峨眉山鹅掌楸组培过程中几种酶活性的变化

探讨了峨眉山野生鹅掌楸茎尖组织培养再生过程中过氧化氢酶（CAT）、吲哚乙酸（IAA）氧化酶、多酚氧化酶（PPO）活性的变化,以了解鹅掌楸组培再生过程中保护酶系统的变化与组培苗生长分化的机制。研究结果表明,鹅掌楸组培再生过程中,过氧化氢酶活性与H2O2含量变化呈负相关,CAT活性较高时,H2O2含量则较低。H2O2含量与鹅掌楸组培苗分化进程密切相关,H2O2可能作为信号因子在芽分化过程中发挥重要作用;IAA氧化酶活性呈现先下降后增加的变化规律,从而影响IAA氧化降解途径,调控细胞分裂素与生长素含量的比值,影响鹅掌楸芽的再生;PPO活性随培养时间的增加而升高,引起组培苗的褐变或玻璃化,甚至生长畸形。     

红颜草莓茎尖组织培养的器官发生途径研究

为探究红颜草莓茎尖组培苗器官再生途径,以其茎尖为外植体进行组织培养,观察其器官再生过程中的形态学和解剖学变化特点。结果表明:红颜草莓茎尖离体再生的芽原基起源于茎尖形态学上端表皮层的薄壁细胞,属外起源;表皮层的薄壁细胞先分化形成芽原基,随后芽原基周围的皮层薄壁细胞再分化出叶原基;芽原基和叶原基共同发育形成不定芽;不定芽再生途径为器官型。不定芽基部组织受激素诱导于形成层分化出根原基,同时不定芽基部表皮层细胞也可分化出根原基。故不定根外起源方式既有内起源也有外起源,但不定根都属于诱生根原基。不定芽和不定根中的输导组织将整个组培苗连接成一个整体,形成完整植株。     

同功酶技术在鹅掌楸属树种分类中的应用研究

笔者运用同工酶电泳技术和形态学对鹅掌楸属树种的分类进行了探讨,结果表明：各种间不仅在形态上存在很大差异,而且同工酶酶谱也存在很大差异,鹅掌楸在Pgm的基因位点有1条特有的谱带（等位基因d）,杂种鹅掌楸2条谱带（等位基因a、d）都不存在;鹅掌楸在Shdh的基因位点有1条特有的谱带（等位基因a）,北美鹅掌楸和杂种鹅掌楸都不存在这条谱带。根据这个试验结果可以鉴定鹅掌楸、杂种鹅掌楸、北美鹅掌楸。     

鹅掌楸育苗技术研究初报

通过对鹅掌楸不同种源、不同育苗密度、不同育苗方式、不同播种时间及芽苗培育措施的试验,总结出鹅掌楸育苗的最佳方式和关键技术措施。     

鹅掌楸属

鹅掌楸仅有两个种,一种是美国东部的鹅掌楸,另一种是中国大陆中部的鹅掌楸。美国鹅掌楸的树皮黑灰色,味苦,老树皮变厚,并有深沟。冬芽长椭圆形,微扁平,深红色,被两片托叶包围,落叶后     

鹅掌楸两段育苗技术

鹅掌楸是优良的造林树种,采用芽苗移栽培育鹅掌楸苗木,具有根系发达、地径增大、苗木粗壮均匀、分化小、节约育苗成本、造林成活率高等特点.总结多年的鹅掌楸育苗实践,把其两段育苗的关键技术进行介绍,供生产实践中参考.     

中国鹅掌楸生殖生物学研究取得进展

由南京林业大学林学系樊汝汶副教授主持的校科研基金“中国鹅掌楸生殖生物学研究”课题于今年元月通过了由林业部科技司组织的专家通讯鉴定。评审专家们一致认为该课题从林业生产实际出发,选题正确,研究目的明确,并且运用基础学科——植物形态学、胚胎学、生殖生物学进行研究揭示了我国稀有种中国鹅掌楸瘪籽的原因,有利于该树种的保存和繁衍。在学术上,首次揭示了中国鹅掌楸有性生殖的全过程,提出了可授期的形态指标,丰     

鹅掌楸属种间F1杂种与亲本的叶下表皮微形态研究

鹅掌楸属种间正、反交Ｆ１杂种及双亲的扫描电镜（ＳＭＥ）观察表明：马褂木和反交Ｆ１的下表皮细胞具明显乳突,北美鹅掌楸和正交Ｆ１则呈现平坦状;北美鹅掌楸和正交Ｆ１下表皮气孔密度显著高于马褂木与反交Ｆ１;杂种与双亲的下表皮蜡质纹饰和气孔器形态没有表现出明显差异;正、反交Ｆ１的气孔开口明显大于双亲。     

