几种优良松树外生菌根菌扩繁条件研究

对华美牛肝菌(Boletus edulis,504)、黄豹斑鹅膏(Amanita pantherina,EG)、黄色须腹菌(Rhizipogen luteous,HX)、彩色豆马勃(Pisolithus tinctorius,Pt2)等4种优良外生菌根真菌进行了生长速度、培养特性及其生长规律的比较研究,以确定各种优良菌根真菌的最适生长条件。     

外生菌根菌对抗性黑松和赤松不同家系生长影响

为了提高从日本引进的抗松材线虫病的黑松和赤松优良家系在引种地新环境下的成活和生长能力,2005～2006年对松树抗性家系开展了优良外生菌根菌肥的施用试验.连续跟踪调查发现,抗性赤松和黑松9个家系施用Be菌肥后,大部分家系的苗高和地径生长量比对照提高或显著提高;5种外生菌根菌剂(Ap、La、Be、Pt1和Pt2)对抗性黑松的促生作用显著,对地径的促生效果优于苗高,且各菌根菌肥间的促生作用差异不明显;对3种菌根菌(Be、La、Rl)的固体菌剂和泥浆菌刺进行施用效果比较,表明Rl使用泥浆菌剂蘸根施用效果优于固体菌剂直接施用;Be和La则因家系不同效果有所不同.总体来看抗性黑松和赤松采用菌根化造林明显提高了松树生长量.     

马尾松外生菌根菌的培养和育苗效应研究

对彩色豆马勃、厚环乳牛肝菌、血红铆钉菇等７株菌根菌株在４种培养基、３种温度梯度下的生长状况和马尾松苗期接种效果进行研究。结果表明：改良麦芽汁培养基是外生菌根菌的适宜培养基；彩色豆马勃适应力强，明显促进马尾松苗期生长，菌根感染率高，但各菌株之间存在差异；厚环乳牛肝菌不适宜马尾松的苗期生长。     

火炬松容器苗侧根的生长与彩色豆马勃外生菌根的关系

<正> 用接种彩色豆马勃菌 (Pisolithus tincto-rius,以下简称Pt)的火炬松(Pinus taeda L.)容器苗,在较差的立地条件上造林,可以提高苗木的生长量和保存率;但在一般立地条件上,这种容器苗并不比具有天然外生菌根的苗木好,也不比接种Pt的裸根苗好。由于容器的局限性,减少了松苗的根量,致使幼小的苗木根系盘旋生长,与营养土一起     

松材线虫病媒介昆虫的调查

1991—1992年从松材线虫病死木中收集的28种昆虫中检出3种天牛,1种小蠹和1种白蚁等5种昆虫携带松材线虫Bursaphelenchus xylophilus,其中松褐天牛是传播松材线虫最主要的媒介昆虫,松褐天牛的携带率为62.5%,平均携带量为4601条/头。用每头天牛分离出的线虫,接种1株马尾松和黑松近200株,到秋天56%的马尾松和92%的黑松感染松材线虫病致死。其它4种携带松材线虫的媒介昆虫小灰长角天牛、台湾长角天牛、松枞坑切梢小蠹和黑翅土白蚁的携带量在10.5条/头以下,携带率在12.5%以下。     

四川松树、桉树外生菌根菌种类调查

对四川省马尾松、湿地松、火炬松、桉树等人工幼林及少数天然林的外生菌根菌进行了调查研究。研究表明,我省松树林下外生菌根真菌资源丰富,鉴定出9科18属50种,其中马尾松林下有40种,占80％,松、桉幼林下的种类单一、采色豆马勃、多根硬皮皮勃、黄色须腹菌为松类人工幼林下的优势菌根菌,随着树龄的增加,菌根种类也不断增加。桉树林下仅发现大孢硬皮马勃。     

