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本文从芽休眠的分类、影响休眠的因素、休眠的研究进展、休眠的调控等方面来综述了国内外在芽休眠研究方面的进展,并讨论了芽休眠研究中存在的问题,最后对今后的研究工作提出了一些建议。 相似文献
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《林业科学》2021,57(10)
种子休眠是由外界环境因素或者种子自身遗传特性诱导产生的,是具有生活力的种子在有利环境下仍不能萌发的现象。种子休眠与萌发是2种既相互区别又相互联系的发育状态,具有休眠特性的种子只有休眠解除才可能萌发,种子休眠在一定程度上决定其发芽所需的环境。为了对种子休眠与萌发现象有更全面的认识,本文在收集国内外林木种子休眠、休眠解除及萌发研究文献的基础上,总结了常见林木种子休眠产生的原因以及休眠类型划分系统,探讨休眠产生的机制,阐述内源激素调控种子休眠、阐述光信号调控种子休眠、Ca~(2+)调控种子休眠、基因控制种子休眠、细胞膜变论等学说;概述了种子通过层积处理、物理方法、化学方法以及激素等解除休眠的方法;种子恢复吸胀则表示已进入萌发阶段,其伴随着形态、生理生化及分子层面的复杂变化。同时讨论当前研究的薄弱之处,并提出应对种子休眠与萌发的启动转录、基因调控、遗传表达等分子调控机制展开更深入的研究,以期为林木种子休眠解除与萌发机制方面的研究提供依据,为林木种子贮存、苗木繁育、种植推广及开发利用等提供参考。 相似文献
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以4年生牡丹‘洛阳红’为试验材料,经历0～42 d低温处理观测其芽萌动成花情况,探讨上海地区牡丹花芽低温休眠解除过程中需冷量和生理生化指标的动态变化规律.结果表明:处理7d为低温累积期,处理14 d即可启动休眠解除但萌动率(52.8％)和成花率(27.8％)均较低;基本解除休眠需要21 d低温处理,萌动率可达90.3％,但成花率为51.6％;而彻底解除休眠则需要至少低温处理28 d,成花率急剧增加至71.8％.花芽中可溶性蛋白和可溶性糖的变化趋势类似:休眠完全解除前随着低温累积量的增加急速增加,彻底解除后随着需冷量的增加变化趋缓.花芽内源激素及其比值的动态变化表明,GA3和ABA的含量变化与花芽体眠解除的进程分别呈显著的正、负相关;在基本与彻底解除休眠区间内二者含量急剧变化,GA3/ABA的值可以直接显示花芽休眠的程度.进一步证明GA3是最为重要的促进休眠解除激素,而ABA则是休眠解除的主要拮抗物. 相似文献
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低温解除牡丹芽休眠进程中内源激素的变化 总被引：4，自引：0，他引：4
以4～5年生牡丹'胡红'为试材,研究1～7周不同低温处理时间对其开花展叶的影响.根据花芽萌动和开花情况结合激素的变化动态,将低温解除花芽休眠进程划分为:低温累积期、休眠解除启动期、休眠基本解除期、休眠彻底解除期4个时期.分别测定低温处理期内和进入温室后内源GA,,ABA,CTK,IAA及其比值的变化.结果表明:低温期内GA,,ABA,CTK质量分数的增减和GA,/ABA比值的变化可明显地反映低温解除花芽休眠的进程.其中,GA,/ABA比值的变化与休眠的进程直接对应.进入温室后牡丹花芽内各激素的变化进一步证明GA3和CTK是解除休眠的促进物,ABA是解除休眠的抑制物.低温解除牡丹休眠是通过调节休眠解除的促进物和抑制物之间的平衡来实现的,是多因素综合作用的结果. 相似文献
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植物抗寒性的生理生态学机制研究进展 总被引：31，自引：1，他引：31
综述植物在冷驯化过程中发生的一系列生理生化变化.环境对植物抗寒性的影响主要与光诱导、温湿度以及气候的变化有关.植物表面形成冰层会引起植物的无氧呼吸,导致植物受害;光抑制诱导活性氧的产生,从而导致植物光合系统的退化,抗寒能力下降,而短日照诱导植物休眠,有利于植物抗寒.光敏色素则被认为是启动冷驯化的光受体;植物通过冷驯化增加碳水化合物的积累及病原体相关蛋白的合成,以增强对低温病原体的抵抗能力;气候的变化使植物遭受了更大的冷伤害风险.微管最初遇冷时部分的解体可以有效诱导植物抗寒性;抗氧化酶活性增强,植物体内糖、脯氨酸、多胺等内含物含量上升.植物休眠状态中的生理变化(种子的休眠、芽的休眠)与ABA敏感性的差异有关.对植物抗寒性分子机制的研究表明:COR基因的表达对于植物抗寒性和冷驯化是十分关键的;与气候梯度有关的基因梯度的分布说明寒冷地区的树种更为抗寒;多表型性状的数量性状分析,为重要的农艺性状标记辅助选择(MAS)提供基础.对植物抗寒过程中的信号转导进行研究发现,Ca2 是低温下参与调节冷驯化应答机制中信号转导途径的重要的第二信使.未来植物抗寒领域的研究热点为信号转导和基因调节,低温抗性的遗传学和遗传应用及代谢组学,气候变化对于植物抗寒的影响等方面. 相似文献
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陈伟 《中南林业科技大学学报(自然科学版)》2006,26(4):16-21
采用酶联免疫吸附法(EL ISA)和细胞石蜡切片法,研究光皮桦离体培养形态建成过程中芽原基、根原基形成、发育的特点以及光皮桦离体培养形态建成过程中5种内源激素含量的变化规律,阐明光皮桦离体培养过程中芽原基、根原基形成、发育的过程、特点以及内源激素的变化对离体培养形态建成过程中所起的调控作用,为建立高效的光皮桦离体培养体系提供科学依据.结果表明:在光皮桦离体培养形态建成过程中,芽原基起源于皮层的薄壁细胞,根原基起源于韧皮部内;在芽和根的形态建成过程中,外源激素的添加使光皮桦某些内源激素发生了变化,从而对芽和根的形态建成起调控作用;内源激素ZR、ABA、IAA,iPA的增加对芽的形成、发育起到促进作用;内源激素IAA、ABA,iPA的增加对根的形成、发育起到促进作用. 相似文献
