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。     

武汉地区百合鳞片扦插技术研究

为提高武汉地区百合鳞片扦插繁殖系数,试验设计了不同鳞片部位、扦插时间、扦插深度3个处理,从扦插产生的籽鳞茎大小和数量来看,春季用百合种球的靠外层鳞片扦插效果最好。     

青岛百合扦插繁殖技术的研究

以野生的青岛百合鳞茎为扦插材料,将鳞茎分为内中外三层剥取其鳞片,观察鳞片在不同温度、不同基质中扦插的效果。结果表明:影响扦插效果的重要因子是温度和基质,在温度为25℃,珍珠岩基质中,内层鳞片扦插效果最好。     

激素和变温处理对百合鳞片扦插繁殖的影响

以亚洲百合品种‘精粹’为试材,探讨GA3和IBA以及不同培养温度对鳞片扦插繁殖的影响。结果表明:低浓度IBA处理(IBA-80mg·L-1-1h)的繁殖系数较大、小鳞茎形成的整齐度较高,IBA处理可在较短时间内促使小鳞茎膨大;若培养时间充分,GA3处理更有利于形成个体较大的鳞茎。5℃低温预处理加速IBA处理母鳞片淀粉的降解和总可溶性糖的利用,进一步提高IBA处理的繁殖系数、平均级数和小鳞茎直径;但5℃低温预处理与GA3处理结合,抑制母鳞片中淀粉的降解以及小鳞茎对可溶性糖的吸收利用,致使小鳞茎生长缓慢。本试验条件下IBA-100mg·L-11h结合5℃低温预处理为提高繁殖系数和整齐度的最佳处理;GA3-100mg·L-1-2h结合25℃恒温培养最有利于小鳞茎的发育膨大,为获得优良个体的最佳处理。     

细叶百合组培继代培养与生根移栽的研究

为建立细叶百合离体快繁的再生体系,对细叶百合组培苗的继代培养、生根培养及移栽条件进行了研究。结果表明:继代培养在MS 6-BA 2.0 mg/L NAA0.1 mg/L上培养基上鳞茎的增殖系数为6.95,且苗粗壮、长势良好;生根培养在1/2MS IBA 0.5 mg/L生根最快,生根率达100%,根粗壮,平均每个小鳞茎生根8.77条,平均根长为2.85 cm,苗长势较好;移栽基质以泥炭土效果最好。     

百合花的繁殖

百合种类较多，繁殖时可根据不同种类、不同时间，采取适宜的措施。常见的有播种、分小鳞茎、鳞片扦插和分株芽等4种方法．     

不同药剂在撑绿竹3~#扦插育苗试验中的应用

采用萘乙酸、HC复合生长素、高锰酸钾处理与清水作对照进行了撑绿竹 3#的主枝扦插试验。试验采用 3次重复的随机区组试验设计 ,以成活率、平均根数、平均根长度和枝蔸芽萌发率为评价指标。试验结果表明 :不同药剂处理对于撑绿竹 3#(撑篙竹×大绿竹 )的主枝扦插成活率、平均根数与对照存在极显著差异 ,成活率平均提高10 .76 % ,平均根数提高 1.51条 ,平均根长仍提高 0 .81cm。其中以萘乙酸 50× 10 - 6 浸枝条 1h处理效果最好 ,成活率比对照提高 2 1.6 % ,平均根数比对照提高 4 .0条。另外 ,萘乙酸和HC复合生长素对撑绿竹3#扦插成活后枝芽萌发成笋有较大的促进作用     

不同基质对卷丹百合鳞片扦插繁殖效应的研究

为降低生产成本和增加食用百合鳞片繁殖效应,在已有研究的基础上,选用市场较易获得的6种不同配比基质,并对栽培在6种基质中鳞片繁殖效应进行了详细观察和统计分析;为更准确评价不同基质对卷丹百合鳞片扦插繁殖效应,在采用DPS数据处理软件进行分析的同时,利用灰色关联度分析法进行综合评价。结果表明：卷丹百合鳞片扦插繁殖以采用泥炭＋沙或泥炭＋蛭石两种混合基质较好,增殖的小鳞茎数及其球径等综合性状良好。     

温度对东方百合西伯利亚扦插繁殖的影响

以东方百合西伯利亚(Siberia)鳞片为供试材料,在19℃、21℃、23℃、25℃、室温5种温度条件下进行扦插繁殖,观察鳞片小籽球分化和新根产生情况。结果表明:在19℃条件下,鳞片籽球分生数为3.37个,籽球平均直径为1.22cm,生根数是7.27条,平均根长达到7.77cm,这些指标在所设的5种温度梯度中表现最好。19℃是东方百合适宜的扦插温度。随温度升高,各项指标表现下降趋势,25℃时表现最差。     

荞麦叶大百合鳞片扦插技术

对荞麦叶大百合的鳞片扦插技术进行试验,结果表明:用浓度为100 mg/L的IBA溶液处理鳞片,可以有效地提高鳞片的扦插成活率和生根数;选用泥炭土、珍珠岩(1∶1)基质作为扦插基质,有利于提高成活率;采用斜插的方式扦插荞麦叶大百合的鳞片可以显著提高成活率;在0℃下经25 d的低温冷藏处理可以有效的提高鳞片的扦插繁殖的成活率和生根数。     

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。     

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.     

Key Habitats in the Norwegian Production Forest: A Case Study

This study investigated the forest history, structural characteristics, the presence of fungal species suggested to indicate ecological continuity in old-growth forest, and the species composition of saproxylic beetles in 30 old forest ''woodland key habitats'' (WKHs), and compared them with production forest in the same age-class in south-eastern Norway. No statistically significant differences in forest characteristics, community of saproxylic beetles or number of red-listed beetles were found between the WKHs and the production forest, probably owing to a combination of profound long-term logging and a lack of will to delineate sufficiently large WKHs in the one area with significantly less forestry impact. The study indicates the advantage of including forest history information in WKH selection where such data exist, and the importance of restoring habitats in heavily exploited forest landscapes.