乌桕种子的脱蜡处理法

乌柏是我国特产的经济树种,种子能榨油、点灯、制机器润滑油与墨油等。种子外的蜡质可做肥皂与蜡烛的原料。乌柏在播种育苗前,必须除去柏子上的白色蜡层,这样才能使种子充分吸收水分,提早发芽,并防止鸟类啄食种子,以免种子遭受损失。过去脱蜡法有两种:用草木灰或石碱浸     

厚荚相思种子催芽试验总结

介绍一种有利提高厚荚相思苗木质量最有效的种子催芽方法，解决了厚荚相思播种育苗时因种子表面的蜡质层而致种子发芽先后参差不齐的问题，在生产中具有一定的参考价值。     

紫穗槐播种育苗试验

紫穗槐种子外壳紧裹蜡质,影响吸水。播种育苗如不作催芽处理,不但发芽迟缓,出苗极不整齐,而且影响苗木的质量与产量。笔者自2003年以来,连续3年在0.9亩圃地上用高温热水浸种催芽育苗,累计收获壮苗20.6万株。对紫穗槐播种育苗的方法与结果,作了初步试验,现初报如下。高温热水浸种催芽的探索用高温热水浸种的目的在于融化种子外层的蜡质,人为破坏种子的生理休眠,促其萌发。但是采用多高温度热水和浸泡多长时间恰到好处?有关资料上说得不甚明了。2003年春第一次采用40℃温水浸泡,不停搅拌,使种子均匀受热,半小时后用漏勺捞出,置荫凉处冷却,并喷…     

油树育苗试验初步报告

一、前言油树适应性强,分布较广,木材坚硬,果实含油较高,是我国北方重要木本油料树种之一。近几年来,我省许多地区和单位开始大面积育苗、造林,由于油树果实用冷榨法榨油后,种子外表还附有油脂和蜡质,种壳坚硬,透水通气性差,难以吸水发芽,加     

小粒种咖啡种子发芽指标测定

咖啡种子质量是确保咖啡育苗中出苗率和壮苗率的关键指标,试验采用常规沙床催芽育苗方法,以周（w）为测算时间单位,对小粒种咖啡种子发芽指标进行测算,探讨用发芽指标衡量小粒种咖啡种子质量。结果显示,发芽势（GE）、发芽率（GP）、发芽指数（GI）、活力指数（VI）、发芽速率系数（CRG）、发芽速率指数（IRG）、发芽整齐度系数（CUG）和发芽时间变异系数（CVT）指标的平均值分别为81.6%、96.8%、28.19、236.94、0.2724、19.36、1.4137和0.2295,重复数的平均值具有较好的代表性,可作为衡量小粒种咖啡种子质量的参考指标。     

汉中地区山桐子大田育苗种子萌发试验初报

大田育苗条件下山桐子种子不同处理方法对其萌发的影响的结果表明:用水温40℃浸种4 h处理山桐子种子,揉捻去除种子表层蜡质,发芽率达10%~15%,添加洗衣粉、纯碱、草木灰揉捻去除种子表层蜡质对种子萌发率提高没有效果,1年生苗育苗密度100株/m2较适宜,播种量900~1 200 g/亩。     

依兰香播种育苗研究初报

依兰香一般用种子繁殖。由于其种皮厚,表皮背面有一层蜡质,不易渗水,播后很难吸胀开裂,需较长时间胚根才能伸出,所以出芽慢,不整齐。目前国外有关这方面的资料较少。据马尔加什报导,用70°—80℃温水浸种,冷却后即行播种,能促进种子萌发。我们引用此法进行了试验,结果不太满意。云南西双版纳依兰香种子成熟期正处冬季低温阶段,种子发芽更慢。如何搞好播种育苗工作,是急待研究解决的问题。从1973——1978年以来,我们对依兰香种子处理和冬季育苗进行了反复试验,现将我们的初步认识概述于后:     

山椒子播种技术初探

山椒子(Uvaria grandiflora Roxb.)作为一种野生果树资源,有重要的栽培和发展前景。本文探讨20、40、60℃温水浸泡种子对其发芽的影响,得出播种前用40℃温水浸泡种子1h可提高种子发芽率,缩短平均发芽时间,提高种子发芽能力,为今后山椒子播种育苗提供参考。     

