共查询到20条相似文献，搜索用时 500 毫秒
1.
毛竹种子萌发对温度和光照的响应 总被引：5，自引：3，他引：5
在气候箱内模拟环境条件下,探讨了不同温度和光照对毛竹种子萌发的影响。结果表明:光处理和黑暗处理下,毛竹种子萌发的最适温度区域在均为15~30℃,黑暗处理在各温度梯度下的萌发时间都小于或等于光处理,最大萌发速率出现在30℃(光处理)、20℃(黑暗处理),最大萌发率分别出现在黑暗处理的25℃下。控制实验下,10℃黑暗处理下毛竹种子萌发率仍然可以达到8%,在经历了采后3~4个月的储存后,毛竹种子实际萌发率可以达到56%。可以用二次曲线模拟累积萌发率曲线。 相似文献
2.
3.
香果树种子休眠和萌发的生理特性 总被引：11，自引：0，他引：11
为了解决香果树Emmenopterys henryi种子萌发困难的问题,使用不同的光照条件较系统地研究了香果树种子休眠和萌发的生理特性.结果表明:香果树种子属典型的光敏感性种子,在黑暗中无论恒温或变温条件下均完全不能萌发;整个萌发过程需1 000 lx光照强度和每天照光16 h;在光照条件下适宜的萌发温度为20℃、25℃恒温,其次是30℃恒温和30℃(日)、20℃(夜)变温. 相似文献
4.
5.
光照条件对旱冬瓜种子萌发和幼苗生长的影响 总被引：6，自引：0，他引：6
种子萌发及幼苗光合实验的结果表明，早冬瓜种子具有需光萌发的特性，黑暗中即使种子处在适于萌发的温度和水分条件下，种子仍保持休眠状态，需接受光照刺激才能解除休眠而萌发，故播种育苗时种子不宜盖土。早冬瓜幼苗生长的初期光补偿点为12μmo1／m^2s，光饱和点为1000μmo1／m^2s，具有一定的耐阴能力，适宜在50％遮荫条件下生长。随着月龄的增加，耐阴能力下降。6月龄苗光合补偿点上升到21μmo1／m^2s，光饱和点超过2000μmol/m^2s，只有在全光照的条件下才能生长良好，遮荫会降低幼苗高生长量和基径粗生长量。晴天，早冬瓜幼苗光合作用存在“午睡现象”，当植株处于缺水状态时，光合作用的“午睡现象”会更加强烈。表明早冬瓜适宜种植在次生裸地或撂荒地，种植后应及时除草进行透光抚育。 相似文献
6.
领春木种子休眠与萌发特性 总被引：3，自引：0，他引：3
周佑勋 《中南林业科技大学学报(自然科学版)》2009,29(1)
领春木种子(翅果)具生理休眠特性.对光和温度有特殊的要求,在光照条件下恒温和变温中均能萌发;在黑暗条件下,则仅能在变温中萌发.低温(5 C)层积40 d促进了种子的萌发,但仍不能使黑暗条件下恒温中的种子萌发.果翅存在抑制物质是引起种子休眠的主要因素,去掉果翅可使种子在光照下迅速而充分萌发.种子(翅果)最适的萌发条件是光照条件下15、20℃恒温和30℃日/20℃夜变温. 相似文献
7.
测定了香红椿（Cedrela odorata）、神圣愈疮木（Guaiacum sanctum）和柠檬树（Calycophyllum candidissimum）种子萌发所需要的条件、并对光强对在尼加拉瓜开阔地、半开阔地和干旱森林林冠下所营造的香红椿和神圣愈疮木的苗存活率和生长的影响进行了研究。结果表明,在20-35℃常温条件下,柠檬树在有光照条件下种子萌发率显著高于黑暗条件的种子萌发率;香红椿和神圣愈疮木的种子在光照和黑暗条件下都有一定程度的萌发,最适萌发温度均为20-25℃。研究还表明,变温条件培养并没有提高3个树种的种子萌发率。在林冠层下和开阔地上神圣愈疮木苗木的存活率分别为70％和80％,两种条件下的周径相对生长速率分别为1．42mm／月和1．88mm／月。总的来说,在3个树种中,香红椿幼苗存活率较低,特别是在冠层内生长的幼苗。以上结果说明：柠檬树种子萌发需要光照;而香红椿和神圣愈疮木种子萌发对温度条件较为敏感。神圣愈疮木幼苗在裸地条件下存活率较高,可以作为退化土地造林备选树种。图2表2参43。 相似文献
8.
3种锦鸡儿属植物呼吸代谢和生长对环境温度变化的响应 总被引：1，自引：0，他引：1
为了研究柠条锦鸡儿和中间锦鸡儿种间、伊金霍洛与和林格尔中间锦鸡儿种源间呼吸代谢和生长特点,利用量热仪在温度10~40℃之间每5℃为间隔温度,分别测定相同条件下培养出来的来自不同生态环境的小苗的呼吸速率和代谢热速率。通过计算,结果表明：3种植物在不同的温度条件下底物碳的转化效率（ε）与呼吸速率（R co2）和生长速率是不同的,由于植物生长对原生境温度已产生很强的适应性,所以在原产区以外的地区引种有可能失败。 相似文献
9.
