二球悬铃木冬芽休眠的温度特性

为了探讨树木冬芽休眠与分布的相互关系以及悬铃木冬芽休眠机理,研究了悬铃木冬芽休眠的温度特性.结果表明：（1）悬铃木冬芽具有浅冬休眠特性,在25℃条件下即使深休眠期的冬芽也能够部分萌发,萌芽率达到40﹪～60﹪,但在15～20℃低温下不能萌发,而随着经历低温量的增加,休眠逐渐得到解除,在春季的10～15℃低温下也能萌发;（2）悬铃木冬芽的休眠解除的低温范围较大,5℃与12℃具有同样的低温效果,15℃也有较大的低温效果,甚至20℃也有低温效果,不同于温带树种,但与横跨亚热带与暖温带分布的山桐子相似;（3）9～10月份为悬铃木的休眠导入期,10月下旬进入深休眠期,同时进入休眠解除期,经过冬季低温信号的诱导,休眠得以解除,保证春季冬芽的正常萌发;（4）悬铃木冬芽能否萌发取决于芽鳞的阻碍作用力与生长点、叶原基或花原基萌发力的平衡状态,当阻碍力大于萌发力表现为冬芽不能萌发,当阻碍力小于萌发力表现为冬芽的萌发;（5）芽鳞除了具有阻碍作用和抵御冬季寒冷干燥气候外,还具有利用冬季低温解除其休眠的作用,在解除其休眠的过程中既提高了生长点、叶原基或花原基的萌发力,也降低了芽鳞的阻碍力;（6）悬铃木冬芽内的主芽和副芽休眠特性不同,在主芽萌芽能力弱时,副芽的萌芽能力增强,反之,主芽萌芽力强时,副芽的萌发就会受到抑制,当主芽能够经过冬季低温解除休眠能够萌发时,冬芽内的副芽重新进入休眠状态,可能是系统维持的一种生态适应;（7）二球悬铃木能横跨亚热带与暖温带广泛栽培正是由悬铃木冬芽休眠的生理生态特性决定的.     

单氰胺对葡萄休眠过程中冬芽水分和碳水化合物的影响

以酿酒葡萄品种'赤霞珠'和'霞多丽'为材料,对其冬芽休眠进程和休眠过程中冬芽水分和碳水化合物含量的变化进行分析.结果表明,(1)在陕西杨陵地区气候条件下,'霞多丽'、'赤霞珠'分别在12月20日和1月9日达到深度休眠,随后开始休眠解除阶段.(2)在芽休眠过程中,两个品种冬芽的总水分含量、自由水含量和淀粉含量均随休眠的加深而降低,随休眠的解除而增加,而冬芽的束缚水含量、束缚水/自由水比值、可溶性糖含量均在休眠加深阶段持续上升,在休眠解除阶段逐渐降低.(3)单氰胺处理后,两品种冬芽中自由水含量显著增加,束缚水的比例同时显著降低,且'赤霞珠'的变化幅度大于'霞多丽',但其总水分、可溶性糖和淀粉等含量在休眠过程中无显著变化.(4)葡萄冬芽中的水分含量及存在状态、可溶性糖含量和淀粉含量的变化与其休眠进程密切相关;单氰胺处理能够增加冬芽自由水含量,降低其束缚水含量,从而有效打破葡萄休眠.     

葡萄休眠解除过程中冬芽组织活性氧与抗氧化系统的变化特征

以酿酒葡萄‘赤霞珠’(红)和‘霞多丽’(白)为试材,通过考察其自然休眠过程和打破休眠(单氰胺处理)过程中冬芽组织活性氧及抗氧化系统的变化,探讨葡萄休眠机制。结果表明:(1)在陕西杨陵地区,早熟品种‘霞多丽’在12月20日左右进入深度休眠,第2年1月29日进入休眠解除阶段;晚熟品种‘赤霞珠’在1月9日左右达到深度休眠,2月18日左右进入休眠解除阶段;单氰胺处理可促进葡萄休眠的解除。(2)葡萄休眠过程中,活性氧O2.-和H2O2含量在休眠初期逐渐增加,深度休眠时含量最高,休眠解除过程中含量降低,从而促进休眠的解除;超氧化物歧化酶(SOD)活性在休眠中一直降低,休眠解除后活性上升;过氧化物酶(POD)活性在休眠前期较低,随后活性上升,休眠解除过程中活性又降低;过氧化氢酶(CAT)活性在休眠过程中持续上升,随后维持在较高水平;抗坏血酸-还原态的谷胱甘肽(ASA-GSH)循环在休眠前期较弱,休眠解除过程中逐渐增强。研究发现,葡萄进入休眠后,其冬芽抗氧化能力逐渐降低,至深度休眠时抗氧化能力降至最低,随着低温积累需冷量得到满足,活化了抗氧化系统进而抗氧化能力迅速提高,休眠被解除。     

