山苍子嫩枝扦插生根过程的形态解剖学研究

研究山苍子[Litsea cubeba(Lour.)Pers]扦插不定根的发生过程,为山苍子扦插繁殖提供理论依据。以山苍子一年生嫩枝为试材进行扦插,观察生根过程中外部形态变化;同时,利用常规石蜡切片法制片对山苍子扦插过程中不定根的形成过程进行解剖观察。结果表明,在山苍子插穗中无原始根原基存在,根原基由维管形成层的部分薄壁细胞诱导分化而来,进而发育为不定根,属于诱导生根型;愈伤组织是由皮层薄壁细胞、维管形成层的部分薄壁细胞诱导产生,且愈伤组织中未观察到根原基,不定根的发生与愈伤组织的出现不存在直接关联。山苍子属于非愈伤组织生根型树种。     

红缨海棠嫩枝扦插生根解剖学观察

为探索插穗根原基诱导发生部位及不定根发育过程,以红缨海棠嫩枝插穗为研究对象,定期取样插穗基部制作石蜡切片,开展解剖学观察。结果表明:红缨海棠嫩枝扦插后,可由愈伤组织和皮部诱导产生不定根;解剖学观察扦插穗条内不存在潜伏根原基,插穗生根为诱导生根型;经NAA处理后的嫩枝插穗,根原基诱导产生于插穗基部愈伤组织以及穗条内的髓射线与皮层交界处、维管形成层处、髓射线与环髓带交界处等4个部位,根原基诱导及不定根形成时间不超过20 d。     

棱角山矾扦插生根解剖学机理研究

为探讨棱角山矾生根的机理提供解剖学依据,本研究应用光学显微技术对棱角山矾扦插苗生根过程进行解剖学观察,结果表明：棱角山矾穗条内没有发现潜伏根原基,生根类型为诱导生根型。根原基源于髓射线与形成层交接处的细胞分化而成,愈伤组织中未发现根原基,为非愈伤组织生根类型树种,为较易生根树种。     

紫花含笑组培苗生根解剖机理研究

应用光学显微技术对紫花含笑组培苗生根过程进行解剖学观察,结果表明：紫花含笑增殖苗在诱导生根前,没有根原始体,说明其生根类型为诱导生根型;在生根培养基中诱导生根时,发现根原基由髓射线与形成层交接处的薄壁细胞分化而成;生根过程中诱导产生的愈伤组织的存在,对根原基的形成有一定刺激作用,同时为后期不定根的生长提供营养,因此认为,适当诱导出愈伤组织,对紫花含笑不定根的生成起到重要的促进作用。本研究为紫花含笑组培苗生根机理提供了解剖学依据。     

秤锤树插穗生根的解剖学观察

从解剖学角度研究了秤锤树插穗生根的机制.结果表明:插穗扦插前在木质部、韧皮部、形成层以及皮层等部位都不存在潜伏根原基,根据生根类型的划分,秤锤树不定根应属于诱生根原始体.不定根根原基可由形成层细胞、愈伤组织细胞分化而来,逐渐突破皮层,伸向外部.     

华北五角枫嫩枝扦插生根形态解剖学分析

从形态学和解剖学的角度观察华北五角枫插穗不定根的发育过程,结果表明：插穗茎内无根原基,后期在愈伤组织内发现根原基。愈伤组织起源于形成层薄壁细胞团,15d后不定根原基发育成不定根并伸出周皮之外。不定根根原基属于诱生根原基。     

五裂茶藨子扦插生根形态观察及解剖学研究

五裂茶藨子(Ribes mereri Maxim)为虎耳草科落叶灌木,具有较高的经济价值和良好的观赏价值,值得在林业产业、园林中推广应用。本文以五裂茶藨子硬枝为材料,进行了生根解剖方面的研究与探讨,结果表明:五裂茶藨子为诱发根原基,根原基起源于髓射线和维管形成层交界处,解剖中愈伤组织没有发现根原始体,且在扦插过程中观察到皮部生根,五裂茶藨子属于皮部生根类型。     

金花茶扦插生根类型比较及不定根形成的解剖观察

为研究金花茶(Camellia chrysantha)在扦插过程中插穗的生根类型、诱导方式、部位以及不定根的发生和发育过程,以当年生金花茶充分木质化枝条为试材,开展不同生长调节剂和插穗类型的扦插生根类型比较,并通过石蜡切片法,对插穗生根部位进行解剖学观察。结果表明,清水处理的插穗(CK)只有愈伤生根出现,生长调节剂处理的插穗均有愈伤生根和皮部生根出现,其中生长调节剂Q2 (IBA 500 mg/L+NAA 200 mg/L)处理的插穗生根率最高(96.89%);单叶单芽插穗生根效果显著好于两叶两芽插穗。扦插前的金花茶插穗内无潜伏根原基存在,不定根由扦插后形成的诱生根原基发育而成,其中皮部产生的不定根起源于木质部和韧皮部之间维管形成层的薄壁细胞,愈伤产生的不定根是由愈伤组织自己形成的木质部外侧一些近圆形的薄壁细胞团特化而成。金花茶属诱导生根型树种。     

