微量元素对油松苗生长的影响

于年间在哈尔滨园林研究所苗圃,用不同的微量元素和不同浓度浸泡种子和喷洒苗木进行了微量元素对油松苗木生长刺激作用的实验。实验结果表明,用1%和02%浓度的Mn浸泡的种子发芽效果最好,与对照组相比,1%浓度Mn处理的种子发芽率提高了9%~19%,0.2%浓度Mn处理的种子发芽率提高了12%-14%。用硼处理的种子的发芽率最低。对用微量元素施表肥(叶部喷洒)而言,Mn和Mo微量元素效果较好,且低浓度处理效果更好。用低浓度Mn和Mo喷洒的苗木的高度和叶绿素含量均比未处理的苗木高。与种子浸泡法相比,叶部喷洒的效果更好。表7参7。     

Effects of simulated acid rain on seedling emergence and growth of five broad-leaved species

lntroductionAcidrainemergedasanenvironmentalissueofincreasingconcernintheIate197osinChina.TheresuItsofnationwidemonitoringdatagatheredshowedthatwidespreadoccurrenceofacidrainwasconcentratedinsouthernpartoftheYangtZeRiver,especiallyinsouthwesternregion,whereprecipitationintheIate198oswasfoundtohaveaveragepHvaI-uesbetWeen3.5and4.8(Yang1989;Xu199O).ow-ingtotheincreasingseriousnessofacidraininsouthwesternChina,aseriesofresearchprogramshavebeensetupbytheNationaIEnvironmentaIPro-tectionoffice…     

吲哚丁酸对一串红种子萌发及幼苗生长的影响

不同浓度吲哚丁酸(IBA)对一串红种子萌发及幼苗生长影响的研究结果表明:10-6 mg/L的IBA可以增加一串红种子的发芽率、侧根数、叶绿素含量和根系活力。     

土壤质地和种子成熟度对水翁种子发芽和幼苗生长的影响

文章研究了不同土壤质地、种子成熟度和果肉对水翁Syzygium nervosum种子发芽和幼苗生长的影响,结果表明:不同质地的土壤对水翁种子的最终发芽率影响不大,但对种子发芽的速度和幼苗的株高有显著影响,种子发芽速度为砂土壤土砂壤土,幼苗株高为砂土砂壤土壤土;种子的成熟度对种子的发芽率和幼苗的株高有显著影响,幼苗株高为成熟种子未成熟种子过熟种子;果肉对种子的发芽率和幼苗的株高影响不大,但对早期发芽的速度有影响。     

种子不同保存方法及播种时间对水紫树发芽和幼苗生长的影响

以田间调查数据为基本资料,对极耐湿的水紫树种子进行沙藏和冷藏保存,分别于3月17日、4月1日播种,对其播种苗的发芽、幼苗生长进行统计分析。结果表明：冷藏保存的种子发芽慢,持续时间长,而沙藏保存的种子发芽相对较快,持续时间短,苗齐较冷藏处理早21 d。沙藏保存种子的幼苗高、地径的全年平均累计生长量极显著大于冷藏处理。3月17日播种的幼苗高、地径的全年平均累计生长量极显著大于4月1日播种幼苗的生长量。     

Effect of sowing date on seedling emergence of species with seeds enclosed in a stony endocarp

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.     

4种盐胁迫对黑种草种子萌发的影响

为探讨盐胁迫对黑种草种子萌发及幼苗生长的影响,用不同浓度的NaCl,Na2SO4,MgCl2单盐溶液和质量比NaCl∶Na2SO4=2∶1的复合盐溶液处理黑种草种子,观测不同处理下黑种草种子的发芽率、发芽势、发芽指数、萌发活力指数、盐害指数,以及幼苗叶面积、胚根长度和胚芽长度的变化。结果表明:盐溶液处理均对黑种草种子的萌发有显著抑制作用;浓度为1.50%的盐胁迫均能导致种子活力丧失;胚芽和叶片比胚根对盐胁迫更敏感。     

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。     

种子贮藏和播种方式对红椆发芽及苗木生长的影响

以红椆种子为试验材料,进行贮藏和播种方式对红椆种子发芽和苗木生长的影响试验。结果表明:不同贮藏方式对红椆种子发芽率有极显著影响;不同播种方式对红椆种子发芽率和苗木地径生长无显著影响,但对苗木成活率和苗木高生长影响极显著。     

小叶青冈种子萌发与休眠特性研究

采集了小叶青冈分布最北缘的种群的果实,对其果实和种子的形态性状进行了详细的测量分析,并详细探讨了其种子萌发的特性。结果表明,小叶青冈果实长的变异幅度显著大于果实宽的变异幅度;种子干重占果实干重的比例高达74%,种子含水量显著高于果实的含水量。去除果皮和低温层积显著提高了小叶青冈种子萌发率和萌发速率。最终推断小叶青冈种子存在明显的休眠现象,休眠的类型为浅生理休眠。     

Differentiation of seed germination and early seedling growth in ten provenances ofEucalyptus microtheca

