油松毛虫质型多角体病毒的观察

油松毛虫(Dendrolimus tabulaeformis Tsai et Liu)分布于我国河北、山西、陕西、山东、(泰山)、辽宁(阜新、朝阳、昭盟南部)。主要为害油松,是油松林的毁灭性食叶害虫。为了寻找一种“天然的”松毛虫防治剂,对松毛虫进行经济、有效的生物防治,我们在林地调查和室内观察、分析的基础上,于1977年9月在辽宁省建平县富山公社鱼山子林地的油松毛虫体内,发现并分离获得油松毛虫质型多角体病毒~[1]。最近作了组织切片和多角体及病毒粒子的电镜观察,现将结果报道于后。     

中国山杨群体CDS遗传多样性格局与谱系地理分析

[目的 ]基于REF6与BRR2a基因，探讨中国山杨不同群体遗传多样性分布格局、迁移路线，以及群体遗传变异与环境变化的关系。[方法 ]获取REF6与BRR2a基因的CDS序列，计算不同CDS序列的分子多样性指数，构建单倍型网络图以及系统发育树。[结果 ]在西南群体中，REF6基因和BRR2a基因3种中性检验的平均值均为负值，核苷酸多态性均低于北方和中部群体。中国山杨群体系统发育树与单倍型网络图结果显示外类群首先与中国山杨北方群体聚集在一起，西南群体往往聚集在末端，且两种基因的单倍型在北方与中部多样性较为丰富，西南群体中单倍型种类相对单一。[结论 ]中国山杨从北方迁移到南方，为了适应云贵高原独特的气候环境，位于西南地区的群体经历了强烈的自然选择，发生了局部适应。     

纵带球须刺蛾核多角体病毒病的初步研究

纵带球须刺蛾是八宝树、柿和橄榄等许多林木和果树的害虫。在广州一年发生1—3代。幼虫一般7—8龄。它可感染一种疾病,经电镜观察表明,是属一种核多角体病毒病。多角体为四面体、六面体或不规则形,大小约为0.7—1.5μm。具外膜的病毒粒子杆状,长约260—320 nm,宽约60—70 nm。病毒粒子在多角体内成束或单个排列。每个病毒束一般有2—7个病毒粒子。此病毒有很强的感染力,并且因剂量、虫龄的不同而有差异。在自然情况下,它常诱致流行病,是控制此虫种群数量的重要因素。此病毒不感染家蚕和马尾松毛虫。     

两种叶蜂的肠型核多角体病毒

<正> 近年来,我国对森林害虫的病毒相当重视,已分离出不少昆虫病原病毒。这些病毒的寄主多数为鳞翅目昆虫,而且多是具有包涵体的病毒类群。我们在调查广东重要林业害虫病原病毒的工作中,于1980和1981年,相继从两种叶蜂中,观察到一类特殊类型的病毒——肠型核多角体病毒。这类病毒的特点是:在一般情况下,只引起寄主中肠病变,在其它组织中看不到病毒。多角体仅发生于中肠细胞核内,大小为0.5-1.5微米之间。病毒粒子包含于蛋     

外斑埃尺蠖核型多角体病毒新株

1988年从危害刺槐的外斑埃尺蠖（Ectropis excellens Butler)病死虫中分离出一株病毒。经电镜观察且种新核型多角体病毒。其多角体大小为0．64－1．92μm。病毒粒子呈杆状，大小为292nm×71．3nm。     

杨小舟蛾新病毒的鉴定及其生物活性研究

[目的]杆状病毒在农林害虫的生物防治中起着重要的作用,本研究鉴定1株具有高毒力的杨小舟蛾新病毒,为害虫的生物防治提供新病毒资源.[方法]通过研究该病毒的超微结构和生物活性确定其生防潜力.[结果]超微结构表明,该病毒包涵体多呈椭圆形,平均大小为0.43?×?0.21?μm;包涵体中包埋一个杆状病毒粒子,具有颗粒体病毒结构...     

柏毒蛾颗粒体病毒病初报

自然患病死亡的柏毒蛾幼虫，虫体表皮极易破碎，流出黄褐色粘稠体液，无腐臭味。经提取，该病毒在电镜下观察，颗粒体形态多样，大小约为３００～４００×２００～２５０μ；病毒粒子两端圆滑，大小约为２００～２８０×４０～５０μ。每个颗粒体内包含１个病毒粒子。经测定为ＤＮＡ型。分类命名属杆状病毒科，颗粒体病毒属。     

一种有效的蚜虫基因组DNA提取方法

蚜虫属于同翅目(Homoptera)蚜总科(Aphidoidea)和球蚜总科(Adelgoidea),世界上已知种类为4 000多种[1],我国已报道的种类1 000余种[2]。蚜虫大多数是害虫,它们刺吸植物汁液,直接影响植物生长,同时间接传播病毒病害,造成农业上的损失,如棉蚜(Aphis gossypiiG lover)、麦长管蚜(Macrosiphum avenae(Fabricius))等;少数种类如五倍子蚜(Schlechtendalia chinensis(Bell))是重要的资源昆虫,具有较高的经济价值[3]。蚜虫身体微小,形态变异大,生活习性复杂,并具有多型多态现象,研究它较为困难,尤其是在分类和鉴定、近缘种的识别等方面,传统的研…     

美人蕉花叶病的发生与防治

美人蕉花叶病是栽培中的1种重要病害,初期、中期和末期发病症状呈现一定规律.美人蕉花叶病病原物常见有3种病毒,侵染发病规律特点主要受传染途径和发病因素影响.从种子、种苗、种根品质、栽植环境、栽植土类型、水肥管理及除杂清园、病虫防治几个方面提出综合防治方案.     

