不同光源对柚木组培苗生长发育的影响

该研究采用不同光源处理柚木组培继代苗,通过测定株高、叶宽、叶鲜重、全株干重、叶绿素含量和观察叶片上下表皮结构,研究不同光源对柚木组培苗生长发育的影响,并筛选适宜其快速生长发育的光环境。结果表明:不同光照下顶芽培养的植株高生长顺序为H_(FL)﹥H_(1RB)﹥H_S﹥H_(2RB)﹥H_(3RB)﹥H_D,茎段培养的腋芽高生长顺序为h_(FL)﹥h_S﹥h_D﹥h_(1RB)﹥h_(2RB)﹥h_(3RB)。LED红蓝组合灯(2RB、3RB)处理下植株最大叶宽显著大于荧光灯(FL)、全光谱灯(S)和无补光设备(D)处理,并随RB光强增加,最大叶宽及叶鲜重显著增加。全株干重以D和S光照处理显著低于其它光照处理。RB系列和S光照处理下的叶绿素总含量高于对照FL和D处理组。2RB和3RB光照处理下叶片的上表皮细胞不规则多角形,相互镶嵌排列,其它光照处理下上表皮细胞呈圆形。下表皮气孔数量在有补光设备处理(S、RB、FL)时是无补光设备处理(D)的1.5倍以上,2RB和3RB光照处理下气孔张开度大于对照FL和D处理组,且保卫细胞呈井型突起。参试光源中,柚木组培苗增殖阶段选择荧光灯或全光谱灯为好,高生长显著,腋芽分化和生长快,有利于提高增殖率;而RB红蓝组合灯(3RB、2RB)适合壮苗培养,叶大苗壮,全株生物量大,且叶表面结构发育成熟,有利于提高光合作用。     

Micropropagation of Acacia mearnsii from ex vitro material

Multiple shoots were produced from nodal explants, of 30-day-old in vitro grown seedlings and from pretreated 3- and 9-month-old greenhouse grown Acacia mearnsii plants, respectively. Explants were sterilized using 0.1% and 0.2% HgCl2 for 15 min for 3- and 9-month-old explants, respectively. Nodal explants were induced to form multiple shoots when placed on MS medium supplemented with 2.0 mg l –1 benzyladenine. Rooting of these shoots was achieved on MS medium supplemented with 1.0 mg l –1 indole-3-butyric acid. Plantlets were acclimatized in transparent plastic containers under greenhouse conditions with a 90% success rate.     

黄独脱毒苗种质离体保存及其遗传稳定性和病毒变化的初步研究

以黄独脱毒苗带芽茎段为外植体,以MS为基本培养基,采用正交实验和单因子实验方法研究了无机盐水平、蔗糖、甘露醇和植物生长抑制剂PP₃₃₃对黄独脱毒苗离体保存的影响。结果表明,黄独脱毒苗带芽茎段在25±1℃下保存于附加2.0 mg·L^-1 KT、0.5 mg·L^-1 NAA、30 g·L^-1蔗糖、20 g·L^-1甘露醇和4 mg·L^-1 PP₃₃₃的1/4MS培养基上,180 d后其成活率可达90%以上。离体保存后的脱毒苗经形态指标和生理生化指标以及RT-PCR分析测定没有发生遗传变异,也没有检测到PVY病毒。本实验结果为药用植物黄独脱毒苗的种质保存提供了一条简单有效的途径。     

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。     

Studies on Transgenic Potato with High Essential Amino Acid Encoding Gene

Leaf discs of potato (Solanum tuberosum) "Dongnong 303” sterile seedlings were inoculated with Agrobacterium tumefaciens strain C58C1 harbouring a helper plasmid pGV2260 and a binary vector plasmid pPZH1. Wounded leaves formed kanamycin-resistant calli on a selective medium. The transformation rates ranged from 4 % to 38 % for different varieties. Regenerated transgenic plantlets confirmed by NPT Ⅱ (neomycin phosphotransferase) activity assay and DNA hybridization have been obtained. The data of amino acid assay revealed that the contents of most amino acids of the transgenic microtubers displayed various increments as compared with those of control microtubers and that the content of total amino acids increased by 96.1% over the control.     

Plantlet differentiation in leaf and root cultures of birch (Betula Pendula roth.)

The newly-formed leaves on plantlets differentiated from shoot bud cultures of Betula pendula, when excised and grown on a fresh medium produced callus from the margins or regenerated leafy shoots, roots and plantlets. After 4 weeks, upon transfer to murashige and Skoog (MS) medium supplemented with 3-indoleacetic acid (IAA) + 6-(4-hydroxy-3-methyl-trans-2-enyl)aminopurine (zeatin) + 6-aminopurine (adenine), 15–20 plantlets were produced from each explant. Likewise, the roots also showed meristematic activity at several sites, and produced nodulated callus on MS + α-naphthaleneacetic acid (NAA) + 6-(3-methyl-2-butenyl-amino)purine (2-iP) + adenine, and ultimately differentiated plantlets. Anatomical studies showed that initiation of callus takes place by meristematic activity in epidermal cells of leaves, and cortical cells of roots. Cytological investigations revealed no change in chromosomal complement.     

The effects of KNO3 concentration in callus induction medium for wheat anther culture

KNO₃ concentration was found to significantly affect the anther culture of wheat (Triticum aestivum L.). When KNO₃ was increased from 0 to 15 mM (in cultivar Jinghua 1) or from 10 to 15 mM (in cultivars 2531-10, Xiaoyan 759 and Norin 10), the callus induction frequency increased significantly. When KNO₃ was increased further above 20 mM, the callus induction frequency decreased significantly in all the tested cultivars. The subsequent frequency of green plantlet regeneration increased significantly, and the ratio of green to albino regenerants increased sharply when KNO₃ concentration increased. Further experiments found that the decrease of callus induction frequency in the medium with too much KNO₃ might be caused by NO₃ ^- ion alone, while the effect of KNO₃ on green plantlet regeneration might be caused by both K⁺ and NO₃ ^- ions, and that the effects of NO₃ ^- concentration were independent of NH₄ ⁺ concentration in the medium.     

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．     

Controlled mycorrhizal initiation as a means to improve root development in somatic embryo plantlets of hybrid larch (Larix × eurolepis)

This study represents the first report of in vitro mycorrhization of somatic embryo-derived plantlets. Effects of fungi on the rooting of plantlets as well as on their ultra-structure were studied. Embryo-derived plantlets of a hybrid larch ( Larix × eurolepis Henry) were grown aseptically in the presence of four ectomycorrhizal fungi. One month after inoculation with Laccaria laccata, Hebeloma cylindrosporum and Pisolithus tinctorius , the number of plantlets which had developed a well-growing root system was significantly improved compared with controls. Furthermore, root branching was strongly stimulated by L. laccata and H. cylindrosporum , which were more efficient species than P. tinctorius and Suillus grevillei . Development of the root system was concomitantly accompanied by an enhancement of shoot growth, except for plantlets inoculated with S. grevillei , which died after three to six months. At the ultrastructural level, cross-sections of lateral roots made six months after inoculation, showed the presence of a Hartig net in the case of L. laccata and H. cylindrosporum , whereas no such net was observed with the two other fungi. With S. grevillei , some perforating hyphae penetrated the cortical cells and resulted in cell death. Evidence of a relationship between structure and efficiency of the association was found.