四倍体刺槐嫩枝插穗生根的解剖学观察

通过对四倍体刺槐嫩枝插穗扦插前和扦插后的切片观察,结果表明:(1)在插穗的切口处有愈伤组织,在愈伤组织内未发现产生根原基;(2)四倍体刺槐嫩枝茎内无潜伏根原基,不定根由诱生根原基发育形成,诱生根原基源于髓射线细胞的分裂和分化。     

树木插条生根解剖学研究

本文对银杏等18种树木插条生根解剖学进行了研究,基本上搞清了根原基的起始部位和分化发育过程。最初都是起源于薄壁组织,接着分化出根原基发端细胞,再发生于根原基的发端,最后是根原基的发育和根的形成。     

桉树扦插生根的解剖学研究

对扦插易生根的赤桉15272（E．camaldulensis）和较难生根的直杆桉（E．maidenii）的插条进行解剖学研究，发现易生根桉树插条内未见潜伏根原细胞存在，根原细胞必须由插穗处理后才能诱导形成；在解剖学上，易生根的赤桉15272比直杆桉有生根部位多、生根快和生根数量多的特点．     

三种杨树扦插生根期间内源激素水平的比较研究

用高效液相色谱（ＨＰＬＣ）和气相色谱（ＧＣ）法，分析银白杨、毛白根和山杨的对照、ＮＡＡ处理和ＮＡＡ＋ＢＡ处理硬枝插穗（芽、皮）的内源ＡＢＡ、ＩＡＡ和玉米素含量在扦插生根期间的变化。试验表明，硬枝扦插生根是潜伏根原基存在与否和皮部内源激素平衡两方面的原因决定的。银白杨皮部的ＩＡＡ／ＡＢＡ比值和玉米素含量高，潜伏根原基有迅速恢复生长的条件，能自发生根成活。毛白杨的ＩＡＡ／ＡＢＡ比值和玉米素含量都低，需     

生长调节剂对欧洲鹅耳枥水培生根的影响

[目的]筛选适合欧洲鹅耳枥水培生根的植物生长调节剂处理方法,并讨论欧洲鹅耳枥水培苗与土培苗的差异,为欧洲鹅耳枥生根机制研究及进一步生理生化研究提供理论基础.[方法]以欧洲鹅耳枥硬枝枝条为试材,研究不同植物生长调节剂种类、质量浓度和处理时间对生根率、愈伤组织率、存活率、平均根数、平均根长、皮部生根枝条率、皮部平均根数、切...     

巨尾桉扦插育苗技术研究

采用不同母株年龄的穗条、不同类型的插条、不同基质配比及不同浓度生根剂进行巨尾桉扦插育苗试验。结果表明:巨尾桉插条随母株年龄增大其生根率和生长量下降;嫩枝扦插生根率高、平均根数多、生长快;用珍珠岩和红土等量均匀混合的基质扦插效果好;用质量分数为50×10-6~200×10-6浓度的IBA浸泡2 h,能较大幅度提高扦插成活率。     

Distinct effects of auxin and light on adventitious root development in Eucalyptus saligna and Eucalyptus globulus

Adventitious rooting is essential for vegetative propagation of woody species. We studied the effects of auxin and light on the development of adventitious roots in cuttings obtained from seedlings of Eucalyptus saligna Smith and E. globulus Labill in an attempt to characterize the adventitious rooting process and identify factors controlling rhizogenesis. Root development was scored as rooting percentage, root density (roots per rooted cutting), mean rooting time and root length. In both species, rooting time was reduced in the presence of auxin. Cuttings from 2-month-old E. saligna seedlings were responsive to lower auxin concentrations than comparable cuttings from E. globulus seedlings. Cuttings from 3-month-old E. saligna seedlings rooted promptly and rooting was not significantly affected by light conditions. In contrast, rooting of cuttings from 3-month-old E. globulus seedlings exhibited recalcitrant behavior and no roots were formed if illuminated during the root formation phase. Effective root regeneration of E. globulus cuttings was obtained by a 4-day exposure to 10 mg l(-1) IBA and culture in darkness during the root formation step. Loss of rooting capacity with seedling age was more pronounced in E. globulus than in E. saligna. The possibility of switching adventitious rooting off and on by manipulating light regime and exogenous auxin supply in E. globulus, and the constitutive nature of rooting in E. saligna may provide useful models for examining the rooting process at the biochemical and molecular levels in Eucalyptus.     

