贵州省马尾松主要群体的遗传多样性分析

利用ISSR分子标记技术对贵州省马尾松主要分布区天然林群体、贵州省都匀马尾松种子园基因收集区、种子园建园亲本及子代进行了遗传多样性分析,结果表明:贵州省马尾松天然林群体保持较高的遗传多样性;由于种源间基因交流频繁,贵州省马尾松变异主要存在于种源内;都匀马尾松种子园和子代仍然存在较高的遗传多样性水平,人工选育过程中并没有导致遗传范围变窄,种子园还有进一步选择的潜力;种子园收集区遗传多样性较低,需要进一步收集种质资源加以补充。该研究结果可以为贵州省马尾松种质资源的收集与保存、种子园遗传管理以及贵州省马尾松多世代育种策略的制定提供参考依据。     

青海云杉群体同工酶变异的研究

本文利用聚丙烯酰胺凝胶垂直板电泳技术,研究了青海云杉4个天然群体8个基因位点表达的5种同工酶的变异模式。结果表明,青海云杉具有较高的遗传变异性,多态位点百分率为49.95％,每位点等位基因平均数为2.38,平均期望杂合性为0.212。群体分化水平较低,平均基因分化系数为0.023。群体间遗传距离平均值为0.01224,遗传距离和空间距离间存在正相关性,其间相关系数为0.8409,空间上相距较近的群体在遗传上具有较高的相似性。     

马尾松优良家系再选择研究

马尾松是我省最重要的造林树种,在工农业生产、生态环保等方面有着重要的作用。本研究根据已掌握的马尾松群体及个体的遗传变异规律,进行遗传测定,开展二层次选择,充分挖掘种内各层次变异,达到最佳增益水平,大大提高马尾松的经营水平。     

湖南桂阳马尾松种子园遗传多样性的ISSR分析

本研究从100条ISSR引物中筛选出11条多态性引物,对湖南桂阳马尾松第二代种子园共87份样品进行遗传多样性分析,共扩增得到246个多态位点。采用PAUP4.0软件分析,获得两个主要群体(广西群体和城步群体),在城步群体内,湖南和贵州两省的家系被分开。再对两个主要群体采用POPGEN32软件分析,结果表明:在桂阳第二代种子园内总的多态位点百分率达98.80%,总的Shannon信息指数为0.583 7,Nei's基因多样性指数为0.400 3,2个群体的多态位点百分率分别为93.57%、98.80%,各群体间的基因分化系数为0.036 3,基因流为13.258 6。这表明桂阳第二代马尾松种子园的遗传多样性水平高,个体间的基因多样性变异大,该种子园所采用的建园方式是可取的。     

马尾松苗期生长性状的遗传分析

马尾松分布极为广泛,是一具多种用途的树种,已有众多的研究报道了其群体和个体的遗传变异,但这些研究都未曾把群体和个体变异结合起来加以分析。我们从1983年开始,连续5年进行了马尾松育苗试验,旨在通过多年的苗期试验,掌握苗期生长性状遗传变异的大小和不同变异层次的方差分量比例,以及若干重要遗传参数,以正确制订马尾松育种方案。材料与方法我们于1983—1987年,在浙江淳安和安徽屯溪两试验点进行了马尾松育苗试验。育苗皆采用随机区组设计,双行小区,各试验重复3—5次不等。整个试验分为两大类:种源试验和自由授粉子代测定,详见表1。     

马尾松制浆造纸性能的群体变异及适应性试验

研究马尾松木材化学组分，制浆性能在群体中的变异及不同伐木材制浆造纸适应性，结果表明上述性状天然群体和种源试林群体中都存在一定变异，具有一定选择潜力。该验发现２０年生伐龄木材制浆性能有一定优越性。采用短周期速生材造纸是可行的，但其关键在于造育幼龄材木材密度高的品系。     

用同工酶研究马尾松群体的遗传结构

本文应用同工酶分析技术结合形态、生长和物候等表型性状,分析了福建省沙县境内的5个马尾松天然小群体的遗传结构。结果表明,马尾松群体具有较高的遗传变异水平,5个小群体的多态位点百分率达64.5％,等位基因平均数为1.65,平均期望杂合度为0.216。小群体间的分化程度不高,5个小群体的平均遗传距离为0.0047;同工酶测定的总变异中,2.4％来自小群体间,其余的变异(97.6％)来自小群体内;而表型性状总的遗传变异中,6.5％左右来自小群体间,其余的变异(93.5％)来自小群体内。     

马尾松数量性状相关遗传参数的多元分析与比较

对马尾松数量性状 3种相关遗传参数的多元分析结果表明 ,分枝类型在马尾松的选择中有一定意义     

马尾松种源,林分和家系“三水平”试验及其相互关系

马尾松种源、林分和家系“三水平”试验及其相互关系干少雄（四川省林业科学研究院）研究树种的性状遗传变异是进行树种改良的基础工作。对马尾松进行多层次、多性状综合研究可评定马尾松群体选择与个体选择的效益，探寻最佳选择方案，并为生产上提供有效的遗传改良途径。...     

