林木种子的发芽技术

依据林木种子的生理、形态特征、解剖结构、在通常采用的6种发芽方法中，选择适合于种子特征（形态、生理）的发芽方法，经100个树种，3000多个种批的发芽验证，总结了4类种子的发芽要点，技术条件，给出100个树种发芽率的最高值，为绿化造林、苗木培育的种子发芽提供参考依据。     

槭属植物种子解剖生物学的研究

对黑龙江省分布的11种槭属植物种子,从形态特征、解剖特征、种子休眠特征、结实规律、种子萌发等方面进行了详细的观测和分析,结果表明:种子外观最大者为拧劲槭,最小为小楷槭;除茶条槭成熟率较高外,一般年份其他种子成熟率30%～50%;槭树种子室温储藏5年,发芽率50%以上;解除槭树种子胚休眠0～10℃低温效果显著,3～4 个月低温即可完成胚的生理后熟.同时描述了槭树种子形态特征与解剖特征间关系.     

干旱半干旱地区主要乔灌木种子形态特征及生理生态特性的研究

干旱半干旱地区,属荒漠、半荒漠及干旱草原地带,自然条件严酷,植被稀少,植物种类比较单纯。一些乔灌木树种种子,在干旱半干旱特定条件下,形成了特有的形态特征和生理生态特性。种子多被有毛、翅或刺;荚果类种子成熟后,果荚自动开裂;一些种子的外种皮木质化;许多种子的外部形态呈圆形或椭圆形;种粒小,每一果实内数量很多;浆果类的果实,大部色泽鲜艳。大多数种子没有生理性休眠;没有生理性休眠的种子发芽都比较快;这些种子发芽温度比一般种子要求高;除个别种子大部属光发芽型;有的树种从开花开始种子就开始成熟,边开花,边结实。这些特点都为其繁衍生存创造了有利条件。干旱半干旱地区乔灌木果实、种子资源丰富,广泛用于食品、医药、轻工业等,具广阔的开发利用前景,应加强研究,保存抗逆基因,培育新品种、新类型,充分发挥经济效益。本文附有简表,对干旱半干旱地区主要乔灌木种子形态特征、生理生态特性及其品质指标、种子贮藏、育苗播种处理方法等进行了统计、分析。     

三十种树木种子发芽条件试验

在测定树木种子生活能力时,一定要在满足该树种的发芽条件下,才能使其发芽。本文用4种促进树木种子发芽的方法,对30种比较难发芽的树种进行试验,提出了各树种最合适的发芽试验方法,为种子检验工作提供了测定依据。     

18个木兰科树种播种育苗技术初步研究

对引入的18个木兰科树种进行了播种和育苗技术研究,对种子的形态特征、优良度、千粒重及发芽率进行了测定,并记载了种子的发芽过程。结果表明,发芽率为4%~81%,发芽率较高的树种分别为深山含笑、云南拟单性木兰、粗枝木莲、苦梓含笑、麻栗坡老君山含笑,其它多数种类的发芽率均低于50%;落叶木莲及大果木莲,马关木莲发芽率最低。另从种子发芽持续时间来看,大多数树种的发芽持续时间在20天以上,麻栗坡老君山含笑所需时间最多,约为42天。木兰科树种宜采取随采随播的育苗方法,播种期拟定在10月下旬至11月中旬为宜。     

树木种子发牙条件试验初报

具有生活力的种子的发芽能力,取决于种子内在因素(如生理成熟等)和适宜的环境条件。未生理成熟的休眠种子,有的也可采取一些适当的措施促进生理成熟,使之发芽。握掌各树种的发芽条件和促进发芽的措施是种子检验方法标准化的前提,也为育苗时种子处理提供合理的方法。试验所用种子来自本所试经林场育苗用的生产性种子。发芽天数以置床之日开始计算,发芽势天数计算是以开始发芽高峰那天,发芽率天数计算至发芽末期开始一连5天发芽不足1％时的前一天。     

种子成熟的特点

一般树种的种子多是生理成熟在先,一段时间之后才达到形态成熟。但也有的种子生理与形态成熟时间几乎一致,或相隔时间很短,如柳树、榆树、泡桐等,当种子达到生理成熟后就自行脱落,应注意及时采收。也有生理后熟的种子,如银杏。当假种皮呈黄色变软,由树上脱落,此时胚还未发育完全,不能立即播种。需经适当条件下的贮藏,采取一定措施才能正常发芽。     

