青钱柳种子休眠机制

青钱柳种子具有深休眠特性。对青钱柳离体胚及不同处理种子的萌发试验、种壳透水性和透气性测定以及种子各部分内源抑制物质的提取、生物测定和鉴定等的研究表明:1)青钱柳种胚基本不存在休眠,果皮和种皮存在一定的机械束缚和透水、透气性障碍,果皮中存在活性较强的内源抑制物质是引起青钱柳种子休眠的主要原因。2)种子各部分甲醇浸提液的生物测定结果说明,青钱柳种子各部分均含有内源抑制物质,抑制活性为果皮>种皮>完整种子>种胚。3)对抑制活性最强的果皮甲醇提取液采用系统溶剂法进行初步分离,生物测定结果表明各分离相中乙醚相的抑制活性最强,GC-MS鉴定结果显示乙醚相中相对含量为35.09%的组分是具有较强抑制作用的香草酸。研究结果首次较系统地阐明青钱柳种子的休眠机制。     

山合欢种子超干燥贮藏的生理生化效应

采用正交设计从种子含水量、包装方法、保存温度和预回湿方法4个因素来探索山合欢种子超干燥保存的可行性。用硅胶将种子脱水至1.42%～6.35%6个含水量梯度,结合不同处理密封保存1年,随后测定发芽率和一些生理生化指标,包括相对电导率(RC)、脯氨酸(Pro)、丙二醛(MDA)、超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)、可溶性总糖含量和脂肪酸组分。结果表明:种子含水量和预回湿方法对发芽率有显著影响,超干种子与未经超干处理的种子相比,发芽率有明显提高;超干种子发芽率与相对电导率和丙二醛含量呈显著负相关,与脯氨酸含量和3种抗氧化酶活性呈显著正相关;超干种子的油酸和α-亚麻酸含量比对照提高。适宜的超干处理能使抗氧化酶活性增强,使不饱和脂肪酸和可溶性总糖的含量增加,从而减缓种子生活力下降。     

Effect of electrostatic field on seed germination and seedling growth of <Emphasis Type="Italic">Sorbus pohuashanesis</Emphasis>

A study was conducted to determine the effects of electrostatic field (ESF) treatment on seed germination and seedling growth of Sorbus pohuashanesis. The experiments were arranged by uniform design computed by the Data Processing System (DPS), including three levels of seeds soaking time, four levels of ESF intensity and four levels of ESF treatment time, with 12 treatments. Ten seeds were used in each treatment with three replicates. Seed vigor, seed germinating ability, emergence rate of seedling, survival rate of seedling, and seedling height and diameter, as well as the change in activities of superoxide dismutase (SOD), soluble protein contents, total chlorophyll contents, soluble total sugar contents in leaves of S. pohuashanensis seedlings were measured after ESF treatments. The experiment results show that ESF treatment could improve the water absorption ability of dry seeds of S. pohuashanensis, resulting in fast germination at room temperature under light conditions. Combined treatment of ESF with cold stratification could increase seed germination percentage significantly (to 42.20%), promote seedling height growth, affect leaf SOD activity, and could raise contents of total chlorophyll, soluble protein, and total soluble sugar in leaves. Seed soaking time had a significant effect on seed relative electroconductivity, seed germination under light, SOD activity, soluble protein content and total soluble sugar content of seedling leaves. ESF intensity exerted a moderate effect on these indexes. ESF treatment time only had significant effect on total chlorophyll contents, no evident effect on other indexes.     

八棱海棠种子解除休眠方法的研究

对八棱海棠种子分别进行赤霉素溶液浸泡处理、低温裸层积、低温层积以及赤霉素与低温层积结合等处理,而后进行发芽试验,统计分析发芽率、发芽势和发芽指数等指标.结果表明:赤霉素溶液浸泡不能完全打破种子休眠;低温层积是解除种子休眠的有效方法,层积80 d后,即可解除种子休眠;赤霉素溶液浸泡后,再低温层积可显著缩短层积时间.     

Cryopreservation of dormant orthodox seeds of forest trees: mazzard cherry (Prunus avium L.)

? The sensitivity of dormant seeds of mazzard cherry (Prunus avium L.) of Polish provenances to extreme desiccation and/or the ultra-low temperature of liquid nitrogen, LN (?196 °C), was investigated to identify the optimum seed water content (w.c.) at this temperature.

