Seedling culture ofKalopanax septemlobus

Experiments on temperature-accelerated germination, seeding quantity, and optimum density of seedling were made forKalopanax septemlobus. The experimental results indicated that the seeds ofkalopananx septemlobus had physiological dormancy because of unmature embryo and existence of inhibitory matter in the seed. Temperature-accelerated germination was a preferable and essential way to assure the germination. Seed dormancy could be overcome through accelerating germination. Firstly, warm treatment should be done, morphological maturity occurred, then, followed by lower temperature treatment, reaching physiological maturity. Seeding quantity, optimum density and the relations between density of seedlings and yield were studied. Responsible Editor: Chai Ruihai     

东北地区刺楸种子解除休眠及催芽育苗的研究

通过不同试验材料、GA3应用和变温层积催芽对比试验,对刺楸种子解除休眠进行研究的结果表明:鲜种+GA3+(15℃,30 d;冷冻,90 d;-4~0℃,90 d)处理方法发芽率达到90.2%,出苗率达到81.5%;气干种温水(72 h)+GA3+(13~18℃,90 d;0~4℃,90 d)处理方法发芽率达到76.3%,出苗率达到66.4%。采用鲜种进行变温催芽处理对刺楸种子发芽率、出苗率和1年生苗木质量提高具有显著作用(p<0.01和p<0.05)。研究表明,刺楸种子属于形态-生理休眠类型,采用鲜种+GA3+变温层积催芽的综合处理方法能有效解除刺楸种子休眠。     

Improving seed germination and seedling growth of Omphalea oleifera (Euphorbiaceae) for restoration projects in tropical rain forests

To improve the restoration of tropical rain forests, we tested the germination of seeds of Omphalea oleifera collected from soil (S) and from trees (T) in the 2001 dry season (Spring), at the beginning of a dry season (2005a, winter) and in the rainy season (2005b, winter). All seeds had high water content (WC, 31–33%), and the lipid content varied from 14 to 46%. Seedlings from seeds collected in 2001 were subjected to moderate water stress as a preconditioning treatment for severe stress. T-seeds collected in the dry season had high WC, rapid and high germination percentage; S and T-seeds collected in winter (2005) had also high WC but were dormant. GA₃ (250 ppm) broke this dormancy. S-seeds collected in the dry season or at the beginning of it had relatively low WC and low and delayed germination. Some 2001 S-seeds produced albino seedlings. The critical water content for maintaining ecological longevity in these seeds was ∼15%. Seeds collected in 2005b that were dehydrated for 20 days in a moist and fresh atmosphere lost their viability, showing recalcitrant behavior. T-seeds with the lowest lipid content (2005a) after dehydration maintained low germination (15 ± 18%). In all samples the seed size varied widely and was not predictive of seed WC. Embryos taken from dehydrated seeds had two to four times higher WC than the seeds, but germination did not take place. Laboratory and field germination of dormant seeds showed that viability may be maintained for at least 2–3 months on a moist substrate (soil or agar). Moderate water stress at the seedling stage reduced the efficiency of biomass production. Response to this water stress was expressed more in physiological traits than in morphological characters, consequently biomass allocation was maintained and plants retained most of their morphological characteristics (root:shoot ratio, leaf area ratio, specific leaf area, leaf weight ratio). Moderate water stress did not increase the tolerance of seedlings to severe stress, causing leaf shedding and plant death. For restoration purposes we recommend that T-seeds be germinated immediately avoiding dehydration. The use of S-seeds could result in unhealthy seedlings. Seed recalcitrance and the response to moderate water stress restrict germination and establishment to small gaps, where this species naturally grows. We suggest that before introducing O. oleifera in restoration programs, a plant cover should be built to reduce soil water deficit. It is necessary to improve methods to increase potential seed longevity in storage.     

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.     

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.     

青钱柳种子赤霉素处理育苗研究

为了研究青钱柳种子破除休眠,提前播种出苗的方法。采用赤霉素不同浓度溶液对青钱柳种子进行"浸泡后直接播种"、"浸泡并沙藏后播种"2组种子处理育苗试验。结果表明:浸泡后直接播种没有打破种子休眠,播种当年出苗率为0,第2年才出苗;浸泡并沙藏后播种能打破种子休眠,播种第1、2年均出苗,总出苗率13.54%~28.13%,第1年出苗率2.08%~5.21%,占总出苗率的9.1%~27.8%。其中,赤霉素500、750 mg/L浓度溶液浸泡及沙藏处理后,破除种子休眠效果明显,当年出苗率为5.21%,依次占总出苗率的23.8%、27.8%,是适宜的种子处理溶液浓度。     

