小叶锦鸡儿固沙群落草本种群重要值与生态位的研究

本文以不同恢复阶段小叶锦鸡儿群落内的草本物种为研究对象,分析了植被恢复过程中草本种群的重要值与生态位动态特征。结果表明:在5年,10年和天然锦鸡儿群落中狗尾草的重要值最大,而在21年锦鸡儿群落中地锦占优势地位;狗尾草和烛台虫实在整个演替过程中生态位宽度值都较大,大多数物种的生态幅度较窄;随着恢复时间的延长,群落内种群之间生态位重叠的平均值呈下降趋势,群落的生态位配置得到改善,种间关系和群落结构趋于稳定。     

宁夏盐池荒漠化草原人工封育区生态位研究

运用Levins生态宽度指数及Pianka生态位重叠指数对宁夏盐池荒漠草原人工封育区2002年及2003年生态位宽度及生态位重叠进行计量。结果表明:2002年封育区茵陈蒿、狗尾草生态位宽度值最大,分别为0.758、0.505,是02年封育区的优势种;03年封育区的优势种是茵陈蒿、狗尾草、老瓜头、苦豆子,其生态位宽度值分别为0.868、0.567、0.563、0.552。最大生态位重叠值02年与03年均未出现在优势种之间,02年出现在赖草与叉枝鸦葱、新疆猪毛菜与志远之间;03年出现在沙珍棘豆与中亚虫实、沙珍棘豆与狭叶米口袋、中亚虫实与狭叶米口袋之间。     

The ecological role of dew in assisting seed germination of the annual desert plant species in a desert environment,northwestern China

It is important to understand the effects of dew events on non-mucilaginous seed germination of annual desert plant species during dry seasons, which is critical to maintaining long-term soil seed banks in a harsh desert environment. We hypothesize that dew deposition also assists in the non-mucilaginous seed germination of annual desert species. A common field dew treatment experiment was conducted in the Linze Inland River Basin Research Station to investigate the effects of dew deposition on the seed germination of four annual species, including Agriophyllum squarrosum, Corispermum mongolicum, Bassia dasyphylla and Halogeton arachnoideus. The results showed that the presence of dew significantly increased seed germination percentages and decreased the nonviable seed percentages of B. dasyphylla and H. arachnoideus, whereas there was no such trend for the seeds of C. mongolicum and A. squarrosum. The ecological effects of dew on the seed germination and viability of the annual desert plants were species specific. Although dew wetting is insufficient to cause seed germination, it may help in priming the seeds.     

不同类型沙地长穗虫实的繁殖分配及其与个体大小的关系

研究了不同类型沙地一年生植物长穗虫实的繁殖分配及其与个体大小的关系.结果表明:①不同类型沙地长穗虫实的个体大小、繁殖器官大小、单株种子数以及株高等其他地上部分特征均表现出极显著的差异性,其大小排列顺序为:固定沙地>半固定沙地>流动沙地,即表现出随沙面的固定而逐渐增大的趋势;②不同类型沙地虫实繁殖分配、单株种子重和种子均重也不相同,其差异程度从不显著到极显著不等;③不同类型沙地虫实个体大小与繁殖器官大小均呈极显著的正相关关系,个体大小与繁殖分配在不同类型沙地呈负相关关系,其中在流动沙地和固定沙地上达到显著水平;④个体大小与单株种子数、单株种子重之间存在正相关关系,但流动沙地相关程度较低;⑤不同类型沙地上虫实繁殖分配具体表现为,流动沙地为34.9%,固定沙地和半固定沙地大于50%,即随着沙面固定程度的增加,一年生植物种虫实倾向于将更多的资源和能量用于繁殖生长.这一结论不仅有助于分析该植物对沙生生境的适应对策,也有助于对种群繁殖对策理论问题的深入探讨.     

1983-2003年浑善达克沙地中部沙丘植被在放牧条件下的比较

为了研究长期放牧条件下植被的变化,采用样方调查方法分析了1983-2003年浑善达克沙地中部的沙丘植被在放牧条件下的变化.期间,物种多样性、生物量和盖度在第1个10年缓慢下降,而第2个10年则加速下降,在沙丘阳坡形成了以适口性差的一年生草本植物为主的稀疏植被,阴坡以木本树木为主.且表现为木本植物的降低速度比草本植物慢....     

