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通过对刺楸进行打破休眠和变温催芽试验,研究了刺楸种子深度休眠的机理和催芽方法,结果表明:引起深度休眠的主要原因是种胚发育不完全,尚需一定的时间和温度条件才能完成种胚的发育,种子采收后须立即用湿河沙堆藏,层积处理的天数不少于120d。 相似文献
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4种槭树种子的休眠原因及催芽方法试验 总被引:1,自引:0,他引:1
乡土树种鸡爪槭、色木槭、元宝枫和美国红枫等4个树种的种子都具有显著的休眠特性。采用人工介入手段进行休眠原因和催芽技术试验研究,结果表明:这4种槭树种子的种皮含有的化学物质和机械性阻碍导致了槭树种子的休眠;采用层积处理和GA3赤霉素浸种,能明显缩短种子的休眠期;彻底解除供试种子的休眠方法就是延长浸种沙藏层积的时间。措施,对保证育苗生产,提高出苗率和出苗整齐度有一定的研究价值。文章从层积处理和赤霉素处理入手,研究不同条件下催芽处理的效果,以此解释休眠的原因。 相似文献
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天女木兰种子层积过程中种胚的研究 总被引:3,自引:0,他引:3
通过对天女木兰种子层积过程中胚的发育、呼吸变化等进行研究,得出休眠的原因及影响其休眠的因素。结论是采用赤霉素浸种变温层积催芽的方法,是解除天女木兰种子休眠的较好途径。 相似文献
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为了打破天女花种子休眠,对其种子催芽技术进行了研究。结果表明,种胚未完成发育是天女花种子休眠的主要因子,种皮的机械约束对种子萌发影响不大。用250μg/g的GA浸种可加速种胚的分化、发育。不进行催芽处理,当年不能出苗。种子在催芽过程中,必须进行浸种,后经低温沙藏,再经变温或高温催芽,才能解除休眠。 相似文献
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祁连圆柏种子萌发特性及其解除休眠技术研究 总被引:1,自引:1,他引:0
《林业实用技术》2016,(7)
为探讨祁连圆柏(Sabina przewalskii Kom.)种子休眠机制,对祁连圆柏种子进行种皮透水性、胚萌芽抑制物等直接和间接测定及各催芽措施对种子发芽育苗的影响研究,结果表明:祁连圆柏种子发芽极其困难,种壳虽骨质坚硬,但不影响种子的透水性能。祁连圆柏外果皮和果肉、种仁中均存在着影响种子萌发的抑制物质,但不影响种子发芽。种子形态成熟后,进入深度漫长的休眠生理后熟期,才能解除其深度休眠。 相似文献
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Genetic diversity and genetic differentiation of natural Pinus koraiensis population 总被引:1,自引:0,他引:1
FENG Fu-juan HAN Shi-jie WANG Hong-mei 《林业研究》2006,17(1):21-24
Genetic diversities and genetic differentiations of the four Pinus koraiensis populations (Gaofeng Forestry Farm at Tangwanghe in Yichun City, Erdaobaihe Town in the Changbai Mountains, Shcngshan Forestry Farm in Heihe City, in China, and the suburb of Vladivostok City in Russia) were analyzed by using ISSR PCR technique. The results of 15 primers amplification showed that the ratio of polymorphic site of P koralensis population was 60.7%. Euch primer had 3.6 polymorphic sites, The diversity levels of the four P. koraiensis populations were rather higher compared with those of other Pinaceae species. The genetic diversity levels of t: koraiensis populations grown in the center region were higher than those grown in the edge zone. The genetic diversity of r3 koraiensis mainly came from the interiot of the population, accounting for 73% of total genetic diversity. There were no positive correlation between genetic distances and geographical distances for the four P koraiensis populations. The gradual decrease of natural distribution region of P. koraiensis was due to anthropic destroy and environmental factors (i.e. fire and wind throw), rather than the lower genetic diversity. 相似文献
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[目的]通过研究滇重楼种子层积过程中不同阶段内源激素含量与种胚长度的动态变化情况来探讨种子休眠机理.[方法]应用酶联免疫吸附法测定不同阶段种子内激素含量.[结果]种子萌发过程中,脱落酸(ABA)含量由54.34 ng·g-1·FW降至32.16 ng·g-1·FW,赤霉素(GA)、玉米素核苷(ZR)显著升高,吲哚乙酸(IAA)含量波动较大,但整体呈逐渐升高趋势,随层积时间延长,未萌发种子中ABA含量持续降低,GA含量与GA/ABA值持续升高,仍显著低于已萌动种子中激素含量(p<0.05);种子在层积42天后,种胚开始膨胀,胚率快速增加;相关性分析结果,内源激素含量及比值与种胚生长呈显著相关(p<0.05),其中,GA/ABA值对种胚生长的影响最大.[结论]种子萌发过程中仅ABA含量降低不足以解除滇重楼种子休眠,同期GA含量升高和GA/ABA值达到某一阈值时能有效的解除滇重楼种子的休眠和促进胚的发育;种子在层积40天左右后,由于各项激素的综合作用,滇重楼种子由休眠状态逐步转变为破除休眠状态和萌发状态. 相似文献
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Xiangxiang Fu Hongna Liu Jie Xu Jiajia Tang Xulan Shang 《Scandinavian Journal of Forest Research》2014,29(6):542-551
The combination of gibberellin acid (GA) soaking with moist chilling plays a pivotal role in seed dormancy breaking. However, knowledge involving physiological and biochemical mechanisms for such a response is limited. This work focused on the effects of GA3 and moist chilling on overcoming seed dormancy as well as the response of endogenous hormones and nutrient reserves to dormancy release in Chinese dogwood (Cornus kousa var. chinensis). Seeds subjected to GA3 soaking and moist chilling exhibited a high germination percentage (average 97%), and the combination of 500 mg·L?1 GA3 soaking for 3 days followed with moist chilling for 50 days was more effective than other treatments. For GA3 treatments, lipids were initially hydrolyzed during the first stage of moist chilling (0–20 days), resulting in the increase of starch and soluble sugars, while proteins were kept relatively stable. During the second stage (20–50 days), contents of lipids, starch, soluble sugars, and proteins decreased by 46%, 82%, 61% and 59%, respectively. Abscisic acid (ABA) contents and ratios of ABA to GA3 in GA3 treatments decreased by nearly 70% and over 90%, respectively, when dormancy was terminated. However, endogenous GA3 contents in all treatments significantly increased with prolonged moist chilling. The present results provide insight into the metabolic mechanism involving hormonal regulation and mobilization of reserves during the release of seed dormancy in Chinese dogwood. 相似文献