女贞种子和幼苗对模拟酸雨的反应

将女贞种子和１年生幼苗置于不同ｐＨ值的模拟酸雨条件下观测和分析其形态和生理变化。结果表明,不同处理间女贞种子发芽率无统计上的显著差异,但ｐＨ２．０和ｐＨ３．５的模拟酸雨对种子发芽显示了一定的抑制作用。在ｐＨ２．０的模拟酸雨条件下,女贞幼苗叶片表现明显的受害症状,叶绿素含量下降,细胞透性增加,叶汁液酸化,从而使幼苗生长严重受阻。在ｐＨ３．５的处理下幼苗没有表现明显的形态和生理变化,但生长量呈现下降趋     

秃叶黄皮树和黄檗种子萌发习性的比较

对秃叶黄皮树和黄檗种子进行了种子形态、种皮透水性、发芽率等方面的比较研究。结果表明：种皮对秃叶黄皮树和黄檗种子的透水性有较大影响，前者透水性较后者好；秃叶黄皮树种子的田间发芽率为68．7％，极显著高于黄檗的36．3％；秃叶黄皮树种子和黄檗种子具有休眠特性，且秃叶黄皮树种子的休眠较黄檗浅，经过低温层积后两种种子的萌发率都有所提高。     

'紫梗籽银'桂种子休眠原因的初步探讨

通过对‘紫梗籽银’桂种子种皮结构的电镜扫描、种子发芽率、生活力、种皮吸水量测定以及种子不同部位浸提液对白菜种子萌发影响的试验,初步探讨了‘紫梗籽银’桂种子的休眠原因。结果表明,‘紫梗籽银’桂种子坚硬的外种皮不是引起休眠的原因,种子的休眠可能是由于种皮和种仁内含有发芽抑制物质引起的。     

Seedling growth and establishment in natural stands of yellow-cedar (Chamaecyparis nootkatensis) seedlings derived from the use of modified seed dormancy-breaking treatments

Following dispersal from the parent tree, seeds of yellow-cedar (Chamaecyparis nootkatensis[D. Don] Spach) exhibit low germination, primarily as a result of coat-imposed dormancy. Dormancy of the mature (intact) seed is effectively terminated by traditional warm/cold treatments. A chemical treatment using the anaesthetic 1-propanol combined with a three day warm water soak (30 °C), a two day GA₃ treatment and 60 d of moist chilling not only promotes high germinability of yellow-cedar seeds, but also elicits vigorous post-germinative growth following seedling emergence under nursery greenhouse conditions. Here we compare the effectiveness of the more traditional warm/cold treatments with the chemical treatment in terms of their capacity to elicit vigorous growth and establishment in natural stands following transplant of seedlings from a nursery greenhouse environment. Two seed lots (42313 and 43697) and open-pollinated seed from parent trees 13-6 and 19-8 showed equivalent seedling growth in natural stands following the chemical treatment and two traditional warm/cold treatments typically used for dormancy breakage by the forest industry and by the Ministry of Forests in British Columbia. The chemical protocol offers the advantage of reducing the time required to break seed dormancy. We have now demonstrated that it yields seedlings that exhibit vigorous growth and are capable of withstanding the vagaries of the environment.     

红皮云杉最佳播种量的研究

本文描述了红皮云杉的最佳播种量的研究，结果表明，其最佳播种量为１５ｋｇ／ｍｕ，这不但可以节约种子，而且还可以提高苗木质量。     

Enhancement of seed germination in Macaranga peltata for use in tropical forest restoration

We used pre-sowing treatments v/z., soaking seeds in concen- trated sulphudc acid （CSA）, gibberellic acid （GA）, combined treatment of CSA ＋ GA and mechanical scarification to overcome seed dormancy and enhance synchronous germination of Macaranga peltata seeds. We analysed percent seed germination data by logistic regression and con- finned that except in GA treatment, time and acid concentration together were crucial for enhancing germination. The combination treatment of CSA and GA resulted in higher percent germination （up to 74%） than either treatment used separately, but produced defective seedlings （26%）. Mechanical scarification of seed coat had the greatest impact in enhanc- ing germination （78%） and reducing imbibition time （6 days） against the control （0%）. Germination studies and SEM analysis confirmed that seed germination in M. peltata was inhibited by seed coat dormancy.     

