青钱柳种子不同部位发芽抑制物质的测定

对青钱柳种子不同部位乙醚提取液进行了生物测定并对果皮和种皮提取液进行GC-MS鉴定,结果表明:青钱柳种子不同部位乙醚提取液的抑制强度为果皮>种皮>种胚;果皮和种皮乙醚提取液的GC-MS鉴定结果显示,青钱柳种子中存在庚酸、辛酸、棕榈酸和邻苯二甲酸二乙酯等发芽抑制物质。对邻苯二甲酸二乙酯和棕榈酸标准品进行生物测定,确定其半抑制浓度(IC50)分别为478.63μL/L和602.56mg/L。     

紫椴种皮透性及种子浸提物生物效应的研究

采用称重和生物测定的方法,对紫椴种皮透水性及种子各部分浸提物的生物效应研究,实验结果表明,紫椴种子种皮透水性较差,不易吸水。紫椴种子的胚乳、种皮、果皮中确实都含有萌发抑制类的物质,按照其抑制强度从大到小依次为种皮、果皮、胚乳(胚),且该抑制物质浸提液浓度高则抑制性强,浸提液浓度低则抑制性弱。紫椴种子胚各有机相及水相对白菜种子发芽率的抑制活性从大到小依次为:乙酸乙酯相,石油醚相,乙醚相,水相,甲醇相;对白菜种子胚根长抑制活性从大到小依次为:石油醚相,水相,乙酸乙酯相,乙醚相,甲醇相。种皮的各有机相及水相对白菜种子发芽率和胚根长的抑制活性从大到小依次为:甲醇相,水相,乙醚相,乙酸乙酯相,石油醚相。果皮的各有机相及水相对白菜种子发芽率和胚根长的抑制活性从大到小依次为:甲醇相,乙酸乙酯相,石油醚相,乙醚相,水相。     

4种山楂种子中抑制物质活性的比较

为了研究抑制物质与山楂种子休眠的关系,用80%的甲醇提取4种山楂种子内果皮、种皮及种胚的抑制物质,再用系统溶剂分离法将甲醇提取物分离为石油醚相、乙醚相、乙酸乙酯相、甲醇相及水相5相组分;用各相组分处理白菜种子,通过白菜种子发芽试验对抑制物质进行生物测定。结果表明,4种山楂种子各部位的乙醚相、乙酸乙酯相及甲醇相分离物抑制活性较高,石油醚相及水相分离物抑制活性较低;大山楂(伏山楂和大旺)种子较小山楂(辽宁山楂和抚宁野生山楂)种子每粒所含抑制物质活性高。     

综合处理措施对解除青钱柳种子休眠的影响

研究了综合处理措施对青钱柳种壳结构和透性的影响,并对休眠解除过程的果皮浸提液进行了生物测定。结果表明:浓硫酸处理可在一定程度上破坏青钱柳种子木质坚硬的种壳结构;在酸蚀处理基础上再进行GA3浸泡和GA3拌沙层积处理,随着层积时间的延长,种壳表面出现孔洞且逐渐变大,种胚含水量和种子呼吸速率显著提高,果皮浸提液抑制作用显著降低,裂口萌动种子中可能具抑制作用的物质种类减少。说明综合层积处理能有效破坏青钱柳种子坚硬的种壳结构,改善种皮透性,促进果皮中抑制物质的降解,从而加速种子休眠的解除。     

‘紫梗籽银’桂种子内源抑制物质分析

以‘紫梗籽银’桂(Osmanthus fragrans'Zigengziyin')种子为试材,对其内果皮、种实内源抑制物质进行提取、生物测定,并采用GC-MS进行鉴定。结果表明:1‘紫梗籽银’桂种子内果皮、种实均含有抑制种子萌发和幼苗生长的物质,且内果皮、种实中各分离相的抑制效果均不相同。其中石油醚相抑制作用最弱,乙酸乙酯相和甲醇相抑制作用较强。2GC-MS鉴定结果显示,‘紫梗籽银’桂种子内果皮、种实中存在多种抑制物质,包括棕榈酸、油酸、9,12-十八碳二烯酸等发芽抑制物质,主要为脂肪酸类物质。     