新疆山地鸟类和哺乳类多样性及其区系特征

新疆各类陆栖脊椎动物近 70 0种 ,占中国这一类动物种数的 32 %,其中鸟兽资源尤其丰富 ,计有 42 5种鸟类和 1 5 5种兽类 (哺乳类 ) ,占中国鸟兽种数的 31 %。本文主要以新疆三大山区———阿尔泰山、天山、昆仑 -阿尔金山地区鸟类和哺乳类动物的多样性及区系分布作综合性介绍和分析。根据实地考察和以往文献资料 ,新疆阿尔泰山区记录在 1 2 4种鸟类 ,其中古北界北方型鸟类 5 1种 (占 41 .1 %) ,中亚型鸟类 31种 (占 2 5 .0 %) ,广布种鸟类 2 7种 (占 2 1 .8%) ,其他类型1 5种 (占 1 2 .1 %) ,显出以北方型泰加林鸟类为主的鸟类区系特征 ;分布的 5 0种兽类 ,区系上以古北界北方泰加林为主 ,即北方型兽类占该山区种数的 5 2 %。天山山区记录的鸟类大约2 81种 ,北方型种类占绝对优势 ,即北方型 1 0 6种 (占 37.72 %) ,北方广布型 76种 (占 2 7.0 4 %) ,中亚型 39种 (占 1 3.88%) ,高地型 1 8种 (占 6.41 %) ,广布型 33种 (占 1 1 .74%) ,东北型 9种 (占 3.2 1 %)。兽类分布有 62种 ,北方型兽类区系占优势 ,有 30种 (占 48.40 %) ,广布型 1 2种 (占 1 9.40 %) ,中亚型 1 1种 (占 1 7.70 %) ,特有种 9种 (占 1 4.5 0 %)。昆仑—阿尔金山地区 96种鸟类中 ,中亚类型成份占 2 8.1 %,高地型成分占 2 6%,北方型成?     

乌鲁木齐及附近地区蚁科区系的初步调查

对乌鲁木齐及附近地区蚁类的调查表明 ,计有 2亚科 1 3属 37种 ;区系组成以蚁属FormicaL .和弓背蚁属CamponotusMayr的种类较为丰富 ,分别有 1 5种和 6种 ;区系成分较为复杂 ,含古北种、新北种和广布种 ,其中 ,古北种有 30种 ,占总数的 81 % ;古北种下含泛古北种、中亚细亚种、欧洲种、欧洲中亚种、特有种、地中海种、欧洲—西伯利亚种、中央亚细亚种 ,而泛古北种最多 ,达 1 2种 ,占 32 .4 % ;其次为中亚细亚种有 7种 ,占 1 8.9% ;在所记录的种类中 ,草地蚁Formicapratensis,小林蚁 F .polyctena等多为中生性的种类 ,主要分布于森林地带或林间草地 ;草原箭蚁C .aenescens,草原原蚁P .epinotalis多分布在荒漠、半荒漠地带 ;褐色收获蚁Messorclivorum为乌鲁木齐地区的优势种 ,较为广泛地分布于乌鲁木齐及周边地区     

Responses of rare and common segetal species to wheat competition and fertiliser type and dose

Fertiliser application is considered crucial for determining the crop–weed competition relationship by stimulating plant growth and modulating the competition for below‐ground (soil nutrients) and above‐ground resources (e.g. light and space). Segetal species, those preferentially inhabiting cereal fields, have suffered a strong decline, owing to agricultural intensification. Under continued pressure, particularly the rarest species may disappear. In this study, we aimed to assess the competitive ability of common and rare segetal species when growing with wheat and how this competitive relationship is modulated by the type (organic and mineral) and dose (low or high) of fertilisation in a pot experiment. The segetal species grew better at higher doses of fertilisers when growing alone. However, when growing with wheat, they were outcompeted by the cereal plants. Overall, flowering was not affected by the competition with wheat under the different fertiliser regimes. Only the onset of flowering of some segetal weeds tended to be delayed by crop competition. Some rare species were more affected by the competition with wheat, indicating that they may be disadvantaged in a community context. However, not all rare segetal species tested responded in the same way, which highlights that competitiveness alone is a poor predictor of the rarity of segetal species.     