培养因子对朱蕉试管苗繁殖的影响(简报)

以红边朱蕉试管苗为材料,研究不同光强(1000、2000、3000、5000lx)、不同温度(21、26、31°C)、不同光周期(光照9、14、19、24h/d)对朱蕉芽增殖及生根的影响。结果表明:3000lx,26°C,光照14h/d有利于芽的增殖:而适当增加光强、提高温度、延长光照时间,能促进根的生长。     

鄱阳湖自然保护区蚌湖和中湖池苦草冬芽的调查

1998年 1 2月对鄱阳湖自然保护区内蚌湖和中湖池苦草冬芽进行调查。苦草生活冬芽的平均长度为 3 .0 5± 0 .5 6 cm,平均直径为 0 .84± 0 .1 4cm,平均鲜重为 1 .0 3± 0 .3 0 g,平均干重为 0 .3 0± 0 .1 0 g,含水量为 70 .6 2 %。生活冬芽在蚌湖和中湖池的平均密度分别为 1 5 .8个 /m2和 2 4 .3个 /m2 。苦草冬芽在蚌湖的分布比较均匀 ,在中湖池各采样点的分布有显著差异 ,这种差异与不同采样点的基质状况有关。苦草生活冬芽在基质中分布最大深度为 3 5 cm,在0— 1 0 cm土层中所占比例最大 ;冬芽死亡数以 2 0— 3 0 cm土层中所占比例最大。冬芽分布深度对其以后的萌发有重要影响。     

盾叶薯蓣试管株芽的诱导

以盾叶薯蓣(Dioscoreazingiberensis)试管植株为材料,选取带芽茎段为外植体,转接到株芽诱导培养基上15d后,原茎段基部开始产生株芽突起,30d后每一茎段可产生3-5个已生根的株芽,株芽诱导率为100%,株芽诱导数为180个/40株,其移栽成活率可达90%以上。株芽形成的适宜培养条件:温度为26±2℃,光照时间14hd-1,光照强度为1500-2000lx;适宜培养基组成为:MS+6-BA4.0mgL-1+IBA1.0mgL-1+蔗糖6%-9%+活性炭0.5%+琼脂7%。离体诱导的盾叶薯蓣试管株芽能直接发育为新植株,为盾叶薯蓣的快繁提供了一种新的方法。     

紫斑牡丹休眠地下芽在组织培养条件下的发育研究

以紫斑牡丹（Paeonia rockii T.Hong et Li J.J.)休眠地下芽为材料,对同一时期打破休眠的地下芽在3种不同培养基上的发育状况、不同时间低温处理后在同一培养基上的发育,以及不同时期休眠地下芽在同一培养条件下的发育进行了比较研究。结果表明：MS＋BA 1mg/L NAA 0.5mg/L 2,4-d 0.5mg/L最有利于打破休眠的地下芽发育;不同低温处理对休眠地下芽的萌发率及发育速率作用明显不同,其中,720h的低温处理效果最佳;彻底打破休眠的不同时期地下芽在同一培养条件下发育速率基本一致。     

葡萄休眠的自然诱导因子及其对休眠诱导期冬芽呼吸代谢的调控

以高需冷量葡萄品种‘夏黑’为试材,研究短日照、长日照和自然光照3个条件下,葡萄冬芽休眠的自然诱导因子及其对休眠诱导期冬芽呼吸代谢的调控机制.结果表明: 自然低温、短日照2个环境因素单独或共同作用均能诱导葡萄冬芽进行自然休眠.短日照在诱导葡萄冬芽进入自然休眠的过程中起主导作用,自然低温起辅助作用;温度相同条件下,日照时间越短对葡萄冬芽自然休眠的诱导作用越强.总呼吸速率达到峰值是葡萄冬芽休眠诱导期结束的标志.在自然休眠诱导期间,葡萄冬芽磷酸戊糖途径运行活性和容量占总呼吸的比例迅速上升,其中自然条件的葡萄冬芽分别由16.0%和20.1%上升至22.3%和26.0%.自然低温是诱导葡萄冬芽底物氧化水平上呼吸途径发生变化的主导因素,短日照起促进作用.在葡萄冬芽自然休眠诱导期间,交替途径运行活性和容量占总呼吸的比例迅速上升,其中自然条件葡萄冬芽分别由19.4%和27.3%上升至38.2%和46.8%.自然低温和短日照均可诱导葡萄冬芽电子传递链水平上呼吸途径发生变化.     