An investigation of seed germination and early seedling growth ofEucalyptus microtheca was based on seed collection from 10 widely separated provenances in Australia. Genetic variation of seed germination and early seedling growth was observed among a series of provenances whose natural habitats range from different climatic condition. In the ten provenances, both the model of seed relative germination percentage and the model of seed total germination percentage fitted Logistic regression [y=a/(1+exp(-ex+b))]. In comparison with provenances from four high temperature (mean annual maximum temperature >30.0 °C; mean annual minimum temperature >17.0 °C) areas, six low temperature (mean annual maximum temperature <30.0 °C; mean annual minimum temperature <17.0 °C) areas showed the fast germination rate and the high total germination percentage. For each provenance we have 45 seedlings equally divided into three watering levels (100%, 50%, and 25% of field capacity), and studies on relationship between early seedling growth and climatic factors of the natural habitat of provenance. In control treatment, height growth of the seedling has been associated with intrinsically the driest quarter precipitation in the seed collection areas of provenance. In all the treatments, length growth of the biggest leaf of the seedling was related to mean annual maximum temperature and mean annual minimum temperature in origin of provenance. In contrast, basal diameter growth of the seedling was related to mean annual minimum temperature of the seed collection areas in water stress treatment. From an ecological viewpoint, the fast germination rate and the high total germination percentage of the seed and rapid early growth of the seedling appear to be favourable adaptations to the climatic conditions prevailing in the natural habitat of provenance. Responsible Editor: Chai Ruihai     

Overcoming seed dormancy of mooseer (Allium hirtifolium) through cold stratification, gibberellic acid, and acid scarification

Mooseer(Allium hirtifolium Boiss.) is bulbous perennial herb widely used in pharmaceutical and food industry in Iran.We studied germination of mooseer seeds in two separate experiments.In the first experiment,we evaluated four treatments:sulfuric acid scarification,sandpaper scarification,cold stratification,and gibberellic acid(GA 3) application.In the second experiment,we evaluated combinations of these treatments.All treatments in the first experiment had no effect on seed germination,suggesting that mooseer seeds have physical and physiological dormancy.In the second experiment,the highest germination percentage(86.6%) was observed after five minutes scarification with sulfuric acid(75% v/v),followed by 60 days of cold stratification.Duration of sulfuric acid scarification(5,10,and 20 min) did not affect germination rates,but increasing duration of cold stratification(from 15 to 60 days),increased germination from 28.3% to 86.6%.Our study showed that mooseer seeds have both physical and physiological dormancy.     

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.     

Restoring rainforest species by direct seeding: Tree seedling establishment and growth performance on degraded land in the wet tropics of Australia

The establishment and growth performance of directly seeded rainforest tree species on degraded sites was investigated in the wet tropical region of north east Queensland, Australia. Trials were established at three degraded sites previously covered by rainforest, using two different sowing times (the beginning and end of the wet season), and a range of species having different seed sizes and successional status. The results two years after sowing showed that the effects of sowing time on tree seedling establishment were small despite pronounced differences in cumulative rainfall received by the seedlings. Results suggested that at some sites more serious weed competition might be avoided by sowing later in the season. Although some small seeded early successional species could grow quickly, the establishment of these was found to be significantly negatively affected by the growth of weeds, and in most cases, large seeded species showed more consistent establishment. On the other hand the growth rates of larger seeded species were often rather slow, limiting their contribution to early site capture. Results indicate that direct seeding can be a viable establishment method, but the identity of species to be used, the circumstances under which they should be directly sown and the most appropriate timing of sowing will vary with situations. Species characteristics, including seed size, growth rate potential and light requirement will be important to consider in relation to the probable conditions that will develop for seedlings following germination (particularly in relation to plant competition) with or without post-sowing site management, such as removal of weeds.     

Effects of seed mass and emergence time on seedling performance in Castanopsis chinensis

Seed mass and emergence time may influence fitness of plants. The experiments were conducted to investigate the effects of seed mass and emergence time on the performance of seedlings of Castanopsis chinensis, a large evergreen tree species with limited tolerance of shade. The treatment consisted of three light regimes: 100%, 15% and 2% of full sunlight. Germination rate and germination time showed a significant correlation with seed mass. Germination rate differed among the three light regimes. Early-emerging large-seeded seedlings in 100% light produced the heaviest seedlings, while those resulting from smaller late-emerging seeds and grown under 2% light regime produced the lightest seedlings. Relative growth rate (RGR) decreased with seed mass in all three light regimes, and seedlings of C. chinensis have a higher RGR in high and intermediate light levels compared to low light. In contrast, the effect of emergence time on RGR was not significant. The growth of C. chinensis seedlings were significantly influenced by seed size, emergence time, and light conditions. For each month, the mean height of seedlings was significantly greatest for large-seeded seedlings and significantly lowest for small-seeded ones, irrespective of emergence time and light conditions. Regeneration success of C. chinensis appears to be regulated by the interactive effect of seed mass, emergence time and light regime.     

