4种螺旋线虫记述

记述了采自山东、山西和浙江等地不同寄主根围的4个螺旋线虫群体,根据主要形态学特征分别鉴定为双角螺旋线虫(Helicotylenchus digonicus)、小头螺旋线虫(H.microcephalus)、双宫螺旋线虫(H.dihystera)和翅尾铗螺旋线虫(H.pteracerus)。其中H.pteracerus为国内新记录种,H.microcephalus为浙江省首次报道。     

一种雌虫具尾尖突松材线虫的鉴定

为明确从辽宁省枯死红松病木中分离到的一种雌虫具明显尾尖突线虫群体的分类地位,采用改良漏斗法分离样品中的线虫并进行形态学鉴定,通过灰葡萄孢Botrytis cinerea人工培养观察雌虫尾尖突的形态变化,并基于rDNA 28S和ITS基因序列分析对其进行分子生物学鉴定。结果显示,经形态学鉴定初步判定该线虫群体为松材线虫Bursaphelenchus xylophilus,具有典型的雄虫交合刺和雌虫阴门盖,但雌虫尾末端宽圆且无尾尖突的个体极少,只有2%～3%,其余雌虫个体尾末端有长约1.8μm(0.2～3.2μm)的尾尖突。但经人工培养产生的后代雌虫尾端均钝圆,无尾尖突。结合形态学和分子生物学鉴定结果,最终确定该线虫群体为松材线虫R型株系。松材线虫雌虫具有明显尾尖突的现象虽较为罕见,但仍会影响松材线虫的准确鉴定,需引起林业部门和口岸植物检疫部门的高度关注。     

螺旋线虫属一新种——具膜螺旋线虫

 本文报道了从香港的葱(Allium fistulosum)的根际土中采集到的螺旋线虫属(II elivoty-leuchus Steinet,1945)一新种,具膜螺旋线虫新种(II elicotylenchus membranatus sp.nov.)。该新种区别于螺旋线虫属中已知种的显著特征是具有阴门膜。其与近似种II elicotylenchus rotundi-cauda Sher,1966的区别,除了有阴门膜外,体形较小(L=533~681μm),侧尾腺孔位置较后(位于肛前2个体环到肛后3个体环)。     

安徽省合肥市大蜀山风景区植物根际螺旋线虫种类记述

利用Cobb过筛法分离合肥市大蜀山植物根际螺旋线虫属线虫,在光学显微镜下用de Man法观察并测计形态特征,比对相关文献资料,将大蜀山螺旋线虫Helicotylenchus spp.鉴定为阿布拿马螺旋线虫H.abunaamai、非洲螺旋线虫H.africanus、H.mucronatus和假强壮螺旋线虫H.pseudorobustus,除假强壮螺旋线虫外,均为安徽省首次记录,H.africanus和H.mucronatus为国内首次记录。     

深圳口岸进出口苗木螺旋线虫的鉴定

１９９１～１９９７年对深圳、广州、东莞、南海、三水、江门、开平、新会的花场进行了线虫调查,共采集根际土壤样品５０７个,发现１３４个样品含有螺旋线虫,占２６．４％,而且螺旋线虫是主要的寄生种类,经鉴定为双宫螺旋线虫（Ｈｅｌｉｃｏｔｙｌｅｎｃｈｕｓｄｉｈｙｓｔｅｒａ（Ｃｏｂｂ,１８９３）Ｓｈｅｒ,１９６１）,寄主植物共６８种,其中绝大多数为我国双宫螺旋线虫的寄主新记录。１９９４～１９９７年经深圳口岸入境,从香港、台湾、泰国、比利时、荷兰进口的５批次、２０种苗木也检获双宫螺旋线虫。     

中国四省(区)葡萄根围螺旋线虫种类记述

描述了采自陕西、山东、广西、宁夏 4省 (区)葡萄根际的 6种螺旋属线虫 :双宫螺旋线虫(Helicotylenchus dihystera)、外异螺旋线虫 (H exallus)、双角螺旋线虫 (H .digonicus)、H .digitiformis、H .platyurus、H .multicinctus。其中后 4种螺旋线虫均为我国葡萄上的首次报道     

广东省螺旋线虫种类鉴定初报

前言螺旋线虫Helicotylenchus spp的外形通常弯曲呈弓形或螺旋形,因而得名。作者将多年来从广州郊区、湛江、召庆、惠阳及汕头等地区所采集的标本,进行了初步鉴定(材料与方法,参阅植物检疫,1991年第5卷第4期,253页):在甘蔗的     