班克木种子形态及发芽特征在种内与种间的变异

对引自澳大利亚的班克木属5个种18个种源进行种子形态、质量以及发芽特征测定,结果表明:班克木属种子形态、质量和发芽特征在种间和种内均有不同的差异表现;香花班克木种子千粒质量最大,约106.5 g,为其他种的4～9倍;种子千粒质量与发芽率无显著相关;除红花班克木在试验期间未发芽外,其余4个种的发芽率皆高于60％,强力班克木发芽率最高,约80％;长圆叶班克木和强力班克木种子发芽速度最快,而香花班克木发芽速度最慢;发芽始期、发芽速度、发芽率、胚轴长、胚根长都和经度呈极显著正相关(P＜0.01),即自西澳的珀斯至东澳的塔斯马尼亚地区,种子的发芽始期越晚,发芽速度慢,发芽率越高,胚轴和胚根的生长量越大.对于5种班克木的发芽特征的研究表明:强力班克木在广州的适应性最强,其发芽率最高,发芽速度最快,发芽最早且胚根长度最大.     

四种常见针叶树种种子发芽对水分胁迫的响应

本文通过用PEG(聚乙二醇)配制不同浓度溶液,模拟不同土壤水势梯度,达到不同水分胁迫水平,进行柳杉、杉木、马尾松、侧柏等树种种子发芽水分胁迫实验。研究结果表明;水势在0～-0.6Mpa,除马尾松外,其余三种树种随水势下降,种子发芽率、发芽指数、苗长、活力指数均呈下降趋势。水势降至-0.86 Mpa时,各树种种子发芽均受完全抑制。其中侧柏在水势降至-0.6Mpa时,种子发芽已受完全抑制。综合比较,各树种种子的耐旱能力大小依次为:马尾松>杉木>柳杉>侧柏。     

珍贵壳斗科树种种苗繁殖研究

选择壳斗科中的主要用材树种、水土保持树种和干瘠裸露地绿化树种共15种，对这些树种的开花与结实期、采种与种子处理和贮藏、果实与种子形态、育苗方法、幼苗形态特征等做了深入的研究，取得较为显的成果。     

Fluorescein diacetate as a viability stain for tree roots and seeds

Fluorescein diacetate (FDA) was tested as a viability stain for roots of green ash as well as for seeds of green ash and 10 other tree species. The viability level indicated by FDA staining of green ash roots agreed well with root growth potential results, bud condition assessment, and foliage browning measurements. In seed viability experiments, the FDA staining intensity of embryos was related to germination in 9 out of 11 species tested using a 30 minute stain incubation period. In the other 2 species, eastern hemlock and Scotch pine, embryo FDA staining intensity and germination were also similar, provided an 18 h stain incubation period was used. When two seedlots of differing viability were tested in each of white spruce, Douglas-fir, and pitch pine, significantly higher germination was reflected in significantly higher embryo FDA staining intensity. In Sitka spruce seed that was heat treated to produce a range of viabilities, the semilog plot of germination (log scale) and FDA staining intensity of the embryo (linear scale) had an r²= 0.95. Based on these preliminary results, FDA shows promise as a rapid viability stain for tree roots and seeds.     

Effects of tallowtree seed coat on seed germination

We measured physiological parameters including water uptake, in-vitro embryo germination ratio, and seed coat structure observed by scanning electron microscopy (SEM) to explore the influence of seed coat on the germination of seeds of tallow tree (Sapium sebiferum (Linn) Roxb.). Tallow tree seeds had good water permeability. We found that germination of cabbage seeds was inhibited when cabbage seeds were soaked in extracted solutions from tallow tree seed coat. Seed coat structure at the side of the radicle appeared to be a barrier to seed germination. We tested methods to break tallow tree seed dormancy. Dormancy of tallow tree seeds was overcome by soaking the seeds in 500 mg·L-1 or 1000 mg·L-1 GA3, followed by 100 days of cold stratification.     

