不同碳源氮源对腐霉菌株生长的影响     

徐同 《浙江大学学报(农业与生命科学版)》1996,(1)

在喀麦隆芋芳根涡病病原研究中，测定了不同碳源、氮源对分离自喀麦隆芋艿田间及来自中国的腐霉菌株生长习性的影响。实验结果表明，除了钟腐霉（Ｐｙｔｈｉｕｍｖｅｘａｎｓ）菌株只能吸收葡萄糖、果糠而不能吸收蔗糖外，其余腐霉菌株均能利葡萄糖、果糖、蔗糖作为碳源。所有试验菌株均不能利用半乳糖、麦芽糖及可溶性淀粉。钟腐霉菌株之形态特征与特殊碳源营养的相关性显示了用碳源作为菌株鉴定辅助标准的可行性，氮源营养试验结果表明，所有腐霉菌株均能利用四种氮源，根据不同氮源对菌丝生长的影响，依次为Ｌ－天门冬氨酸，Ｌ－精氨酸，硝酸铵，硝酸钾。  相似文献   

草地类型梯度分析   总被引：4，自引：0，他引：4  

李卫军  许鹏 《草业学报》1994,3(2):6-11

紫泥泉地区位于天山北坡低山带，具有代表性的冬春秋放牧场。本文应用数量分类（ＴＷＩＮＳＰＡＮ）、排序（ＤＣＡ）和回归分析方法研究了草地类型的分类及其分布的梯度规律。研究结果表明：该地区的草地类型按传统分类划分出１８个型，ＴＷＩＮＳＰＡＮ分类结合ＤＣＡ排序归纳出８个型，其中６个型为地带性草地类型，２个型为非地带性草池类型；地带性草地类型沿水热梯度分布，非地带性草地类型沿质地梯度分布。  相似文献   

West african okra — Morphological and cytogenetical indications for the existence of a natural amphidiploid of Abelmoschus esculentus (L.) Moench and A. manihot (L.) Medikus     

J. S. Siemonsma 《Euphytica》1982,31(1):241-252

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ITS—RFLP分析进行昆虫病原线虫斯氏属和异小杆属的分类鉴定   总被引：2，自引：1，他引：2  

李菁菁  韩日畴等 《昆虫天敌》2002,24(3):97-104

本研究通过PCR扩增和六种限制性内切酶（AluⅠ，HinfⅠ，MboⅠ，RsaⅠ，HaeⅢ和PvuⅡ）酶切，对国内害虫防治上常用的几种昆虫病原线虫，包括斯氏属S.car-pocapsae,S.feltiae和S.glaseri以及异小杆属H.bacteriophora,H.zealandica,H.indicus和H.megidis等8个品系rDNA-ITS进行分析。建立起可以区分各线虫种的标准RFLP图谱。该方法快速简便，稳定可靠，需要的样品量少。可以用于新鲜的，或冻存的样品，甚至分析单条的线虫，不仅可进行昆虫病原线虫的快速分类鉴定。而且进一步可以应用于线虫田间释放的辅助监测。实际田间感染率的测定和线虫毒力的比较。  相似文献   

Orobanche species and population discrimination using intersimple sequence repeat (ISSR)     

H Benharrat  C Veronesi  C Theodet  P Thalouarn 《Weed Research》2002,42(6):470-475

Summary Orobanche species are commonly identified using morphological characteristics. In many cases, the distinction of closely related species is difficult, and a molecular tool is more suitable to differentiate them. In this study, genomic polymorphism between morphologically distinct species was investigated through amplification by polymerase chain reaction (PCR) of intersimple sequence repeat (ISSR) regions. Five primers were used to study genetic variation in the morphologically distinct species O. hederae and O. amethystea, as well as the closely related species O. cernua and O. cumana. For the first two species, all the primers detected genetic polymorphism. Anchored primers allowed the identification of more specific molecular markers than non‐anchored tri‐ and tetranucleotide primers. Genetic polymorphism was investigated among three O. hederae populations using the two types of primer. One non‐anchored and two anchored primers detected intraspecific variation, which was not correlated with the geographical location of those populations. The primer (GATA)₄ detected polymorphism between five specimens each of O. cernua and O. cumana species collected from different countries, permitting these two closely related species to be clearly differentiated. This study demonstrated that ISSR markers can be highly reliable for precise identification of Orobanche species.  相似文献   

