陆地棉组织培养中再生植株的形态解剖学研究

在显微和超微水平不同层次上对陆地棉(Gossypium hisutum L.)再生植株中正常苗和玻璃苗叶及根端的形态结构进行了观察比较。结果表明:试管玻璃苗叶表面凹凸不平,气孔下陷,萎缩变形,表皮细胞形态不规则,排列不整齐,叶表面蜡质分布不均匀,其数量也较少;叶肉无明显的栅栏组织分化,细胞中叶绿体含量少、形态小,结构异常。超微结构显示,大部分叶肉细胞中叶绿体基粒片层分布少而含较多的基质片层,其它细胞器如线粒体、高尔基体、内质网等含量少或缺。叶脉维管组织发育不良,导管分子数目少,木质化程度低,根尖短而细,生长点仅由少数具分生能力的细胞组成,根冠细胞大,但数量少。正常苗形态结构基本类似于实生苗。     

蕨组织培养与快繁技术研究

以蕨的根状茎顶芽、幼嫩带节根状茎为外植体,接种于诱导培养基上,培养30d后,顶芽分化形成绿色小球（GGB）,继续生长30d后分割,用于继代增殖或转换培养基诱导形成试管苗;根状茎段由茎节处萌发新枝,20—30d后,形成丛生苗,分割后培养长成具有不定根的丛生试管苗。通过诱导形成绿色小球（GGB）和丛生苗两条途径均可快速繁殖蕨的试管苗。试管苗经过“炼苗”后移入温棚,生长良好．     

NAA、IBA和PP333对怀山药试管苗生长发育的影响

就不同生长调节剂对怀山药试管苗生长发育的影响进行了系统的研究。结果表明 :( 1 )NAA、IBA和PP3 3 3 均能诱导根的生成 ,但根形成的时间、发生方式及发达程度均不相同。低浓度的NAA( 0 .1～ 0 .5mg.L 1)有利于根的生成 ,但高浓度的NAA(≥ 2mg .L 1)则易形成愈伤组织 ,且随着浓度的升高 ,愈伤组织化程度变大 ,根多来源于愈伤组织 ;IBA( 0 .1～ 2mg .L 1)对根的生成较为有利 ,其中以IBA 1mg .L 1的生根效果较好 ;PP3 3 3 ( 0 1～ 8mg.L 1)有利于根的生成 ,根形成的最早、最多 ,且随着浓度的升高 ,根更加粗壮发达。 ( 2 )PP3 3 3 抑制试管苗的纵向伸长生长 ,使株高降低 ,但却显著地促进了根系的发育 ,使试管苗生长健壮 ,叶色浓绿 ,叶片增多。这种效应随着PP3 3 3 浓度的升高而加强。从培养壮苗的角度来看 ,PP3 3 3 ( 2～ 4mg.L 1)是最佳浓度     

Somatic embryogenesis,organogenesis, and regeneration from leaf callus culture of <Emphasis Type="Italic">Decalepis hamiltonii</Emphasis> Wight &; Arn., an endangered shrub

Summary A novel protocol has been developed for inducing somatic embryogenesis from leaf cultures of Decalepis hamiltonii. Callus was obtained from leaf sections in Murashige and Skoog (MS) medium supplemented with α-naphthaleneacetic acid (NAA)+N⁶-benzyladenine (BA) or 2,4-dichlorophenoxyacetic acid (2,4-D)+BA. Nodular embryogenic callus developed from the cut end of explants on media containing 2,4-D and BA, whereas compact callus developed on media containing NAA and BA. Upon subsequent transfer of explants with primary callus onto MS media containing zeatin and/or gibberellic acid (GA₃) and BA, treatment with zeatin (13.68μM) and BA (10.65 μM) resulted in the induction of the highest number of somatic embryos directly from nodular tissue. The maturation of embryos took place along with the induction on the same medium. Embryogenic calluses with somatic embryos were subcultured onto MS basal medium supplemented with 4.56μM zeatin+10.65 μM BA. After 4wk, more extensive differentiation of somatic embryos was observed. The mature embryos developed into complete plantlets on growth regulator-free MS medium. A distinct feature of this study is the induction of somatic embryogenesis from leaf explants of Decalepis hamiltonii, which has not been reported previously. By using this protocol, complete plantlets could be regenerated through indirect somatic embryogenesis or organogenesis from leaf explants in 12–16 wk.     

The development of an efficient cultivar-independent plant regeneration system from callus derived from both apical and non-apical root segments of garlic (<Emphasis Type="Italic">Allium sativum</Emphasis> L.)

Summary Callus induction and later plant regeneration were studied in four widely grown garlic (Allium sativum L.) cultivars from Europe. Root segments from in vitro plantlets were used as starting material. In addition to cultivar effects, the effects of auxin and cytokinin levels and the position of the segments on the root were studied. There were no statistically significant differences among cultivars for the number of root segments that induced callus in the two series of experiments. The average induction frequency was 34.7% in the first series of experiments. Callus induction on apical root segments was significantly higher compared to callus induction on non-apical root segments in the second series of experiments. Two months after callus induction, callus lines were transferred to a regeneration medium consisting of Murashige and Skoog basal medium supplemented with 30gl⁻¹ sucrose and 1 mgl⁻¹ (4.6μM) kinetin. Calluses derived from different experiments were quite uniform with respect to their regeneration potential. Also it was found that our regeneration system was cultivar-independent. The average shoot regeneration frequency was 17.9% in the first series of experiments. Highly significant differences were found in the frequency of shoot regeneration among different callus induction treatments. When the cytokinin 6-(γ,γ-dimethylallylamino)purine (0.1mgl⁻¹∶0.5 μM) was present during callus induction, shoot regeneration ranged from 30.10 to 47.60%. Shoot regeneration from callus induced on non-apical segments was higher, although not significant, compared to callus induction from apical root segments in the second series of experiments. All in all, an efficient callus induction and plant regeneration system was developed from both apical and non-apical segments taken along the entire length of the roots. This system has potential to be used for garlic transformation.     