松材线虫病知识简介

我市濠江区自去年以来陆续发生松树枯死现象，经省权威机构鉴定确认为松材线虫病。松材线虫病是松材线虫寄生在松树体内所引起的一种毁灭性病害，主要危害马尾松、黑松、黄松、赤松、海岸松和黄山松等松属植物，在国际国内被列为重要的检疫对象。现将松材线虫病有关知识介绍如下：     

一种马尾松菌根辅助细菌--短芽孢杆菌的筛选及鉴定

【目的】菌根辅助细菌与菌根真菌是林木根际重要的微生物菌群，为探讨二者互作关系，采集马尾松人工林中有外生菌根真菌彩色豆马勃子实体的菌根根际土壤，对分离获得的74株细菌进行菌根辅助细菌的筛选。【方法】通过干皿对抗法筛选获得1株能高效促进外生菌根真菌彩色豆马勃(Pt2)和红绒盖牛肝菌(Xc)生长的菌根辅助细菌 MPt17。【结果】MPt17菌株对 Pt2和 Xc菌丝生长的平均增长率分别为48.6%和25.0%，其胞外代谢产物对 Pt2和 Xc菌丝生长也有明显的促进作用，平均增长率分别为129.6%和29.5%，该菌株的胞外代谢产物对Pt2和 Xc的生物量也有相一致的影响，生物量增长率分别为124.2%和34.2%。盆栽试验结果表明，双接种 Pt2－MPt17处理、双接种 Xc-MPt17处理、单接种 Pt2、单接种 Xc 和单接种 MPt17较未接种处理的马尾松苗高分别提高78.0%，68.2%，32.7%，39.2%和53.4%，地径分别提高46.3%，57.5%，17.5%，23.8%和25.0%。由此可以确定MPt17既是菌根辅助细菌又是根际促生细菌。通过对 MPt17菌株的菌落形态观察、BIOLOG 细菌自动鉴定仪鉴定及16SrDNA序列测定，初步鉴定该菌株为短芽孢杆菌(Brevibacillus reuszeri)，在 GenBank 数据库中的登录号为KF891383。【结论】MPt17菌株与外生菌根真菌 Pt2和 Xc 双接种马尾松幼苗对苗木的生长都具有明显的促进作用，而且 MPt17菌株单接种马尾松幼苗也能在一定程度上促进苗木的生长。通过外生菌根真菌( EMF)－菌根辅助细菌( MHB)－植物三者互作机制进行植物生长研究的方法，对类似研究具有重要意义。     

干旱胁迫对马尾松菌根化苗木水分生理和光合特性的影响

以马尾松Pinus massoniana 1年生苗为材料,采用双因素随机区组试验设计,6个接种处理,分别为牛肝菌7 Suillus luteus,牛肝菌1,鸡油菌Cantharellus cibarius,彩色豆马勃Pisolithus tinctorius Strain Pt 715,土生空团菌Cenococcum geophilum Strain Cg SIV和对照(不接种);4个水分处理,土壤相对含水量分别为正常(65±5)%、轻度胁迫(50±5)%、中度胁迫(35±5)%和重度胁迫(25±5)%,比较分析马尾松菌根化及非菌根化苗木,在干旱胁迫下水分生理和光合特性的差异。结果表明,外生菌根真菌通过提高叶片相对含水量,增加束缚水含量,降低苗木水势、自由水和水分饱和亏缺,从而改善苗木水分状况,增强苗木保水能力;外生菌根真菌增加了苗木叶绿素含量,提高了苗木光合速率,各处理间差异显著(P 0.05)。较高的叶绿素含量使菌根化苗木的光合速率增强,气孔导度、胞间CO2浓度和资源利用效率也提高,从而降低蒸腾速率、气孔限制值和光合耗氧量,减少气孔对水分的阻力,提高菌根化苗木的含水量;马尾松菌根化苗木主要是通过提高光合利用效率来适应干旱环境,其抗旱能力由强到弱为:牛肝菌1土生空团菌牛肝菌7鸡油菌彩色豆马勃对照。     