桉树扦插生根过程中抑制物的研究

对按树体内酚类、单宁类、水溶物和总酸度的初步研究,提出酚类和单宁类物质是抑制接树扦插生根成活的主要物质。把易生根的赤拉15022（E.camaldulensis）和难生根的直干桉（E．maidenii）在同一环境下扦插,在打插期间,对插穗的上述物质进行动态测定．并调查其困地的生根率,通过数理统计分析得出了以上结论。这对于解决按树生很难的问题,明确了一个新的思路。     

吲哚乙酸处理桉树插条后氧化酶活性及同工酶变化与生根关系的比较研究

尾叶桉MLA无性系（简称MLA）为难生根植物，尾叶桉U6无性系（简称U6）和刚果12号桉W5无性系（简称W5）为易生根植物。MLA的插条内的POD、IAAO活性较U6、W5的高、而PPO活性比U6、W5的低，用IAA处理桉树的插条后，在扦插生根的不同阶段，插条内的POD、PPO、IAAO活性呈现规律性的变化，蛋白质含量呈上升趋势。POD、PPO同工酶谱带也随生根的进程出现增多现象。本文讲座了3种氧化酶与桉树插条生根的关系。     

Effects of IBA on the rooting of branch cuttings of Chinese jujube (<Emphasis Type="Italic">Zizyphus jujuba</Emphasis> Mill.) and changes to nutrients and endogenous hormones

‘Zhongqiusucui’ jujube secondary shoots were treated with 3-indolebutyric acid (IBA) at three concentrations, 500, 1000 and 1500 mg/L. Results show that IBA could significantly enhance rooting and root characteristics of cuttings and were best with IBA at 1500 mg/L. In the rooting process, the formation of adventitious roots was related to the consumption and accumulation of nutrients (soluble sugars and proteins) and the changes in endogenous hormones in phloem, leaf tips and leaf bases. The rooting of cuttings had a positive correlation with the consumption of soluble sugars during the period of callus formation and with the accumulation of soluble sugars during adventitious root formation and growth. Rooting was positively related to the breakdown of soluble proteins in the phloem when the callus formed, and had a positive correlation with its accumulation during adventitious root formation and growth. Leaf tips and leaf bases showed a reverse trend in changes of soluble protein. However, together with the phloem, leaf tips and leaf bases regulated and controlled the formation and development of adventitious roots. The main activities of soluble proteins exist in the leaf tips as this was the main source of soluble proteins. The relation between rooting and IAA (indole-3-acetic acid) content in phloem was positive and thus a high concentration of IAA could benefit the induction and formation of adventitious roots. However, rooting was negatively related with ABA (abscisic acid) and GA (gibberellic acid) and a high concentration of both could inhibit the induction and formation of adventitious roots. Rooting had a positive correlation with phloem IAA/ABA ratios, and higher ratios could improve rooting. Low concentrations of ZR (zeatin riboside) triggered the induction of adventitious roots, while higher concentrations promoted root growth. Endogenous hormones in leaf tips and bases had an impact on rooting. The activities of endogenous hormones mainly existed in leaf tips because they play a major role in the production and consumption of IAA and its ABA content increased during rooting. The ZR in leaf tips influenced the rooting of cuttings, especially in the callus formation and rooting stage. Leaf tips were the main source of GA.     

Low temperature, IBA concentrations and optimal time for adventitious rooting of Eucalyptus benthamii mini-cuttings

Eucalyptus benthamii is a forest species of economic interest that has difficulty with seed production and also is considered to have difficulty with adventitious rooting using propagation techniques,such as cutting or mini-cutting.We aimed to assess the adventitious rooting percentage under different storage times in low temperatures and at various IBA(indole-3-butyric acid) concentrations to determine the optimal time of permanence for rooting Eucalyptus benthamii minicuttings in a greenhouse.Shoots collected from mini-stumps cultivated in a semi-hydroponic system were used to obtain the mini-cuttings.For the first experiment,the mini-cuttings were stored at 4℃ for 0(immediate planting),24,48,72,96 and 120 h.The second experiment evaluated the rooting dynamic to determine the optimal time of permanence for minicuttings in a greenhouse.The basal region of the mini-cutting was treated with various IBA solutions:0(free of IBA),1,000,2,000,3,000 and 4,000 mg·L-1.Every seven days(0(immediate planting),7,14,21 and 28 days),destructive sampling of the mini-cuttings was performed to evaluate the histology of the adventitious rooting.Eucalyptus benthamii minicuttings should be rooted immediately after the collection of the shoots.The 2,000 mg·L-1 IBA concentration induced a greater speed and percentage of adventitious rooting,and an interval of 35 to 42 days was indicated for permanence of the mini-cuttings in the greenhouse.Exposure to low temperature induced adventitious root formation with diffuse vascular connections.