白刺花胚性愈伤组织诱导及体细胞胚发生和萌发

探讨不同因素对白刺花下胚轴、子叶2种外植体胚性愈伤组织诱导及体细胞胚发生和萌发的影响。以B5和MS为基本培养基,研究2,4-D、6-BA和TDZ对白刺花下胚轴和子叶胚性愈伤组织的诱导;在MS培养基上添加不同浓度2,4-D,研究胚性愈伤组织增殖情况;采用ABA,探究对体细胞胚发生的影响。结果表明:下胚轴比子叶更易诱导胚性愈伤组织,筛选出2种外植最佳的胚性愈伤组织诱导培养基均为MS+2.0 mg/L 2,4-D+0.5 mg/L TDZ+0.5 mg/L 6-BA,胚性愈伤组织诱导率分别为77.3%和41.0%。15.0 mg/L ABA、0.2 mg/L 2,4-D和2.0 mg/L 6-BA有利于体细胞胚发生,1/3MS+0.2 mg/L NAA+0.1 mg/L 6-BA+2.0 g/L活性炭+25 g/L蔗糖+7 g/L琼脂的培养基可使体细胞胚萌发率达80%以上,再生植株移栽成活率高达90%。白刺花外植体种类及培养基类型均会影响胚性愈伤组织的诱导,其中下胚轴诱导效果优于子叶;MS培养基较适合启动细胞脱分化形成愈伤组织,2,4-D对胚性愈伤组织的增殖保持有调控作用,ABA有利于体细胞胚的发生。     

‘SK4—316’胡萝卜体胚的诱导和培养

以'SK4-316'胡萝卜无菌苗的下胚轴为外植体,研究不同培养基配方和培养条件对愈伤组织诱导、体细胞胚间接发生及其同步化培养的影响,以及不同脱分化时间、脱分化培养基及外植体续存时间对体细胞胚直接发生的诱导及其培养的影响.结果表明:含3%蔗糖、0.8%琼脂的1/2MS + 2,4-D 2.5 mg/L + 6-BA(或KT)0.5 mg/L + CH 300 mg/L是诱导愈伤组织的良好培养基;1/2MS + 2,4-D 1.25 mg/L + KT 0.25 mg/L + 6-BA 0.25 mg/L(含3%蔗糖)适于愈伤组织分化并诱导体胚发生,0.02% ABA对体胚的诱导有促进作用,0.06% ABA或15% PEG能促进体胚成熟;外植体在MS + 2,4-D 1.0 mg/L固体培养基上脱分化培养48 h,再转入MS + CH 300 g/L液体培养基中可诱导体胚直接发生,但随着外植体续存于诱导培养基中时间的延长,体胚发生变异的几率也渐增.     

2.4-D、6-BA对人参体细胞胚胎发生过程的影响研究

本实验以人参芽胞、二年生人参根、实生苗的茎、叶为外植体研究了体细胞胚的发生条件,并对其发生过程中可溶性蛋白、相关酶活性及内源激素的变化等进行了研究。结果表明,诱导愈伤组织的培养基为MS+2,4-D 4.0mg/L + BA 0.2mg/L;在MS+2,4-D 1.0mg/L + KT 0.2 mg/L培养基上继代培养,可获得胚性愈伤组织;在无2,4-D的培养基上可诱导出胚状体。将胚状体转入无任何激素的MS培养基上继续培养,之后转入1/2MS培养基上获得再生植株。组织细胞学观察表明人参胚状体的起源方式为单细胞起源。在体细胞胚胎发生过程中,多糖和淀粉含量在早期胚时较低,可溶性蛋白含量、POD及PPO活性在早期胚时最高;IAA在早期胚时期含量最高,在成熟胚时期ABA含量最高,而ABA/IAA比值在成熟胚时较高,利于体细胞胚的发育成熟。cDNA-AFLP 分析表明胚状体发育不同时期的人参培养物基因表达不同,从而导致了分化和发育。培养物HPLC分析表明胚胎发生试管苗总皂苷含量比子叶胚时期高4倍多。单体皂苷差异较大。     

