水分胁迫对杂种马褂木与双亲重要生理性状的影响

水分胁迫状态下鹅掌楸属 (Liriodendron)种间正反交F1 杂种及双亲的一些重要生理性状的研究表明 :水分胁迫状态下亲本与杂种叶片的相对含水量、叶绿素含量、蛋白质含量的降低速率和RNase活力的升高速率排序为马褂木 >北美鹅掌楸 >正交F1 >反交F1 ;短时间水分胁迫对马褂木伤害最大。3H Gly标记取得的直接证据证明 ,水分胁迫导致亲本与杂种RNase基因在翻译水平上表达而从头合成RNase ,RNase基因表达强度排序为马褂木 >北美鹅掌楸 >正交F1 >反交F1 。蛋白质生物合成抑制剂取得的间接证据表明 ,水分胁迫状态下双亲RNase活力升高除与细胞质mRNA翻译有关外 ,还可能涉及叶绿体和 或线粒体RNase的释放、活化和 或合成 ,而正反交杂种RNase活力升高可能主要来自细胞质mRNA的翻译而不涉及到叶绿体和 或线粒体。上述实验证据充分证明 ,杂种马褂木正反交F1 杂种具有对水分胁迫抗性的显著超亲杂种优势 ,而正反交杂种中反交F1 的抗性又强于正交F1 。研究结果从水分胁迫抗性差异角度揭示了杂种马褂木强大正向生长、适应性和抗性杂种优势现象形成的分子机理 ,并表明在杂种马褂木杂种优势固定利用实践中必须特别注意反交F1 杂种无性系的选育与开发     

杂交马褂木扦插技术研究

<正>杂交马褂木是北美鹅掌楸与马褂木杂交而成的一个马褂木新品种。北美鹅掌楸与马褂木都属木兰科植物,是十分罕见而古老的树种。杂交马褂木具有生长速度快,树形优美,花型花色美观等明     

鹅掌楸属杂交育种研究初报

从湖北省京山县虎爪山林场鹅掌楸种源试验林中选择优良种源中的优良单株北美鹅掌楸5株、鹅掌楸10株及亚美马褂木1株作为杂交亲本,进行鹅掌楸的种内种源间杂交、鹅掌楸与北美鹅掌楸种间的正交和反交、北美鹅掌楸与亚美马褂木的回交等4种交配模式,共计75个杂交组合。获得球果1 162个,种子171 992粒,出苗4 131株,当年保存64个杂交组合,2 796株。综合4种交配模式,亲本及亲本交互作用对于杂交所获球果形态特征、1 a生苗木生长量等具有极显著的影响;母本对种子田间发芽率具有极显著影响,而父本对其影响不显著。     

用RAPD标记进行鹅掌楸杂种识别和亲本选配

杂种马褂木是以鹅掌楸属 (Ｌｉｒｉｏｄｅｎｄｒｏｎ)现存两个种中国马褂木 (Ｌ .ｃｈｉｎｅｎｓｅ(Ｈｅｍｓｌ.)Ｓａｒｇ .)和北美鹅掌楸 (Ｌ .ｔｕｌｉｐｉｆｅｒａＬ .)为亲本所创造的种间杂种 ,由叶培忠教授于 1 963年首次育成。 30多年的栽培试验表明 ,该杂种不仅在生长和     

杂交马褂木扦插技术研究

杂交马褂木是北美鹅掌楸与马褂木杂交而成的一个马褂木新品种。北美鹅掌楸与马褂木都属木兰科植物,是十分罕见而古老的树种。杂交马褂木具有生长速度快,树形优美,花型花色美观等明显杂交优势,被称为木本郁金香,其在抗寒、抗病虫害等方面也强于中国马褂木。另外杂交马褂木还是一种优良造纸树种,可作工业原料林大规模栽植。     