山楂种子层积过程中抑制物质的变化

为研究抑制物质在种子休眠中的作用及层积解除休眠的机理提供理论依据,分别提取、分离了经不同时间层积处理后的山楂种子的种壳、种皮和种仁中的抑制物质.并就白菜种子的发芽进行实验,对各分离相的抑制作用进行了生物测定,以干藏种子作对照,研究其抑制物质的分布及其在层积过程中的变化情况.结果表明:山楂种子的种壳、种皮和种仁中均含有抑制发芽的物质,从种子各部位提取物分离得到的7个分离相中,除种壳和种皮各有1相分离物对白菜种子的萌发没有抑制作用以外,其余各相分离物均能显著地抑制其发芽;抑制物质的作用随着层积时间的延长而逐渐降低;层积至5个月时,种壳和种皮各有4相分离物具有抑制作用.种仁有6相;层积至6个月时,种壳有3相分离物具有抑制作用,种皮和种仁分别有1相与2相;此时种子的休眠仍没有解除,这说明在山楂种子的不同部位存在着抑制物质,这是山楂种子休眠期长的重要原因.     

兴安升麻种子内源抑制物质活性的研究

兴安升麻种子具生理后熟、休眠的生理特性,通过对比实验研究其内源抑制物质存在的部位和抑制作用。用兴安升麻种子制备蒸馏水粗提物、甲醇粗提物,取白菜种子、小麦种子浸于粗提物中进行萌发实验,根据幼苗生长情况测定各粗提物抑制活性。结果表明,兴安升麻种子的种皮和胚乳均存在较高活性的内源抑制物,且抑制作用随着质量浓度的增大而增强。蒸馏水粗提物在相同质量浓度下抑制作用均高于甲醇粗提物。同时,兴安升麻种子不同部位抑制物质的含量存在一定的差异,表现为种皮高于胚乳。     

山楂种子抑制物质的提取分离及生物测定

为了更深入地了解山楂种子的休眠机理,以野生山楂种子为试材,用80%的甲醇溶液对其内果皮、种皮和种胚进行浸提,然后测定提取物对白菜种子发芽的影响;将浸提物分离成A、B、C、D、E、F、G共7相,浓缩后分别测定其对白菜种子发芽的影响。结果表明,山楂种子的内果皮、种皮、种胚均含有发芽抑制物质,其抑制作用依次减弱。7个分离相中除了种皮的A相及内果皮的G相对白菜种子发芽没有影响外,其余各相均显著抑制发芽。     

极度濒危树种羊角槭的种胚发育与休眠解除

【目的】揭示羊角槭的种胚发育与萌发抑制机制,获得破除休眠、提高种子发芽率的有效方法,以提高种群繁育效率,扩大羊角槭种群数量以缓解目前极度濒危的生存现状。【方法】连续3年调查统计浙江天目山自然保护区2株人工种植羊角槭种胚发育结实情况,通过白菜种子发芽试验研究种子不同部位(外种皮、内种皮、种胚)的萌发抑制作用,并通过不同处理(剥除外种皮、激素浸种与低温沙藏)探索打破种子休眠促进萌发的方法。【结果】羊角槭种胚发育不良且存在单株个体间差异,3年平均饱满种胚率仅9.73%~33.98%,饱满种胚平均生活力52.22%,饱满种胚率低于其他槭属植物。羊角槭内、外种皮与种胚均存在萌发抑制物质,外种皮与种胚提取物对于白菜种子的萌发抑制作用更强;内源ABA含量测试发现,种胚ABA含量最高,达1 818.58 ng·g~(-1),其次为外种皮1 053.34 ng·g~(-1)、内种皮859.05 ng·g~(-1),种子内各组织的萌发抑制作用与内源ABA含量直接相关;采用不同处理方法(剥除外种皮、激素浸种与低温沙藏)打破休眠试验发现,未剥除种皮种子低温沙藏及种子剥皮室温沙藏均不能萌发,而剥去外种皮种子经一定时间的低温沙藏可打破胚休眠,使得种子萌发率提高到30%;剥去外种皮种子进行不同激素(GA_3,6-BA)、不同浓度与浸种时间处理,发现激素浸种时间对于羊角槭种子发芽率有极显著影响(P0.01),浸种激素种类或浓度均对羊角槭种子发芽率影响不显著(P0.05);对剥除外种皮种子配合适当浓度的外源激素(GA_3,6-BA)浸种处理再行低温沙藏可提高羊角槭种子发芽率,其中以100 mg·L~(-1)GA_3或200mg·L~(-1)6-BA浸种12 h效果最好,种胚发芽率分别达到46.67%与43.33%,可作为羊角槭打破休眠促进萌发的适合方法推荐应用。【结论】羊角槭种子败育率高、空瘪现象严重,这与花粉供应限制有关,异株授粉作为自交补充有助于授粉成功、胚发育,在构建保护群落时应避免分散、零散的种植,减小个体间距、促进异交结实,以提高种群繁育效率;羊角槭种子同时存在外种皮强迫休眠和胚休眠,内源ABA是种子萌发的主要抑制物质;通过剥除外种皮结合激素浸种、低温沙藏能够提高种子萌发率。该研究对于扩大羊角槭种群规模、实现这一极小种群树种的种群恢复与可持续保育目标具有重要意义。     

