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1.
肉桂离体胚超低温保存研究 总被引：1，自引：0，他引：1
对不同含水量肉桂离体胚进行超低温(LN2)保存,采用不同冷冻方式、解冻方式及防冻剂预处理,并测定超低温保存前后的脱氢酶、电导率、α-淀粉酶生理生化指标。结果表明:超低温保存的技术关键是减少保存材料在脱水过程中所受的伤害,以及采用适宜的冷冻和解冻方式和添加适宜的防冻剂。防冻剂预处理可以适当提高保存含水量,增加含水量范围。肉桂离体胚没有添加防冻剂时最适宜保存含水量为30%~40%(w∶w),采用快冻快解处理。防冻剂预处理后的保存效果比没有防冻剂预处理的更佳,采用缓冻快解或快冻缓解处理较为适宜。 相似文献
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LN2保存锥栗种子的生理生化特性研究 总被引：3，自引：1，他引：2
运用LN2-（196℃）保存手段，结合添加和不添加防冻剂预处理，通过对锥栗种子LN2保存前后种子质量特性和胚酶活性的分析，对其长期保存的可行性进行研究，结果表明：含水量是影响锥栗种子和离体胚LN2保存的重要因素，LN2保存应进行适度脱水。当无防冻剂预处理时，LN2保存宜采用15%～20%含水量区间，冷解冻方式采用MF-MT。当有防冻剂预处理时，各种酶活性的保存要比无预处理的要好，LN2保存宜采用20%～25%含水量区间，冷解冻方式采用MF-ST。 相似文献
3.
运用LN2 ( - 196℃ )保存手段 ,结合添加和不添加防冻剂预处理 ,通过对锥栗种子LN2 保存前后种子质量特性和胚酶活性的分析 ,对其长期保存的可行性进行研究 ,结果表明 :含水量是影响锥栗种子和离体胚LN2 保存的重要因素 ,LN2 保存应进行适度脱水。当无防冻剂预处理时 ,LN2 保存宜采用 15 %～ 2 0 %含水量区间 ,冷解冻方式采用MF MT。当有防冻剂预处理时 ,各种酶活性的保存要比无预处理的要好 ,LN2 保存宜采用2 0 %～ 2 5 %含水量区间 ,冷解冻方式采用MF ST。 相似文献
4.
LN2保存甜槠种子脱氢酶特性研究 总被引：2，自引：0，他引：2
应用超低温(-196℃)手段保存甜槠种子，通过对甜储种子离体胚超低温保存后脱氢酶活性的方差分析和Q检验法多重比较分析，对其长期保存的可行性进行研究，结果表明：含水量是影响甜槠种子离体胚超低温保存的重要因素，超低温保存应进行适度脱水、无防冻剂预处理，在20％含水量，缓冻缓解方式条件下，离体胚脱氢酶活性最高。 相似文献
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【目的】研究板栗胚轴的临界含水量,探索板栗种子低温保存技术和胚轴超低温保存技术,为板栗等顽拗性种子设施保存提供参考。【方法】以采自山东济南的‘烟泉’品种板栗种子为试验材料,剥取其胚轴,使用硅胶快速脱水至目的含水量,测定不同含水量胚轴的萌发率。基于差示扫描量热技术(DSC),分析不同含水量胚轴的热力学特征,根据胚轴含水量和对应热焓关系测算胚轴临界含水量。运用低温密封保存法保存板栗种子,采用直接冷冻法、程序冷冻法、玻璃化冷冻法和程序玻璃化冷冻法对不同含水量板栗胚轴进行超低温保存测定。【结果】1)含水量从初始的61%降至25%时,胚轴萌发率未明显下降;当含水量降至20%时,萌发率降至82.1%;当含水量降至10%,萌发率降至25.6%。