南高丛蓝莓‘奥尼尔''工厂化组培快繁技术研究

为了建立南高丛蓝莓‘奥尼尔’工厂化组培快繁技术体系,该文以带腋芽的茎段为外植体,研究外植体灭菌、丛生芽诱导、丛生芽增殖培养、瓶内生根以及移栽驯化。结果表明：（1）外植体最佳灭菌方法为10%NaClO处理15 min,污染率降低至14.44%,诱导率达49.38%;同样添加1.5 mg·L^-1ZT,以WPM为基础培养基诱导出的丛生芽明显多于MS。（2）丛生芽增殖的最佳培养基为WPM+NAA 0.1 mg·L^-1 +ZT 1.5 mg·L^-1 ,接种60 d后增殖系数达8.6,长势良好;瓶内生根的最佳处理方式为先用500 mg·L^-1 IBA浸蘸20 s,然后接种于WPM+IBA 0.2 mg·L^-1的生根培养基中,培养90 d后,生根率、有效生根率、生根数量和根长分别达到96.3%、96.3%、12.7条和43.3 mm,且根系较发达、粗壮。（3）生根苗在移栽基质Ⅰ（河沙∶蛭石∶珍珠岩=1∶1∶1）的移栽成活率最高,达92.22%。以上说明,外植体经10%NaClO处理15 mi...     

南高丛蓝莓快繁技术体系研究简

以南高丛蓝莓试管无菌丛生芽为材料,对南高丛蓝莓丛生芽的诱导与增殖、继代次数对丛生芽诱导增殖的影响、瓶内生根、瓶外生根、不同生根方式试管苗移栽成活率的大小进行了研究。南高丛蓝莓丛生芽诱导与增殖培养基以WPM+ZT 2.0 mg·L^-1较佳,增殖倍数可达3.50;继代6次丛生芽增殖倍数可达24.00;瓶内生根生根培养基以WPM+ZT 0.5 mg·L^-1+IBA 0.1 mg·L^-1为佳,生根率可达80.73%±3.17%,生根周期为100 d;试管芽用25 mg·L^-1 IBA溶液浸蘸10 s,以1/6 WPM为营养液加珍珠岩作基质,生根率可达到80.00%±5.00%,生根周期为40 d;瓶外生根试管苗移栽成活率是瓶内生根试管苗的2倍。基本建立了南高丛蓝莓的试管快繁技术体系,为南高丛蓝莓的工业化育苗奠定了技术基础。     

Development of shoot inHydrangea macrophylla I. Terminal and axillary buds

The structure of shoots, in particular of winter buds, ofHydrangea macrophylla was examined. The non-flower-bearing shoot is usually composed of a lower and an upper part, between which a boundary is discernible by means of a distinctly short internode. This internode is the lowermost of the upper part, and it is usually shorter than the internodes immediately above and below, although the internodes tend to shorten successively from the proximal to the distal part of the shoot. Variations exist in the following characters among the terminal bud, the axillary bud on the lower part of the shoot and the axillary bud on the upper part: (1) length of bud; (2) character of the outermost pair of leaf primordia; (3) degree of development of secondary buds in the winter bud; and (4) the number of leaf primordia. Usually, the terminal bud contains several pairs of foliage leaf primordia with a primordial inflorescence at the terminal of the bud, but the axiallary bud contains only the primordia of foliage leaves in addition to a pair of bud scales.     

光周期对菊花花芽分化及其叶片和芽内源多胺含量的影响

以切花菊品种神马为材料,研究不同光周期(16h昼/8h夜;12h昼/12h夜;8h昼/16h夜)对菊花花芽分化过程中叶片和芽内腐胺(Put)、亚精胺(Spd)和精胺(Spm)含量的影响.结果显示:(1)16h/8h处理植株始终没有花芽分化,8h/16h处理的花芽分化开始和完成分别在处理后第13.9天和第23.1天出现,比12h/12h处理的分别提前1.7d和2.8d.(2)16h/8h处理叶片和芽中Put、Spd和Spm含量始终都没有明显变化,而8h/16h和12h/12h处理的叶片和芽中Put、Spd、Spm含量都比16h/8h处理的明显增加,而且8h/16h和12h/12h处理的叶片Put和Spd含量在处理第10天和第20天时出现2个高峰,芽中Put和Spd含量在处理第15天时出现一个高峰;另外,8h/16h处理的叶片和芽中Put、Spd含量比12h/12h处理的有所增加,但差异不显著.结果表明,菊花神马是质型短日照植物,短日照可诱导神马叶片和芽内合成多胺,而且日照时数越短,越有利于叶片和芽内Put、Spd、Spm的积累和促进花芽分化.     