? Germination and seedling emergence tests in this study showed that there is no critical seed w.c. for deeply desiccated seeds (stone w.c. 1.6%), although such desiccated seeds were sensitive to the temperature of LN in the seedling emergence test. For seeds frozen in LN, the highest germinability was observed at w.c. of 9.0–16.9%, but seedling emergence was then significantly lower than in nonfrozen seeds. The 2-year of storage in LN of seeds desiccated to 7.8% w.c. did not decrease germinability after thawing, in comparison with 2-year of storage at ?3 °C. Storage in LN showed that if seeds were stored after breaking of their dormancy, germinability after storage was lower because of the necessity of seed desiccation to the lower level (～ 8%) of w.c. after stratification (before storage). Secondary dormancy was induced in seeds desiccated after stratification.

? The results of this study demonstrate the potential for long-term cryopreservation of mazzard cherry seeds in forest gene banks.

     

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。     

Seed dormancy in bay laurel (Laurus nobilis L.)

The germination of bay laurel (Laurus nobilis L.) seeds wasexamined both in the laboratory and in the field during twoyears. Seeds were collected from a grove in a garden in the townof Drama, Northern Greece, by mid November in the first year andby late November in the second year. The seeds with and withoutpericarp were given a warm-moist (20 °C day/12 °C night) oncold-moist (4±1 °C) treatment in peat or sand. After treatment theseeds were placed in the germinator along with controls. Thegermination of seeds with and without pericarp was alsoinvestigated in the field (late fall sowing). It was found thatthe pericarp caused dormancy. In seeds without pericarp,cold-moist and warm-moist stratification both proved to besuccessful in breaking embryo dormancy (100% and 96% successrespectively). The required stratification duration was 50 daysfor the warm-moist and 60 days for the cold-moist treatments.During the cold-moist stratification no germination was observed.On the other hand, seeds started to germinate during thewarm-moist stratification by about the 50th day. In the fallsowing germination was 20% for seeds with pericarp and 41% for seeds without pericarp. Drying bay laurel seeds caused areduction of the seed germination.     

核桃休眠期伤流发生的影响因素(英文)

为揭示影响休眠期核桃伤流发生因素,以"绿岭"核桃1年生枝条为试材,研究了核桃枝条淀粉酶活性、淀粉含量、可溶性糖含量、枝条的相对电导率及组织结构等与伤流量的关系。结果表明:1年生枝条中的淀粉酶活性与伤流量呈显著正相关或极显著正相关,相关系数为0.729 6～0.901 7;枝条中的淀粉含量与伤流量呈负相关,相关系数为-0.800 54～-0.636 12;枝条中的可溶性糖含量与伤流量呈极显著正相关,相关系数为0.881 42～0.968 55;在-5～5℃之间枝条的抗寒性反应程度影响枝条伤流量的大小;枝条在休眠前期和中期的伤流量与材部面积呈极显著正相关,与导管面积、材部面积/横断面积呈显著正相关,与皮部面积/横断面积呈显著负相关。分析表明伤流总量与树皮面积/横断面积呈显著负相关。淀粉酶活性、可溶性糖含量和导管面积是影响1年生核桃枝条的重要因素。     

Germination of <Emphasis Type="Italic">Juniperus procera</Emphasis> seeds in response to stratification and smoke treatments,and detection of insect-damaged seeds with VIS + NIR spectroscopy

Seeds of Juniperus procera collected from five provenances across its geographic range in Ethiopia were subjected to cold-moist stratification at 5°C or 10°C for 6–12 weeks. The effect of aqueous smoke solution in overcoming the light requirement for germination, and the potential of visible (VIS) and near infrared reflectance (NIR) spectroscopy for sorting sound and insect-damaged seeds were also investigated. Highly significant differences in germination were detected among provenances (P < 0.0001) and stratification periods (P < 0.0001), but not between temperature regimes (P=0.111). Seeds from the south and southeast distribution ranges had higher percentage germination after 6 weeks of stratification than seeds collected from north, northwest and central ranges of distribution. The smoke treatment did not affect germination regardless of whether the seeds were exposed to light. Exposure to light increased germination capacity three fold. Sound and damaged seeds were distinguished with 90% accuracy using VIS + NIR spectroscopy. It can be concluded that dormancy in juniper seeds varies with provenances, and cold stratification for 6 weeks alleviates dormancy in some seed lots. Tentatively, smoke treatment seems ineffective in overcoming photo-dormancy in juniper seeds. VIS + NIR spectroscopy has demonstrated a great potential for sorting damaged seeds, thereby upgrading seed lot purity.     

