GA3、IBA以及不同基质对精粹百合鳞片扦插繁殖的影响

以亚洲系精粹百合为试材,研究了外源GA3和IBA以及锯木屑、草炭2种基质不同培养方式下对鳞片繁殖的影响。结果表明:锯木屑埋片处理最有利于提高繁殖系数和生根数量,而锯木屑扦插处理形成的小鳞茎个体较大,萌发率高。植物生长调节剂处理各因素的影响效力为激素种类>处理时间>质量浓度。IBA显著促进了小鳞茎形成和发根,且根与小鳞茎同时发生;GA3处理有利于获得个体较大、形状匀称的健壮鳞茎,但繁殖系数较低,根的数量较少,小鳞茎形成1周后基部开始生根,18℃下GA3显著促进了小鳞茎的萌发。培养过程中母鳞片贮藏物质的消耗进程不同:IBA处理的鳞片20℃培养60d后应及时移栽防止小鳞茎腐烂,GA3处理可延长至80d;对照与GA3处理效果相近,但需要较长培养时间和最佳培养温度。     

不同药剂处理对短梗五加种子后熟过程中相关物质代谢的影响

采用不同质量浓度GA3、KNO3处理短梗五加种子,并对层积过程中种子的胚率、可溶性糖、可溶性蛋白及淀粉含量变化进行研究。结果表明:GA3100 mg·L-1和清水处理种子的胚率最好,2种药剂处理均可以提高未层积前种子可溶性糖的含量,GA3100 mg·L-1和KNO310 g·L-1处理可显著提高未层积种子的淀粉含量,GA3300 mg·L-1和KNO310 g·L-1处理可显著提高未层积种子的可溶性蛋白含量,而清水更有利于储藏物质的转化。     

西洋百合“卢浮宫”的组培技术研究

以鳞片为外植体、MS为基本培养基,以不同激素成分及不同质量浓度水平下诱导西洋百合"卢浮宫"的小鳞茎状突起,进行组培试验。结果表明:"卢浮宫"百合的诱导以取其完整的鳞片为外植体、并以鳞片背部突起处紧贴于MS 6 BA2 0mg·L-1 NAA0 2mg·L-1的培养基上诱导效果为最好。"卢浮宫"百合的诱导是由外植体(鳞片)产生小鳞茎状突起而分化成苗的,并不经愈伤组织分化产生。筛选出的最佳继代增殖培养基为MS 6 BA0 7mg·L-1 IBA0 3mg·L-1,生根培养基为1 2MS 6 BA0 3mg·L-1 IBA0 7mg·L-1。移植基质选择河泥和珍珠岩(体积比7∶3)混合,成活率达98%。     

鹰咀扁桃花蕾在低温应激反应中糖含量的变化

为了探明扁桃花蕾的低温应激反应机制,以鹰咀扁桃大蕾期花蕾为试验材料,对花蕾进行4、-2、-4和-6℃低温处理,每6 h取样1次,观测24 h内花药、鳞片、花萼和花瓣4个部位可溶性糖含量、淀粉含量变化,分析比较花药、鳞片、花萼和花瓣4个部位的低温应激反应及抗寒性。结果发现,随着温度降低、时间延长,可溶性糖含量先升高后降低再升高;淀粉含量先降低后升高;总糖含量先升高后降低再升高;可溶性糖/总糖值先升高后降低。花药、花瓣和花萼在-2℃处理下24 h、-4℃处理下18 h和-6℃处理下12 h即有明显的低温应激反应发生,鳞片在-4℃处理下18 h和-6℃处理下12 h才有明显的低温应激反应发生。4个部位的低温应激反应程度由强到弱依次是花药、花瓣、花萼、鳞片,抗寒性由弱到强依次是花药、花瓣、花萼、鳞片。     

赤霉素GA_3对不同层积催芽紫椴种子萌发的影响

为探讨解除紫椴种子休眠的方法,进行了不同温度层积催芽试验,并在此基础上进行了赤霉素GA_3处理后对紫椴种子萌发过程中贮藏物质的影响研究,结果表明:在前期高温后期低温(T20-5)的处理下种子具有较高的萌发指数,50 mg·L-1GA_3可使紫椴种子可溶性糖含量在萌发初期快速升高,以提高种子对逆境的适应能力;而150 mg·L-1GA_3对可溶性糖含量的增加具有抑制作用。GA_3处理对紫椴种子淀粉分解具有促进作用,但不同层积温度对淀粉水解酶活性有影响,为提高淀粉酶活性和可溶性蛋白含量,可适当提高GA_3浓度。     

不同保鲜剂对月季切花保鲜生理初探

实验探讨了不同浓度保鲜剂对月季切花‘粉后'的花径、花枝鲜重变化率、花瓣可溶性糖含量及丙二醛(MAD)含量的影响.结果表明:Ⅵ处理(10%蔗糖+200mg·L-18-HQ+75 mg·L-1GA3+25 mg·L-16-BA)保鲜效果最好,平均花径最大,花枝鲜重变化率最高、花瓣可溶性糖含量及丙二醛(MAD)含量最低.     

