杨树新品系苗期抗性指标测试

杨树苗期抗性性状测试是良种选育中的一个重要指标,也是抗性育种多性状选择的重要环节,它关系到选育的成功与否。本文采用测试品系15个,即分别为J、B、A、LB、IC、50、52、53、54、01、5、中S、中H、中M号杨,分别在黑龙江省牡丹江市的北安乡丰收村、绥阳林业局二道岗子林场、海林市旧街乡杨林村、迎春林业局科研所苗圃等4个地点进行杨树苗期抗性性状测试,以小黑杨为对照种。综合不同苗龄型测试结果,抗寒能力较强的品系为5、J、B号杨等9个,冻害指数均为0;抗黑斑病能力较强的品系为J、LB、54、中M、B号杨;抗锈病能力较强的品系为54、50、LB、5、53号杨;不同地点抗病性状比较,黑斑病与锈病发病程度为丰收>迎春>二道岗子。     

杨树伐根嫁接更新造林优良品种的筛选试验

以小美旱杨为砧木,选择107杨、108杨、111杨、沙兰杨、北抗创新杨1号、中林2001杨和转基因杨7个杨树品种作接穗进行伐根嫁接,在北京大兴区分别设置了3块试验地的3个品种对比试验。结果表明:1)以小美旱杨为伐桩,3块试验地中北抗创新杨1号成活率和保存率均最低,其余6个品种接穗成活率和保存率分别在80%和90%以上。2)试验地1嫁接品种107杨、108杨、111杨的平均胸径、树高和单株材积均较大,且之间无显著差异;试验地2嫁接品种107杨、沙兰杨的平均胸径、树高和单株材积与北抗创新杨1号差异显著,107杨与沙兰杨的平均胸径、树高和单株材积差异不显著;试验地3嫁接品种107杨的平均胸径、树高和单株材积与中林2001杨、转基因杨差异显著,中林2001杨与转基因杨的平均胸径、树高和单株材积差异不显著。3)107杨、108杨、111杨、沙兰杨是适宜杨树伐根嫁接造林的优良品种。     

黑杨派无性系幼苗生长特性的研究

以黑杨派无性系014杨、111杨、177杨、LX-6和中辽1号为试验材料,对其1年生幼苗的生长性状进行研究。结果表明:5个杨树无性系苗高与地径年生长符合"S"型生长曲线;014杨、177杨、111杨和中辽1号速生期为7月19日至8月28日,LX-6速生期则为6月29日至8月28日;各无性系平均叶面积9月27日为最大值,各无性系单株总叶面积9月7日为最大值;苗高与地径、单株总叶面积及净光合速率呈极显著或显著正相关,地径与单株总叶面积、净光合速率呈显著正相关。     

不同杨树品种主要经济指标差异性分析

笔者对7a生的20个杨树品种的生长量、形率、材性和树皮厚度等指标进行了差异性分析。结果表明:欧美46、鲁山杨、圣山杨和欧美14在单株材积和木材基本密度显著优于对照(中嘉8号和中潜3号),材积遗传增益为47.50%、34.55%、34.51%和22.05%;胸高形率、绝对形率和正形率的变化范围分别为0.5678～0.6876、0.5211～0.6557、0.5349～0.6661,半常绿杨在形率指标上显著优于其它品种,而其它品种之间没有显著差异;纤维指标和树皮厚度没有显著差异。     

南酸枣家系叶及生理性状的研究

对51个南酸枣家系和1个对照进行播种育苗,观察萌发和苗期生长,结果表明:叶样湿/干重、单株叶湿/干质量、复叶叶面积、单株叶面积、叶空隙率、叶比重、叶相对含水率和相对电导率在家系间均达到显著和极显著差异,通过综合选择可以获得生长快、抗性强的家系;综合叶及生理性状多个指标,以30、31、34和7号家系为苗期表现最佳家系,它们分别来自饶平和龙川,入选的目的家系或单株,是今后持续抗性育种改良和推广栽培的重要材料。     

杨树不同品种苗期生理指标测定研究

研究以杨树不同品种的3个生理指标:叶面积、叶绿素含量、光合特性等分析为主并比较它们各方面的差异。经过试验,结果表明:3个指标最优者分别是97号杨、108号杨、111号杨。     

阜新市常用杨树品种生长状况调查

对小钻杨、群众杨、黑林1号、哲林4号、中绥12号、中荷64号6个杨树品种胸径、树高、材积生长指标和自然整枝能力开展研究,结果表明:中荷64号生长指标表现最佳,中绥12号次之,且差异显著;自然整枝能力哲林4号最佳,中荷64号和中绥12号稍差。中荷64是阜新地区被调查杨树品种中速生性最佳的品种。     