几种匍匐翦股颖成熟胚愈伤组织诱导及植株再生

利用成熟种子作为外植体,分析了2,4-D对匍匐翦股颖胚性愈伤组织诱导与植株再生体系的影响,并对体细胞胚的发生过程进行了观察.实验结果表明,在2.0 mg/L 2,4-D 0.1 mg/L 6-BA时胚性愈伤组织的诱导频率最高.随着2,4-D浓度的增加,愈伤组织的诱导和分化能力明显下降.在再生过程中采用1.0 mg/L的6-BA达到了比较好的效果,愈伤组织的再生频率大部分在90%以上.同时发现适当提高肌醇浓度可以使苗长得较为粗壮.在实验中发现匍匐翦股颖的体细胞胚发生过程为球形胚、心形胚、鱼雷胚和子叶胚.     

不同激素对花生离体分化的影响

对TDZ和2,4-D等激素在花生成熟胚外植体分化中的影响进行了研究.结果表明,花生成熟胚3～5 d龄实生苗的幼叶和胚轴在低浓度TDZ的诱导下,可分化产生高频不定芽和少量体细胞胚,转到无激素MS培养基或MS BA 0.5 mg/L NAA 0.4 mg/L的培养基后形成丛生苗.丛生苗分离后转入含1/2 MS(大量元素) IBA 0.4 mg/L的培养基中诱导生根,可形成完整的再生植株.幼叶分化率高于胚轴,但胚轴分化成苗速度快.无菌水浸泡16～24 h的胚轴在5～ 30 mg/L 2,4-D的诱导下,分化产生低频不定芽;而胚叶则产生高频体细胞胚,但畸形较严重.     

2,4-D、BA对人参体细胞胚胎发生过程的影响研究

以人参芽胞、二年生人参根、实生苗（茎、叶）为外植体研究了体细胞胚的发生条件,并对其发生过程中可溶性蛋白、相关酶活性及内源激素的变化等进行了研究。结果表明,诱导愈伤组织的培养基为MS＋2,4-D4．0mg／L＋BA0．2mg／L;在MS＋2,4-D1．0mg／L＋KT0．2mg／L培养基上继代培养,可获得胚性愈伤组织;在无2,4-D的培养基上可诱导出胚状体。将胚状体转入无任何激素的MS培养基上继续培养,之后转入1／2MS培养基上获得再生植株。在体细胞胚胎发生过程中,可溶性多糖和可溶性淀粉含量在早期胚时较低,可溶性蛋白含量、POD及PPO活性在早期胚时最高;IAA在早期胚时期含量最高,在成熟胚时期ABA含量最高,而ABA／IAA比值在成熟胚时较高,利于体细胞胚的发育成熟。     

云南大叶茶体细胞胚发生及体细胞胚苗形成体系的建立

利用云南大叶茶(Camellia sinensis var.assamica Kitamura)胚性细胞系(CL_1)中悬浮培养物,建立了高频率同步化体细胞胚发生及体胚苗形成体系。以改良的MS为基本培养基,将CL_1中培养物由液体保持培养基(0.1mg/L 2,4-D 0.5mg/L 6-BA)继代转入液体诱导培养基(0.05mg/L 2,4-D 0.50mg/L6-BA),暗培养诱导28d,转入不含任何激素的液体分化培养基中再培养28d,获得了不同发育时期的体细胞胚,其发生频率为81.5％。不同发育时期的体细胞胚用不同目的细胞筛收集,在液体生长培养基(1/2 MS 1.0mg/L GA_3 0.5mg/L 6-BA)中培养发育成熟。ABA有利于高质量体细胞胚的形成。20～70月大小的体细胞胚在固体生长培养基中成苗转换率为75％。在液体悬浮培养条件下观察记录了体细胞胚发育过程,证实其过程与合子胚的形态发生过程相似。     