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Leucaena leucocephala and Acacia farnesiana are tree species used for several agricultural purposes in the Mediterranean region. The seeds of these species exhibit dormancy,
causing delayed germination. Two experiments were conducted to investigate the effect of pre-sowing treatments (scarification,
hot water, or soaking) on seed germination of L. leucocephala and A. farnesiana. In one experiment, seeds were exposed to three pre-sowing treatments: control, sandpaper scarification, or soaking in 70°C
water for 4, 8, 12, 16, 20, or 24 min. In another experiment, seeds were soaked in 70°C water for 20 min, and then soaked
in water at room temperature for an additional 24, 48, or 72 h or blade scarified. In general, soaking the seeds of the two
species in hot water was more effective in breaking seed dormancy than scarification. Sandpaper scarification was not effective
for either species. Blade scarification increased A. farnesiana seed germination to 56%, indicating that seed dormancy was mainly a consequence of hardseededness.
L. leucocephala seeds collected from Jordan University of Science and Technology (JUST) site and soaked in 70°C water for 20 min and then
soaked for 24, 48, or 72 h had germination rates above 97%. Our results suggest that blade scarification of A. farnesiana seeds and soaking of L. leucocephala seeds in 70°C water for 20 min are effective treatments to break seed dormancy and enhance seed germination of these vital
species. 相似文献
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选择长白山针阔比9∶1、8∶2、7∶3的云冷杉过伐混交林,探讨直径结构、空间格局、蓄积生长、林下更新以及植物多样性等林分结构问题,为恢复红松为主的针阔混交林,提出结构调整思路。研究表明:由于过去以不合理的非经营性采伐,红松成主要择伐对象,红松不同年份各径阶株数变化幅度较大,直径18 cm开始出现缺损株数现象,缺乏中、大径组株数,导致母树数量、结实量和种源减少,造成在主要树种中红松更新最差的问题,不利于林分正向演替。不同针阔比混交林空间格局与其主要树种空间格局并非完全一致,在同一林分不同树种间存在差异。针阔比9∶1、8∶2、7∶3的混交林空间格局分别为随机分布、聚集分布和均匀分布。其中,红松分布格局主要呈聚集分布。因此,恢复以红松为主的针阔混交林,以红松和珍贵阔叶树种作为目标树种,采取目标树培育方法,伐除影响其更新和生长的林木,而将云冷杉和一般阔叶树作为伴生树种,逐渐减少云冷杉的优势,最终逐渐恢复成红松阔叶混交林;对针阔比8∶2和7∶3混交林红松分布格局,采取人工补植、间伐等措施,结合天然更新,向随机分布进行调整;采取人工补植、清理母树周围枯枝落叶层等措施人工辅助红松天然更新。 相似文献
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Elias Pipinis Elias Milios Olga Mavrokordopoulou Pavlos Smiris 《Journal of Sustainable Forestry》2018,37(4):375-388
The aim of the present study was to investigate the effect of the natural sequence of temperature conditions between the time of seed sowing and their germination on dormancy release of Prunus avium, P. mahaleb, P. divaricata, P. laurocerasus, P. spinosa, Cornus mas, C. sanguinea, and Celtis australis seeds which are enclosed in a hard stony endocarp. According to their collection date, the seeds (with the endocarp) of the above species were sown outdoor in summer, autumn, and winter and the number of emerged seedlings was counted during the following two springs. For all species, the first sowing date was immediately after seed collection and cleaning. In all species, seedling emergence occurred in early spring and dormancy was released only after the exposure of seeds to specific season conditions. The exposure of seeds of all studied species, except C. australis, to a period of warm temperatures prior to winter was necessary for dormancy breaking and germination. Autumn sowing of P. laurocerasus and C. sanguinea seeds, which were collected in summer, and the sowing immediately after seed collection of the rest species, resulted in a maximum percentage of seedling emergence in the following spring. 相似文献