丹红杨×通辽1号杨杂交子代叶形性状的遗传变异分析

[目的]对丹红杨(美洲黑杨)×通辽1号杨(小叶杨)422个F_1代无性系叶的形态学指标进行分析,揭示杨树派间杂交群体叶形性状的遗传变异规律,为进一步解析其叶形性状的遗传机制奠定基础。[方法]使用Yaxin-1241便携式叶面积仪结合手工测量的方式,对杂交子代当年扦插材料的叶面积、叶长、叶宽、叶周长、叶柄长、侧脉夹角和最大叶宽距叶尖长度等7个指标进行测量,计算叶长宽比、叶柄相对长、最大叶宽位置和叶缘因子,利用SPSS软件完成相关、通径、遗传以及主成分分析。[结果]丹红杨和通辽1号杨两亲本叶面积、叶长、叶宽、叶周长、叶柄长、侧脉夹角、叶长宽比、叶柄相对长以及最大叶宽位置等9个指标差异显著,子代变异丰富且呈连续的正态分布。在10个叶形指标间45对相关关系中,36对呈显著或极显著水平。通径分析结果表明,叶长和叶宽是决定叶面积的主要因素。通过主成分分析得到2个主因子,累计解释80.19%的叶形变异,子代第一主成分的标准化值全部介于两亲本之间,并有64.69%与父本分布在同侧,第二主成分则均匀分布在中亲值两侧。对于表征叶片大小的2个指标叶面积和叶柄长,多数子代小于中亲值且其均值更接近父本,而表征叶片形状的叶柄相对长和最大叶宽位置与之相反,其余指标接近中亲值。除叶长宽比、侧脉夹角以及叶缘因子外,子代叶形指标大多介于两亲本之间。[结论]丹红杨和通辽1号杨叶形性状差异显著,杂交子代叶形性状存在丰富的连续性变异,且性状间关联紧密,叶长和叶宽是决定叶面积的主要因素。叶面积、叶柄长以及最大叶宽位置等性状存在明显的遗传偏向性,杂交子代叶片形状与丹红杨更为接近,呈较强的母本效应,而叶片大小则表现出偏向父本小叶杨的遗传效应。30.09%子代的综合叶形指标具有超亲现象,选择潜力较大,在今后的育种实践中可加以利用。     

无絮杨高接换头试验初报

选用中红杨、中林46杨、欧美107杨等3种目前最常见的5~7a生杨树作砧木,用新选育的彩叶无絮杨、无絮杨1号、无絮杨2号等3个无絮杨新品种(品系)作接穗,进行高接换头嫁接试验,结果为试验的9个嫁接组合植株成活率和接穗成活率都在80%以上,中红杨、中林46、欧美107都可以作砧木嫁接这3个无絮杨新品种,并且砧木之间在嫁接植株的冠幅和高度生长无显著差异;3个无絮杨接穗新品种植株冠幅生长无显著差异,高生长无絮杨1号与无絮杨2号差异不显著(P0.05),都显著高于(P0.05)彩叶无絮杨,在优先考虑高接换优后树体冠幅生长时,应优先选用彩叶无絮杨,以满足生长生长需求、丰富园林色彩,优先考虑高接换优后树体高度生长时,应优先选用无絮杨1号、无絮杨2号品种。     

日本栗叶面积与叶片生物量计算方法的初步研究

以6年生日本栗品种＂辽栗10号＂与＂大峰＂为试材,对其叶长、叶宽、单叶面积、单叶干重、冠幅、冠高、单株叶片生物量进行了测定。研究不同品种间叶片长宽比值和比叶面积的差异性,叶片长、叶宽和叶片长宽乘积与单叶面积的相关性以及冠幅、冠高与单株叶片生物量的相关性。结果表明：不同品种间叶片长宽比、比叶面积均无显著差异;对日本栗叶长、叶宽、叶片长宽乘积与单叶面积进行一元回归方程拟合,决定系数与修正决定系数均达极显著水平（P〈0.0001）,其中以叶片长宽乘积与单叶面积的一元二次回归方程回归效果最好,决定系数达0.987 9,修正决定系数达0.987 7;单株叶片生物量与冠幅面积和冠高的二元线性回归关系达极显著水平（P〈0.0001）,决定系数达0.997 2,修正决定系数达0.996 4。在生产上,可以通过测量冠幅面积、冠高计算出单株叶片生物量和叶面积指数,该方法操作简单,具有较高应用价值。     

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.