栾树种子休眠生理及催芽技术的初步研究

通过解剖观察,发现栾树种子的种皮是由多层石细胞构成的角质层,它阻挡水分进入种子。通过柱层析对内源激素进行分离提取,再用气相色谱进行鉴定,结果证明,无论是休眠种子还是解除休眠的种子,其种皮和种胚中都含有脱落酸(ABA);但通过生物鉴定证明,解除休眠的种子,其种皮提取物和种胚提取物对白菜籽均无抑制作用,因此认为ABA不是导致种子休眠的唯一物质,此外一定还有其他物质起作用,是何物质尚待进一步研究。以上结果表明,栾树种子是种皮具有不透性而胚又生理休眠的种子。为打破休眠,曾试验过多种药剂,结果证明用浓硫酸处理1—3小时再层积3—4个月最佳。     

Flotation techniques to improve viability of Juniperus polycarpos seed lots

The germination of freshly collected Juniperus polycarpos(K. Koch) seeds is very low and attributed to the large proportion of nonviable seeds in the seed lots.Thus, the aim of this study was to improve seed lot quality by removing nonviable seeds using two flotation techniques: incubation-drying-separation(IDS) and modified specific gravity(MSG) separation. We examined different IDS conditions(the specific incubation time, subsequent drying time and sorting media) for effectively sorting out nonviable seeds; and tested the feasibility of modified SG separation, which involved soaking seeds in water for a certain period before sorting in different concentrations of sucrose solution. Viable seeds were expected to absorb and metabolically bind more water during soaking than dead seeds could, and hence be sorted effectively depending on the viscosity of the sucrose solution. The viability of the seeds that floated or sank was determined in a topographical tetrazolium chloride(TTC) test. For the IDS trial,7 days incubation followed by 9 h of drying and sedimentation in pure water or 200 g L-1sucrose solution identified, respectively, 75 and 82 % of the seeds as viable(sunken) seeds. For the MSG trail, 77 % viable seeds were recovered in the sunken fraction when seeds were soaked for 48 h then immediately sorted in 600 g L-1sucrose solution. In both cases, the loss of viable seeds in the discarded floating fraction was only 4 %. The results demonstrate that both IDS and MSG separation techniques substantially improved seed lot viability, but MSG separation is simple and needs no modern seed handling facility, and its efficacy relies on seed mass(due to the initial soaking) and the specific density and viscosity of the flotation medium.     

Flotation techniques to improve viability of <Emphasis Type="Italic">Juniperus polycarpos</Emphasis> seed lots

