巨尾桉去皮主干含水率分布规律的探讨

通过对巨尾桉去皮主干含水率的测定和分析表明：其含水率的分布是随着树干上的位置升高而呈直线上升,树干３Ｈ／１０处的含水率最具代表性,１．３ｍ与Ｈ／２处的含水率的均值可为树干含水率平均值     

香榧苗木繁育方法研究进展

为了更好地研究香榧繁育技术,对香榧苗木繁育方法及容器苗培育技术的研究进展进行了综述。香榧的苗木繁育方法有播种、嫁接、扦插以及组织培养,目前生产实际中最常用的方法为嫁接。     

浙江省磐安县香榧种质资源调查

磐安县香榧栽培历史悠久，资源丰富。2002年和2003年6—10月，作者对磐安县香榧的种质资源及自然分布进行了调查，将全县香榧的品种类型资源分成长榧类、圆榧类两大类，主要有细榧、大香榧、丁香榧、獠牙榧、大圆榧、中圆榧、小圆榧7个品种(或类型)，主栽品种是细榧，其余属自然类型；论述了几个主要品种(或类型)的经济性状，同时提出了加强对磐安县香榧种质资源保护，大力发展、推广细榧这个优质品种，合理开发利用其它自然类型等发掘利用建议。     

不同接种和处理方式对巨桉幼苗青枯病发生的影响

桉树青枯病的发生由于影响因素较多导致其人工接种重复性差,因此需要获得稳定的青枯病感染,同时在此基础上可以进行桉树苗期青枯病的防治研究。在本研究中采用水培后伤新根和袋苗未经水培直接伤根后转移到青枯菌液中浸泡6、12、18、24 h后移植,调查桉树幼苗青枯病发病率和生长状况,同时通过在接种前喷施不同浓度的BR、Me JA、SA 3种激素,诱导桉树抵抗青枯菌侵染,调查处理后苗木死亡率。结果表明,未经过水培直接伤根移植的苗木更容易感染青枯菌,经过24 h菌液浸泡处理后的幼苗的死亡率,达到86.67%,同时发现SA对缓解桉树青枯病的发病有明显的作用,且在喷施浓度为0.001 mmol时使用,青枯菌侵染的植株仍有75.0%的存活率。本研究获得了桉树幼苗稳定感染青枯病的一种方式,为室内研究桉树幼苗感染青枯病的机制奠定基础,同时获得了降低桉树青枯病发生的处理方式,为桉树苗期青枯病的防治提供一种方案。     

铝处理对2个桉树无性系幼苗丙二醛含量的影响

采用室内水培试验法,研究了铝处理对广西区2个优良桉树无性系(Eucalyptus grandis×E.urophylla No.9和E.urophylla No.4,分别记为G9、G4)根系及叶片内MDA含量的影响。结果表明:2个桉树无性系根内MDA含量均比叶内高;铝处理下,2个桉树无性系幼苗的MDA含量明显升高,G4根中MDA含量最高,达11.49μmol·g-1,根中MDA含量比叶中高,桉树无性系幼苗根部受铝伤害较叶严重。     

Evaluation of Schizophyllum commune Fr. potential for biodegradation of lignin: A light microscopic analysis

Lignin biodegradation potential of Schizophyllum commune Fr. is studied by using sound wood blocks of Ailanthus excelsa, Azadirachta indica, Tectona grandis, Eucalyptus sp. and Leucaena leucocephala. Initially, in vitro wood decay test showed minor weight loss, but it became rapid after one month. After 120 days of incubation, weight loss was minimum in T. grandis (24.05%) whereas it was maximum in A. excelsa (34.44%). Treated test blocks were characterised by enlargement of pits on ray cell wall, formation of additional boreholes in rays, separation of fibres and cell wall thinning and formation of ‘U’-shape notches. Fungal hyphae moved through the xylem cell lumen, and intercellular spaces formed in response to separation of fibres. Hyphae traverse in adjacent cell through the cell wall pits or by making additional boreholes. In all the species studied, xylem fibres and parenchyma (axial and ray) cells were more susceptible while vessels were resistant to fungal attack. In advanced stage of decay, fibres and axial parenchyma lost their rigidity while vessel walls showed uneven thinning. In the tension wood, G-fibres remained unaffected initially but loosening and separation of gelatinous layer facilitated fungal action and showed similar pattern of cell wall deterioration. Among the wood of different species studied, Tectona was more resistant whereas Ailanthus was more susceptible to fungal attack.     

Extractants for available boron in limed acid soils and its correlation in crops with high carbon storage capacity (Tectona grandis)

The objective of this work was to evaluate the efficiency of six extractants for available boron in acid soils undergoing to liming, and to correlate the results of soil analysis with foliar response seen in the teak plants in greenhouse conditions. Acid soil samples were collected and their chemical characterization was performed using standard analysis protocols. Later, agricultural lime was added to the experimental units in greenhouse conditions in order to control the soil acidity and these were incubated for 30 days. Six extracts for available boron were evaluated and correlated with response in the plant by foliar analysis. It is concluded that a high dissolution power of boron extractant solution produces a high sensitive in the determination of the changes of boron concentration in the limed acid soil. These methods are seen to be not adequate for the determination of available boron contents at high concentrations.     

武平县2个桉树品种前期生长及抗冻性

对武平县尾叶桉U6、巨尾桉DH3229 2个桉树品种前期（1、2和3年）生长及抗冻害能力进行了对比分析。结果表明：1年生尾叶桉U6的胸径、树高均极显著地大于巨尾桉DH3229;2年生巨尾桉DH3229抗冻害能力极显著地大于尾叶桉U6;3年生巨尾桉DH3229的胸径、树高均极显著地大于尾叶桉U6。综合2个桉树品种前期生长及抗冻害情况,武平县发展桉树速丰林宜选择巨尾桉DH3229。     

Virtual trees and light capture: a method for optimizing agroforestry stand design

In agroforestry systems, the distribution of light transmitted under tree canopies can be a limiting factor for the development of intercrops. The light available for intercrops depends on the quantity of light intercepted by tree canopies and, consequently, on the architecture of the tree species present. The influence of tree architecture on light transmission was analysed using dynamic 3D architectural models. The architectural analysis of Acacia mangium and Tectona grandis was performed in Indonesian agroforestry systems with trees aged from 1 to 3 years. 3D virtual trees were then generated with the AmapSim simulation software and 3D virtual experiments in which tree age, planting density, planting pattern and pruning intensity varied were reconstructed in order to simulate light available for the crop. Canopy closure of trees was more rapid in A. mangium than in T. grandis agroforestry systems; after 3 years the quantity of light available for A. mangium intercrops was three times lower than under T. grandis. Simulations with A. mangium showed that practices such as pruning and widening tree spacing enable to increase the total transmitted light within the stand. On T. grandis, modification of the tree row azimuth resulted in changes in the spatial and seasonal distribution of light available for the intercrops. These results are discussed in terms of agroforestry system management.

香榧新造林地抚育管理现状和发展对策

从诸暨市的实际出发,对香榧新造林地的现状和存在的问题进行调查,并就如何促进香榧的发展提出相应对策。