以濒危树种极东锦鸡儿成熟种子为材料,研究极东锦鸡儿种子物理性状和温度对其种子萌发及幼苗生长的影响。结果表明:极东锦鸡儿种荚结实率较低,且约有1/4种子受虫害;成熟种子含水量为6.6%,千粒重18.6 g。种子长、宽和厚存在一定变异。种子长度平均为0.42 cm,宽度平均为0.27 cm,厚度平均为0.24 cm,长宽比为0.64。种皮透水性良好。不同温度条件对种子发芽率具有极显著影响。25℃条件下种子发芽率最高,为38.33%。随着温度的升高或降低,种子发芽率降低。发芽试验的第八天是计算种子发芽势的适宜时期。不同温度条件对极东锦鸡儿幼苗高度的影响极显著,对胚根长度影响显著。25℃有利于幼苗高度和胚根长度的增加,较高温度(30℃)有利于幼苗生物量增加。 相似文献
10.
环境因素对风箱果种子萌发的影响 总被引：1，自引：0，他引：1
以风箱果自然成熟的种子为研究对象,对影响种子萌发的环境因素进行了研究.结果表明:种子属于需光性种子,光照能够促进种子萌发.在10～25℃条件下,种子均能萌发,以20℃发芽率最高[(78.33±1.67)%],萌发速度最快[(23.61±2.29)%];播种深度显著影响种子的出苗率(P<0.01),不覆土(O cm)出苗率高达(68.33±6.01)%;超过0.5 cm,出苗率显著降低,2 cm时出苗率为O;种子在土壤中萌发时,土壤的适宜含水量为40%,此时出苗最快[(15.44±0.15)%],出苗率最高[(51.67±1.67)%],幼苗的死亡率也较低[(16.67±8.82)%].自然条件下,温度不是种子萌发的限制因子,影响风箱果种子萌发和幼苗成功定居的关键因子是土壤含水量、光照以及播种深度. 相似文献
11.
采用聚丙烯酰胺凝胶电泳（PAGE）对豆科槐属植物苦豆子和狼牙刺的过氧化物酶（POD）同工酶进行了分析。结果表明：POD同工酶酶带在苦豆子和狼牙刺的种子和芽中存在着明显的差异，芽中POD酶带总体染色比种子深；从两种植物POD同工酶谱的比较反映出，狼牙刺的抗逆性生理作用高于苦豆子。 相似文献
12.
The effects of the presence of a medium, seed moisture content, warm and chilling treatments on the germination response of European rowan (Sorbus aucuparia L.) seeds of Irish origin were investigated with the aim of reducing precocious (or premature) germination and maximising germination after pretreatment. After adjusting seed moisture content, seeds of two lots were subjected to warm treatment for 0–6 weeks followed by 0–50 weeks of chilling. The seeds then were allowed to germinate at a constant 15 °C with 8 h lighting per day or 20 (dark)/30 °C (light). Some seeds were treated in the fully imbibed (FI) state in a medium (standard operational treatment). Seed lot effects were evident, but treatment effects were consistent in each lot. Warm treatment greatly increased germination and reduced precocious germination. The presence of a medium was not required to achieve high germination and seed moisture content close to the FI state was needed to maximise germination. Climate change may reduce the ability of this species to regenerate naturally, favouring other species that require less chilling. 相似文献
13.
种间竞争对甘草柠条生物量积累和分配的影响 总被引：1，自引：1，他引：1
研究不同种植密度和不同混栽比例条件下甘草和柠条的生物量积累、分配模式及种间竞争动态.结果表明:混栽后甘草和柠条播种苗的平均单株生物量较纯栽都有所降低,柠条受种间影响的程度较甘草大.混栽甘草的根部和单株生物量较纯栽分别减少了18.12%和14.52%,地下部分受到的影响较地上部分大;混栽柠条的根部和单株生物量较纯栽分别减少了36.51%和44.74%,地上部分受到的影响较地下部分大.甘草根、茎、叶和单株生物量混栽与纯栽之间的差异都不显著;柠条根、茎、叶和单株生物量混栽与纯栽之间的差异达到显著和极显著水平.总的来说,混栽条件下甘草和柠条的相对总生物量(RYT)随着生长时间延长和密度的增大呈减小趋势.低密度混栽时,甘草和柠条表现出一定的互惠关系;高密度混栽时,二者共用资源受限,表现出相互拮抗的关系,且随着生长时间延长而加强.混栽比例不同,甘草和柠条的种间竞争率(CR)存在一定的差异,在柠条占有较大比例的处理(甘草20%;柠条80%)中,甘草的竞争力较小;在甘草占有较大比例(甘草80%;柠条20%)和两者比例相等的处理(甘草50%;柠条50%)中,甘草的竞争力均大于柠条.苗期甘草在混栽群体中具有较强的竞争优势. 相似文献
14.