激素及低温层积处理对北五味子种子贮藏物质的影响

采用激素及低温层积处理北五味子种子,研究其胚率及贮藏物质含量变化。结果表明:激素及低温层积处理可促进胚形态、生理后熟及贮藏物质代谢,其中6-BA 50 mg·L-1、GA3 200 mg·L-1处理的胚率、可溶性蛋白、总核酸、裂口率和发芽率显著高于其他处理。     

离体贮藏条件对养分消耗及百合鳞茎鳞片生活力的影响

日本进行了一项研究 ,调查不同贮藏条件 ,如温度 [对照 ( 2 5℃ )或 5℃ ]、大气压 [对照或ＣＡ( 50 %Ｎ2 50 %ＣＯ2 ) ]和养分 (对照或含 3%蔗糖的ＭＳ培养基 ) ,在 180ｄ内对麝香百合鳞茎鳞片鲜重、水分、氨基酸、可溶性蛋白质、糖、淀粉、谷氨酸脱氢酶和苹果酸脱氢酶含量的影响。测定从鳞片小鳞茎生长来评价鳞茎鳞片生活力。在对照条件下 ,10～ 4 2ｄ鳞茎鳞片的氨基酸、可溶性蛋白质、糖、淀粉和苹果酸脱氢酶含量下降 ,其活力也下降。最初2 0ｄ ,谷氨酸脱氢酶活性下降到原来的 1/ 10 ,尔后逐渐回升接近原有水平。鳞茎鳞片的活力与其鲜重…     

H_3BO_3及植物生长调节剂对锥栗花粉萌发率的影响

为了研究锥栗花粉萌发的最适条件,以白露仔花粉为试材,采用花粉离体培养法,探索了H3BO3和2,4-D、GA3、IBA、NAA及其组合对锥栗花粉萌发率的影响。结果表明:(1)在单因素处理试验中,H3BO3与这4种植物生长调节剂都能促进锥栗花粉萌发,其中以H3BO3、2,4-D、GA3、IBA的促进作用较为明显,最适浓度分别为100、1.0、60.0、2.0 mg·L-1,萌发率分别达到了41.75%、40.66%、38.73%、43.15%(CK的萌发率为18.28%);(2)在正交试验中,4种因子的配比能显著提高锥栗花粉萌发率,最佳配比为:100 mg·L-1 H3BO3+2.0 mg·L-1 2,4-D+70.0 mg·L-1 GA3+2.0 mg·L-1 IBA,其萌发率达到62.34%,比对照提高了44.06%。     

银叶金合欢组织培养研究

为建立银叶金合欢(Acacia podalyriifolia)组培快繁技术体系,对其外植体类型与灭菌处理方法以及不定芽诱导、增殖和生根培养基进行了优化筛选。结果表明,组培最适外植体为半木质化枝条上部;灭菌处理方式以75%酒精处理10 s,0.1%升汞处理5 min为宜,其污染率为38.67%,诱导率达54.33%;最适宜诱导培养基为MS+6-BA 0.5 mg·L-1+IBA 0.01 mg·L-1+GA3 0.3 mg·L-1,诱导率为64%;最佳增殖培养基为MS+6-BA 0.6 mg·L-1+IBA 0.05 mg·L-1+GA3 0.1 mg·L-1,增殖系数为3.44;最佳生根培养基为l/4 MS+NAA 0.2 mg·L-1+IBA 0.8 mg·L-1,生根率为67.1%;移栽基质为黄心土+沙(V黄心土:V沙=2:1),移栽成活率可达85%以上。     

Browsing Damage on Pine (Pinus sylvestris and P. contorta) by a migrating moose (Alces alces) Population in Winter: Relation to Habitat Composition and Road Barriers

In Scandinavia, moose (Alces alces L.) sometimes cause severe browsing damage to economically-important pine. Moose-vehicle accidents have spurred construction of fences along roads, and these may interfere with moose migration between summer and winter ranges, or the road alone may be a barrier. If this happens and moose build up along roads, landowners may suffer economically. Therefore, this study investigated whether roads, fences or other factors influence the use of young pine stands by moose. Eighty stands along roads in northern Sweden were evaluated in which individually-browsed branches were counted on 9972 pines. Moose browsing was not significantly related to birch (Betula pendula Roth, B. pubescens Ehrh.) density, nor did it differ between pines (Pinus contorta Douglas or P. sylvestris L.). However, increased pine density, site productivity and proximity to a highway were associated with increased browsing. Further large-scale studies are needed to understand moose habitat selection and the effects of roads.     