ORGANIC SUBSTANCE METABOLISM DURING SEED GERMINATION OF PINUS BUNGEANA

The metabolism of fats,proteins and carbohydrates and change of enzyme ofseeds of pinus bungeana during the germination were conducted by the methods of gas-—liquid chromatography,flow injection,colorimetric analysis of spectrophotometer,toprovide theoretical basis for seeds dormancy,germination and storage of seeds of foresttree.The results indicate that(1)carbohydrates were first utilized during germination ofseed of pinus bungeana;(2)stored substances in seeds began to decompose quickly afterradicale broke through seed coats;(3)the activity of enzymes in the seeds does not alwayscoincides with the increase or decrease in quantity of its responsible substance duringgermination of the seed.Changes in stored substance relate to metabalism of othermetabolism of other materials and the use of hydrolysates.     

青钱柳的多功能价值与繁育利用技术研究进展

青钱柳是我国特有的珍稀树种。集药用、保健、用材、观赏多用功能于一身，以青钱柳叶为主要原料的降糖、降压系列产品备受青睐；速生性状明显，为家具良材；其树姿优美，果似铜钱，是前景看好的美化树种。然而青钱柳种子发育差，自然更新能力弱，需要加强对青钱柳的濒危机理及人工繁殖技术的研究，为青钱柳的开发利用提供有效的原料保障。     

Longevity of <Emphasis Type="Italic">Juniperus procera</Emphasis> seed lots under different storage conditions: implications for ex situ conservation in seed banks

Juniperus procera Endl. is economically important timber species, but its populations are extremely small and fragmented in its natural habitat, thus, calling for immediate ex situ conservation. Here we examined the effects of seed sources and storage temperature on the longevity of Juniperus procera seed lots through collection and preservation of seeds in seed banks. Seeds were collected from nine sites across the species natural distribution in Ethiopia and stored in four warehouses: modern cold room (5℃), mud house (15℃), concrete block house (17℃ or corrugated iron house (20℃) for 42 months. Every three months, a random sample of stored seeds were drawn and tested for germination. A highly significant variation (p < 0.01) in germination of stored seeds was observed among different storage environments, seed lots, and duration of storage. Over the storage period, seeds stored in the cold room had the highest mean percentage germination, followed by the mud house, corrugated house and blocket house. The cold room (41%) and the mud house (38%) maintained the same level of germination as the intitial germination of the seedlotds (42%). The variation in longevity of stored seeds was significnatly correlated with the initial germination of seed lots (r > 0.80; p < 0.01). Cold storage also resulted in enhancement of germination through its stratification effect that terminated the non-deepphysiological dormancy of juniper seeds. In conclusion, seed lots with good initial germination can be effectively stored in cold room (5℃) up to four years. In the absence of modern cold stores, mud houses can be used as a good alternative to store seeds at local level.     

Callus culture of Cyclocarya paliurus (Batal.) Iljinskaja leaves

The hormone combinations and dark culture of the callus induction for Cyclocarya paliurus (Batal.) Iljinskaja leaves were     

Organic substance metabolism during seed germination ofPinus bungeana

The metabolism of fats, proteins and carbohydrates and change of enzyme of seeds ofpinus bungeana during the germination were conducted by the methods of gas-liquid chromatography, flow injection, colorimetric analysis of spectrophotometer, to provide theoretical basis for seeds dormancy, germination and storage of seeds of forest tree. The results indicate that (1) carbohydrates were first utilized during germination of seed ofpinus bungeana; (2) stored substances in seeds began to decompose quickly after radicale broke through seed coats; (3) the activity of enzymes in the seeds does not always coincides with the increase or decrease in quantity of its responsible substance during germination of the seed. Changes in stored substance relate to metabalism of other metabolism of other materials and the use of hydrolysates.     