植物激素对杉木种子发芽和幼苗生长的影响

试验结果表明，植物激素对杉木种子发芽势，发芽率，田间出苗数，杉木幼苗生长及苗木出圃合格率均有显著影响。以赤霉素浓度２５×１０＾－６的溶液处理杉木种子的效果最佳。种子处理后宜稀播。     

Enrichment of big-leaf mahogany (Swietenia macrophylla King) in logging gaps in Bolivia: The effects of planting method and silvicultural treatments on long-term seedling survival and growth

To insure adequate regeneration and future timber yields of mahogany (Swietenia macrophylla King), many logged forests will have to be restocked through enrichment planting and managed using silvicultural techniques that maintain this species’ long-term survival and growth. This study compared the effects of planting method and two silvicultural treatments on the survival and growth of mahogany seedlings in logging gaps in Bolivia. We tested the hypotheses that survival and growth will be higher among transplanted seedlings than seedlings established from sown seeds and higher in silvicultural treatments that reduce competing vegetation and increase light. The first silvicultural treatment consisted of gaps logged 6 months prior to planting, gaps logged just prior to planting, and gaps treated with herbicide prior to planting. The second treatment, applied 12 months after planting, consisted of manual vegetation cleaning around mahogany seedlings in half of the gaps. The first hypothesis was supported in terms of initial seedling growth but not survival, which was similar between planting methods during the 12-92 months after planting. Transplanted seedlings grew significantly faster than those established from sown seeds during the first year, but this growth advantage disappeared by the second year. Although transplants were 84 cm taller than seed-sown seedlings by the end of the study, this height gain was probably not worth the cost of growing and transplanting seedlings. The second hypothesis was supported in terms of both survival and growth. A significantly greater proportion of seedlings survived in herbicide (62%) compared to 6-month-old (46%) and recent gaps (18%) and in cleaned (51%) versus control gaps (39%). Seedlings initially grew faster in herbicide and recent gaps than in 6-month-old gaps. These differences among silvicultural treatments were largely explained by canopy cover, which, throughout the study, was at least 14% lower in herbicide gaps and 9% lower in cleaned gaps relative to their respective alternatives. By 64 months growth diminished to near zero and no longer differed among gap treatments, despite lower canopy cover in herbicide gaps. By 92 months, saplings in herbicide gaps were only 145 and 77 cm taller than those in recent and 6-month-old gaps, respectively. To maximize survival and growth of mahogany seedlings in logging gaps while minimizing costs, silvicultural strategies should focus on direct seed sowing and appropriately timed interventions (i.e. manual cleaning) to control competing vegetation.     

Germination and early growth of sown Quercus robur L. in relation to soil preparation, sowing depths and prevention against predation

A field experiment was established in the autumn of 1992 in order to study predation of acorns, germination and early growth of oak seedlings. The experiment was established on a clearcut and an adjacent oak shelterwood in southern Sweden. In the experiment, a total of 6 840 acorns were sown. The sowing was carried out with different vegetation control and soil preparation treatments and with different planting depths.The germination percentage was highest for acorns sown at five cm depth and lowest for acorns sown on top of the soil, and lower for acorns sown in areas where the humus layer had been removed than in areas where the humus layer was retained. There was no difference in the percentage germination after two growing seasons between acorns sown inside the shelterwood and acorns sown on the clearcut. The height of the seedlings was lowest when the humus was removed while the number of leaves per seedling was lowest for seedlings in untreated areas after two growing seasons. Furthermore, seedlings in untreated areas showed the lowest relative height growth rate during the second growing season. In spite of higher biomass of ground vegetation in undisturbed areas compared to treated areas, no effect of the soil and vegetation control treatments could be found on soil water potentials. The soil temperature and photosynthetic active radiation at seedling level were higher in areas where soil preparation and vegetation control had been performed. However, it was concluded that neither low soil water availability nor low light levels could be the only cause of lower relative height growth rate during the second growing season for seedlings in undisturbed areas.     

金丝桃果实、种子形态及发芽特性的研究

以金丝桃果实和种子为研究材料,1）观察到金丝桃果实形态为卵圆形、红褐色,果皮有水泡状突起;种子形态为圆柱形、深褐色,在显微镜下可看到种皮具有花生壳式的网纹;2）采用浸种、小苏打、赤霉素、冷藏处理金丝桃种子,测定其发芽时间、发芽率、发芽势,结果表明金丝桃种子具有胚休眠特性,赤霉素（500mg／L）和冷藏处理能促进金丝桃种子的发芽,且赤霉素效果较好。     

刺槐种子萌发过程中的生理生化变化

用刺槐种子为材料．初步研究了刺槐种子萌发过程中可溶性糖、可溶性蛋白、丙二醛（MDA）、脯氨酸、过氧化物酶（POD）活性、多酚氧化酶（PPO）活性的变化。结果表明：刺槐种子在萌发过程中．可溶性糖和可溶性蛋白含量呈下降趋势,丙二醛和脯氨酸含量有不程度的升高,POD和PPO的活性都有大幅度升高。