（拟）松材线虫耐久型四龄幼虫（LⅣ）的形态及其分化变异

本文对浙江省宁波市松材线虫病疫区内的松材线虫和拟松材线虫的耐久型四龄幼虫(LⅣ)的形态及其分化变异作了观察研究.结果表明,松墨天牛成虫体内携带的松材线虫和拟松材线虫的LⅣ在形态上完全相同;同一来源的(拟)松材线虫的LⅣ既可发育形成松材线虫,也可形成拟松材线虫.它的分化变异结果受寄主等环境因子影响,规律是:带尾尖突的LⅣ离开松墨天牛成虫进入黑松多变为无尾尖突的松材线虫;进入马尾松多变为带尾尖突的拟松材线虫.     

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.     

Decomposition and nutrient loss from prunings of different contour hedgerow species in tea plantations in the sloping highlands of Sri Lanka

Contour hedgerows of multipurpose tree species in the sloping tea lands of Sri Lanka are expected to reduce soil erosion and also add significant amounts of plant nutrients to the soil via periodic prunings. The objective of this experiment was to characterize the biomass decomposition pattern and quantify the amount of nutrients added through prunings of six tree species (Calliandra calothyrsus, Senna spectabilis, Euphatorium innulifolium, Flemingia congesta, Gliricidia sepium and Tithonia diversifolia) currently being used in hedgerows associated with tea. Withered leaf and stem prunings (50 g) were enclosed in 2-mm litter bags, placed at 5-cm depth and retrieved after one, three, six, nine and 12 weeks. Loss of initial dry weight, N, P and K was measured. Single exponential decay function adequately described both dry weight and nutrient loss. Tree species differed significantly in their rate of breakdown with decomposition constants (k) varying from 0.0299 to 0.2006 week⁻¹ for leaves and from 0.0225 to 0.0633 week⁻¹ for stems. Gliricidia showed the highest k for leaves with the rest in the following descending order: Senna > Tithonia ≥ Euphatorium > Calliandra > Flemingia. A similar pattern was observed for loss of all nutrients with Calliandra and Flemingia always having lower k values than the rest. Although N immobilization was not observed, immobilization of P and K was observed during the first week of incubation in some species, particularly in stem prunings. Annual biomass of prunings differed significantly between tree species in the following descending order: Calliandra > Senna > Flemingia > Tithonia > Gliricidia > Euphatorium. Calliandra added the greatest amount of nutrients annually to the soil with Euphatorium adding the least. Calliandra prunings provided the annual total K requirement and 49% of the N requirement of mature tea. However, none of the species provided more than 5% of the P requirement. It is concluded that among the tree species tested, Calliandra and Flemingia are the most suitable for contour hedgerows in tea plantations of this agroclimatic region because of their higher soil nutrient enrichment capacity and slower decomposition rates which would minimize leaching losses. This revised version was published online in June 2006 with corrections to the Cover Date.     

Effects of Seed Weight and Seed Type on Early Seedling Growth of Pinus sylvestris under Harsh and Optimal Conditions

The effects of seed weight and seed type on seedling growth of Pinus sylvestris (L.) were studied by seeding individually weighed orchard and stand seed in different mixtures under harsh (direct seeding in field) and optimal (seeding in nursery) conditions. In the nursery experiment an increase in the seed weight from 3 to 7 mg increased the seedling height by 10-27% and total weight by 27-113%, and decreased the height/diameter ratio by 5-6% after 2 yrs. With elimination of seed weight effects, orchard seedlings were 2% taller than stand seedlings in year 2. Without elimination of seed weight effects, orchard seedlings were 7-13% taller. In the field experiment an increase in the seed weight from 3 to 7 mg increased seedling height by 18-65%, stem volume by 81-274% and the number of top-buds by 23-34% in year 5. After elimination of seed weight effects, orchard seedlings were 7-13% taller than stand seedlings and without elimination of seed weight effects 20-21% taller after 5 yrs. Even after elimination of both seed weight and genetic effects orchard seedlings were 3-9% larger than stand seedlings in the field experiment. In conclusion, the influence of seed weight and seed type on growth traits and slenderness is highly significant and the influence seems to be greater in harsh conditions.     