A new species of Malus in China,Malus shizongensis Liu sp. nov          下载免费PDF全文

LIU Zhen-zhong  LI Zhong-xing  GAO Hua  BAO Cha-na 《农业科学学报》2020,19(10):2451-2457

Based on morphological, molecular biological, and molecular systematic studies, we describe here a new species of Malus from Yunnan, China. We compared the morphology of this new species, Malus shizongensis Liu sp. nov, with three Malus species, including M. hupehensis, M. baccata, and M. micromalus. Although the appearance of M. shizongensis was similar to these three species, it differed in height, branch color, branch hair, and flower color. To better identify the taxonomy of this new species, genome of M. shizongensis and that of seven Malus species, including M. prunifolia, M. sylvestris, M. sieversii, M. hupehensis, M. baccata, M. robusta, and M. micromalus were analyzed. A phylogenetic tree based on genome analysis indicated that M. shizongensis was close to M. hupehensis. Furthermore, M. shizongensis had its species-specific SNPs, and the number of species-specific SNPs was similar to that of three close species(M. hupehensis, M. baccata, and M. micromalus). Based on the above information, we named this new species as M. shizongensis Liu sp. nov.  相似文献   

Skull size and shape variation in Psammomys spp. (Rodentia,Gerbillinae) from Tunisia,with emphasis on the impact of allometric variation on species recognition     

Hanene Khemiri  Paolo Colangelo  M’barek Chétoui  Saïd Nouira 《African Zoology》2016,51(3):145-152

In Tunisia both Psammomys obesus and P. vexillaris are found. These taxa have been the subject of taxonomic controversy for some time, due to variability in the classical morphological characters used for taxonomic recognition. In this study we investigated skull size and shape variation in the genus Psammomys by using geometric morphometrics to evaluate the extent of intra- and interspecific shape variation and explicitly tested for the impact of allometric shape variation on species discrimination. Eleven populations of the two species from 10 localities in Tunisia were studied. Statistical analyses of size and shape showed large size variation within P. obesus, but no shape differences were revealed among populations of this species. Interspecific analysis revealed that P. vexillaris had the smallest skull. Principal component analysis and Procrustes distances showed good discrimination between the two species after removal of the allometric component of shape variation. The results obtained show that allometric-related shape variation could mask discrimination between the two Psammomys species. This finding might explain the uncertainty in classification of these species in the past. The interspecific allometric-free phenotypic differences observed may be associated with adaptive processes linked to the different environmental and trophic preferences of the two species.  相似文献   

A new and unusual species of Parachiton (Mollusca: Polyplacophora) from South Africa     

《African Zoology》2013,48(1):93-98

A new species of the genus Parachiton, P. hodgsoni n.sp., which inhabits shallow water off the South African coast, is described. The radula is unusual for the genus Parachiton. It consists of about 160 transverse rows of very small mature teeth of which the major lateral teeth have very narrow tridentate cusps. The intermediate valves are granulose with the granules arranged in widely spaced, longitudinal rows on the central area of the valves. There are 20–31 longitudinal rows on the central areas of the intermediate valves. Variability in the morphology of the tail valve is shown.  相似文献   

地图衣的2个中国新记录种     

李雪  李超  王海英 《现代农业科技》2013,(6):146-147

地图衣主要分布于极地和温带高海拔地区,全世界约有200种。中国已经发现的地图衣仅有28种。该文报道了地图衣的2个中国新记录种(Rhizocarpon concentricum和R.geminatum),并提供了这2种地衣的详细特征照片。  相似文献   

我国麻黄属的分类问题   总被引：8，自引：0，他引：8  

沈观冕 《干旱区研究》1993,10(1):39-48

本文对我国麻黄属植物进行了分类整理,计有2组15种2变种1变型。其中增补了国内原有12种4变种的记载,同时对易于混淆的种进行了讨论。  相似文献