莲花山自然保护区青海云杉叶锈病初步研究

青海云杉叶锈病是莲花山自然保护区云杉林中发生的一种重要病害，病原为祁连金锈菌。该病菌为缺夏[Ⅱ]型，[0]、[Ⅰ]阶段寄生在青海云杉当年生针叶上，[Ⅲ]、[Ⅳ]阶段转主寄生在青海杜鹃上，并在转主寄主青海杜鹃上越冬。每年6月底至8月底发病，病害发生较为严重。25％粉锈宁500倍液防治效果较好，平均防治率达93．2％。     

31个杂交杨无性系对青杨叶锈病的抗性评价

在大田条件下对从北美新引种的31个杂交杨无性系对青杨叶锈病的抗性进行调查和评价的结果表明:所引进无性系对杨树叶锈病的抗性表现出很大的差异,从高度抗病到高度感病均有,但没有免疫的无性系。HE-2,XMH-10,XMH-9,HE-1,XMH-1,XMH-11,XMH-12,XMH-2,MH-8,XMH-7这10个无性系表现出高度抗病性,MH-9,DMH-3,MH-10,MH-4,MH-1,MH-6,MH-7,MH-2这8个无性系表现为高度感病。DN、NE杂交的大多数无性系有较高的抗病性,而TD、TN杂交的绝大多数无性系为感病或高度感病。同一杂交组合的不同无性系间,其抗性存在很大差异,有高抗,也有高感。     

Influence of clonal susceptibility,leaf age and inoculum density on infections by Melampsora larici-populina races E1 and E3

A study was conducted on the influence of clonal susceptibility, leaf age and inoculum density on the incubation and presporulation periods, and on the intensity of attack of Melampsora larici-populina races El and E3, under controlled conditions, on artificially inoculated poplar leaf discs. Both races were more virulent on susceptible clones and on 5- to 15-day-old leaves. On susceptible clones the intensity of attack increased progressively with the increase of inoculum density. Where there was complete coverage of the leaf surface, uredia were smaller in size as a result of the increase in density. The incubation period and, above all, the average presporulation period of susceptible clones proved to be longer with 1- to 3-day-old leaves and, generally, with the oldest. The epidemiological consequences of these results are discussed.     

Photosynthesis patterns during the establishment year within two Populus clones with contrasting morphology and phenology

Diurnal and seasonal photosynthesis patterns were studied in poplar clones Populus tristis Fisch. x P. balsamfera L. cv. Tristis #1 (NC 5260) and Populus x euramericana (Dode) Guiner cv. Eugenei (NC 5326, Carolina poplar) during their first season in the field in a short rotation, intensive culture plantation. Photosynthetic rates were low in immature leaves; increased basipetally on the shoot and peaked in leaves that had recently reached full expansion; and thereafter declined in lower-crown leaves in both clones. Photosynthesis was associated with leaf age and stomatal conductance in immature leaves; adaxial photosynthetic photon flux density (PPFD) and leaf temperature in recently mature leaves; and leaf age and adaxial PPFD in lower-crown leaves. Diurnal photosynthesis patterns within trees were highly variable due to differential light interception among leaves. Results of clonal comparisons of photosynthetic rates were dependent on which leaves were pooled for comparison and how photosynthesis was expressed. Compared to Eugenei, Tristis produced smaller leaves which had higher unit-area photosynthesis rates. The more indeterminate Eugenei outgrew Tristis principally because it more fully utilized the growing season for leaf area production. Photosynthetic production integrated over the growing season was closely related to dry matter production in both clones.     

Photosynthetic response of poplar leaves at different developmental phases to environmental factors

With economic incentives and interests in fast-growing poplar trees for short-rotation production of fiber and veneer, many new poplar hybrids have been bred and planted in China, but how to match the new poplar clones to suitable sites and maintain their higher growth rates is still not very clear. In this study, the photosynthetic response of poplar leaves at various developmental stages during two seasons (summer and autumn) was explored and mechanistic models for the photosynthesis of poplar leaves at different developmental phases in response photosynthetic active radiation (PAR), temperature, and relatively humidity were established using the optimization software package 1st Opt. Mature poplar leaves in autumn had significantly higher photosynthetic capacity than leaves at other stages and seasons. Based on the models established for poplar leaves at different phases, the main limiting factors for photosynthesis at the research site were high PAR and temperature in the summer and low PAR in the autumn. Our results highlight the importance of selecting suitable sites, pruning and stand density control during the plantation development to maintain higher photosynthetic rates of poplar trees and to establish optimum cultivation patterns for various utilization of poplar plantations.     