稀土对马占相思和大叶相思种苗的影响

用10～1000 mg/L稀土溶液对马占相思和大叶相思浸种24 h后的试验结果表明：适宜浓度的稀土溶液可促进马占相思和大叶相思种子内含物的转化,从而促进种子的萌发和幼苗生长,但同一稀土溶液对不同树种的适宜浸种浓度不同。马占相思以10 mg/L处理有利于提高种子发芽势并缩短发芽时间;大叶相思10～30 mg/L处理显著提高种子发芽率和发芽势,但没有显著缩短发芽时间。200 mg/L及以上浓度浸种对2种树种种子萌发有抑制作用。考虑指标多重比较差异及经济因素,10 mg/L处理较利于马占相思和大叶相思幼苗高和根系生长。     

Effects of seed traits on the success of direct seeding for restoring southern Thailand’s lowland evergreen forest ecosystem

The success of direct seeding, as a low-cost approach to forest restoration, varies with tree species and seed characteristics. A system to predict which tree species are likely to be suitable for direct seeding would therefore be useful for improving forest restoration projects. Therefore, this study aimed to determine the effects of seed traits on the success of direct seeding to restore tropical forest in southern Thailand. Seeds of 19 indigenous lowland tropical forest tree species were collected, from both the east and west sides of the Thailand peninsular and the following parameters measured: seed size, shape, coat thickness and moisture content. Field trials were established to determine seed germination rates and to calculate a “direct seeding suitability score” for each species, which combined seedling establishment and growth rates. Seed size, shape and moisture content were associated with germination percentage. Species with higher seedling survival tended to have large or intermediate-sized seeds, round or oval seeds and seeds with low or medium moisture content. Only seed coat thickness was significantly correlated with the suitability score (r = 0.65, p < 0.01). Seed coat thickness >0.4 mm coincided with higher rank suitability score. These conditions successfully predicted the success or failure of direct seeding for 15 out of 19 species tested. Eight tree species are recommended as suitable for restoring lowland evergreen forest ecosystems in southern Thailand, by direct seeding.     

Germination ecology of twelve indigenous and eight exotic multipurpose leguminous species from Ethiopia

The germination requirements of seeds of 20 leguminous species were studied in three experiments. In the first experiment, seeds were subjected to mechanical scarification, sulphuric acid and boiling water treatments. In the second experiment, they were treated with dry heat at 60, 80 and 100°C. In the third experiment, seeds were placed at different temperature regimes (10, 15, 20, 25 and 30°C) on a thermogradient. Sulphuric acid treatment improved germination in all the species while mechanical scarification improved germination in 18 out of 20 species. Boiling water treatment improved germination in 15 species but proved to be lethal to five species. Similarly, germination was significantly improved in 11 out of 16 species treated with dry heat. Germination was faster and higher at both 25°C and 30°C and the optimum temperature for germination was between 20°C and 30°C for all the species. Mechanical scarification, sulphuric acid and boiling water treatments as well as dry heat were effective to overcome seed coat imposed dormancy in the species studied. It was not possible to recommend a treatment which is equally effective for all the species. However, boiling water is a practical method for achieving rapid, uniform and high germination except in five of the species for which it proved to be lethal. In the latter case, either mechanical scarification or sulphuric acid treatment should be used. Seeds of Millettia ferruginea should be sown when they are fresh to get high germination as they tend to lose their viability during storage. Results from the present study show that once the dormancy in leguminous species with hard seed coats is broken, the seeds germinate in wide ranges of temperature.     

Seed germination and seedling emergence of four tree species of southern China in response to acid rain