鹅掌楸生理生态研究现状综述

木兰科鹅掌楸属,目前仅存2个物种,即中国鹅掌楸（Liriodendron chinense）和北美鹅掌楸（L.tulipifera）。中国鹅掌楸是国家Ⅱ级珍稀濒危保护植物,国内许多学者对其进行了研究。但对鹅掌楸生理生态研究的较少,本文将从鹅掌楸生殖生理生态、生长生理生态、光合生理生态、逆境生理生态、林分生理生态等5个方面介绍鹅掌楸生理生态研究的概况。同时,在已有研究的基础上,探讨未来研究的重点,促进中国鹅掌楸生理生态研究进展。     

黄金梨叶片再生过程扫描电镜观察

为了从形态学水平上研究黄金梨的再生过程,以其叶片为试材,用扫描电镜观察其再生过程,试验结果如下:无论是不定芽再生还是不定根的产生,都是先产生愈伤组织,后形成芽或根的类分生组织、分生组织,最后形成不定芽或不定根,类分生组织数量远远多于分生组织,分生组织数量多于成型的不定芽和不定根。     

核桃雌花分化的内源激素模式

在雌花芽分化阶段,应用气液色谱-电子捕获或氢焰离子技术,对3年生早、晚实类型核桃实生幼树分别检测了雌花芽和营养芽中内源细胞分裂素、赤霉素、生长素和脱落酸的水平。依次用它们的相对量来表示,两种芽中激素水平的变化可以简单描述如下: 雌花芽:(+,-,-,-); 营养芽:(-,+,+,+)。这个模式揭示:(1)雌花芽分化是四种激素作用于芽分生组织的某一特定平衡的结果;(2)细胞分裂素与赤霉素的比值与这些组织形成雌花原基的理论和实际能力有正相关的关系,雌花芽的比值为“+/-”或3.0,营养芽为“-/+”或1.2。对内源激素模式的实际意义,以及核桃童性的本质问题等也进行了讨论。     

Effect of GA(4 + 7) on the initiation and development of the inflorescence bud of evergreen azalea

Apical buds of evergreen azalea (Rhododendron sp.) were treated with GA(4 + 7) at different stages of development. Treatment of vegetative buds stimulated shoot growth, slightly delayed both flower initiation and development, but increased the number of flower primordia. Treatment at the time of floral transition induced bud abortion at an early stage of the reproductive development. Treatment of inflorescence buds which contained at least one complete flower substituted for chilling in overcoming dormancy and prevented inflorescence bud abortion.     

Time and method of floral initiation and effect of paclobutrazol on flower and fruit development in Shorea stenoptera (Dipterocarpaceae)

Small Shorea stenoptera Burck. (Dipterocarpaceae) trees of reproductive age growing in an arboretum in west Java were studied to determine the pattern of vegetative shoot development, the time and method of floral initiation and the effect of paclobutrazol on floral enhancement. Vegetative buds were enclosed by two stipules between which was a leaf primordium, a small axillary vegetative bud and another pair of stipules. This sequence was reiterated five to seven times before the vegetative apex was visible. At the time of floral initiation, axillary buds developed into floral spikes and compound inflorescences formed at the end of drooping branches. A compound inflorescence might bear many floral spikes and each floral spike bore many flowers. The compound inflorescence was a modification of the reiterative developmental pattern observed in vegetative shoots. The time of floral initiation began in late June or early July and continued until about November. Floral enhancement using paclobutrazol as a soil drench was attempted in mid-July, but this was later found to be after the onset of floral initiation, and the treatment failed to enhance flowering; however, it appeared to enhance the rate of floral and fruit development. The similarity in vegetative bud development among dipterocarp genera suggests that the time of floral initiation may be easily determined in many species based on simple dissection techniques.     

