 0.5 3%蔗糖;(2)芽苗分化培养基:MS 6-BA 1.5 3%蔗糖;(3)芽苗继代增殖培养基:MS 6-BA 1.0 3%蔗糖;(4)壮苗生根培养基:1/2MS IBA 0.2 1.5%蔗糖.     

白叶瓶子草的组织培养和快速繁殖

1 植物名称 白叶瓶子草(Sarracenia leucophylla Raf). 2 材料类别 嫩芽茎尖. 3 培养条件 不定芽诱导培养基:(1)1/3MS+6.BA3 mg·-1(单位下同)+NAA0.3;不定芽增殖培养基:(2)1/3MS+6-BA2+NAA0.1;壮苗培养基:(3)1/4MS+1 g-L-1活性炭;生根培养基:(4)1/4MS+IBA 0.5+NAA 0.1+1 g-L-1活性炭.     

尾叶桉叶片的离体培养和植株再生

1植物名称尾叶桉(Eucalyptus urophylia). 2材料类别无菌萌发种子苗的幼叶片. 3培养条件萌发培养基:(1)MS 3%蔗糖.诱导分化培养基:(2)MS 6-BA 0.8～1.5 mg·L-1(单位下同) KT 0.5 NAA 0.1 3%蔗糖.丛生芽增殖和生长培养基:(3)MS 6-BA 0.2 NAA 0.02 3%蔗糖.生根培养基:(4)1/2MS NAA 0.5 2%蔗糖;(5)MS NAA 0.5 2%蔗糖;(6)改良H NAA 0.5 2%蔗糖.以上培养基均加入0.65%琼脂,pH 5.8.培养温度(25±2)℃,光照1 6 h·d-1,光照度1900～2000lx.     

E.s.r. of free radicals in irradiated uracil-beta-D-arabinofuranoside.

Electron-spin-resonance measurements have been made on single crystals of uracil-beta-D-arabinofuranoside, which were irradiated by 4-0 MeV electrons at 77 K. At low temperatures, two radicals have been identified, one attributed to a hydrogen abstraction from 05' in the sugar moiety and the other to a radical anion located on the pyrimidine ring. The former is very unstable and seems to act as a precursor to other unidentified radical species stable at 77K. At room temperature, the main resonance is due to hydrogen addition to C5 and is probably produced by protonation of the anion. This same radical is also produced by X-irradiation at room temperature.     

Radical formation in salts of pyrimidines. II. Cytosine. HCl crystals.

Radicals produced by X-irradiation at 77 K and at 300 K of cytosine. HCl crystals have been analysed by electron spin resonance spectroscopy. Four radicals have been identified: the anion radical of the cytosine molecule, the radical resulting from H-addition at position C6, the radical resulting from H-addition at position O2, and finally a radical resulting from addition of a Cl- to nitrogen N3. Hückel molecular orbital calculations are presented, which support the hypothesis according to which in unsaturated pyrimidines the site of hydrogenation or protonation depends on the state of the molecule.     

Changes in the ordering of lipids in the membrane of Dunaliella in response to osmotic-pressure changes. An e.s.r. study.

Changes in the ordering and motion of lipids in response to changes in the external solute concentration have been studied by using the 5-nitroxide stearate (5NS) and 16-nitroxide stearate (16NS) spin probes in the plasma membrane of the halotolerant unicellular alga Dunaliella salina. Increases in ordering of the 5NS probe and decreases in motion of the 16NS probe were observed in cells equilibrated over 18 h at increasing NaCl concentrations. These changes probably resulted from the influence of the high NaCl concentration on the charged phospholipid head groups of the membrane. A short-term (less than 100 min) decrease in the order parameter, S, of the 5NS probe was observed for cells swollen by exposure to a sudden decrease of NaCl concentration from 5.0 to 2.5 M. After 100 min the value of S for 5NS was close to the value obtained in cells that had been equilibrated in 2.5 M-NaCl for 18 h. Since the cells had regained their original size and shape by 100 min it was assumed that the short-term decrease in S was associated with the swelling. A similar result was obtained when the cells were suddenly changed from 3.0 M- to 1.5 M-sorbitol. Conversely, an increase in S was observed for cells shrunk when the external solute concentration was doubled from 1.5 M- to 3.0 M-NaCl. As the cells regained their original size and shape the value of S decreased to the value observed in cells that had been equilibrated in 3.0 M-NaCl for 18 h. It is suggested that the changes in S are related to the movement of lipid into or out of a reservoir of membrane material as the membrane shrinks or expands. This movement of lipid maintains the tension of the membrane below the value at which it is disrupted. Such changes in lipid ordering could provide a mechanism whereby information about external osmotic-pressure changes is transmitted across the cell wall.