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Tropical stem-succulent trees store large quantities of water in their trunks yet remain leafless during the early and mid dry season. In contrast to most other tropical trees, bud break of vegetative buds is not induced in fully hydrated stem succulents between the winter solstice and the spring equinox by leaf abscission, abnormal rain showers or irrigation. Vegetative buds of leafless trees are therefore in a state of endo-dormancy similar to that of temperate perennial plants during early winter. Highly synchronous bud break regularly occurs soon after the spring equinox, often weeks before the first rainfalls of the wet season. These observations suggested that endo-dormancy and bud break might be induced by declining and increasing photoperiods after the autumn and spring equinoxes, respectively. In phenological field observations, we confirmed highly synchronous bud break after the spring equinox in many trees of five stem-succulent species in the northern and southern hemispheres. Shoot growth of potted saplings of Plumeria rubra L. was arrested by a decline in day length below 12 h after the autumn equinox, but continued in saplings maintained in a 13-h photoperiod. Conversely, exposure to a 13-h photoperiod induced bud break of dormant apical buds in saplings and cuttings in January, whereas plants maintained in the natural day length of < 11.7 h remained dormant. Photoperiodic control of endo-dormancy of vegetative buds in stem succulents is thus supported by field observations and experimental variation of the photoperiod. At low latitudes, where annual variation of day length is less than 1 h, bud dormancy is induced and broken by variations in photoperiod of less than 30 min. 相似文献
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油桐花芽分化期内源激素含量的变化 总被引：3，自引：0，他引：3
为给油桐花芽分化及花期调控的研究提供理论依据.在观察油桐花芽形态分化的显微结构的基础上,测定并分析了该时期油桐叶片中内源激素ZR(玉米索核苷)、IAA(生长素)、GA(赤霉素)、ABA(脱落酸)含量的变化情况.结果表明:当花芽生理分化期,ZR(玉米素核苷)、IAA(生长素)、GA(赤霉素)、ABA(脱落酸)的含量迅速下降,到花芽形态分化开始前降到较低水平;花芽形态分化开始后,ZR(玉米素核苷)、IAA(生长素),GA(赤霉素),ABA(脱落酸)的含量呈现出前期上升、中期波动、末期上升的变化规律;花芽生理分化期,ZR/GA、ZR/IAA、ABA/GA和ABA/IAA之值迅速上升,而当花芽形态分化期,各比值在较高水平上的波动大.后期下降.因此,内源激素间的平衡与综合作用促进了花芽的分化. 相似文献
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According to prevailing theory, air temperature is the main environmental factor regulating the timing of bud burst of boreal and temperate trees. Air temperature has a dual role in this regulation. First, after the cessation of growth in autumn, prolonged exposure to chilling causes rest completion, i.e., removes the physiological growth-arresting conditions inside the bud. After rest completion, prolonged exposure to warm conditions causes ontogenetic development leading to bud burst or flowering. During the past three decades, several simulation models based on chilling and forcing have been developed and tested. In recent modeling studies of the timing of bud burst in mature trees, the simpler thermal-time models that assume forcing starts on a fixed date in the