广西马尾松第2代育种群体的组建

【目的】基于广西马尾松第1代育种群体的8片20年生及以上的子代测定林测定试验,在综合评价育种目标性状与遗传多样性的基础上,选择建立马尾松第2代育种群体,为马尾松高世代育种研究提供重要材料。【方法】采用SAS分析软件依据线性模型对子代生长量数据进行统计分析,并据此进行第2代优树选择。采用SSR分子标记对第2代优树进行遗传多样性分析、亲本分析及遗传距离估算,根据优树间遗传距离对第2代育种群体进行结构划分。【结果】在参试的子代测定林中,参试家系间在生长性状上均达到极显著差异;多数子代林的材积指标家系遗传力处于中等以上水平(h~2≥0.2),适于开展优良家系选择。基于此,采用配合选择与单株选择相结合的方法选择出第2代育种群体材料163株,平均遗传增益为21.95%。采用16对SSR引物对该第2代育种材料进行遗传多样性研究,16个位点共检测到45个等位变异。每个位点平均观察等位基因数(NA)为2.7,多态率为100%;平均有效等位基因数(Ne)为1.54;Shannon多样性指数(I)平均为0.49;平均观测杂合度(H_o)为0.32。采用Coancestry Version 1.0软件计算出第2代育种群体的平均共祖系数为0.042,育种群体状态数为11.9;根据16对SSR引物的扩增结果,采用CERVUS2.0软件对构建的第2代育种群体材料进行父本分析,发现在包含163个优树的第2代群体中,有57个个体在置信度95%的情况下可以确定父本,另有102个个体在置信度80%的情况下能够确定父本。为了有效避免高世代杂交育种过程中发生近交,以遗传距离为指标对第2代育种群体材料进行聚类,根据距离聚类结果将163个体划分为10个亚系,编号为桂GC2-A—桂GC2-J。在建立马尾松第2代种子园时,拟采用以下策略:从每个亚系中选择一定数量的最佳无性系作为精选群体建园;在进行下一代杂交育种时,进行亚系间的交配,使育种群体整体的近交程度保持在一个相对较低的水平。【结论】根据研究结果初步建立了由163株优树组成的广西马尾松第2代育种群体。该群体具有较高的遗传多样性,个体间的近交程度较低。根据遗传距离对第2代育种群体进行亚系划分,设计出"系间杂交、系内慎交"的高世代杂交育种策略,可有效避免近交,为有计划地开展马尾松高世代杂交育种奠定基础。     

云南红豆杉天然群体的遗传多样性和群体分化

利用云南红豆杉Taxusyunnanensis种子的单倍体胚乳,采用水平淀粉凝胶电泳技术,对分布于金沙江流域的云南红豆杉天然群体的遗传多样性和群体分化进行了研究.对8个酶系统15个酶位点的分析结果表明该地区的云南红豆杉天然群体遗传变异水平较高,多态位点比率P=0.933,等位基因平均数A=2.90.平均期望杂合度He=0.290;4个小群体间遗传分化很小.基因分化系数GST=0.071.云南红豆杉天然群体具有明显丰富的遗传变异和较小的群体间分化,其原因是云南红豆杉寿命长、风媒异花授粉、种子传播、基因交流频繁.     