俄罗斯木质包装中杨树伞滑刃线虫的鉴定

宁波口岸从来自俄罗斯的杨树木质包装中截获一种伞滑刃线虫,经形态学和分子生物学研究,鉴定为杨树伞滑刃线虫。该线虫与伪伞滑刃线虫十分近似,主要鉴定特征是:阴门盖明显腹弯,近阴门盖后半部的虫体明显凹陷;雄虫交合刺近远端边缘平直,无明显凹陷,远端盘状突十分显著;雌虫尾亚圆柱形或近圆锥形,尾端多数呈多变的尾尖突状,偶尔几乎钝圆。该线虫人工培养后雌虫尾形多数介于圆柱形和圆锥形之间,这与原始文献的报道有差异。这是我国口岸首次截获该线虫。     

宁波口岸首次截获弗氏伞滑刃线虫

宁波口岸于2008年7月从来自荷兰的木质包装中截获一种伞滑刃属线虫.该线虫虫体细长,侧区有4条侧线.雄虫交合刺细弱,基顶略呈方形,有时背弯;喙突显著,末端锐尖;远端有较小盘状突.尾乳突7个.雌虫有小阴门盖,尾圆锥形,尾端钝尖,有时呈尾尖突状.经形态学比较、测量以及ITSRFLP图谱比对,鉴定为弗氏伞滑刃线虫(Bursaphelenchus fuchsi Kruglik & Eroshenko,2004).目前除俄罗斯、德国外,未见该线虫的报道.     

截获纽带科2种线虫记述

本文针对从荷兰进境鸡爪槭根围中检疫截获的2种纽带科线虫进行了形态和分子鉴定,分别确定为小头螺旋线虫Helicotylenchus microcephalus Sher和强壮盘旋线虫Rotylenchus robustus(Thorne) Loof&Oostenbrink。前者在输出国家无相关文献报道,2种线虫在鸡爪槭上发生尚属首次报道。根据截获时线虫种群数量来看,前者为优势种类,2种线虫的虫口比例大约为50∶1。同时,在鸡爪槭根系上发现明显病理变化症状。     

A comparison of crop and non-crop plants as sensitive indicator species for regulatory testing

The effectiveness of regulatory non-target plant testing using crop species to predict the phytotoxicicity of herbicides to non-crop species was evaluated for eleven herbicides. These herbicides were representative of eight chemical classes and six modes of action. Data for non-crop plants from pre-emergence and post-emergence efficacy screening studies were compared with those for the most sensitive crop species defined by regulatory tests conducted to meet US EPA requirements. Testing under pre-emergence conditions for ten compounds indicated that for five of the compounds (K-815910, trifluralin, pyridyloxy A, pyridyloxy B and cyanazine), the most sensitive crop species was more sensitive than all the non-crop species evaluated. For metsulfuron-methyl, chlorimuron-ethyl, hexazinone and bromacil, only one of the non-crop species evaluated was more sensitive than the most sensitive crop species from regulatory tests. Data for the tenth compound, chloroacetamide, showed that four of 32 non-crop species tested in efficacy screens had at least one rate at which greater visual effects were observed than were observed for the most sensitive crop response in a regulatory test. The results of post-emergence exposure comparisons for five of the compounds (pyridyloxy A, cloransulam-methyl, chlorimuron-ethyl, cyanazine and hexazinone) indicated that the most sensitive crop species were more sensitive than all the non-crop species evaluated. Data for pyridyloxy B, metsulfuron-methyl and bromacil indicated that only one of the non-crop species evaluated was more sensitive than the most sensitive crop species. For trifluralin, three of the eight non-crop species were more sensitive than the most sensitive crop species. Data for K-815910 indicated that four of the fourteen non-crop species tested were marginally more sensitive than the most sensitive crop, but were within the same range of sensitivity. These results indicate that the current regulatory test batteries and methods using crop species effectively provide suitable sensitive indicator plants for the eleven diverse herbicides evaluated. This comparison indicates that crop species sensitivity to test substances is likely to be representative of non-crop herbaceous species response, regardless of chemical class, mode of action and magnitude or route of exposure.     