2) DSC热分析显示,随着胚轴含水量降低,结晶起始温度、峰值温度和热焓均呈规律性下降趋势,二者显著正相关。当含水量降至25%时,结晶起始温度降至-37.2℃,峰值温度降为-44.1℃,热焓值降为5.0 J·g~(-1)dw;当含水量降至20%时,冷却结晶和加热熔融阶段均无结晶峰出现。3)以胚轴含水量和对应热焓测算,‘烟泉’品种板栗胚轴的萌发率开始显著下降的脱水临界含水量为23.9%。4)将板栗种子密封保存在2℃低温环境下6个月,种子萌发率、胚根和胚芽长度无显著性变化(P0.9)。5)在4种超低温保存方法中,程序玻璃化冷冻法和玻璃化冷冻法的胚轴萌发率高于直接冷冻法和程序冷冻法,程序玻璃化冷冻法效果最好。【结论】板栗胚轴含水量降至20%及以下会对胚轴萌发活力产生影响,属于典型顽拗性种子。基于差示扫描量热技术,结合不同含水量胚轴萌发情况,可有效确定板栗等顽拗性种子的临界含水量,‘烟泉’品种板栗胚轴的临界含水量为23.9%。板栗种子在2℃低温密封保存条件下可有效保存6个月以上,其萌发率、根胚胚芽长度无显著变化。加入冷冻保护剂PVS2可提高板栗胚轴超低温保存后的萌发率。 相似文献
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《经济林研究》2014,(4)
为建立刺楸组织培养体系,选取刺楸成熟胚、休眠芽及幼嫩茎段进行离体培养,探讨不同消毒时长、培养基种类及激素浓度对刺楸离体快繁的影响。结果表明:由于刺楸种子为胚乳性种子,因此选用刺楸的成熟胚进行离体培养,无论采用何种消毒方式均未获得成功;而休眠芽及幼嫩茎段分别使用0.1%的Hg Cl2消毒12、10 min时灭菌效果最佳;在对休眠芽和幼嫩茎段进行离体培养时筛选出1/2MS+6-BA2.0 mg/L+NAA0.1 mg/L为最适培养基及激素组合,腋芽萌发率可以达到66.7%和88.5%;生根培养时1/2MS+NAA0.1 mg/L+20 g/L蔗糖为最适培养基;移栽后1周,生长正常,长势良好。 相似文献
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为了开辟银杏种质保存新途径,以中南林学院经济林研究室选育的湖南梅核Ⅰ号变异类型为材料,对银杏种胚超低温保存进行了研究.结果表明:银杏胚对脱水不太敏感,但胚含水量(胚中水的质量与胚干物质质量的百分比)低于12%时,试管苗生长发育异常;简单无菌风干燥脱水后的胚,液氮保存后恢复生长时,仅观察到子叶有限伸长、胚根生长、胚轴处产生大量白色的愈伤组织;无菌风干燥后的胚再经高浓度冰冻保护剂处理,超低温保存后再接种于培养基上,可产生再生植株. 相似文献
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木本植物种质超低温保存的研究进展 总被引：18，自引：1，他引：18
木本植物种质的超低温保存研究对生物多样性保护和植物生物技术都具十分重要的意义.根据我们的统计,已有40多个属60多个种的木本植物被进行了超低温保存试验,其中大多数是90年代的新报道.种子、胚、胚轴和体胚的保存常用干冻法;茎尖和分生组织的保存大多用玻璃化法或包埋脱水法;愈伤组织和悬浮细胞的保存大多用两步法或玻璃化法.木本植物种质的超低温保存近年来呈现2个特点,一是顽拗型植物胚轴和体胚的冻存报道较多;二是玻璃化法和包埋脱水法等新技术不断应用. 相似文献
11.