拟南芥矮小丛生突变体的分离与分子鉴定

顶端优势是指侧生分生组织的生长被主茎或主花序所抑制.最近的研究通过分离和鉴定顶端优势发生改变的突变体开始揭示顶端优势的分子机制.通过T-DNA标签法分离了拟南芥矮小丛生(bushy and dwarf 1, bud1 )突变体.突变体植株的表型包括顶端优势丧失、株型矮小,表明bud1 突变体存在生长素代谢、运输或信号传导的缺陷.一个对生长素特异反应的启动子驱动的报告基因在bud1 中表达模式改变.生长素敏感性和运输能力的测定表明这两个过程在 bud1中均正常.以上结果显示bud1 表型是生长素代谢缺陷的结果.遗传分析表明BUD1 为半显性突变且与一个T-DNA插入共分离,可通过iPCR方法分离.     

The dose of 1-naphthaleneacetic acid determines flower-bud regeneration in tobacco explants at a large range of concentrations

Short-term applications of very high concentrations of 1-naphthaleneacetic acid (NAA) to expiants from flower stalks of tobacco (Nicotiana tabacum L. cv. Samsun) induced flower-bud regeneration to the same extent as longer or continuous incubation on lower concentrations. The maximum number of flower buds per explant after 15 d of culture was obtained not only by continuous culturing at 1 mol·l^–1 NAA but also by 12 h of culturing at 22 mol·l^–1 or 0.5 h at 220 mol· l^–1, followed by incubation on medium without auxin for the remaining period. Continuous application of such high concentrations resulted in callus formation or caused the death of the explanted tissue. In all experiments in which auxin concentration and time of application were independently varied, the product of concentration and time determined the number of buds formed. Most, but not all, of the NAA taken up by the tissues was converted into conjugates. In expiants which had received a dose which was optimal for regeneration, the internal concentration of free NAA remaining beyond the pulse period was between 1.7 and 6.2 mol·l^–1. Suboptimal applications led to lower values, supraoptimal treatments to much higher internal concentrations. The physiological effect, which depends on the internal hormone concentration, thus manifested itself as dose-dependent with regard to applied hormone.Abbreviations BAP N⁶-benzylaminopurine - NAA 1-naphthaleneacetic acid     

Dormancy-associated gene expression in pea axillary buds.

Pea (Pisum sativum L. cv. Alaska) axillary buds can be stimulated to cycle between dormant and growing states. Dormant buds synthesize unique proteins and are as metabolically active as growing buds. Two cDNAs, PsDRM1 and PsDRM2, were isolated from a dormant bud library. The deduced amino acid sequence of PsDRM1 (111 residues) is 75% identical to that of an auxin-repressed strawberry clone. PsDRM2 encodes a putative protein containing 129 residues, which includes 11 repeats of the sequence [G]-GGGY[H][N] (the bracketed residues may be absent). PsDRM2 is related to cold- and ABA-stimulated clones from alfalfa. Decapitating the terminal bud rapidly stimulates dormant axillary buds to begin growing. The abundance of PsDRM1 mRNA in axillary buds declines 20-fold within 6 h of decapitation; it quickly reaccumulates when buds become dormant again. The level of PsDRM2 mRNA is about three fold lower in growing buds than in dormant buds. Expression of PsDRM1 is enhanced in other non-growing organs (roots root apices; fully-elongated stems >elongating stems), and thus is an excellent “dormancy” marker. In contrast, PsDRM2 expression is not dormancy-associated in other organs. Received: 10 December 1997 / Accepted: 23 January 1998     