Effects of Root Freezing on the Physiology and Growth of Picea glauca,Picea mariana and Pinus banksiana Seedlings Under Different Soil Moisture Regimes

The root systems of 2-yr-old Picea glauca, Picea mariana and Pinus banksiana seedlings were submitted to various frost temperatures during an artificial frost to induce different levels of root damage. Frost-damaged and control seedlings were placed in a greenhouse under high and low soil moisture regimes. Seedling growth and physiology were evaluated periodically. Seedling survival was reduced when root damage reached levels of 60-80%. Root systems of all three species showed partial to total recovery by the end of the experiment. In general, root freezing damage caused reductions in seedling growth, with these reductions becoming less significant over time. Root damage had little to no effect on black spruce and jack pine seedling physiology, while white spruce CO 2 uptake decreased with increasing root damage. Shoot nitrogen content of all three species decreased slightly with increasing root damage.     

Stand Structure in Pine,Spruce and Deciduous Forests: A Comparison Between Finnish and Russian Karelia

This study investigated the stand structure in pine, spruce and deciduous forests in the border district of Finland and Russia. A total of 46 mature forest stands was selected as pairs, the members of each pair being as similar as possible with respect to their forest site type, age, moisture and topography. The stands were then compared between the two countries by means of basal areas and number of stems. The proportions of dominating tree species were 2-12% lower, and correspondingly the proportions of secondary tree species higher, in Russian forests. The density of the forest stock was also higher in each forest type in Russia. The forests in the two countries differed most radically in terms of the abundance of dead trees. The amount was two to four times higher in Russian deciduous and spruce forests, and in pine forests the difference was 10-fold. The stand structures indicated that Russian coniferous stands, in particular, were more heterogeneous than intensively managed pine and spruce stands in Finland.     

Growth and Terminal Bud Formation in Picea abies Seedlings Grown with Alternating Diurnal Temperature and Different Light Qualities

The root collar diameter and the height:diameter ratio are of particular importance in container-grown seedlings where a high density in the containers may produce spindly seedlings. Temperature regimes and light quality are known to affect plant growth. The aim of this study was to identify responses in Picea abies (L.) Karst. seedlings grown with light providing different red:far-red ratios and under temperature regimes with alternating day (DT) and night temperature (NT) from negative (DT < NT) to positive (DT > NT) difference (DIF) between DT and NT. Experiments were conducted in controlled environment chambers and in a daylight phytotron. Only limited thermoperiodic responses appeared in P . abies seedlings with respect to seedling height and dry weight accumulation. The formation of terminal buds, however, was clearly delayed in seedlings grown at negative DIF. The results indicate a requirement for day extension light that is high in far-red, to prevent terminal bud formation under natural short-day conditions. An extended study should be conducted to clarify the minimum level of light intensity and the optimal light quality needed to prevent terminal bud formation under natural short-day conditions.     

CAD与建筑设计的关系

本文分析了CAD在设计中引起的正面和负面影响,并进行了系统的阐述,从而使设计者在应用中能够保持客观的态度。     

Natural Regeneration in Clear-cuts: Effects of Scarification,Slash Removal and Clear-cut Age

The effects of soil scarification (mounding), slash removal and clear-cut age on the natural regeneration in clear-cuts was evaluated using data from four sites in southern Sweden. The treatments were carried out during a good seed and establishment year for birch ( Betula pubescens Ehrh. and B. pendula Roth). Scarification had the strongest positive effect on the density of naturally regenerated seedlings, especially in birch, but also in pine ( Pinus sylvestris L.) and spruce [ Picea abies (L.) Karst]. Slash removal had a positive effect on birch density. No statistically significant effect of clear-cut age was found. In addition, no statistically significant interactions between clear-cut age and scarification or slash removal were found. The ingrowth of field vegetation was the fastest in areas that were not scarified, less rapid in areas scarified on old clear-cuts, and the slowest after scarification in fresh clear-cuts. In conclusion, it may be possible to control the density of birch during a good establishment year for birch. If birch is desired, the best combination of treatments is to remove the slash and scarify; otherwise, these treatments should be avoided.     