Relative natural resistance of Populus deltoides clones against defoliator Clostera cupreata (Lepidoptera: Notodontidae) in northern India

Populus deltoides (poplar) that is extensively being planted commercially in agroforestry combinations in northern India is prone to attack by a defoliating insect, Clostera cupreata. In order to evaluate the relative susceptibility/resistance of different clones and to identify the resistant ones, 80 clones of American origin were evaluated in Dehra Dun, India. The feeding potential of the pest on different clones varied significantly. The clones were grouped into six categories depending on their susceptibility as most resistant or R1 (12 clones), moderately resistant or R2 (14 clones), marginally resistant or R3 (10 clones), marginally susceptible or S1 (17 clones), moderately susceptible or S2 (18 clones) and most susceptible or S3 (nine clones). Clone 110120 of Tennessee was most resistant where as Oklahoma clone 104 was most susceptible to this pest. Amongst the most resistant clones (R1), only three clones, WSL-4, WSL-12 and WSL-18 (source: WIMCO Seedlings Ltd, India) were found to be superior, in terms of growth increment, as compared to the standard and most widely planted clones in northern India i.e. G-3 and G-48, and are promising clones for plantation in defoliator prone areas.This revised version was published online in November 2005 with corrections to the Cover Date.     

Comparison of photosynthetic induction and transient limitations during the induction phase in young and mature leaves from three poplar clones

We tested the hypothesis that leaf age affects photosynthetic induction, because conductance to CO2 diffusion usually decreases with increasing leaf age. Photosynthetic inductions, primarily determined by the light modulation of Rubisco activity and stomatal opening, were investigated in both young and mature leaves, as defined by leaf plastochron index (LPI), from three poplar clones: Populus alba L., P. nigra L. and P. x euramericana (Dode) Guinier. In all clones, maximum assimilation rates (A max), maximum stomatal conductance (G Smax) and dark respiration rates (RD) were higher in young leaves (LPI = 3-5) than in mature leaves (LPI = 10-14), and A max decreased from P. alba via P. x euramericana to P. nigra. The clones with high photosynthetic capacity had low induction states 60 s after leaf illumination (IS60; indicating a slow initial induction phase), and required less time to reach 90% photosynthetic induction (T90). In contrast, the clone with the lowest photosynthetic capacity (P. nigra) exhibited high IS60 (high initial induction state) but a long induction time (high T90). A comparison of mature leaves with young leaves revealed significantly (P < 0.01) lower IS60 values in mature leaves of P. nigra only, and significantly higher T90 values in mature leaves of P. alba only. In all clones, young leaves exhibited a lower percentage of maximum transient stomatal limitation during photosynthetic induction (4-9%) compared with mature leaves (16-30%). Transient biochemical limitation, assessed on the basis of the time constants of Rubisco activation (tau), was significantly higher in mature leaves than in young leaves of P. alba; whereas there were no significant differences in tau between young and mature leaves of the other poplar clones. Thus, our hypothesis that leaf age affects photosynthetic induction was confirmed at the level of transient stomatal limitation, which was significantly higher in mature leaves than in young leaves in all clones. For the induction parameters IS60, T90 and tau, photosynthetic induction was more clone-specific and was dependent on leaf age only in some cases, an observation that may apply to other tree species.     

辽宁省当前主要杨树优良新品种

近些年来 ,辽宁省杨树研究所在杨树良种选育研究中 ,通过杂交、引种等手段 ,相继培育出荷兰 3930杨、辽宁杨等 10余种更新换代优良品种 (无性系 ) ,在生产造林中广泛应用。文章着重介绍了这些良种的来源、形态、抗性、生长特性及适生推广区。主要优良品种 (无性系 )有 :①荷兰3930杨、3934杨 ;②辽宁杨、盖杨、辽河杨 ;③欧美杨 10 7、10 8;④ 92 0 5杨、92 0 7杨 ;⑤小×胡 2 3号、小×胡 19号杨     

Ermittlung und Bewertung quantitativer Virusresistenz von Pappeln nach Inokulation mit Pappelmosaik-Virus (poplar mosaic virus,PopMV)

Determination and evaluation of quantitative virus resistance in poplars inoculated with poplar mosaic virus (PopMV). Statistical analysis of data on symptom severity and virus concentration in PopMV-infected leaves were used to determine differences in virus resistance among poplar clones. These differences were confirmed in ultrastructural studies.     

Differentiation of poplar and willow clones using RAPD fingerprints

The technique of random amplified polymorphic DNA (RAPD) fingerprinting was used to differentiate species and identify clones of 15 poplar and 15 willow clones (ramets of three poplar clones were also included to verify the stability of the results). Four random DNA primers (Deca-11, Chl-1, Chl-4 and Chl-10) and an M13 universal primer were used to determine DNA polymorphism among the clones. Based on the DNA banding pattern obtained with the four DNA primers by polymerase chain reaction (PCR) amplification we conclude that RAPD fingerprinting with properly selected primers can be used for clonal and species differentiation of poplar and willow. The technique is simple, accurate and inexpensive.