The germination of freshly collected Juniperus polycarpos (K. Koch) seeds is very low and attributed to the large proportion of nonviable seeds in the seed lots. Thus, the aim of this study was to improve seed lot quality by removing nonviable seeds using two flotation techniques: incubation-drying-separation (IDS) and modified specific gravity (MSG) separation. We examined different IDS conditions (the specific incubation time, subsequent drying time and sorting media) for effectively sorting out nonviable seeds; and tested the feasibility of modified SG separation, which involved soaking seeds in water for a certain period before sorting in different concentrations of sucrose solution. Viable seeds were expected to absorb and metabolically bind more water during soaking than dead seeds could, and hence be sorted effectively depending on the viscosity of the sucrose solution. The viability of the seeds that floated or sank was determined in a topographical tetrazolium chloride (TTC) test. For the IDS trial, 7 days incubation followed by 9 h of drying and sedimentation in pure water or 200 g·L^?1 sucrose solution identified, respectively, 75 and 82 % of the seeds as viable (sunken) seeds. For the MSG trail, 77 % viable seeds were recovered in the sunken fraction when seeds were soaked for 48 h then immediately sorted in 600 g·L^?1 sucrose solution. In both cases, the loss of viable seeds in the discarded floating fraction was only 4 %. The results demonstrate that both IDS and MSG separation techniques substantially improved seed lot viability, but MSG separation is simple and needs no modern seed handling facility, and its efficacy relies on seed mass (due to the initial soaking) and the specific density and viscosity of the flotation medium.     

Effect of growing media on seed germination and vigor in biofuel tree species

To evaluate laboratory germination media, seed germi- nation rates and methodology for both Jatropha curcas and Pongamia pinnata were counted in different germination medium, such as river sand, quartz sand and vermiculite. The seeds of both species were sown at 2-cm depth of river sand, quartz sand and vermiculite. We evaluated methodologies of seeds of J. curcas and P. pinnata by ISTA （Interna- tional Seed Testing Association）. The results showed that river sand is the best medium for tree seeds planted at 2-cm depth of River sand. Vermiculite was second best. On paper media, there were many abnor- mal seedlings and this media were unsuitable for germination of the larger seeds.     

Pigment composition and location in honey locust (Gleditsia triacanthos) seeds before and after desiccation

Gleditsia triacanthos L. pods were harvested at San Lorenzo del Escorial, Madrid, Spain, before and after seed desiccation. Maturing green pods, harvested from trees, contained soft light-green seeds, whereas fully mature brown pods, collected on the ground, contained hard dark-green seeds. Based on visual inspection of seeds, it was determined that the green color is located in the cotyledons and embryo of soft seeds but mainly in the seed coat of hard seeds. High performance liquid chromatographic analysis indicated that both hard and soft seeds contained the same set of photosynthetic pigments as fully developed leaves, but in different proportions. The hard and soft seeds mainly differed in their chlorophyll a to chlorophyll b ratio and in the composition of the xanthophyll cycle pool of pigments. Fluorescence at -196 degrees C revealed that the molecular organization of the pigment molecules in the seed coat of hard seeds differed from that in intact cotyledons of soft seeds and intact green leaves. The -196 degrees C fluorescence spectra also revealed the presence of a small heterogenous pool of non-photoactive protochlorophyll(ide)s, similar to those found in dark-grown tissues of gymnosperms and angiosperms.     

Effects of osmoconditioning on mitochondrial respiration and phosphorylation in soybean seeds

Cotyledon mitochondrion respiration and oxidative phosphorylation activity were studied in two groups of soybean seeds. One group was primed with polyethylene glycol (PEG) for different periods of time, and the other was unprimed (control), and both were then exposed to imbibition at low temperatures before their germination. The results indicated that when L-Malate (L-Mal)and α-Ketoglutarate (α-Kg) were used as substrates, the ADP-stimulated mitochondria respiration rates of control seeds were markedly higher than state Ill respiration rates of primed seeds. However, the osmoconditioning pretreatment significantly enhanced the oxidative phosphorylation activity of cotyledon mitochondrion in 12 h. The oxidative phosphorylation activity of the mitochondrion of primed seeds was normal and the ADP/O value was consistent with the theoretical one. When reduced nicotinamide adenine dinucleotide (NADH) was used as the substrate, the mitochondria of control seeds still had oxidative phosphorylation activity, while ADP/O value was obviously lower than that of mitochondria of primed seeds. When Succinate (Succ) was used as the substrate, the oxidative phosphorylation activity of the primed seeds was normal after priming for 24 h. When different substrates were used, the emerging order of the oxidative phosphorylation activity of the primed seeds was NADH, α-Kg, Succ and in the last place L-Mal.The mechanism of soybean imbibitionl chilling injury and protective effect of PEG priming were discussed.     