枸杞悬浮培养条件下的胚状体发生

在MS培养基上诱导宁夏枸杞下胚轴切段形成愈伤组织,并进行细胞悬浮培养。观察了悬浮培养条件下胚状体的发生过程。<1>观察发现,细胞经悬浮培养几天以后,先形成胚性细胞团,再有胚性细胞团块形成一个或几个胚状体。较大的胚状体也可以形成新的次生胚状体。<1>影响胚状体形成的关键因素是激素的种类及其含量。实验采用的基本培养基为MS,比较适宜胚状体发生的激素是0.2mg/L 2,4-D。同样浓度的2,4-D,会抑制胚状体的进一步发育,用0.2mg/L6-BA代替2,4-D, 则胚状体可以进一步发育并形成小植株。     

党参的离体培养及植株再生的研究

在附加激素的MS培养基上,培养党参下胚轴和无菌芽切段,诱导产生愈伤组织并且再生植株。经过两年多(15个世代)的继代培养,建立了党参体细胞无性系。实验结果表明:(1)培养基MS 0.4mg/L 2,4-D 0.8mg/L Kt 2.0mg/L IAA对愈伤组织诱导及继代培养,MS 0.2mg/L 6-BA诱导外植体产生丛芽和愈伤组织再分化,MS 0.5mg/L NAA 0.2mg/L 6-BA及MS 0.2mg/L NAA诱导生根效果最好。(2)愈伤组织再分化经过胚状体途径。     

白鹤芋体细胞胚胎发生及组织学研究

本研究以白鹤芋品种‘Mojo’的根茎为外植体,研究不同外源激素配比对体细胞胚胎发生的影响,筛选出最佳胚性愈伤及体胚的诱导配方。其后采用体式显微镜和石蜡切片技术对体胚发生途径中的典型时期进行形态学和组织学观察。结果表明,4 mg/L 2,4-D与0.5 mg/L KT作用时,白鹤芋胚性愈伤组织诱导效果最佳,诱导率达87.44%;体细胞胚胎诱导的最佳配方为1.0 mg/L6-BA+0.2 mg/L TDZ+0.2 mg/L NAA。白鹤芋是单子叶植物,其体细胞胚胎的形态形成过程与单子叶植物胚的形态形成过程类似。研究结果表明,白鹤芋体细胞胚胎的形态形成主要分为以下几个阶段:胚性细胞、胚胎、球形胚、椭圆形胚、盾形胚、子叶型胚、成熟体细胞胚。     

Effects of ABA on secondary embryogenesis from somatic embryos induced from inflorescence culture ofAralia cordata Thunb

In order to investigate the effect of ABA on secondary embryogenesis from somatic embryos inAralia cordata Thunb., embryogenic callus and somatic embryos were induced from inflorescence on solid MS basal medium supplemented with 1.5 mg/L 2,4-D after eight weeks without subculture. For mass production of somatic embryos, embryogenic cell clumps were maintained in liquid MS medium supplemented with 1.0 mg/L 2,4-D, and then transferred to 2, 4-D-free medium. When developing embryos at various stages were cultured separately in liquid medium with ABA (0 to 2.0 mg/L) for three weeks, and then cultured in ABA-free liquid medium for two weeks, torpedo-shaped embryos exhibited secondary embryogenesis of 65.9% in only 0.2 mg/L ABA pretreatment. Cotyledonary embryos in cultures by 0.2, 0.5 and 1.0 mg/L ABA pretreatment also exhibited secondary embryogenesis (73%, 9.4% and 6.0%, respectively). However, globular and heart-shaped somatic embryos treated with ABA did not form secondary embryos on their hypocotyl surfaces. When cotyledonary embryos were cultured in ABA-free medium or 0.2 mg/L ABA treated medium for three weeks, and then in ABA-free liquid medium for 6 weeks, the germination frequency was lower in medium with 0.2 mg/L ABA (45.9%) than in hormone-free medium (56.8%). This result seems to be related to the high frequency of secondary embryogenesis. It is suggested that secondary embryogenesis by ABA application depends upon the stage of embryo cultured and the ABA concentration.     