spring have outperformed the chilling-forcing models. We hypothesize that this discrepancy may be due to some element missing from the chilling-forcing models. We tested two new model formulations by introducing reversing, temperature-driven elements that precede forcing and by fitting the models to seven historical time series of data of flowering and leaf bud burst of common boreal tree species. In these tests, both of the new models were generally more accurate in predicting the timing of bud burst than a classical chilling-forcing model, but less accurate than the simple thermal-time model. We therefore conclude that besides chilling, other environmental factors are involved in the regulation of the timing of bud burst. Further work is needed to determine if the regulatory factors derive from air temperature or from some other environmental condition such as changes in light conditions, like day length or night length. 相似文献
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以杜鹃红山茶为材料,采用石蜡切片法观察花芽分化过程,研究该过程与外部形态的相关性及其代谢产物的变化。结果表明:杜鹃红山茶花芽分化于5—9月间持续不断进行,该时段内能观察到处于不同分化阶段的花芽;其过程可分为生理分化期、花原基分化期、萼片原基分化期、花瓣原基分化期、雄蕊原基分化期、雌蕊原基分化期。杜鹃红山茶花芽分化过程与其外部形态特征之间有着相对稳定的关系,可以通过花芽形态特征来对其进行判别。花芽分化期可溶性蛋白质含量先升高后降低,可溶性糖含量及可溶性糖/可溶性蛋白质先降低后升高;RNA、总核酸含量及RNA/DNA的变化趋势一致,均随花芽分化逐渐升高,在花瓣原基分化期达到最高,雄蕊、雌蕊原基分化期降低,而DNA含量在整个过程中一直处于较低水平且变化平缓。 相似文献
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Climatic control of bud burst in young seedlings of nine provenances of Norway spruce 总被引：1，自引：0，他引：1
Detailed knowledge of temperature effects on the timing of dormancy development and bud burst will help evaluate the impacts of climate change on forest trees. We tested the effects of temperature applied during short-day treatment, duration of short-day treatment, duration of chilling and light regime applied during forcing on the timing of bud burst in 1- and 2-year-old seedlings of nine provenances of Norway spruce (Picea abies (L.) Karst.). High temperature during dormancy induction, little or no chilling and low temperature during forcing all delayed dormancy release but did not prevent bud burst or growth onset provided the seedlings were forced under long-day conditions. Without chilling, bud burst occurred in about 20% of seedlings kept in short days at 12 degrees C, indicating that young Norway spruce seedlings do not exhibit true bud dormancy. Chilling hastened bud burst and removed the long photoperiod requirement, but the effect of high temperature applied during dormancy induction was observed even after prolonged chilling. Extension of the short-day treatment from 4 to 8 or 12 weeks hastened bud burst. The effect of treatments applied during dormancy development was larger than that of provenance; in some cases no provenance effect was detected, but in 1-year-old seedlings, time to bud burst decreased linearly with increasing latitude of origin. Differences among provenances were complicated by different responses of some origins to light conditions under long-day forcing. In conclusion, timing of bud burst in Norway spruce seedlings is significantly affected by temperature during bud set, and these effects are modified by chilling and environmental conditions during forcing. 相似文献