The dormancy and vigor of Picea abies seeds were studied after five months of storage at 25 and 75% relative humidity (RH) and 5 and 12 °C. Dormancy was evaluated by studying germination response to light and moist chilling at 12 and 21 °C. Dormancy causing germination reduction in the dark was induced in seeds during storage at 25% RH (5–6% moisture content, MC) in darkness. The dormancy was greater when seeds were germinated at 12 than at 21 °C and after storage at 12 than at 5 °C. The effective dormancy relief by light indicates that germination was under phytochrome control. Moist chilling could partly replace light. According to accelerated aging and leachate conductivity tests, dry seeds could be stored at 12 °C for five months without affecting their vigor. After storage at 75% RH (11% MC) and 5 °C, the seeds germinated slowly and incompletely. The decreased germination response to light indicates that other processes than those mediated directly by phytochrome restricted germination of these seeds. The positive germination response to moist chilling suggested that secondary dormancy was induced in the seeds. However, vigor tests gave some evidence of simultaneous decrease of vigor. Storage at 75% RH and 12 °C decreased germination nearly to 0%. Germination of seeds stored at 75% RH could be stimulated by a short accelerated aging period. 相似文献
15.
9种野生花卉种子生物学特性研究 总被引：2，自引：0，他引：2
该文研究了9种野生花卉的千粒重、含水量、种子形态及种子萌发特性。试验结果表明,在设定的温度范围15～25℃内,种子萌发难易度有明显不同。大花剪秋萝（Lychnis fulgens）和狭苞橐吾（Ligularia intermedia）较易萌发,发芽历程短,萌发的最适温度分别为25℃和20℃,发芽率分别达到97．3％和100％;芹叶铁线莲（Clematis aethusifolia）、短尾铁线莲（Clematis brevicaudata）和棉团铁线莲（Clematis hexapetala）发芽历程长,种子始发芽晚,在20℃条件下发芽率均达到最高,分别为88％,84％和57．3％。野罂粟（Papaver nudicaule）、牛扁（Aeonitum barbatumvar puberlum）、草本威灵仙（Veronicastrum sibiricum）和金莲花（Trollius chinensis）发芽率低,在试验条件下种子最高萌发率分别为29％,20％,17％和4．0％。 相似文献
16.
17.
We investigated seed dormancy and germination in Ficus lundellii Standl. (Moraceae), a native species of Mexico's Los Tuxtlas tropical rain forest. In an 8-h photoperiod at an alternating diurnal (16/8 h) temperature of 20/30 degrees C, germination was essentially complete (96%) within 28 days, whereas in darkness, all seeds remained dormant. Neither potassium nitrate (0.05-0.2%) applied continuously nor gibberellic acid applied either continuously (10-200 ppm) or as a 24 hour pretreatment (2000 ppm) induced germination in the dark. Germination in the light was not reduced by a 24-h hydrochloric acid (0.1-1%) pretreatment, but it was reduced both by a 24-h pretreatment with either H(2)O(2) (0.1-5 M) or 5% HCl, or by more than 5 days of storage at 40 degrees C (4.5% seed water content). In a study with a 2-dimensional temperature gradient plate, seeds germinated fully and rapidly in the light at a constant temperature of 30 degrees C, and fully but less rapidly in the light at alternating temperatures with low amplitudes (< 12 degrees C) about the optimal constant temperature. The base, optimal and ceiling temperatures for rate of germination were estimated as 13.8, 30.1 and 41.1 degrees C, respectively. In all temperature regimes, light was essential for the germination of F. lundellii seeds. 相似文献
18.
19.
Zhang Chen-xia Huang Jin-tian 《中国林学(英文版)》2006,8(3):38-42
1 Introduction Desert shrubs are made up of natural composite mate- rials, composed of cellulose, hemicellulose and lignin. Although there are a large number of hydroxyl groups in them, these are not fully used due to the high crys- tallinity of cellulose and tight interconnection among polymeric components in wood (Cheng et al., 2002). Liquefaction of wood is a new technique in wood in- dustries. It is a novel process which effectively con- verts the chemical composition of wood into macro- … 相似文献
20.
聚乙二醇(PEG)模拟水分胁迫对木荷种子萌发的影响 总被引：2，自引：0，他引：2
采用聚乙二醇(PEG)模拟水分胁迫对木荷种子萌发的影响,结果表明:无论是水培还是沙培、避光还是光照下,木荷种子萌发率、幼苗高度都是随PEG浓度的增加而降低,都在PEG浓度为20%时达到最低;幼苗的相对含水量没有随PEG浓度的增加依次递减;水培自然光照下的萌发率>沙培恢复光照的萌发率>沙培避光的萌发率。由此说明避光能抑制木荷种子萌发,特别是在干旱、避光的情况下木荷种子受抑制更明显。 相似文献