Production of 8-epi-tomentosin by plant cell culture ofXanthium strumarium

This study was conducted to establish a plant cell culture system for the production of medically important secondary metabolites fromXanthium strumarium. The effects of plant growth regulators including NAA, 2,4-D, kinetin, and ABA were examined in terms of callus induction, maintenance of callus and suspension cultures. It was shown that callus was induced upon treatment with NAA while embryo was induced after treatment with 2,4-D. Callus formation was further improved by treatment with ABA and NAA. The level of callusing increased by 17–29% for the seed case, cotyledon, leaf, and hypocotyl and by 96% in the case of the root. Suspension cell lines were established using calli produced from cotyledon, hypocotyl and root and cultured at 25°C under light conditions. The cells grew up to 15 g/L with NAA 2 ppm, BA 2 ppm, and ABA 1 ppm treatment. Supernatants of suspension cultures of cell lines derived from coyledon and hypocotyl produced some distinctive secondary metabolites, one of which was identified as 8-epi-tomentosin, which belongs to the xanthanolides. The amounts of 8-epi-tomentosin produced by the cotyledon-and hypocotylderived cell lines were 13.4 mg/L and 11.0 mg/L, respectively.     

Morphogenetic effects of 2,4-dichlorophenoxyacetic acid on pinto bean (Phaseolus vulgaris L.) leaf explants in vitro

Roots, callus and/or globular structures were produced on primary leaf and distal cotyledon explants of pinto bean (Phaseolus vulgaris L. cv. UI 114) cultured on semisolid MS medium with a wide range of 2,4-D concentrations (0.01 to 80 mg/L) with either 0 or 1.0 mg/L kinetin. Explants rooted at lower 2,4-D concentrations than at those favoring globule formation on callus, although roots, callus and globules often developed from the same explant. Isolated opaque green globular structures developed when callus initiated on media with 3 or more mg/L 2,4-D was subcultured in liquid MS + 30 mg/L 2,4-D. These structures multiplied with a fresh weight doubling time of 8–9 days in MS + 30 mg/L 2,4-D. Although this multiplicative behavior and opaque color were reminiscent of embryoids reported for other species, no cotyledons or roots were seen.Abbreviations 2,4-D 2,4-dichlorophenoxyacetic acid - KIN kinetin - MS Murashige-Skoog medium Cooperative investigations of the Agricultural Research Service, U.S. Department of Agriculture and the Michigan Agricultural Experiment Station, East Lansing, Michigan 48824. Michigan Agricultural Experiment Station Journal article No. 11923     

不同生长调节剂对马蹄金愈伤组织诱导的影响

马蹄金是一种优良的地被兼观赏草坪植物。采用正交设计试验法 ,研究了四种不同生长调节剂对马蹄金子叶、叶片、叶柄和下胚轴愈伤组织诱导的影响。结果表明 :生长调节剂是诱导愈伤组织的关键 ,2 ,4 D对愈伤组织诱导具有显著的影响 ,适宜于马蹄金愈伤组织诱导的培养基及生长调节剂为MS +1 .0mg/L 2 ,4 D +0 .2mg/L 6 BA +0 .2mg/LKT +1 .0mg/Lα NAA。     

Morphology of carrot somatic embryos formed in medium with abscisic acid

Somatic embryogenesis was induced from embryogenie cells derived from cotyledon expiants cultured on MS medium supplemented with 1 mg/L 2,4-D. In order to clarify the effect of abscisic acid (ABA) on the morphology of somatic embryos, embryogénie cell clumps or developing somatic embryos were treated continuously, or briefly, with ABA during culture. When embryogenie cells in MS medium without 2,4-D were treated with 0.04 mg/L ABA for the first week, normal embryos with two cotyledons increased slightly and embryos with anomalous cotyledons decreased. However when cell clumps in 2,4-D-free medium were treated with ABA in the second week normal embryos with two cotyledons decreased prominently and this decrease of normal embryos also occurred in the continuous ABA treatment during culture. Thus the morphological abnormalities in somatic embryogenesis occurred by exogenous ABA treatment beyond globular stage or by continuous treatment. The length of somatic embryos with anomalous cotyledons was larger than that of normal embryos with two cotyledons in control but both the normal and anomalous somatic embryos treated with ABA were almost similar in length. Somatic embryos formed in medium with ABA were larger in size than those in control due mainly to enlarged cotyledons. The enlarged cotyledons were composed of a greater number of cells than those of control. Therefore the enlargement of cotyledon by exogenous ABA seems to be not due to the enlargement of cells in cotyledons.     