达赉湖自然保护区珍稀濒危水禽的分布特点及其保护研究

2006年8月至2007年8月,对内蒙古达赉湖国家级自然保护区珍稀濒危水禽的种类和分布进行研究。结果显示:共观察记录到20种珍稀濒危水禽,隶属于6目7科13属。其中国家I、II级重点保护水禽有14种,被列入《中国濒危动物红皮书》中的有13种,被列入《国际自然保护联盟(IUCN)濒危物种红皮书》中的有10种。4个调查区域中分布于乌兰诺尔地区的物种为最多,有18种,占总数的90%;呼伦沟地区的为最少,仅有7种,占总数的35%。12种为夏候鸟,8种为旅鸟,5月和9月分是迁徙高峰期。保护和管理好现存栖息地,减少人为干扰是目前最好的保护对策。     

新疆霍城县大、小西沟野果林种子植物组成及资源

新疆伊犁霍城大、小西沟野果林是以野樱桃李群落为主的野果林,共有种子植物60科233属500余种.林区野生植物资源丰富,统计表明:有野生果树38种、食用植物30种、饲用植物60种、蜜源植物111种、观赏植物128种、香料植物50种、药用植物113种.其中包括国家重点保护植物9种;新疆维吾尔自治区重点保护植物9种;中国珍稀濒危保护植物3种.通过多次实地调查分析,阐明了霍城野果林野生果树的分布、繁衍规律和植被、生境状况;综述了植物资源类型和用途及野生樱桃李群系生存的濒危程度.并提出在霍城大、小西沟野樱桃李集中分布区建立自然保护区的建议.     

烟粉虱基因组和转录组研究及展望

烟粉虱Bemisia tabaci(Gennadius)是世界性的重要害虫,为物种复合体,其中少数隐种近30年来入侵世界各国,并暴发成灾。在我国,最近几年MED隐种已经逐渐替代了之前入侵的MEAM1隐种,成为我国农田生态系统中的主要致害隐种。基因组和转录组研究的不断深入极大地推动了烟粉虱入侵机制、隐种替代机制、种系发生、不同隐种或地理种群鉴定、抗药性机制、烟粉虱与共生菌互作等领域的研究。本文简要综述了烟粉虱基因组和转录组测序的研究进展,介绍了转录组数据在种的分化和鉴定、共生菌的互作及抗药性研究领域的应用。     

Investigation of threatened arable weeds and their conservation status in Turkey

Agronomic operations carried out in arable lands may cause changes in weed populations and also decrease the number of animal species that depend on these weed species. An emerging paradigm is the conservation and sustainability of weed species. In this study, risk status of arable weeds in Turkey was evaluated and it was determined that 112 of them (76 endemic and 36 non-endemic species) were at risk according to the IUCN Red List. Turkey is extremely diverse, with over 3000 endemic plant species out of nearly 12 000 recorded. Considering endemic weeds, they are classified in the following risk categories: critically endangered (four weed species), endangered (EN) (six), vulnerable (VU) (14), near threatened (seven), least concern (41) and data deficient (DD) (four species). Among the non-endemic weeds, three species are EN, 31 VU and two are DD. The families with the highest threatened weed species are Scrophulariaceae, Fabaceae, Asteraceae, Brassicaceae and Lamiaceae. The identification of weed species in arable habitats and their risk status is a useful tool for assessing and monitoring how the sustainability of weed populations is affected by farming practices. The results show the necessity of adopting new environment-friendly agricultural methods to conserve the high number of endemic weed species under threat in Turkey.     