鹅掌楸属种间杂种F1与亲本花果数量性状的遗传变异分析

对中国马褂木、北美鹅掌楸及其种间杂种Ｆ１１３个花果数量性状的研究结果表明：花被片长度（ＬＰ）等９个性状在类群间差异达显著或极显著程度,可用于类群识别;花药长度（ＬＡ）等１１个性状在类群内个体间差异达极显著程度,说明类群内遗传多样性水平较高;杂种Ｆ１在雄蕊数（ＮＳ）等８个性状上,中国马褂木均表现出较强的遗传优势,花被片宽度（ＷＰ）等４个性状表现为偏父遗传或偏父超亲遗传;从性状间的相关性来看,聚合果气     

亚美马褂木物理力学性能及其用于实木家具的适应性研究

测试亚美马褂木物理力学性能,并与北美鹅掌楸进行对比,结果表明:亚美马褂木吸水性强,湿胀干缩变化大;除顺纹抗压强度外,其余性能均优于北美鹅掌楸,适用于实木家具制造。     

杂种马褂木杂种优势的遗传分析

在叶培忠先生的鹅掌楸属种间杂交育种研究基础上按遗传设计与环境设计开展了扩大北美鹅掌楸遗传基础条件下的正反交以及前人从未做过的回交和F1 间杂交 ,并进行了杂种马褂木杂种优势的遗传分析。结果表明 :(1)正反交F1 、BC1 和F2 4种交配系统杂种的 1a生幼苗普遍存在显著正向生长杂种优势 ;幼苗生长性状在家系间存在极显著差异而在家系内具有很大变异性 ;回交家系表现特别优良 ,因而家系选择、单株选择以及BC1 和F2 利用潜力很大。 (2 )初步提出“光合优势假说”(Photosyntheticsuperiorityhypothesis)作为杂种马褂木和其它杂种树木杂种优势机理的理论解释。 (3)简单估算了一些重要遗传参数     

优良观赏树种杂交马褂木的培育技术

马褂木,又名鹅掌楸,因其叶如鹅掌、马褂而取名。属木兰科鹅掌楸属。杂交马褂木是利用中国马褂木与北美鹅掌楸进行人工授粉培育而成的杂交种。杂交马褂木具有生长快、干形直、材质好,抗病虫能力强等特性,其树形高大,树姿秀美,冠形     

杂种马褂木简介——育种基地·池州市金元苗圃

中国马褂木和北美鹅掌楸,是木兰科鹅掌楸属现存的两个种,因其叶形分别近似清朝服装马褂和鹅的脚掌而得名。由这两个种杂交而得到的杂交种,统称为"杂种马褂木"。我国已故著名树木育种专家叶培忠教授,于上世纪60年代初进行了马褂木和北美鹅掌楸的杂交,并将杂交种推广到全国各地进行试种。叶金山研究员自南京林业大学攻读林木遗传育种学博士学位以来。继承和发展了原有研究成果,经过10多年对杂种马褂木杂种优势理论、性状早晚期相关以及快速繁殖技术的研究,收集引进了国内外鹅掌楸属基因资源,进行了350个组合的杂交,从大量杂种苗木和杂种大树中,选出了520个优良单株,繁殖无性系219个,从中筛选出城市绿化型优良无性系5个,分别命名为"金楸1-5号"。优良特性1、叶形奇特,呈父母本中间类型;叶色由亲本的淡绿变为深绿色;单叶面积增大1-5倍,单株叶片数量增多;发叶早,落叶迟,枝叶繁茂,树形高大挺拔,树冠更加浓密。2、花色鲜艳,良杂种无性系整个花冠呈现金黄色,并且花冠大,花量多,开花时间提早,花期长达一个多月。3、树形高大,主干通直圆满,生长迅速,生长量比亲本大一倍以上。木材材质优良,纤维质量高,是重要的优质用材和纸浆材树种。4、适应范围广泛,耐高温干旱,有较强的抗寒能力,病虫害极少,并能耐修剪和抗大气污染。三十几年的多点试验充分证明,杂种马褂木在我国广大南方、北方和西北地区普遍生长良好。北京引种栽植的杂种马褂木早已经长成成年大树,并正常越冬和开花结实。     

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.