七叶树冬季播种育苗技术

详细总结了七叶树冬季播种育苗的母树选择、种子采集、种子处理、贮藏、整地、播种、覆膜及土、肥、水管理等技术。采取七叶树冬季播种育苗技术,减少了种子的贮藏时间,节约了贮藏成本,降低了因贮藏时间过长,可能出现的种子腐烂风险。通过对比试验,七叶树冬季播种育苗,种子发芽出土时间提前,缩短了种子发芽出土苗周期,提高了种子出苗率和苗木质量。     

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。     

Enhancement of Seed Germination in Trema orientalis (L.) Blume—Potential Plant Species in Revegetation of Mine Wastelands

Natural forest succession takes a long time to accumulate sufficient nutrients to support plant growth and enhance soil microbial activity. Human intervention in selecting native pioneer plant species is therefore required to accelerate sustainable restoration. Trema orientalis (L.) Blume, a fast growing pioneer plant species, has the ability to grow in nutrient deficient soils and proves to have reclamation potential in mine wastelands. However, its use has been limited due to low germination percentages and nonsynchronous seed germination. In the present study we tested the effect of sulphuric acid (H₂SO₄), hydrochloric acid (HCl), gibberellic acid (GA₃), and potassium nitrate (KNO₃) in varying concentrations and time durations on germination percentages and seed germination synchrony. We found that all treatments had a significant effect in predicting seed germination probabilities. Logistic regression analysis revealed that treatment solution and concentration had a significant effect on seed germination. Treatment with concentrated H₂SO₄ for 15 min increased germination up to 92% within 20 days with the least imbibition time (8 days) and highest Seedling Vigor Index (491). The scanning electron microscope images of seeds treated with H₂SO₄ showed complete dissolution of the honeycomb-like network of deposits on the seed coat surface removing the physical barrier and enhancing germination.     

额济纳胡杨林土壤含水量时空变化的研究

使用管状土壤水分仪,对额济纳胡杨林、沙枣林、柽柳林以及其它不同样地的土壤含水量时空变化进行了调查研究。结果表明,大部分样地有大约20CM的干沙层,使表层土壤含水量最低;土壤剖面的30~150CM土层内,随土壤深度的增加,土壤含水量逐渐增大;沙枣林和柽柳林的土壤含水量明显高于胡杨林土壤含水量;土壤质地的变化和三种林型耗水量的差异是土壤含水量高低变化的原因;2004年5月份的土壤含水量明显高于2003年7月份的土壤含水量。     

民勤绿洲沙化退耕地造林树种水分生理及其抗旱性评价

对民勤绿洲沙化退耕地造林树种梭梭、沙拐枣、花棒、柠条、柽柳、毛条、沙枣的水分生理测定的结果表明：耐旱树种具有水势低、水分亏缺大和保水力强以及变化幅度大等特点,7个树种抗旱力大小为梭梭〉柽柳〉花棒〉柠条〉毛条〉沙枣〉沙拐枣。     

外源药剂对四种苗木晾晒失水及造林成活率的影响

采用不同复配药剂对1年生柠条、沙枣、红柳、紫穗槐苗木蘸根处理后进行晾晒的试验结果表明：随着苗木晾晒时间的延长,苗木累计失水率增加,失水速率减小;采用外源药剂处理苗木能够减少苗木起苗后的水分损失,提高造林成活率,且以处理Ⅱ的效果最好。     

羽脉山黄麻的生物学特性及其开发潜力的研究

羽脉山黄麻是1种根系发达、对环境要求较低、适应能力强、材质优良、生长速度快的优良树种,具有良好的防护用途和很高的经济开发利用价值。在目前我国森林资源匮乏、森林质量不高、可用资源不断减少的情况下,大力发展羽脉山黄麻具有重要的生态、经济和社会意义。笔者以三峡库区香溪河流域的调查为依据,分析说明羽脉山黄麻的生物学特性、生理特性、生态特征及树种改良的方法及其开发潜力。     