Distribution of conifer beetles (Scolytidae, Curculionidae, Cerambycidae) and wood nematodes (Bursaphelenchus spp.) in European and Asian Russia

The objective of this paper is to compare, between regions of Russia, conifer beetles found in Scolytidae, Curculionidae and Cerambycidae. Of the 220 species of bark beetles which were found in Russia, 108 species are associated with conifers. Sixty-three species of bark beetles are established in the European region of Russia and 94 species have been found in the Asian region. In Western Siberia 50 species are found. Eastern Siberia — 54 species, Russian Far East — 79 species. Forty-nine species of bark beetles (such as Dendroctonus micans, Ips duplicatas, I. sexdentatus and I. typographus ) are widely distributed throughout all Russian regions. There are 12 species of Pissodes found in all or various parts of Russia. Six weevil species ( Pissodes gyllenhali, P. harcyniae, P. castaneus, P. pini, P. piniphilus and P. validirostris ) are found throughout Russia and Western Europe. Five weevil species have only been found in the Asian region of Russia ( Pissodes cembrae, P. insignitus, P. irrogatus, P. nitidus, P. nemorensis ). Information concerning surveys of Russian conifer forests for wood nematodes, Bursaphelenchus spp., and their vectors is analysed. There is no evidence that B. xylophilus has ever occurred in Russia. Only B. mucronatus has been found. Six species of Monochamus beetles are found in Russia.     

新疆北塔山地区珍稀濒危植物种类及其地理成分

北塔山为中蒙边境的界山,地处新疆境内,属典型干旱山区,植物种类贫乏,区内珍稀濒危植物共计21种,隶属16科16属。其中,国家重点保护野生植物8种,中国物种红色名录收录6种,新疆重点保护野生植物15种;珍稀濒危种子植物区系分布区类型以北温带成分为主,与地中海、西亚至中亚分布及其变型联系紧密,中亚分布类型有微弱渗入;珍稀濒危种水平分布西多东少,集中分布于海拔900~2 000 m,且以旱生灌木、半灌木为主,仅有少量中生和湿生植物。     

Rangeland Monitoring and Invasive Weeds

One of the serious biological obstacles that must be addressed in any comprehensive revision of rangeland ecological condition assessment is what to do with sites dominated by exotic self-invasive species. In certain cases such species have truncated succession so that with a bare minimum of disturbance, the sites will never return to dominance by native perennial species. Are such sites destined to remain always in what is defined as "poor" ecological condition. Many communities dominated by exotic annuals are closed to the recruitment of seedlings of native perennial species. At the same time the communities are open to invasion by other introduced species. Should susceptibility to future invasions be a criteria in assessing the ecological condition of rangeland communities. The sustainability of communities dominated by exotic invasive species is assessing the ecological condition of such communities. Deviation from the plant community concepts of range condition and trend judgement involves setting new benchmark standards. This is an endeavor fraught with many perils.     

Trichoderma: systematics, the sexual state, and ecology

ABSTRACT A chronology is presented that charts the development of a genus and species concept in Trichoderma. Eighty-nine species of Trichoderma have been named, and several species of Hypocrea have been linked to unnamed Trichoderma anamorphs. Eighty-three taxa of Trichoderma and their teleomorphs, Hypocrea spp., have been included in phylogenetic analyses, including 11 species of Hypocrea with unnamed Trichoderma anamorphs. Phylogenetic analyses show that Trichoderma and Hypocrea are congeneric. Trichoderma species not linked to Hypocrea teleomorphs are derived from among species that are linked to teleomorphs, indicating sexual and asexual lineages are not independent of each other. Many more species remain to be discovered and described. Molecular phylogenetic analyses have revealed the existence of more species than have been recognized on the basis of morphology alone. A suggestion is made to modify the International Code of Botanical Nomenclature to enable adoption of a single generic name for Trichoderma/Hypocrea, with Trichoderma being the older and more utilitarian name. As increasing numbers of species are studied, the few morphological characters of anamorph and teleomorph have reached their limit for defining species. DNA-based characters have assumed an indispensable role. Exploration of new niches, such as within tree trunks and new geographic locations, have resulted in a substantial increase in the number of species of Trichoderma. Trichoderma is usually considered a genus of free-living soil fungi but evidence suggests that Trichoderma species may be opportunistic, avirulent plant symbionts as well as parasites of other fungi. Members of the genus Trichoderma are universally present in soils, although individual species may be either cosmopolitan (e.g., T. harzianum) or limited (e.g., T. viride) in their geographic distribution. To facilitate identification of species, a list of correctly identified strains of Trichoderma and their GenBank numbers for sequences of translation-elongation factor EF-1alpha and internal transcribed spacer rDNA is provided.     