Acid rain has become a major concern due to increasing atmospheric pollution,particularly in China.We investigated whether acid rain inhibits the germination of seeds and subsequent emergence of seedling of four tree species from southern China:Cunninghamia lanceolata,Fokienia hodginisi,Pinus massoniana and Phoebe zhennan by simulating acid rain with pH of 2.5,3.5,4.5 and 5.5.We hypothesized that the inhibitory effect of acid rain on germination of seeds and emergence of seedling varies between species and the degree of acidity.A solution of 1 N H_2 SO_4 and 1 N HNO_3 in the ratio of 10-1 was prepared and diluted to four pH levels,and seeds were supplied with solutions of these pH values and distilled water as control and tested for germination in a controlled growth chamber.The results revealed that simulated acid rain of pH 2.5 adversely affected the germination capacity of F.hodginisi and P.zhennan;while all acid solutions significantly increased germination of P.Massoniana;but had no effect on germination of C.Lanceolata seeds.Strong acid solution(pH of 2.5) adversely affected elongation of radicle and hypocotyl as well as fresh and dry weights of radicle and hypocotyl of tender seedlings.The result demonstrated that seedling emergence is more sensitive than seed germination to simulated acid rain,and germination of conifer species are less sensitive than broad leaved species to simulated acid rain.As a whole,acid rain of pH of 3.5 is the threshold level and acid rain below this value will have a detrimental effect on seed germination and seedling emergence.     

用软X射线检验林木种子发芽率的研究

采用HY-35型软X-射线仪对杉木、柳杉,马尾松和香椿等15个树种的种子进行摄影,并进行定位发芽试验。根据各树种种子X光片的成像特征,得出各树种种子各等级的判定粒效(百分比)。将各等级种子进行合理累加,用差异最小的值估测发芽率,其结果与定位发芽试验所得发芽率基本相符。由此认定,此法可以作为测定林木种子发芽率的重要方法加以推广应用。     

色木槭和拧筋槭种子脱水耐性分析——基于含水量、发芽率和ABA含量变化的结果

通过采集不同发育阶段种子并对其进行自然干燥处理,以含水量、发芽率和ABA含量变化为指标,研究了色木槭和拧筋槭种子在自然发育和干燥过程中的脱水耐性变化.结果表明,色木槭和拧筋槭种子虽经历了成熟脱水,但种子仍不耐脱水;其发芽率和活力指数随发育进程而逐渐增加,但随自然脱水进程而逐渐降低;色木槭和拧筋槭种子最大脱水耐性分别出现在花后100 d和120 d;在整个发育过程中,两树种种子的ABA(脱落酸)含量均较低;拧筋槭种子中ABA含量在脱水过程中呈下降趋势,而色木槭种子中ABA含量在脱水过程中虽有升高但变化不显著.推测ABA含量低可能为色木槭和拧筋槭种子不耐脱水的主要原因之一.     

不同处理方法对短序润楠种子发芽的影响

采取不同激素处理和不同贮藏方法,对短序润楠种子进行发芽试验,分析其种子发芽率及发芽势。结果表明：不同激素处理后,种子发芽率差异不显著;浓度100mg／LNAA处理后的种子发芽势最高,说明该浓度下的NAA能促进种子的发芽速率。土壤保湿贮藏处理的发芽势和发芽率明显高于其它处理,因此土壤保湿贮藏是提高短序润楠种子萌发能力比较理想的一种方法。     

The effect of different pre-sowing seed treatments, temperature and light on the germination of five Senna species from Ethiopia

The germination requirements of five Senna species: S. bicapsularis, S. didymobotrya, S. multiglandulosa, S. occidentalis and S. septemtrionalis have been investigated. Seeds possess dormancy which is caused by their hard seed coats hampering maximum, uniform and rapid germination. To overcome this dormancy, seeds of the five species were pre-treated with (a) mechanical scarification, (b) concentrated sulphuric acid for 15, 30, 45 and 60 minutes and (c) boiling water for 15, 30, 45 and 60 seconds. To determine the effects of temperature on the germination of seeds, pre-treated seeds from each species were incubated at 10, 15, 20, 25 and 30°C. Germination was also tested in the dark. Both acid treatment and mechanical scarification resulted in fast and uniform germination. The highest germination (95–100%) for all species was obtained from seeds treated with sulphuric acid for 60 minutes. Mechanical scarification resulted in 100% germination in all the species except S. septemtrionalis (59%). Boiling water improved germination significantly in S. didymobotrya (98%), S. occidentalis (82%) and S. septemtrionalis (97%), but had very little effect on S. multiglandulosa and reduced germination in S. bicapsularis. Senna seeds germinated over a wide range of temperatures with the optimum temperatures for germination falling around 20–25°C. Germination was either completely inhibited or very low at 10°C. Seeds of all species germinated both in light and dark conditions.