北方耐寒型彩色树种引种试验

文章以银果胡颓子、银柳、兰云杉和紫叶稠李等树种为例,介绍了扦插繁殖、组织培养快速繁殖和成树嫁接的关键技术,最后对耐寒型彩色树种在我国北方寒冷地区的引种推广应用前景进行了展望。       

油松种子“引动”处理对发芽效果的影响

试验测定了不同化学药物、浓度、浸泡时间和单纯用水浸泡渗透处理对油松种子发芽的影响。结果表明,阿司匹林、赤霉素、聚乙二醇对油松种子发芽有显著的促进作用,经过3种药物处理的种子在室温11~14℃的情况下,第6天或第7天开始发芽,对照第9天发芽;发芽势（第10天的发芽率）经过处理的在22%以上,高者可达31%,而对照仅为8.3%。单用自来水做渗透引动处理也能提高油松种子的发芽势和发芽率。     

Enhancing germinability of Schinus molle L. seed lot from Ethiopia with specific gravity and IDS techniques

The IDS (Incubation, Drying and Separation) method was tested on Schinus molle L. seeds collected from Ethiopia in an attempt to sort non-viable from viable seeds. Seeds were incubated for 24 h followed by one, three, four, five, six, nine and twelve hours of drying and then separated in water. All IDS treatments gave 80.5–93.5% germination in the sunken fraction compared with 61% for untreated seeds. The mean germination time of sunken seeds reduced from 11.2 (control) to 8.9–9.2 days (IDS-treated). Specific gravity separation in water of untreated seeds was also tested, and the germination capacity of sunken fraction was 83.5% with a mean germination time of 9.3 days. IDS method can, therefore, be used to enhance both percentage and rate of germination of a seed lot of Schinus molle, which is desirable to produce uniform and vigorous seedlings in the nursery or out in the field.     

Germination of Eucalyptus sieberi L. Johnson seeds. II. Internal water relations

At 15-20 degrees C, seeds of Eucalyptus sieberi L. Johnson need to maintain a water content equal to 30% or more of dry weight for approximately 60 h in order to germinate. Several shorter periods of imbibition at 30% water content separated by between 6 and 120 h desiccation were as effective as an unintenupted imbibition in bringing seeds to the point of germination. Even after 8 months' desiccation an earlier imbibition shortened the time required for the completion of germination, although it did not hasten the onset of germination. The water potential of seeds sufficiently hydrated to germinate was about -0.6 MPa, whereas that of the embryo was only about -4.5 MPa. The difference was caused by the inhibition of water uptake by the inner integument of the seed coat. During germination, reserve protein in a small group of cells above the collet was hydrolyzed. Subsequent expansion of these cells caused rupture of the inner integument thereby allowing further water uptake by the embryo. The balance of water absorption and evaporative loss by the outer integument was such that most seeds on a moist substrate but exposed to dry air (6.5-8 x 10(-4) MPa) did not maintain the 30% water content necessary for germination. Thus although able to germinate on seedbeds subject to intermittent drying, E. sieberi seeds have the capacity to avoid germination except under humid conditions.     

Streamside trees: responses of male, female and hybrid cottonwoods to flooding

Cottonwoods, riparian poplars, are dioecious and prior studies have indicated that female poplars and willows can be more abundant than males in low-elevation zones, which are occasionally flooded. We investigated the response to flooding of clonal saplings of 12 male and 9 female narrowleaf cottonwoods (Populus angustifolia) grown for 15 weeks in a greenhouse, along with three females of a co-occurring native hybrid (Populus?×?jackii?=?Populus deltoides?×?Populus balsamifera). Three water-level treatments were provided, with substrate inundation as the flood treatment. In the non-flooded condition, the hybrids produced about four-fold more dry weight (DW) than the narrowleaf cottonwoods (P??P. angustifolia male?>?P.?×?jackii female. This indicates that narrowleaf cottonwoods are relatively flood tolerant and suggests that females are more flood tolerant than males. We propose the concept of 'strategic positioning', whereby the seed-producing females could be better adapted to naturally flooded, low-elevation streamside zones where seedling recruitment generally occurs.