Structural diversity of forest communities on Baihuashan Mountain, Beijing

The structural diversity of forests on Baihuashan Mountain, Beijing, was surveyed by a plotless method combined with branch and leaf coverage estimation in the different layers. New structural indices were constructed, calculated and compared among different communities. On the basis of previous work, structural diversity of forest communities at the stand level was described by a vertical complexity index and a horizontal heterogeneity index. From a correlational analysis among the new indices and other commonly used biodiversity indices, we concluded that the new indices are closely related to a tree height inequality index and the Shannon-Wiener index of the tree and shrub layer, which indicated that the new indices were good at indicating structural diversity in the different forests on Baihuashan Mountain. The results show that, in natural forests, structural diversity of pioneer communities is much lower than in late successive communities. In plantations, structural diversity is determined by the stage of development and tree species. Tending would increase horizontal heterogeneity and decrease vertical complexity. __________ Translated from Journal of Beijing Forestry University, 2007, 29(1): 7–13 [译自: 北京林业大学学报]     

木麻黄对青枯菌的水平及垂直抗性研究

６个青枯假单胞杆菌菌株对７个木麻黄无性系的交互接种试验表明，病害的相对强度在无性系与菌株间存在着显著性差异，无性系与菌株之间的交互作用也极显著。结果说明在木麻黄－青枯菌病理系统中，同时存在着水平抗性和垂直抗性或水平致病性与垂直致病性；这一交互作用特征的揭示对于木麻黄的抗病育种及防滑战略具有重要意义。     

5个印度小桐子品种在云南省引种的初步调查分析

为了研究印度5个优良小桐子品种的种子形态及其在中国生长适应性,在国内进行种子形态测定以及苗期生长指标和生物量指标的测定。结果显示,5个印度品种和一个中国种源的小桐子种子在纵径和侧径上没有显著差异,横径上表现出了显著差异,中国种源的小桐子种子测量平均值为1．043cm,表现最差。而其他印度品种的种子形态指标差异不大。中国种源小桐子在高生长与地径生长方面优于印度品种。通过对印度5个品种的种子形态指标、生长指标、生物量指标和发芽率、含油率等指标表现的主成分分析并综合打分排序,得分由高到低依次为Nellore2、Nellorel、Chittgrh、J—ljist01和J03,前3个印度品种较能适应云南省的生长环境,但在苗期的生长上与中国当地品种存在一定的差异。     

基于空间结构的杉木树冠生长可视化模拟

[目的]定量研究杉木林分中不同空间结构对林木冠形生长变化的影响,实现基于空间结构的杉木树冠生长可视化模拟。[方法]以湖南省攸县黄丰桥国有林场为试验区,在林分中选择并划分空间结构单元,进行冠形和空间结构数据调查,将林木东南西北4个方向的活枝下高、冠高、冠幅作为林木冠形描述因子,将周围木影响距离、相对树高定义为水平空间结构参数Ph和垂直空间结构参数Pv,使用多元逐步回归的分析方法,分析冠形描述因子与年龄、水平、垂直空间结构参数的关系,建立不同空间结构下杉木冠形的生长变化模型。基于B样条曲线模拟杉木冠形,构建不同生长阶段的三维杉木模型,结合三维动态渲染技术,实现杉木树冠生长的可视化模拟。[结果]通过对年龄和水平、垂直空间结构参数的逐步回归分析,结果表明:林木活枝下高、冠高和年龄、垂直空间结构参数呈现显著相关关系,模型决定系数R~2分别为0.754和0.813;林木各向冠幅和年龄、水平空间结构参数呈现极显著相关关系,模型决定系数R~2为0.623。基于杉木树冠生长模型和三维动态渲染技术,实现了树冠在东南西北不同方向的生长可视化。[结论]通过划分空间结构单元的方法选择研究目标并进行数据调查,使用逐步回归的方法,分析杉木冠形数据和年龄与空间结构数据的关系,建立树冠各方向活枝下高、冠高、冠幅的生长模型,结合三维动态渲染技术,使用MOGRE三维渲染引擎作为工具,实现了基于空间结构的杉木树冠生长可视化模拟。     

Improvement of simple impedance tomography method in RF range for estimating moisture distribution in squared timbers

Improvement of the simple tomography method for estimating moisture distribution in squared timbers was conducted by using impedance measurement in the RF range at 250 kHz. The local impedance in the horizontal and vertical directions was measured during natural drying. An inverse procedure using a trial-and-error method was used to reconstitute the cross-sectional moisture distribution from the surface impedance measurement. Two essential corrections for the spatial heterogeneity of the electric field between electrodes and for the calculation error due to the algorithm of the trial-and-error method were introduced to improve the accuracy of the reconstitution of the moisture distribution. The reconstituted moisture distribution matched well that determined by the oven-dry method.     

