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1.
我国根结线虫属(Meloidogyne Goeld,1887)一新种   总被引:1,自引:0,他引:1  
中华根结线虫Meloidogyne sinensis sp.nov.系作者于1981年6月至11月在试验地种植的春、秋马铃薯上采得。该种雌虫会阴区图纹近似圆形,弓部低而圆,背扇近中央和两侧的环纹略呈锯齿状,肛门附近的角质层向内折迭形成一条明显的折纹和肛门上方有许多短的线纹等特征与本属已记载的其他根结线虫的会阴区图纹显著不同。此外,具有比一般根结线虫较长的侵襲期幼虫。雌虫、雄虫和幼虫的口斜较长;背食道腺开口离口斜基部球较远;雌虫排泄孔位置偏后等与近似种M.incognita不同。卵囊通常为褐色,表面粗糙,常附着许多细小的砂粒。  相似文献   

2.
汉中蔬菜根结线虫种类的同工酶酶谱鉴定   总被引:1,自引:0,他引:1  
在形态学鉴定的基础上,运用同工酶电泳技术,对采自汉中市11县区的23个为害蔬菜的根结线虫种群进行了鉴定。结果表明:在所鉴定的种群中,20个种群为南方根结线虫(Meloidogyne incognita),1个种群为花生根结线虫(M.arenaria),1个种群为南方根结线虫和花生根结线虫的混合群体,1个种群为南方根结线虫和北方根结线虫(M.hapla)的混合群体;其中南方根结线虫是汉中市为害蔬菜的主要根结线虫。  相似文献   

3.
利用日立S-570型扫描电子显微镜对悬铃木科(Platanaceae)的一球悬铃木(Platanus occidenlis)、二球悬铃木(Platanus acerifolia)和三球悬铃木(Platanus orientails)的花粉形态进行了观察研究。结果表明,花粉粒均为长球形,具三沟,沟宽,界限不明显;表面具网状雕纹;这些特征分类意义不大。但在网眼大小以及沟膜上是否具有雕纹等方面三种植物有所区别,可以作为种的鉴定依据。  相似文献   

4.
作者自1986年5月至1987年11月对山东蒙阴县境内天麻林场等地的楸树根结线虫病的感染率、危害、症状及其病原线虫种类进行了调查,并通过对病原的雌虫、雄虫和二龄侵袭期幼虫的形态观察、测量、寄主反应及北卡罗来纳鉴别寄主试验,确认中山寺林场楸树根结线虫病病原为爪哇根结线虫(Meloido-gyne javanica(Treub,1885),Chitwood,1949),杨庄苗圃病原为北方根结线虫(M.hapla Chitwood,1949),而天麻林场与蒙阴县苗圃病原主要为以上二种根结线虫,其中以爪哇根结线虫为优势种,偶见极少量南方根结线虫(M.incognita Chitwood,1949)。本文还对二种主要病原线虫的重要鉴别特征作了较详细的描述,为楸根结线虫病的防治提供了必要的基础资料。  相似文献   

5.
 对505片二球悬铃木(Platanus acerifolia (Ait.) Willd.)叶片进行实测,发现两种新现象:一是二球悬铃木三大裂片主脉夹角含有"隐性"黄金数,即以三角函数形式显示的黄金数(0.618和0.382);二是二球悬铃木三大裂片主脉60.00°夹角是叶脉输导水分、养分走最短路径的表现,是一种斯坦纳树结构。统计分析表明,含有"隐性"黄金数的三大裂片主脉夹角(31.72°,38.18°,51.86°和67.55°)占总数的60.69%,呈斯坦纳树结构的60.00°夹角占总数的34.85%,二者合占95.54%。二球悬铃木三大裂片主脉夹角新现象的发现,有利于深化人们对植物结构的认识。  相似文献   

6.
为建立繁殖根结线虫的新方法,利用黄瓜实生苗为宿主,在透明的玻璃瓶中成功繁殖了南方根结线虫、花生根结线虫和爪哇根结线虫,为有效分离根结线虫提供了一条新途径.该方法不仅丰富了繁殖根结线虫的宿主,而且便于随时观察线虫侵染根形成根结的动态过程,也避免了在繁殖过程可能造成线虫逃逸对周围土壤的污染问题.  相似文献   