Potential to harness superior nutritional qualities of exotic baobabs if local adaptation can be conferred through grafting

Baobab leaves form an important part of the local diet in Sahel countries and elsewhere in Africa. Existing leaf nutritional data and agroforestry performance information are based solely on Adansonia digitata L., the baobab of continental Africa. The introduction potential of Adansonia species from the center of diversity in Madagascar and from Australia remains untapped. To assess this potential, the mineral contents and B₁ and B₂ vitamin levels of dried baobab leaves were determined for five-year old trees of A. digitata, A. gibbosa (A. Cunn.) Guymer ex D. Baum, A. rubrostipa Jum. & H. Perrier (syn. A. fony Baill.), A. perrieri Capuron and A. za Baill. grown in an introduction trial in Mali. Nutritional data were evaluated against survival and vigor to identify promising germplasm. Leaf vitamin and crude protein contents were highest in the Madagascar species, especially A. rubrostipa (B₁ 88 mg 100 g⁻¹, B₂ 187 mg 100 g⁻¹, protein 20.7% dry weight). However, the local species far outperformed the introductions in survival, tree height, basal diameter and resistance to termites. We suggest grafting as a way of harnessing the vigor of well-adapted local baobab varieties to the superior nutritional profiles of A. rubrostipa and others. Cross-species grafting tests in Adansonia were successful, thus creating new agroforestry possibilities with different scion/rootstock combinations.     

Modelling of adequate pretwist for obtaining straight timber

Abstract

Wood in general and wooden studs in particular are often distorted owing to uneven shrinkage during the drying process in the sawmill. Twist is often the most detrimental of all types of distortion, and it is caused by spiral grain in combination with variations in moisture content. For sawmills, the objective is to produce dried, straight boards, and one method of dealing with boards with excessive spiral grain is to sort them out and then dry them in a pretwisted position to obtain straight boards after drying. A model using the finite element (FE) method for the simulation of drying twist distortions was first calibrated against laboratory experiments in which boards were dried with and without restraints and pretwists. After the calibration, the FE results were compared with industrial test results for boards that were dried without restraints or with restraints with zero pretwist, i.e. straight restraints. The FE model used an elastic–ideally plastic material model to obtain permanent deformations. The calibration was to set the yield stresses so that there was a good match between FE results and results from the laboratory experiments. The comparison between the industrial test results and the FE results showed that the FE model is capable of realistic simulations of drying boards with and without restraints and presumably also pretwists.     

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。     

Growth of Phlebiopsis gigantea in wood of seven conifer species

Heterobasidion parviporum and Heterobasidion annosum are widely distributed root‐rot fungi that infect conifers throughout Europe. Infection of conifer stumps by spores of these pathogens can be controlled by treating fresh stumps with a competing non‐pathogenic fungus, Phlebiopsis gigantea. In this study, growth of three Latvian strains of P. gigantea and the biological control agent ‘Rotstop’ strain was evaluated in stem pieces of Norway spruce, Scots pine, lodgepole pine, Douglas‐fir, Weymouth pine, Siberian larch and Sitka spruce. The growth rates of one H. parviporum and one H. annosum isolate were also measured in the same stem pieces. The growth rate of P. gigantea varied greatly in wood of different conifer species. It was higher in the three pine species, lower in Norway spruce and lowest in Sitka spruce and Siberian larch, and in Douglas‐fir, this fungus did not grow. The largest area of wood occupied by P. gigantea was in lodgepole pine. Growth of Latvian isolates of P. gigantea in the wood of Pinus and Picea species was comparable to that of the Rotstop isolate. Consequently, stump treatment with local P. gigantea isolates should be recommended. However, our results suggest that Douglas‐fir stump treatment against Heterobasidion by P. gigantea may be ineffective and other stump treatment methods should be considered.