两种松树种子发芽率与生活力测定试验

以湿地松和马尾松2种松类树种种子为试材,进行发芽率与生活力测定试验。结果表明：湿地松和马尾松种子均以沙床上的发芽率最高,不同发芽床上湿地松种子的发芽率差异较大,马尾松种子的发芽率差异相对较小;湿地松和马尾松种子的发芽率与生活力之间均存在极显著正相关,相关系数（R）分别为0．9931和0．9913;湿地松种子发芽率与生活力的回归方程为y=0．9125x-1．7247,马尾松种子发芽率与生活力的回归方程为y=0．9703x-3．4769。     

Effects of fire on germination of Pterocarpus angolensis

Pterocarpus angolensis (Fabaceae) is a leguminous tree species of the miombo region of sub-Saharan Africa that is highly prized for its wood value. We use both experimental exposure to fire, as well as classification of field burned seeds, to predict germination rates in seeds from both husked and unhusked fruits. We find that seed germination and seed persistence in unhusked fruits are maximized by moderate exposure to fire. Germinating seeds had heavier fruit and seeds than those that did not. Finally, seeds without husks persisted in the soil yet continued to germinate even after 18 months in wet soil, indicating potentially long soil longevity. Using these results, we support an intermediate fire exposure model wherein repeated moderate exposure to fire enhances the capability of seeds to emerge from fruits. Seeds from unburned and unhusked fruits were never observed to germinate and had poorer soil longevity than those exposed to moderate fire. Similarly, extreme exposure to fire resulted in poor seed germination rates, often as a consequence of direct fire mortality of seeds. We suggest that early burning resulting in cool fires may augment germination and recruitment in wild populations.     

Application of growth regulators in aqueous media and organic solvents to seeds of Picea abies and Pinus sylvestris

Incubation with acetone and dichloromethane had little effect on the germination of different lots of Norway spruce seeds. This was not the case with Scots pine where almost half the seed lots tested were adversely affected by acetone and dichloromethane. The auxins indole‐3‐acetic acid (IAA) and indole‐3‐butyric acid (IBA) were applied to Scots pine seeds in acetone, dichloromethane and phosphate‐citrate buffer. The uptake of the two compounds was most rapid from acetone. Although the uptake from dichloromethane was slower than from acetone it reached the same level after 6 h. Uptake of the growth regulators from buffer was significantly lower than from the organic solvents. The accumulation of IAA and IBA into the seeds from both acetone and dichloromethane was linear between 0.5 and 10 mM, and between 0.5 and 15 mM from buffer. IAA and IBA levels in infused seeds declined over a 5‐day germination period, the former more rapidly than the latter. The metabolic activity of the IAA degradation system was as effective in seeds after immersion in the organic solvents as seeds immersed in buffer.     

苗圃地鸟害生物防控技术研究

对吉林市江密峰苗圃的鸟类、种群数量及有害或有益状况进行调查,并采用驯化雀鹰进行生物防控鸟害技术研究,结果表明:该苗圃有鸟类24种,隶属3目11科,戴胜等10种鸟类主要捕食苗圃地害虫,属于益鸟。在真正啄食种子的14种鸟类中,危害程度存在明显差异,绝大部分危害较轻,严重危害种子的主要是燕雀和家鸽。使用雀鹰驱赶苗圃地中的鸟类,效果十分理想,不仅种子受损率降到经济允许指标以下,而且很少有鸟类受到伤害。     

四数九里香种子自然萌发和离体萌发条件筛选

为提高四数九里香种子萌发率,研究了最佳浓硫酸处理种子的时间及不同激素处理对四数九里香种子自然萌发的影响,以完整种子和带胚子叶作为外植体,研究不同质量浓度的6-BA、NAA、IBA、GA3对外植体生长的影响,及不同质量浓度活性炭对外植体褐化的影响。结果表明,浓硫酸最佳处理时间为1 min;用200×10-6的IBA处理过的种子发芽率最高,达50%;其次是50×10~(-6)和150×10~(-6)的NAA,其萌发率均为45%;外植体在添加2.5 mg/L 6-BA、0.2 mg/L IBA、0.1 mg/L GA3或0.2 mg/L NAA的培养基上诱导率较高,活性炭为1.5 g/L时外植体褐化程度最低;四数九里香胚培养的最佳培养基为添加2.5 mg/L 6-BA、0.1 mg/L GA3、0.2mg/L NAA和1.5 g/L活性炭的MS培养基。