Vertical, horizontal and azimuthal variations in leaf photosynthetic characteristics within a Fagus crenata crown in relation to light acclimation

An understanding of spatial variations in gas exchange parameters in relation to the light environment is crucial for modeling canopy photosynthesis. We measured vertical, horizontal and azimuthal (north and south) variations in photosynthetic capacity (i.e., the maximum rate of carboxylation: Vcmax), nitrogen content (N), leaf mass per area (LMA) and chlorophyll content (Chl) in relation to relative photosynthetic photon flux (rPPF) within a Fagus crenata Blume crown. The horizontal gradient of rPPF was similar in magnitude to the vertical gradient of rPPF from the upper to the lower crown. The rPPF in the north quadrant of the crown was slightly lower than in the south quadrant. Nitrogen content per area (Narea), LMA and Vcmax were strictly proportional to rPPF, irrespective of the vertical direction, horizontal direction and crown azimuth, whereas nitrogen content per dry mass, Chl per area and photosynthetic capacity per dry mass (Vm) were fairly constant. Statistical analyses separating vertical trends from horizontal and azimuthal trends indicated that, although horizontal and vertical light acclimation of leaf properties were similar, there were two significant azimuthal variations: (1) Vcmax was lower in north-facing leaves than in south-facing leaves for a given Narea, indicating low photosynthetic nitrogen-use efficiency (PNUE) of north-facing leaves; and (2) Vcmax was lower in north-facing leaves than in south-facing leaves for a given LMA, indicating low Vm of the north-facing leaves. With respect to the low PNUE of the north-facing leaves, there were no significant azimuthal variations in leaf CO2 conductance from the stomata to the carboxylation site. Biochemical analysis indicated that azimuthal variations in nitrogen allocation to ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) and in nitrogen allocation between carboxylation (Rubisco and other Calvin cycle enzymes) and light harvesting machinery (Chl pigment-protein complexes) were not the main contributor to the difference in PNUE between north- and south-facing leaves. Lower specific activity of Rubisco may be responsible for the low PNUE of the north-facing leaves. Anatomical analysis indicated that not only high leaf density, which is compatible with a greater fraction of non-photosynthetic tissue, but also thick photosynthetic tissue contributed to the low Vm in the north-facing leaves. These azimuthal variations may need to be considered when modeling canopy photosynthesis based on the Narea-Vcmax or LMA-Vcmax relationship.     

海南岛西南桦的地理分布及其种质资源现状

本文论述了海南岛内西南桦(Betula alnoides Buch—Ham．)天然林水平分布和垂直分布的基本特点：介绍了西南桦在海南岛的种质资源现状及存在问题，为海南岛的西南桦天然林保护与人工林发展提供科学依据。     

森林可燃物的动态特征研究综述

森林可燃物具有很强的空间异质性,其种类、水平分布、垂直分布具有动态的特征,会改变火频率、火灾类型和火强度。长期动态跟踪、监测森林可燃物,把握动态特征,能够及时掌握森林可燃物能量变化,从而更好地预防、监测和扑救森林火灾。文章对森林可燃物的类型、含水率、载量、分布特征等动态特征的研究方法和内容进行了综述,并展望了未来研究热点。     

Spatial pattern and regeneration dynamics in a temperate Abies–Tsuga forest in southwestern Japan

This article reports the regeneration dynamics of a temperate Abies–Tsuga forest in Kirishima Yaku National Park, southwestern Japan, and examines the influence of species coexistence mediated by gap disturbances on biomass production. All trees taller than 2 m in a 1-ha plot were monitored over four growing seasons. Three growth-form groups occupied different vertical layers. Evergreen conifers and deciduous broad-leaved trees tended to be spatially segregated from evergreen broad-leaved trees, which formed thickets in the understorey. The regeneration of understorey evergreen broad-leaved trees was affected by canopy gaps. The recruitment of conifers and deciduous broad-leaved species was not observed during the four growing seasons. This suggests that regeneration is sporadic and the present environmental conditions are not favorable for these canopy species. The mortality and unsuccessful recruitment of conifers and deciduous trees appeared to cause fluctuations in the productivity of the stand. However, an abundance of canopy gaps accelerates the regrowth of shorter species, and the fluctuation of productivity resulting from the population dynamics of canopy species would be partly mitigated by the regeneration of evergreen understorey species. The horizontal and vertical heterogeneity of the temperate mixed forest was a result of the patch structures of the three growth-form groups. The different regeneration patterns among the three groups, which were driven by interactions of species-specific regeneration niches and disturbance regimes, might be an important factor in maintaining the aboveground productivity in a transitional mixed forest between warm-temperate and cool-temperate zones.