Modelling compensatory regrowth with bud dormancy and gradual activation of buds

Many plants show compensatory regrowth after herbivory and dormant buds often have an important role in compensatory responses. Theoretical models have shown that herbivore damage may select for a bud bank, i.e., a pool of dormant buds that are protected from herbivory and that are activated after herbivore damage. Earlier models assumed that undamaged plants cannot activate their dormant buds without damage, although they apparently have sufficient resources for successful seed production through the additional shoots dormant buds could produce. However, many plants are able to gradually activate buds over an extended period of time without any cue from damage. The aim of this study was to analyze how herbivory imposes selection for gradual mobilization of the bud bank. I assume that selection pressures that affect the fraction of buds active at each time point include damage by herbivores, time left to the end of season, and the opportunity costs of dormant buds. I modelled bud dynamics with gradual activation when there is a single damage event and (i) when the seed set of a shoot is not dependent on the time it is active, or (ii) when the seed set of a shoot diminishes with later activation. In addition, I analyzed how (iii) risk of repeated herbivory affects selection for gradual activation. Under these models, gradual activation is optimal over a wide range of herbivory pressures. Selection appears to favour activation of all buds at the beginning of the season only when herbivore pressure is weak and when early shoots have a higher seed set than late shoots. Alternatively, strong herbivore pressure and late damage may select for a large bud bank throughout the growing season, without gradual activation; the bud bank is only mobilized after damage. In this case, damaged plants can overcompensate, i.e. they have a higher seed set than undamaged plants with the same bud activation pattern. Selection for overcompensation demands a stronger herbivore pressure in this current model than in earlier bud bank models. The model never predicts selection for overcompensation when there is a risk of repeated herbivory. This revised version was published online in July 2006 with corrections to the Cover Date.     

Effects of temperature and gibberellin on the activity of endogenous cytokinin-like substances in leaves of Begonia x cheimantha

Changes in activity of endogenous cytokinin-like substances were examined in intact plants and excised leaves of Begonia x chemantha Everett cv. Prinsesse Astrid (Christimas Begonia) by means of the tobacco callus bioassay. Cytokinin activity in the leaves of intact plants was higher in plants grown at 18°C than in those grown at 21° or 24°C. In excised leaves, an increase in cytokinin activity was observed during the first 4 days following leaf detachment. However, after the seventh day cylokinin activity decreased again. This decrease was more profound in leaves exposed to 24°C than in those exposed to 18°C.
Treatment of detached leaves with gibberellic acid (2.8 m M ) caused an increase in measurable cytokinin activity. This increase was more profound in the zones of activity which correspond with zeatin glucosides on paper and Sephadex LH-20 chromatography. Additional zones of activity appeared after Sephadex chromatography. These were of a more slow moving nature with elution volumes corresponding to N^b-(Δ²-isopentenyl)adenine and its derivaties. Water-treated control leaves had higher activity in the regions corresponding to zeatin and zeatin riboside.     

Comparative morphology and development of inflorescence adnation in rattan palms

The morphology and development of inflorescences in 14 genera and 52 species of rattans and related genera of Lepidocaryoid palms were examined. Inflorescences are free (not adnate) in Ancistrophyllum, Eremospatha and Oncocalamus. Adnation between the inflorescence and internode above occurs in Korthalsia, Myrialepis, Plectocomia and Plectocomiopsis. Adnation between the inflorescence and both the internode and leaf sheath above occurs in Calamus, Calospatha, Ceratolobus and Daemonorops. This leaf-borne, but initially axillary, bud is displaced on to the base of the next younger leaf primordium by the second plastochrone. Later elongation of the internode further separates the inflorescence from its original node. Stages of initiation and early development of adnate buds are illustrated for ten species. Vegetative buds of some Calamus species develop like inflorescence buds. However, other species have unusual bud positions which cannot be interpreted at present. The degree of inflorescence adnation tends to be greater in presumably specialized species than in unspecialized ones.     

黄连木雌花芽形态分化研究

采用石蜡切片法观察了黄连木雌花芽的分化过程,以揭示黄连木雌花芽分化规律,为合理调控雌花芽分化质量和数量提供依据.结果表明:黄连木雌花芽的分化时期为当年4月中旬至10月底和翌年3月中下旬至4月上旬,历时345 d左右.具有分化时间早、分化速度快但整个花序分化持续时间长的特点.黄连木雌花芽分化包括花序分化和小花分化2个过程,可划分为未分化期、花芽分化始期、苞片分化期、花序形成期、小花原基分化期、被片分化期、雌蕊原基分化期、雌蕊分化期等8个时期.     

叶芽花芽需热量差异导致植物先花后叶

为探究植物先花后叶的影响因素,本研究以1963—1988年间北京地区杏和山桃展叶和始花物候资料及相应的日最高、最低温度数据为基础,利用偏最小二乘回归法确定杏和山桃叶芽及花芽的需冷期和需热期,进而利用动态模型和生长度小时模型分别估算叶芽和花芽的需冷和需热量。结果表明,依据长期物候观测资料,利用偏最小二乘回归法进行植物需冷和需热量的估算非常有效。先花后叶植物叶芽和花芽需冷量几乎相同,需热量的差异是导致植物先花后叶的主要原因。杏和山桃花芽的需热量分别为2829．7±876．2和1457．2±581．2生长度小时,而相应叶芽需热量却是花芽的两倍之多。基于物候观测的重要性及实用性．中国物种水平上的地面观测应得到进一步深入发展。