青钱柳叶提取物对Caco-2细胞二糖酶活性的抑制作用

采用Caco-2细胞模型,分析了青钱柳Cyclocarya paliurus叶水提物、醇提后的水提物、95%醇提物、乙酸乙酯萃取物和正丁醇萃取物5种不同提取物对Caco-2细胞活力的影响及对Caco-2细胞上麦芽糖酶、蔗糖酶、乳糖酶3种二糖酶活性的抑制作用。结果表明,5种不同提取物中除95%醇提物对Caco-2细胞活力产生一定影响外,其余4种提取物对Caco-2细胞基本无毒性,在200 mg·L^-1浓度提取物范围内培养24～72 h后细胞仍能保持较高活力;对3种二糖酶活性抑制作用效果最好的为醇提后的水提物,尤其是对蔗糖酶和乳糖酶的抑制作用更为明显,最高的抑制率分别达到76.35%和60.13%,其次为乙酸乙酯萃取物,对乳糖酶的抑制率最高达54.41%。从青钱柳叶不同方法提取物的制备流程说明多糖类或中等极性的黄酮甙类有可能是青钱柳叶中抑制二糖酶活性的主要组成成分。     

铅笔柏种子催芽技术初步研究

低温催芽是解除铅笔柏种子休眠的关键因素,必须达到60d以上,赤霉素浸种有一定辅助作用。大粒铅笔柏种子的休眠程度较深,高浓度赤霉素浸种与低温催芽相结合是解除大粒种子深休眠的有效措施。当低温催芽时间足以解除种子休眠时,高浓度赤霉素浸种能够促进大粒和中粒种子的提早发芽且发芽比较集中。     

Collection and care of sweetgum seed

Sweetgum (Liquidambar styraciflua L.), a widely distributed hardwood in the United States and Central America, shows potential for tropical forestry application. Fruit heads change from bright green to yellow in color as they mature, and they can be picked from standing trees or logging slash when the color change occurs. Fruits release their seeds after only moderate drying, and cleaning is easy with air-screen cleaners. Sweetgum seeds are orthodox in storage behavior, and they should be stored at moisture contents of 5 to 10% at 0° to 5° (5 years or less) or –18° (more than 5 years). The seeds exhibit a shallow dormancy that can be overcome with 2 to 4 weeks of stratification at 3°C.     

Effects of storage conditions on dormancy and vigor of Picea abies seeds

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.     

PEG处理对连香树种子萌发与芽苗生长的影响

以连香树种子为试验材料,研究不同质量浓度PEG对种子萌发的影响.结果表明:适宜质量浓度(140～301 g·L-1)的PEG预处理连香树种子,能促进种子萌发和芽苗生长,增加渗透凋节物质如可溶性蛋白、可溶性糖和脯氨酸的含量,提高保护性酶SOD,POD和CAT的活性,降低MDA含量,修复膜系统损伤,提高其抗旱性.在干旱胁迫下,伴随PEG质量浓度的增加,连香树种子萌发和幼苗生长受到抑制,可溶性蛋白含量先升高后降低,可溶性糖、脯氨酸和MDA含量升高,保护性酶SOD和CAT的活性升高及POD活性下降.连香树对干旱胁迫较为敏感,PEG质量浓度≥95 g·L-1对种子萌发、芽苗胚轴和胚根生长产生抑制作用.     

Germination,osmotic adjustment,and antioxidant enzyme activities of gibberellin-pretreated <Emphasis Type="Italic">Picea asperata</Emphasis> seeds under water stress

Germination of dragon spruce (Picea asperata Mast.) seeds pretreated with gibberellin (GA) in response to water stress and changes in the levels of osmotic adjustments as well as in activities of antioxidant enzymes were investigated. With decreasing water potential caused by increasing concentrations of PEG 6000, germination percentage and germination index decreased gradually; the decrease was especially prominent under the serious water stress from PEG −0.6 MPa. In contrast, osmotic regulation substances (free proline and soluble sugar contents), lipid peroxidation (MDA), and activities of antioxidant enzyme (ascorbate peroxidase, catalase, and peroxidase) increased markedly with decreased water potential. Similarly, the values in all parameters under −0.6 MPa PEG treatment were markedly higher than the control and −0.2 MPa PEG treatment. These results suggested that P. asperata seed germination was insensitive to water stress. In addition, seeds pretreated with GA had increased tolerance to water stress as measured by germination percentage and germination index, osmotic regulation substance, and antioxidant enzyme activities.