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华山松是我国西南地区重要的造林树种之一,其球果从雌球花到球果木质化完成的整个发育过程中受到多种生物和非生物因素的影响.在云南省楚雄市紫溪山林场采种基地内球果死亡率达到47.6%,先后有败育、虫害、机械损失、冻害和鼠害5种致死因子导致华山松球果的脱落死亡.在5个致死因子中,虫害的致死力最强,致使球果死亡率达27.2%.由于虫害而损失的球果是其它致死因子造成落果总数的1.33倍.在种子园内造成落果的害虫主要有5种,1年生球果发育阶段,以球果花蝇和球果瘿蚊占主导地位;2年生球果发育阶段,微红梢斑螟的危害是造成落果的主要原因. 相似文献
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Vegetative buds of peach (Prunus persica L. Batsch.) trees act as strong sinks and their bud break capacity can be profoundly affected by carbohydrate availability during the rest period (November-February). Analysis of xylem sap revealed seasonal changes in concentrations of sorbitol and hexoses (glucose and fructose). Sorbitol concentrations decreased and hexose concentrations increased with increasing bud break capacity. Sucrose concentration in xylem sap increased significantly but remained low. To clarify their respective roles in the early events of bud break, carbohydrate concentrations and uptake rates, and activities of NAD-dependent sorbitol dehydrogenase (SDH), sorbitol oxidase (SOX) and cell wall invertase (CWI) were determined in meristematic tissues, cushion tissues and stem segments. Only CWI activity increased in meristematic tissues shortly before bud break. In buds displaying high bud break capacity (during January and February), concentrations of sorbitol and sucrose in meristematic tissues were almost unchanged, paralleling their low rates of uptake and utilization by meristematic tissues, and indicating that sorbitol and sucrose play a negligible role in the bud break process. Hexose concentrations in meristematic tissues and glucose imported by meristematic tissues correlated positively with bud break capacity, suggesting that hexoses are involved in the early events of bud break. These findings were confirmed by data for buds that were unable to break because they had been collected from trees deprived of cold. We therefore conclude that hexoses are of greater importance than sorbitol or sucrose in the early events of bud break in peach trees. 相似文献
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以4年生光皮树嫁接苗为材料,在研究花芽分化过程中解剖学特征的基础上,测定同品系、同龄的光皮树叶内生长素(IAA)、赤霉素(GA3)、玉米核苷素(ZR)、脱落酸(ABA)等4种内源激素含量的动态变化,研究其成花过程中叶片内源激素含量的变化与成花的关系。结果表明:光皮树花芽分化过程可划分为5个时期:花芽未分化期、花序分化期、花萼分化期、花瓣分化期和雌、雄蕊分化期,其中花序分化期还可分为分化前期和分化后期;在花芽分化阶段,IAA、GA3含量保持稳定的相对较低水平,ABA含量高且变化幅度较大,ZR含量相对较低,但随着花的形成含量逐渐升高;高水平的ABA/IAA有利于花芽的形态分化,低水平的ZR/GA3有利于花芽孕育。4种内源激素含量的动态变化均影响光皮树的成花过程。 相似文献