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From four Korean pine (Pinus koraiensis) orchards, 60 clones were selected and analyzed for the fatty acid and amino acid components of the seeds to reveal the variations and correlations of the seed characteristics among the clonal source orchards and clones. The nutritional components of the seeds of the P. koraiensis trees exhibited rich genetic variation; the variation coefficient of the fatty acids was 2.24–66.83 %, while the variation coefficient of the amino acids was 14.70–38.88 %. Relatively high genetic-improvement potential exists for the nutritional components of the seeds. The phenotypic differentiation of the fatty acid and amino acid components reveals that variation within the population (85.18 %) was the primary source for the variation of the fatty acid components; variation among the orchards (63.08 %) was the primary source of the variation of the amino acid components. Data drawn from various clonal source orchards all showed that the seed characteristics were highly controlled by heritability (h2 > 80 %), and the seed characteristics of the P. koraiensis trees exhibited a similar genetic gain trend. The principal components were analyzed to obtain the comprehensive principal component value for each clonal seed orchard. Twelve clones were selected based on a clonal selection rate of 20 %. Correlation and multiple stepwise-regression analyses were conducted, considering different location conditions, to reveal the stable correlations between the seed characteristics to facilitate improvements of the seed yield of P. koraiensis trees and the clonal selection. Species of real characteristics in P. koraiensis were controlled by higher heritability. Genetic gain was obtained by selecting of superior clones. 相似文献
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毛果含笑种子休眠的原因及其休眠的破除 总被引:1,自引:0,他引:1
毛果含笑为分布于云南的珍贵绿化观赏树种,其种子具有休眠习性。为解决毛果含笑种子的有效繁殖问题,从种子的形态结构,种皮的透水性、种子中的萌发抑制物质测定,种子的生活力测定及其种子萌发试验等方面,对毛果含笑种子休眠的原因及破除方法进行了研究。结果表明:种胚发育不完全和种子所含的萌发抑制物质是导致毛果含笑种子休眠的主要原因。毛果含笑种皮具有较好的透水性,与其休眠的关系不大,由此可认为毛果含笑种子的休眠类型为形态生理休眠;用蒸馏水浸泡或赤霉素液浸泡种子均可有效破除毛果含笑种子休眠,促进其萌发。 相似文献
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Ultrasound-associated extraction of seed oil of Korean pine 总被引:8,自引:1,他引:8
ZHANGYing WANGZhen-yu CHENXiao-qiang 《林业研究》2005,16(2):140-142
Experiment on ultrasound- associated extraction of seed oil of Korean pine (Pinus koraiensis) was conducted in Northeast Forestry University, Harbin, China. The factors affecting extraction yield, such as ultrasonic frequency, extracting temperature, extracting time and the ratio of material to liquid (ratio of Korean pine seed to absolute alcohol), were analyzed under specific condition and the optimal extracting parameters were obtained as the ultrasonic frequency 32 000 Hz, the extracting temperature 80℃, the extracting time 50 rain, and the ratio of material to liquid 1: 30. The study demonstrates that ultrasound is a reliable and great efficiency tool for the fast extraction of Korean pine seed oil。 相似文献
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Effect of different seed treatments on dormancy breaking and germination in three species in arid and semi-arid lands 总被引:1,自引:0,他引:1
Seeds of many woody plant species have one of several types of dormancy. They do not germinate unless specific environmental signals are in place or events occur. This study was conducted to evaluate the effects of scarification treatments on seed dormancy and germination of Acacia nilotica (L.) Willd. ex Del., Prosopis juliflora (Sw.) DC. and Dodonaea viscosa (L.) Jacq. The following treatments were applied: T1, untreated seed (control); T2, sulphuric acid (97%) for 45 min; T3, boiling water for 5 min. The seeds were cultured on a Murashige and Skoog (MS) medium after sterilization. The responses of seeds to treatments were compared with each other and with the control treatment. Germination was observed daily for a 30-day period. Results indicated positive responses to treatments, while impermeable seed coats may be responsible for low germination rates in intact seeds as seen experimentally in the untreated control. The highest germination was obtained for P. juliflora and D. viscosa acid-scarified seeds (80.8%-90.8%) and for scarified seeds of A. nilotica (50.2%) boiled in water. The germination indices, i.e., final germination percentage (FG), mean daily germination (MDG) and germination rate (GR), were significantly affected by treatments and species (p<0.01). 相似文献