浙江杭州地区蝶类资源及区系分析

杭州地区有蝶类113种,隶属于12科76属。其中古北东洋共有种48种,东洋种42种,古北种17种,广布种5种。区系分析结果表明,杭州地区蝴类以古北东洋共有种和东洋种为主要成份,属东洋区系范畴,并具有由东洋区向古北区过渡的特征。与江、浙其他地区的蝶类资源进行相似度分析,杭州地区与宁波地区的蝶类资源相似度最高。     

茶尺蠖和灰茶尺蠖幼虫及成虫的鉴别方法

茶尺蠖Ectropis obliqua和灰茶尺蠖Ectropis grisescens是茶园主要害虫,两者为近缘种,外形十分相似,难以区分。为了便于茶叶技术人员识别这两种尺蠖,本研究通过饲养观察,比较了这两种尺蠖幼虫和成虫的形态差异,提出了一种鉴别方法,即通过幼虫第2腹节背面八字形黑色斑纹的形态及该节上2对小黑点的位置进行幼虫鉴别,通过前后翅上外横线的形态进行成虫鉴别。采用分子鉴定对该方法进行了验证,结果表明该方法判别准确,且易于掌握,能准确区分茶尺蠖和灰茶尺蠖。本研究结果对这两种尺蠖的正确识别和田间防治十分有益。     

Detection and Differentiation of Trichothecene and Enniatin-Producing Fusarium Species on Small-Grain Cereals

A large number of Fusarium species are associated with Fusarium head blight of wheat and other small-grain cereals as well as seedling blight and brown foot rot. Different Fusarium species tend to predominate under different environmental conditions and in different regions. In addition to causing disease, these fungi are of particular significance because they produce a number of mycotoxins including the trichothecenes and enniatins that contaminate infected grain. The nature and amount of the mycotoxins that accumulate will alter according to the species or even the particular isolates involved in the infection. It is highly desirable to be able to analyse such complex infections to determine which species and, preferably, which chemotypes are present, in order to understand the factors that affect the pathogenicity of each species and to evaluate the potential risk for contamination of grain with mycotoxins. This paper reports the development of molecular methods, based upon the polymerase chain reaction (PCR), for the detection of mycotoxigenic fungi. Several of the Fusarium species involved are closely related, making the development of specific assays problematic. We describe the development of primers specific to individual species and discuss how this work provides insight into fungal populations and relates to taxonomic studies. In some instances, it is desirable to detect the presence of potential mycotoxin producers rather than individual fungal species. Generic assays have been produced for several genes involved in trichothecene biosynthesis and for enniatin synthetase in order to permit the detection of species able to produce the associated mycotoxins. Additional work is under way to refine assays to enable detection related to the class of trichothecene and chemotype of isolate because of the potential risk posed to human and animal consumers by different trichothecenes.     

杆状病毒新的分类地位和书写方式

2020年10月ICTV更新了主要病毒名录，该文件新增了纳尔达病毒纲Naldaviricetes和勒乏病毒目Lefavirales。勒乏病毒目含中有包括杆状病毒科Baculoviridae在内的3个科，而杆状病毒科分为4个属：甲型杆状病毒属Alphabaculovirus、乙型杆状病毒属Betabaculovirus、丙型杆状病毒属Deltabaculovirus和丁型杆状病毒属Gammabaculovirus，该名录中杆状病毒科有85个主要种。根据ICTV网站病毒名称和种名的书写规范，杆状病毒的种名由其宿主昆虫的种名和病毒特性词（如nucleopolyhedrovirus和granulovirus）组成，其中宿主昆虫的属名首字母大写，其余字母均小写。病毒的种名（在用于系统分类时）书写全部用斜体，但其他情形时病毒名称（包括其宿主的属和种名）均采用正体书写。杆状病毒名称的缩写一般采用宿主属名和种名的前两位双字母＋病毒特性词缩写的方式，但16种传统杆状病毒的缩写仍沿用宿主的属名和种名首位单字母＋病毒特性词的缩写的方式。