拟南芥晚花突变体的筛选

在植物的生命周期中从营养生长到开花是发育过程的重要转折。花启动的时机对生殖生长的成功至关重要。植物开花时间突变体的获得,在揭示植物花发育的奥秘中起了十分重要的作用。本研究以模式植物拟南芥(A rabid op sis tha liana)为材料,将野生型拟南芥(Co lum b ia生态型)的种子用甲基黄酸乙酯(EM S)诱变处理,将经诱变处理的种子M1播种收获M2种子用于突变体筛选。以初生莲座叶片数作为筛选指标,筛选出一株晚花突变体,命名flx(flow ering locus x)。     

Assumption of Phyto-Hormone Regulation and Gene Activation of Phyllostachys praecox Flowering

By determination of the change of endogenous hormone Zr, iPA, GA3, IAA and ABA during different flower bud differentiation stages of Phyllostachys praecox, which is identified through both field observation and lab analysis, and with the reference to the previous research achievements on bamboo flowering, the flowering mechanism assumption of Phyto-Hormone Regulation and Gene Activation of Ph. praecox is induced in this article： Bamboo flower bud differentiation can be divided into 3 stages, i.e. flower bud induction, flower bud initiation and flower bud development; Bamboo leaves sense and receive flowering signals from environments to change its hormone level, esp. ratios of iPA/ABA and iPA/GA3; Flowering gene is activated once the ratios of iPA/ABA and iPA/GA3 reach a proper threshold, and it produces DNA and RNA carrying flowering code and transports them to top or side buds nearby, and then protein necessary for flower bud differentiation comes out, as a result of which the flower bud induction is trigged and started, followed by flower bud initiation and development. In the induction stage, ratio of C/N is nearly constant, but increases in the initiation stage. Therefore it clarifies that the rising of C/N ratio does not bring about bamboo flowering initially, and it is a follow-up reactions of process initiation of bamboo flowering. It proves that bamboo rhizome is directly involved in the flower bud differentiation. This assumption can well explain mysterious phenomena of bamboo flowering, and by integrating the current several assumptions, answer the difficult and perplexing questions regarding bamboo flowering which have not been answered by the present assumptions.     

山鸡椒雌花花芽分化形态特征及碳氮营养变化

目的]了解和掌握山鸡椒雌花花芽分化的形态特征及碳氮营养规律,为山鸡椒人工栽培及杂交育种提供参考依据。[方法]采用石蜡切片法观察山鸡椒雌花花芽分化的组织解剖结构,采用生理试剂盒-分光光度法测定雌花不同分化时期的可溶性糖、淀粉、可溶性蛋白、碳氮比等碳氮营养指标。[结果]表明:(1)山鸡椒雌花花芽分化经过未分化期—花序原基分化期—苞片原基分化期—花原基分化期—花器官分化期5个时期。(2)叶片可溶性糖含量随着花芽分化的发展呈不断升高的趋势,最高可达65.07 mg·g~(-1)。叶片淀粉含量随着分化时期的推进呈先升后降的趋势,其最高值出现在苞片原基分化期,达到81.30 mg·g~(-1),最低值出现在花器官分化期,为52.19 mg·g~(-1)。(3)叶片可溶性蛋白含量在花芽前3个分化期呈持续下降趋势,从61.32 mg·g~(-1)下降到52.48 mg·g~(-1),之后基本保持稳定。叶片中的碳氮比在花芽前3个分化期呈持续上升趋势,从1.49上升至2.61,之后基本维持在较高水平。[结论]山鸡椒雌花花芽分化的内部形态特征与雄花基本一致,雌花花芽分化分为5个时期。山鸡椒雌花花芽分化过程中,叶片中可溶性糖不断升高,而可溶性蛋白下降明显,碳氮比升高且保持在较高水平。     

Influence of temperature on the dynamics of ATP,ADP and non-adenylic triphosphate nucleotides in vegetative and floral peach buds during dormancy

The nucleotides test of endodormancy, which is based on the capacity of tissues to synthesize ATP and non-adenylic triphosphate nucleotides (NTP), cannot be used for floral buds, and it is of questionable use for vegetative buds. In an attempt to find an alternative test, we examined whether the dormancy state of vegetative and floral buds of trees exposed to different temperature conditions during the rest period is directly related to their ATP, ADP and NTP concentrations and ATP/ADP ratio. Once the buds had entered endo- or paradormancy, the nucleotide concentrations and the ATP/ADP ratio were low in the vegetative primordia and very low in the floral primordia. Only after the action of chilling, when the buds were considered to have completed the endodormancy and paradormancy phases, did the nucleotide concentrations increase, accompanied by a steep rise in ATP/ADP ratio. We conclude that the ATP/ADP ratio could be used to characterize the bud dormancy state by comparison with critical values of 1.5 for vegetative primordia and 1.0 for floral primordia.     