福建三明格氏栲保护区优势植物种群竞争的初步研究 总被引：4，自引：0，他引：4
通过对三明格氏栲自然保护区中以格氏栲,马尾松和米储为优势的针阔混交林１０个样地进行调查,估算并比较各优势种群的竞争系数与Ｋ值比的关系。结果表明,耐阴的格氏栲和米槠种群将取代喜光的先锋树种马尾松种群;现存林分中格氏栲种群密度比米槠大,但随着种间竞争的进行,米槠将不断扩大种群密度,达到与格氏栲种群共存的竞争结果。这主要与各树种的生态学特性直接相关,另外也受到环境因素的影响。 相似文献
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浙江天童常绿阔叶林米槠种子雨和地表种子库动态研究 总被引：1，自引：1，他引：0
2008年在浙江天童山常绿阔叶林的林缘和林内2个米槠种群中各选择3株米槠(Castanopsis carlesii),采用种子筐及地表取样等方法,分析了米槠种子雨和地表种子库动态特征、种子存留及其命运。结果表明:米槠种子雨主要出现在10月中旬—11月,持续约50 d,11月3日—17日为高峰期;该地区米槠的种子产量较高,林缘种群高于林内种群,单株平均落果数分别为201.0、120.3个.m-2;种子雨中完好的坚果占52.2%,虫蛀的占29.3%,松鼠啃食的占10.2%,败育的占8.4%,腐烂的占5%;完好种子的长度、宽度分别为(9.01±0.89)mm、(9.25±1.00)mm,粒重为(0.47±0.13)g;在地表种子库中,林缘种群、林内种群完好种子的存留密度分别为1.5、1.0个.m-2,分别占种子库的62.1%、66.4%,动物捕食是种子受损的主要原因。米槠种群较高的种子产量、较低的地表种子存留率等环节限制了米槠种群的天然更新。 相似文献
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不同人为干扰强度对米槠林乔木层组成和物种多样性的影响 总被引：6，自引：0，他引：6
本文从乔木层组成和物种多样性角度探讨不同人为干扰强度(天然米槠林CK、A级择伐更新、B级皆伐迹地天然更新、C级皆伐迹地人工促进天然更新和D级杉木林)对福建武平米储林恢复的影响.结果表明CK、A级和B级乔木层都是以米储为优势种,C级顶极种米槠处于第2优势种,阳性树种裂斗锥处于第1优势种,而D级受人工种植的影响乔木层优势种发生根本性变化而以杉木为优势种;通过乔木层组成和物种多样性分析,随着人为干扰强度的加大种类组成、各科含种数、各科含属数和各属含种数上升到B级或C级后下降或直接下降,而物种多样性指数和均匀度呈线性下降、优势度呈线性上升.特别是D级杉木林乔木层由于以人工种植杉木为优势种控制着整个群落的性质和环境、导致分析的各方面指标与天然米槠林CK相距甚远,目前较难恢复到米槠顶极群落,其余更新方式将能恢复到米槠顶极群落. 相似文献
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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.
Xiang-Ming Wang Bernard Riedl Robert L. Geimer Alfred W. Christiansen 《Wood Science and Technology》1996,30(6):423-442
Summary To better understand the curing and bonding behavior of phenol-formaldehyde (PF) resin under dynamic conditions, flakeboards were manufactured either by conventional pressing at 7% or 12% mat moisture content or by steam injection pressing with 10 or 20 seconds steaming duration. Resin-impregnated glass-cloth samples and lap-shear tension specimens were embedded in the core of each flakeboard. After the flakeboards were pressed for various periods of times, the samples and specimens were quickly retrieved. The degree of resin cure was determined on the resin-impregnated glass-cloth samples by dynamic mechanical analysis. The bond strengths were measured from the lap-shear tension specimens on a mechanical testing machine. The results of resin curing and bonding were then correlated to the performance of the resin-bonded boards, which were evaluated by internal bond, modulus of rupture, modulus of elasticity, and thickness swelling. Resin curing and lap-shear bonding did not proceed simultaneously. In conventional pressing, the mat moisture content (MC) at 12% favored resin curing, but slightly retarded lap-shear bonding, as compared to 7%MC. In steam injection pressing, the rates of resin curing and lap-shear bond strength development were much faster for 20 seconds than for 10 seconds of steaming duration. Longer press times were needed to obtain boards with maximum strength in the 12%MC conventional pressing and the 20-s steam duration steam injection pressing than in those conditions where moisture content was lower or steam time was less. The need for longer press times must be attributed to higher internal vapor pressures and/or lower wood and resin component strengths, rather than to incomplete cure or bonding.This material is based on work supported by the Ministry of International Affairs, Quebec Government, the Natural Sciences and Engineering Research Council of Canada, and Laval University (Quebec City). The work was also supported by the U.S. Department of Agriculture under research joint venture agreement FP-92-1835 相似文献