云锦杜鹃等3种野生杜鹃花属植物在广东天井山苗期生长特性研究*

对云锦杜鹃（Rhododendron fortunei）、毛棉杜鹃（R. moulmainense）和刺毛杜鹃（R. championae）3种野生杜鹃花属植物在广东天井山林场的生长特性包括种子发芽、幼苗形态建成及苗木生长节律进行大田观测,结果表明：云锦杜鹃、毛棉杜鹃和刺毛杜鹃种子成熟度较好,平均发芽率分别为77.83%、65.83%、83.34%,可以用种子进行苗木繁殖;幼苗形态建成较为缓慢需80～95 d,为播种繁殖的关键期。3种植物生长期约为10个月,高生长集中在3月下旬至9月中旬,9月中旬至11月下旬进入缓慢生长期,12月下旬基本停止生长进入休眠期。刺毛杜鹃在12月下旬是否完全进入休眠期有待进一步研究。     

美国五种灌木种实形态特征及其萌发特性的初步研究

采用常规的水浸催芽方法,对引自美国的5种共7个种源的灌木树种种实的萌发特性进行了初步研究。对水浸催芽不易萌发的种实再采取其它催芽方法进行实验。结果表明:黑油脂木(Sarcoba tusverm icula tus)和沙生胶兔木(Chrysotham nus nauseosus ssp.turbina tus)的果实特别容易萌发,采用常规水浸处理即可得到较高的发芽率;不作任何处理即进行直播,其出苗率也很高;而四翅滨藜(Atriplex canescens)、巨四翅滨藜(A.canescens ssp.gigan tea)、三齿滨藜(Atriplex.triden ta ta)和内华达麻黄(Ephedranevadensis)的种实,常规水浸处理发芽率很低,通过混沙催芽、层积催芽等方法可以提高种实的发芽率和出苗率。     

Germination and seedling growth of Quercus vulcanica: effects of stratification, desiccation, radicle pruning, and season of sowing

Effects of stratification, desiccation, radicle pruning, and season of sowing on Quercus vulcanica germination and growth were studied to identify optimum nursery procedures for artificial regeneration of this species. Following stratification (0, 2, 4 and 8 weeks), acorns were germinated, and acorn moisture content and germination performance were also determined at various times during desiccation. In early December unsprouted acorns were planted in containers, and in early April sprouted acorns, which had been stored in polyethylene bags at 4 °C, with radicles left intact or with radicles pruned back to 1.0 cm were planted in containers.Stratification for 2 and 4 weeks did not increase germination percentage but significantly increased germination rate. Germination percentage of the seeds dropped when the moisture content of the seeds was reduced by desiccation, and the critical minimum moisture content of the recalcitrant Q. vulcanica acorns was found to be 11–16%. Spring sowing of sprouted acorns altered the morphology the containerized seedlings and caused the formation of significantly more main roots, but resulted in significantly less shoot height and shoot dry weight. Spring-sown sprouted acorns had also a significant advantage over the fall-sown unsprouted acorns in seedling survival, and thus nursery personnel should not be concerned if acorns sprout before sowing.     

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.     

NaCl对绒毛白蜡种子萌发和幼苗生长的影响

报道了ＮａＣｌ对绒毛白蜡种子萌发，幼苗形态生成，以及不同生理阶段的幼苗对ＮａＣｌ的忍耐能力。ＮａＣｌ能降低种子的发芽质量，不利于幼苗的形态生成。绒毛白蜡在开始形成真叶时期对ＮａＣｌ最敏感，此期幼苗耐盐能力最弱。随着幼苗的生长发育和耐盐能力的增强，两对真叶的幼苗比一对真叶的幼苗在ＮａＣｌ溶液中存活率上升。     

药用植物母猪果种子发芽试验

药用植物母猪果种子外果皮较厚,进行种子繁殖时,剥去外果皮可以提高种子的发芽率.用赤霉素(GA3)和生根粉(ABT2)处理去外果皮的种子,可以迅速减少母猪果种子内含的抑制物质,打破种子休眠,使种子萌发.     

浸种时间与播种密度对半枫荷种子萌发和幼苗生长的影响

为提高半枫荷苗木质量,通过浸种时间与播种密度对半枫荷种子萌发和幼苗生长影响研究。种子萌发试验以半枫荷的种子为材料,设置0h、12h、24h、48h、60h共计5种浸种时间处理,观察记录半枫荷种子的场圃发芽率和发芽势;播种密度试验以半枫荷种子为材料,设置280粒·m^-2、66粒·m^-2、44粒·m^-2、33粒·m^-2共4种不同播种密度,测量1a生半枫荷幼苗苗高、地径、主根长、一级侧根数及生物量。研究结果表明:半枫荷种子的适宜浸泡时间为48h,结合半枫荷苗木的质量和数量,半枫荷的适宜播种密度为44粒·m^-2。     

林木种子休眠研究评述

种子休眠,是指在充分满足各种发芽条件时,有生命力的种子一时不能发芽或发芽困难的自然现象。处于休眠的种子,种皮坚硬、含水量低,细胞内养分处于难溶态,代谢活动较低。一般将种子休眠划分为三个类型:即强迫休眠、生理休眠和综合休眠。种子生理休眠的机理包括:种果皮的抑制;植物激素的作用;种子的二次休眠;综合因素造成的休眠;分子变化等方面。