Risk Perception Among Non-industrial Private Forest Owners

Based on an enquiry, risk perception among non-industrial private forest owners is described in relation to climate change and forestry hazards. Of the respondents, 11% took action to remedy the effects of climate change. Out of a given set, hazards were ranked according to each respondent's experience of recent substantial financial loss to the estate and in relation to his or her willingness to make investments aimed at risk reduction. For each hazard, the respondent assessed the risk in four classes ranging from very high to negligible risk. Six hazards were considered most problematic in all three aspects: browsing damage, falling timber prices, damage by wind, spruce bark beetle, root rot and pine weevil. A majority of the respondents claimed to take action to reduce the risk associated with at least one hazard, while 35% did not know whether they did. Excluding climate change, the need for decision support was the largest in relation to damage by wind owing to a combination of perceived high risk and a high level of ignorance in relation to whether risk-reducing measures were taken.     

Interactions in decomposition and N mineralization between tropical legume residue components

In situ produced plant residues contain a mixture of different plant components of varying quality. To assess synergistic or antagonistic interactions occurring during the decomposition and mineralization of such mixtures, individual plant parts (stems, leaves, leaf litter and roots) or the mixture of stems, leaves and leaf litter of the agroforestry species pigeonpea (Cajanus cajan) or of crop residues of peanut (Arachis hypogaea) or of the weed hairy indigo (Indigofera hirsuta) were incubated in pots for 19 weeks. Periodically, remaining plant residues were sieved out (>2 mm), weighed and N content as well as soil mineral N determined. Above- and below-ground residues of peanut decomposed fastest and showed the largest N release in agreement with their high N concentration and low-acid detergent fibre (ADF) : N ratio. Hairy indigo was hypothesized to be of lower quality than pigeonpea because of its high-polyphenol content. However, it decomposed faster than pigeonpea, largely because of the higher N and lower lignin concentration of its components. Ranking of individual plant components for N mineralization resulted in the following pattern, leaves > leaf litter > roots > stems. In mixtures of the different plant components a similar species order in decomposition was obtained, e.g. peanut > hairy indigo > pigeonpea. The amount of N released from the mixture was dominated by stem material that comprised 46–61% of the mixture. The interactions in mixtures were relatively small for peanut (generally high-quality components) as well as for pigeonpea (low proportion of high-quality components, i.e. N rich leaf material). However, a positive interaction occurred during later stages of N mineralization in the mixture of hairy indigo as it had a significant proportion of N rich components and absence of highly reactive polyphenols. Thus, for plants with low to intermediate chemical quality attributes, manipulating plant composition (e.g. by varying harvest age, affecting stem and leaf proportions) will be important to obtain significant interactions during decomposition when its components are mixed.     

Pasture production and tree growth in a young pine plantation fertilized with inorganic fertilizers and milk sewage in northwestern Spain

The use of organic waste materials such as milk sewage as an organic fertilizer could have the dual advantages of organic-waste disposal and reduced dependence on inorganic fertilizers. The effects of fertilization with (1) conventional mineral fertilization, (2) milk sewage sludge at 40 kg N ha⁻¹ target rate and (3) no fertilization on pasture production and tree growth were examined in an experiment consisting of two pasture mixtures under a one-year-old Pinus radiata plantation with a density of 2500 trees ha⁻¹. The two pasture mixtures were: (1) Dactylis glomerata L. var. saborto (25 kg ha⁻¹) + Trifolium repens L. group Ladino (4 kg ha⁻¹) + Trifolium pratense L. var. Marino (1 kg ha⁻¹); (2) Lolium perenne L. var. Tove (25 kg ha⁻¹) + Trifolium repens L. group Ladino (4 kg ha⁻¹) + Trifolium pratense L. var. Marino (1 kg ha⁻¹). The experiment began in the spring of 1995 using a randomized block design with three replicates in Castro Riberas de Lea (Lugo, Galicia, north-western Spain). Plot size was 12 × 8 m², with a 1 m buffer strip between plots. Two-year data showed that fertilization with either material had a positive effect on pasture production, with no significant difference between the two fertilization treatments. Tree growth in the milk sewage sludge plot was significantly higher than in the control plots. Inorganic fertilization increased pasture production, but affected tree growth negatively. The results show that milk sewage sludge could be used as a fertilizer in silvo-pastoral systems. This revised version was published online in June 2006 with corrections to the Cover Date.