Endogenous hormone levels in explants and in embryogenic and non-embryogenic cultures of carrot

Carrot ( Daucus carota L. F1 hybrid Starca) excised hypocotyls were cultured on Murashige and Skoog medium with and without 2,4-dichlorophenoxy acetic acid (2,4-D) to determine the effect of this plant growth regulator on their further development and their endogenous hormone levels. Culture in the absence of 2,4-D stimulated root development at one end of the hypocotyl segments and increased the endogenous levels of free indole-3-acetic acid (IAA), zeatin/zeatin riboside and N ⁶(Δ²-isopentenyl) adenine/ N ⁶(Δ²-isopentenyl) adenosine, as determined by radio-immunoassay. On the other hand, the presence of 2,4-D in the culture medium promoted callus induction and proliferation, together with abscisic acid (ABA) accumulation, in the hypocotyl segments during the first weeks of culture. When the callus segments generated in the hypocotyl sections cultured in the presence of 2,4-D were cultivated further, the development of two callus types was observed, one composed of preglobular and globular embryos and the other translucent, watery and lacking any sign of organisation. The embryos of the first type germinated when callus segments were transferred to regeneration conditions, while no change was observed when the second type was induced to regenerate. Higher levels of free IAA and ABA were obtained in the embryogenic calli when compared to the non-embryogenic, while no differences were observed among callus types in the other hormones evaluated. The possible role of the different plant hormones during induction of somatic embryogenesis is discussed.     

党参体细胞胚胎发生早期阶段内源脱落酸和细胞分裂素的变化

以党参为实验材料,在附加1mg／L2,4-D3％或7％蔗糖的MS培养基上,成功获得体细胞胚胎发生同步化较高的实验体系。用ELISA方法测定了胚性细胞形成球形胚的过程中,内源ABA和CTK的含量变化。结果表明,在这一过程中内源ABA含量持续增加;内源CTK的组分和含量均发生很大变化,表现在组分iPAs在球形胚形成前急剧增加,球形胚形成期急剧下降,组分ZRs在球形胚形成前上升较缓慢,球形胚形成期急剧上升。     

提高榨菜离体培养植株再生频率

采用榨菜“浙桐1号”品种为材料,以MS为基本培养基,通过对不同植物生长调节剂的组合和不同外植体等主要因素的筛选,大幅度提高了榨菜离体培养植株再生频率。结果表明,2mg／L6．BA 0．2mg／L2,4-D的组合较为适宜,其不定芽再生频率可达50％,且外植体以下胚轴为好：而CPPU和2,4-D的适宜组合为1．5mg／L 0．2mg／L,其不定芽再生频率高达66．67％,最适外植体为带柄子叶。同时,研究结果显示,添加0．25～1mg／L的GA,对榨菜已分化的不定芽的伸长有抑制作用;子叶柄和下胚轴外植体的分化具有极性现象。     

小麦组织培养中体细胞胚胎发生的细胞胚胎学及淀粉消长动态的研究

小麦幼胚在附加2,4-D 2 mg/L+KT0.5 mg/L+LH 300 mg/L+3%蔗糖的MS 培养基上诱导出愈伤组织,继代2—3次后,降低2,4-D 的浓度,该愈伤组织约以60%的频率转变为胚性愈伤组织,继而形成不同发育期的体细胞胚。这些体细胞胚是起源于愈伤组织表层或近表层的单个胚性细胞,体细胞胚经球形胚、梨形胚、盾片胚、成熟胚而成再生植株。在胚性细胞内淀粉粒大最积累,淀粉颗粒大而密集。随着胚性细胞的分裂,淀粉逐渐被消耗,到多细胞原胚期,胚体细胞内淀粉粒趋于消失。球形胚期淀粉粒又开始积累,但到成熟胚期,淀粉积累只限于生长点区域,尔后随着胚体萌发,淀粉含量又趋于减少。这一消长动态过程与小麦合子胚发生中淀粉代谢动态基本一致。