寒地稻田节肢动物群落多样性调查

经田间调查与室内鉴定,发现黑龙江寒地水稻田节肢动物种类有2纲10目49科65种。稻田节肢动物中各目、科的种类数量所占比例差异很大,在植食性昆虫中鞘翅目所占比例最大;在天敌中以蜘蛛类最多;在中性昆虫中,以双翅目比例最大;同时在物种、功能集团和营养层3个组织层次水平上分析了稻田节肢动物群落的结构和多样性。结果表明：在寒地稻田中顶位物种的丰盛度变化不大,而中位物种和基位物种的丰盛度变化明显;种的多样性整体变化幅度最大,8月9日最高,功能团多样性变化幅度不大,营养层多样性有一定波动。     

三江平原毛苔草群落30年物种多样性变化研究

对三江平原1973、1983、2003年3个时期的毛苔草群落的种类组成、频度组成及物种多样性进行分析,并进行了比较研究。结果表明:不同时期毛苔草群落的种类组成差异明显,1973-1983年,毛苔草群落的变化主要体现在物种地位的变化,1983-2003年主要表现为物种组成种类的变化;物种多样性特征的变化表现为1973-2003年,物种丰富度呈下降趋势,物种多样性、均匀性呈先增加而后下降的趋势,优势度与之相反,总体表现均为1973-1983年变化缓慢,而1983-2003年变化较大;物种频度图的分析表明,不同时期毛苔草群落的结构均处于稳定状态,但随着演替进行,群落中有分化和演替的趋势,并且以1983-2003年变化最为明显;通过分析初步认为,毛苔草群落物种组成的变化主要由水位的下降所引起,景观破碎化对物种多样性的影响值得进一步研究。     

中国口岸首次截获攻击茶蜗牛研究

广东南海出入境检验检疫局从三山口岸西班牙进境金琥(Echinocactus grusonii Hildm.)中截获1种活的软体动物,经鉴定为攻击茶蜗牛[Theba impugnata(Mousson,1857)],该物种在中国没有分布记录,是进境植物检疫性有害生物名录中比萨茶蜗牛[Theba pisana(Müller,1774)]的近似种,也是世界自然保护联盟(IUCN)评估为易危级列入"红名单"的物种,为中国口岸首次截获。本文记述了其分类地位、鉴定特征、种群现状、地理分布、生物学和检疫方法,并讨论了易危物种和检疫性有害生物的关系。     

六盘山自然保护区鸟类群落时空变化

为了解宁夏六盘山国家级自然保护区鸟类群落的动态变化,于2011年3月至2012年3月,采用样带法和样点法对该区4种生境中的鸟类分布状况进行了调查。共获得88种鸟类,其中留鸟49种,夏候鸟29种,旅鸟9种,冬候鸟1种。春季鸟类多样性指数最高,冬季最低。各生境的鸟类群落结构季节性变化明显,不同生境中鸟类群落结构也有较大差异,其优势种不同,而且在不同季节也有变化。从全年不同生境中鸟类分布情况来看,乔木林生境中鸟类分布最少,仅29种,农田-居民区生境中分布35种,灌木林中分布40种,水域沼泽生境中分布最多,有43种鸟类在其分布。     

Impact of site conditions and farming practices on the occurrence of rare and endangered weeds on arable land in the Czech Republic

This article documents the impact of site conditions and farming practices on the occurrence of rare and endangered weeds on arable land in the Czech Republic. A survey was conducted between 2006 and 2008 in winter cereals, spring cereals and wide‐row crops. The relationship between the occurrence of plants and explanatory factors was analysed using a multivariate analysis to calculate species frequencies in different types of farming, crops and altitudes. In total, 290 relevés were recorded, with a total number of 172 weed species. Nineteen weeds, classified as rare and endangered species according to the national Czech list, were identified in 106 relevés. The highest effect on the occurrence of rare and endangered weed species was observed for altitude. Almost half of the recorded endangered and rare species belonged to the thermophilous weed vegetation typical for cereals on basic soils. A higher occurrence of endangered species has been confirmed for organic farming, where the sum of frequencies was 4.5 times higher than in conventional farming. Field size was not included in our analyses, but could be a factor affecting weed assemblages. The highest frequency of rare species was recorded in spring cereals, followed by winter cereals and wide‐row crops. Higher numbers were identified within fields with higher weed coverage. Lower farming intensity and diversified farming systems at higher altitudes provided better conditions for the occurrence of rare species than intensively farmed lowlands.     