Somatic embryogenesis and plant regeneration from cotyledon explants of a timber-yielding leguminous tree,Dalbergia sissoo Roxb

Efficient plant regeneration through somatic embryogenesis was achieved from callus cultures derived from semi-mature cotyledon explants of Dalbergia sissoo Roxb., a timber-yielding leguminous tree. Somatic embryos developed over the surface of embryogenic callus and occasionally, directly from cotyledon explants without intervening callus phase. Callus cultures were initiated from cotyledon pieces of D. sissoo on Murashige and Skoog (1962) medium supplemented with 4.52, 9.04, 13.57, and 18.09 mumol/L 2,4-dichlorophenoxyacetic acid and 0.46 mumol/L Kinetin. Maximum percentage response for callus formation was 89% on MS medium supplemented with 9.04 mumol/L 2,4-D' and 0.46 mumol/L Kn. Somatic embryogenesis was achieved after transfer of embryogenic callus clumps to 1/2-MS medium without plant growth regulators (1/2-MSO). Average numbers of somatic embryos per callus clump was 26.5 on 1/2-MSO medium after 15 weeks of culture. Addition of 0.68 mmol/L L-glutamine to 1/2-MSO medium enhanced somatic embryogenesis frequency from 55% to 66% and the number of somatic embryos per callus clump from 26.5 to 31.1. Histological studies were carried out to observe various developmental stages of somatic embryos. About 50% of somatic embryos converted into plantlets on 1/2-MSO medium containing 2% sucrose, after 20 days of culture. Transfer of somatic embryos to 1/29-MSO medium containing 10% sucrose for 15 days prior to transfer on 1/2-MS medium with 2% sucrose enhanced the conversion of somatic embryos into plantlets from 50 to 75%. The plantlets with shoots and roots were transferred to 1/2 and 1/4-liquid MS medium, each for 10 days, and then to plastic pots containing autoclaved peat moss and compost mixture (1:1). 70% of the plantiets survived after 10 weeks of transfer to pots. 120 regenerated plantlets out of 150 were successfully acclimatised. After successful acclimatisation, plants were transferred to earthen pots.     

春石斛优良品种‘森禾2006’组培快繁体系的建立

本文研究了春石斛‘森禾2006’的拟原球（PLBs）诱导、增殖、分化及壮苗和生根,建立了其组培快繁体系。结果表明：‘森禾2006’PLBs最适诱导培养基为1／2MS＋TDZ0．5mg·L-1＋水解酪蛋白2．0gL-1;PLBs增殖培养基为1／2Ms＋水解酪蛋白2．0gL-1;PLBs分化培养基为1／2MS＋KT1．0mg·L-1＋NAA0．1mg·L-1;壮苗生根培养基为Ms＋IBA0．5mg·L-1＋NAA0．1mg·L-1＋香蕉泥100．0g．L-1。     

濒危植物佛手参种子的非共生萌发及种苗的快速繁殖

离体条件下对佛手参种子进行了非共生萌发研究,成功实现了种子萌发,并通过根状茎增殖和分化获得了大量再生种苗。结果表明,成熟佛手参种子难以萌发,而未成熟种子具有萌发能力,萌发率可达到20％,最适萌发培养基为：1／2MS＋1．0-2．0mg·L-1。KT＋0．1mg·L—NAA＋10．0mg·L-1腺嘌呤;根状茎增殖最适培养基为：1／2MS＋3．0mg·L。6-BA＋0．1mg·L-1 NAA＋10．0mg·L。腺嘌呤;芽分化最适培养基为：1／2MS＋I．0mg·L-1 KT＋10．0mg·L-1腺嘌呤。较高浓度的细胞分裂素（1．0mg·L。KT）与较低浓度类生长素（O．1mg·L-1 NAA）的配比对佛手参种子萌发、根状茎增殖及芽分化具有明显的促进作用;较高浓度的NAAA制种子萌发。根状茎与愈伤组织的增殖能力无明显差异,但前者的分化能力却显著高于后者。     

N、P、K异质含量拟南芥试管苗的表型适应特性

以模式种拟南芥为试验材料,有别于自然环境下生长的拟南芥,借助于组织培养方法利用均匀设计对培养基中 KNO 3、NH 4 NO 3、KH 2 PO 4设置处理,探讨试管环境下拟南芥生长发育特性及对营养离子需求吸收特点,结果显示拟南芥本性地通过加强莲座叶与茎生叶的功能以增加生殖生长期的分枝数与苔高;生殖生长期影响试管苗茎生叶数、苔高的离子种类增多,离子的交互作用更加复杂。通过分析模式植物对 N、P、K 异质含量培养基的表型适应特点可推论同一植物在不同时期使用单一培养基是不合理的。