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进行样地调查与树干解析,以研究米槠生长过程。采用米槠容器苗和裸根苗造林,比较造林保存率、胸径、树高、冠幅、变异系数等指标,以了解两种苗木的幼林生长效应,并比较天然林与人工林米槠的早期生长。研究表明,米槠在10-20 a,树高、胸径生长较快;14-30 a,材积生长较快;树龄33 a时,尚未达到数量成熟阶段。米槠容器苗造林的保存率、胸径、树高值均大于裸根苗,其中保存率比裸根苗高9.5%,胸径值大11.3%,树高值大4.6%。比较人工林和天然林的早期生长,人工林树高和胸径值均大于天然林。米槠容器苗造林,可以促进米槠生长,取得较好的造林效果。 相似文献
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Prunus africana, from the moist highlands of sub-Saharan Africa, is subject to great exploitation because its bark is used in the treatment of prostate-related diseases. A better understanding of the biology of its seed could help the ex situ and in situ conservation of the species. Fifty per cent of fresh seeds (46.8% MC) from mature purple fruits harvested in Kenya germinated after 10 days incubation at 25°C. The germination rate was linearly related to constant temperature, giving a prediction for the minimum temperature for germination at ca. 0.6°C. All seeds germinated at 5°C during 4 months fully hydrated storage. P. africana seed is, thus, neither dormant nor chilling sensitive. The relationship between equilibrium moisture content and relative humidity was used to construct a sorption isotherm, against which seed desiccation and storage responses were assessed. Seventy six per cent of mature seeds survived drying to 4.5% MC (22% RH) compared to 17% of seeds from immature purple-green fruits. Although, 25–45% of mature seeds survived at 8–12% MC after 2 months, only 10% remained viable after 6-month storage at 5°C. This study proposes optimum conditions for the artificial regeneration of P. africana seeds and highlights the need for further experiments storing dry seeds at sub-zero temperatures. 相似文献
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We performed desiccation and storage trials to better under- stand storage behavior of Knema attenuata seeds. Mature seeds with moisture content (MC) of 31% exhibited 73% germination. During the period of desiccation (open lab condition) seeds with MC 23% showed 40% germination. After further drying to MC 21% germination was reduced to 16%. Complete loss in viability resulted when seed moisture was reduced to 18%. The seeds stored at -10°C, 0°C, 10°C and 28±2°C (open lab condition) lost their viability within 10 days. Seeds stored in sealed polythene bags and moist sand retained viability for more days than did seeds stored under all other storage conditions. Sensitivity of seeds to lower temperature and desiccation suggest that the storage be- havior of K. attenuata seeds is recalcitrant. Seeds stored in moist condi- tions can, at best, be stored for a period of two months. 相似文献
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摘要：基于2×2联列表,通过x2检验和w检验,并结合共同出现百分率（Pc值）、联结系数（AC值）、点相关系数（φ值）和Ochai指数,对福建省三明市小湖格氏栲自然保护区天然米槠林优势种群联结性进行测算,分析该群落乔木层的种群间关系,探讨其生态种组的划分。结果表明：该群落各种群分布相对独立。反映处于演替的后期阶段或动态平衡阶段;通过综合聚类分析,根据种群之间联结性及其物种生态习性,将20个优势种群划分为3大生态种组。 相似文献
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格氏栲林群落物种多样性研究 总被引：6，自引：3，他引：3
对格氏栲天然林群落的物种多样性和物种重要值进行调查分析 ,初步探讨格氏栲群落乔木树种的演替趋势。格氏栲林群落物种多样性Simpon指数和Shannon -Wiener指数分别达 0 95 8和 3 495 ,显示该群落是相对稳定性较大的群落 ,群落物种多样性丰富 ;群落重要值分析表明格氏栲是该群落的主要优势种。群落演替趋势说明 ,要加强保护格氏栲自然更新 ,通过种子繁殖和萌蘖等方式互补 ,从而使其成为稳定的群落。 相似文献