Predicting yield loss due to interference from two weed species using early observations of relative weed leaf area

Experiments were conducted on linseed ( Linum usiãissimum L.) and autumn-sown field bean ( Vicia faha L.) to test how well the relative leaf area-based yield loss prediction model of Kropff & Spitters could estimate yield loss due to interference from Stellaria media L. (common chick-weed) or barley ( Hordeum vulgare L.) alone or a combination of both S. media and barley . Damage coefficients were calculated for all comparisons. Generally, the model provided a better estimate of yield loss due to interference from barley than from S. media because of both the variability in crop yield response stemming from S. media's plasticity and the generally minor crop yield response to S. media interference. The addition to the model of a parameter accounting for asymptotic yield loss was, generally, not warranted for either S. media or barley in the single-weed species data sets. When both S. media and barley were present as weed species in the crop, the model that fitted the data best for six out of 10 data sets was the one in which a separate damage coefficient was included for both species. There was no evidence that the presence of S. media influenced damage coefficient values for barley. However, in the presence of barley a parameter accounting for asymptotic yield loss was warranted for S. media in the two-weed species model. The combination of the addition of this parameter and the presence or barley affected the values of the damage coefficients for S. media in the two-weed species compared with the single-weed species models. Consequently, it was shown for these two weed species that two-weed species yield loss prediction models parameterized using data from single-weed species experiments generally resulted in different estimates of yield loss in comparison with models parameterized using data from two-weed species experiments.     

Germination requirements for 29 terrestrial and wetland wild plant species appropriate for phytotoxicity testing

BACKGROUND: Species selected for phytotoxicity testing have been limited to a few standard crop species owing to restrictive recommendations at the regulatory level. However, guidelines by the Organisation for Economic Development and Cooperation (OECD) were recently amended in 2006 to include a list of herbaceous non‐crop plant species suitable for testing. The objective of this study was to outline the optimum germination requirements for a selection of wild species for which seeds were readily available from commercial suppliers. RESULTS: Of the 29 herbaceous terrestrial and wetland species included in this study, all achieved 50% germination and 23 reached > 70% germination to meet the criterion outlined in the OECD guidelines. Most species attained their maximum germination within 14 days or less. Cold stratification of imbibed seeds improved germination for 14 species. Increasing sowing soil depth did not improve seed germination. The variance attained in this experiment between replicates was low, especially for species with > 70% germination (standard error ～5%). CONCLUSION: The present study showed that 23 of the 29 species tested required minimal pretreatments and produced consistent, reliable and uniform germination reaching at least 70%. The inclusion of wild plant species in regulatory testing should be given real consideration. Copyright © 2008 Crown in the right of Canada. Published by John Wiley & Sons, Ltd     

我国南方地区主要根结线虫DNA变异的RAPD分析

 本试验用5组随机引物对来自我国南方地区的30个根结线虫种群进行RAPD分析,并从中筛选出多态性较好的引物12个。共扩增出179条DNA多态带,各供试种群间存在着丰富的遗传多态性。扩增结果表现出种间差异大于种内差异的共同趋势,这表明上述12个引物能够较客观地反映种群间亲缘关系的远近。北方根结线虫与另外3种线虫(南方根结线虫、爪哇根结线虫、花生根结线虫)的亲缘关系最远;在3种主要根结线虫中,爪哇根结线虫与南方根结线虫的亲缘关系相对较近。基于种群间的相似系数分析和应用UPGMA法构建的聚类树状图,显示出不同的根结线虫在较低的相似性系数范围聚类,而绝大多数种内的不同种群均以较高的相似性系数聚在一起,这与形态分类基本一致,反映了形态学分类的分子遗传本质,同时也表明了应用RAPD技术进行根结线虫亲缘关系分析和种类鉴定具有合理性和可行性。本文还对RAPD方法对南方根结线虫小种鉴定的可能性进行了初步探讨。     

准噶尔盆地南部农区野生饲用植物资源研究

为了解准噶尔盆地南部农区野生饲用植物资源,调查研究了该区域野生饲用植物的科属组成及其生活型和生态型特点,并对其适口性和营养价值进行了分析。结果表明：该区共有野生饲用植物34科145属214种,优势科有禾本科(38属71种)、藜科(18属22种)、菊科(15属21种)、豆科(14属19种)、苋科(8属11种)、十字花科(8属10种);生活型植物以草本植物(1～2年生124种,多年生62种)为主,占86.92%,木本植物有28种,占13.08%;生态型植物以中生为主(183种)。依据适口性可将该区野生饲用植物划分为优、良、中、低4个等级,其中优等95种、良等77种、中等36种、低等6种。营养成分丰富且适口性较好的饲用植物主要集中在禾本科(21种)、豆科(17种)和藜科(13种)。