Effects of exogenous gibberellin and auxin on shoot elongation and vegetative bud development in seedlings of Pinus sylvestris and Picea glauca

The hormonal control of stem unit (foliar appendage and axillary structure, if present, plus subtending internode) number and length was investigated in shoots of Scots pine (Pinus sylvestris L.) and white spruce (Picea glauca (Moench) Voss). Seedlings were treated with six gibberellins (GA1, GA3, GA4, GA5, GA9 and GA20) and two auxins (indole-3-acetic acid (IAA) and naphthaleneacetic acid (NAA)) when either neoformed growth was occurring or the terminal vegetative bud was developing. Hormones were applied by drenching the shoot tip, injecting the stem or spraying the foliage. Combined results for all three application methods indicated that shoot elongation in first-year seedlings (i.e., neoformed growth) was promoted in both species by GA1, GA3, GA4 and, less obviously, by GA9. This promotion was attributable to an increase in length, rather than number, of stem units. However, the number of stem units formed during terminal bud development, as reflected in the number of needles (white spruce) or cataphylls (Scots pine) present on the shoot resulting from the terminal bud, was stimulated by GA1, GA3 and GA4 in both species and by GA9 in Scots pine. The GA-induced increase in the number of preformed stem units was associated with increased bud width in white spruce and increased bud length and resulting shoot length in Scots pine. In contrast, application of IAA or NAA either did not affect or inhibited both neoformed growth and terminal bud stem unit number, depending on the application method and concentration. We conclude that, in the Pinaceae, (1) GA stimulates the activity of both the subapical meristem during neoformed growth and the apical meristem during vegetative bud development, and (2) the early non-hydroxylation pathway, via GA9, is the major route of GA biosynthesis. The role of auxin in the control of stem unit number and length remains to be resolved.     

Overhead irrigation increased winter chilling and floral bud production in Eucalyptus nitens

Eucalyptus nitens requires a sufficiently cold winter to produce flower buds. In areas in South Africa where E. nitens commercial plantations as well as breeding and production seed orchards are located, winter chilling is often insufficient for floral bud initiation. Hence, under such conditions, E. nitens floral bud and seed crops are poor and inconsistent. The local industry is almost entirely dependent on paclobutrazol (PBZ) applications for encouraging flowering in E. nitens seed orchards. Between 2008 and 2010, an experiment was conducted to investigate the potential of overhead irrigation (sprinkling) as a means of supplementing winter chilling to improve floral bud production in E. nitens. The treatments included three levels of sprinkling (nil, 10 weeks and 16 weeks duration), two levels of PBZ (nil, 0.025 g a.i. per mm basal stem circumference) and two grafted clones (prolific flowerer and shy-flowerer). Sprinkling reduced E. nitens daytime bud temperatures by as much as 16.2 °C on warm, dry winter days. In 2009 (cold winter) and 2010 (warm winter), sprinkling increased chilling accumulation by 44% and 72% (nil versus maximum sprinkling), respectively. In 2009, in the absence of PBZ, sprinkling resulted in a higher percentage of trees of either clone producing umbels (flower buds) compared with the control. In the warmer 2010 winter, sprinkling again increased flowering, with the number of flowering shoots and umbels per tree being significantly higher than the control at p < 0.05. In both 2009 and 2010, PBZ showed a strong additive effect to winter chilling on E. nitens floral bud production. The E. nitens clone × chilling × PBZ flowering interaction was complex and warrants more detailed investigation in future. Overhead sprinkling offers a practical method of supplementing winter chilling and improving floral bud production in high-chill-requiring temperate eucalypt species such as E. nitens.     

Pollen development and floral morphology of Populus pseudo-simonii

Pollen development and floral morphology of Populus pseudo-simonii were investigated by stain-squashing and anatomical techniques. It took approximately 16 days for the pollen to develop from pollen mother cells to mature pollen in the greenhouse. Meiosis of pollen mother cells was regularly applied and completed by a process of simultaneous cytokinesis. Pollen development was considerably asynchronous. The meiotic division was initiated at the bulgy middle position of the flower bud and proceeded towards the tip and base of the bud. The number and size of the nucleoli varied during pollen development and at most eight nucleoli formed in each daughter nucleus at the meiotic telophase, suggesting a paleopolyploid origin of the genus Populus. An association between floral morphology and pollen development was found and the ratio of width to length of flower buds or catkins presented an S-shaped curve related to pollen development as a function of time. The investigation on the pollen development and floral morphology of P. pseudo-simonii is important for further cross breeding programs of the section Tacamahaca.