7.
<正> 一、前言 线虫是一类较低等的动物,寄生于植物根内的线虫,叫做根结线虫,在分类上隶属于线形虫动物门(Nemathelminthes)、线虫纲(Secernentea)、垫刃目(Tylenchida)、根结线虫科(Meloidogynidae)、根结线虫属(Meloidogyne)。目前已报导83种,我国报导53种。  相似文献   

8.
利用茶叶渣、生活污泥和猪粪为原料按不同比例充分混合并进行强制好氧静态发酵,得到C/N在11~17之间的腐熟堆肥,分别以它们作为盆栽番茄的土壤有机添加物,以评估其在控制爪哇根结线虫形成根结中的作用.从堆肥中的N、P和K与根结数之间的关系看,基本上呈现出随堆肥中氮和磷含量的增加,根结数量下降的趋势.在相对低K含量范围内,根结数随K含量的升高而下降;而在相对高K含量范围内,根结数却随K含量的增加而增加,氮钾比在1~2之间时的抑制效果最好.与对照组相比较,用添加比例在30%~50%的腐熟堆肥可以明显减少根结线虫在番茄上的根结数量,而且随着添加比例的增加,根结数量呈指数下降.  相似文献   

9.
研究了BC2001生防菌对南方根结线虫卵和卵囊孵化影响,及对南方根结线虫二龄幼虫的影响。结果表明BC2001对线虫分散卵的相对抑制率达87.3%、对卵囊的相对抑制率达40.50%,而对二龄幼虫的校正死亡率达92%;从显微结构上看,BC2001对卵和二龄幼虫的抑杀作用主要是通过菌体附着,引起卵和虫体内物质泡化聚集,最终消解。在人工接种条件下,BC2001菌在大田防治中对根结线虫虫口基数的相对抑制率达57.8%。  相似文献   

10.
利用石蜡连续切片方法对悬铃木(Platanus acerifolia Willd.)幼苗初生维管系统进行了研究.结果表明:二球悬铃木具有较长的子叶节区,几乎占幼苗下胚轴的全部;根端为外始式二原型(或真二原假四原)辐射中柱;子叶节区下部的结构较原始,具有中始式二原型单中柱;中部出现具髓的中始式二原型管状中柱阶段;上部与茎的内始式真中柱极为相似且较短,所以只存在子叶节区茎结构连接区;上胚轴的苗区具有内始式真中柱;由于二球悬铃木幼苗子叶节区结构具有中始式二原型单中柱,子叶为二叶迹;而胚芽起源的营养叶为三叶迹;幼苗子叶节区类型属于顶枝伸长型,结构原始.  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

15.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

16.
Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.  相似文献   

17.
以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.  相似文献   

18.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

19.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

20.
Quality traits in wheat (Triticum aestirum L.) were studied by quantitative trait locus (QTL) analysis in a recombinant inbred line (RIL) population, a set of 131 lines derived from Chuan 35050 × Shannong 483 cross (ChSh). Grains from RILs were assayed for 21 quality traits related to protein and starch. A total of 35 putative QTLs for 19 traits with a single QTL explaining 7.99-40.52% of phenotypic variations were detected on 10 chromosomes, 1D, 2A, 2D, 3B, 3D, 5A, 6A, 6B, 6D, and 7B. The additive effects of 30 QTLs were positive, contributed by Chuan 35050, the remaining 5 QTLs were negative with the additive effect contributed by Shannong 483. For protein traits, 15 QTLs were obtained and most of them were located on chromosomes 1 D, 3B and 6D, while 20 QTLs for starch traits were detected and most of them were located on chromosomes 3D, 6B and 7B. Only 7 QTLs for protein and starch traits were co-located in three regions on chromosomes 1D, 2A and 2D. These protein and starch trait QTLs showed a distinct distribution pattern in certain regions and chromosomes. Twenty-two QTLs were clustered in 6 regions of 5 chromosomes. Two QTL clusters for protein traits were located on chromosomes 1D and 3B, respectively, three clusters for starch traits on chromosomes 3D, 6B and 7B, and one cluster including protein and starch traits on chromosome 1D.  相似文献   

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