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41.
根据形态学特征挑选了7株采自甘肃甘南境内的野生羊肚菌,应用rDNA-ITS序列进行了比对技术分析。结果表明,7株野生羊肚菌归属为4个种:粗柄羊肚菌Morchellav crassipes、羊肚菌M.esculenta、黑脉羊肚菌M.angusticeps和高羊肚菌M.elata。根据分子系统树发现,粗柄羊肚菌和羊肚菌属于黄羊肚菌类群,而黑脉羊肚菌和高羊肚菌属于黑羊肚菌类群。  相似文献   
42.
从南方红豆杉(Taxus chinensis var.mairei)根部树皮内表皮中分离得到69株内生真菌,通过HPLC检测发酵液中紫杉醇含量,共获得7种紫杉醇产生菌,同时,通过形态学分析以及ITS序列分析确定分别属于链格孢属(Alternaria)、葡萄孢盘菌属(Botryotinia sp.)、刺盘孢属(Colletotrichum)、拟茎点霉属(Phomopsis)和枝孢菌(Cladosporium),其中链格孢属真菌紫杉醇产量最高,平均为271.54μg/L,是目前见诸报道的产量最高的链格孢菌,亦是从红豆杉根部树皮中筛选出的紫杉醇产量较高的野生菌株之一。该菌株的发现为紫杉醇高产菌的选育提供了又一优良的种质资源。  相似文献   
43.
本研究从秤锤树叶片中分离内生菌进行分子鉴定,并接种到无菌组培苗中研究其对植株生长的影响。研究结果显示,从秤锤树叶片中共分离获得7株真菌。扩增出的6个菌株经ITS测序,在NCBI网站上进行基因序列比对,鉴定出其中5株菌株均属于球毛壳菌(Chaetomium globosum),1株属于子囊菌(As-comycete)。进一步实验表明:分离的菌株多数对组培苗的株高生长影响不大,可初步鉴定其为内生菌,其中的属于球毛壳菌的F和H菌株对无菌苗的株高有明显的促进作用。  相似文献   
44.
通过核基因ITS2片段研究四种鲇形目鱼类进化   总被引:5,自引:0,他引:5  
采用鲇形目鱼鱼类通用引物扩增了鲇形目鱼类4种鱼,长吻(Leiocassi longirostris)、南方南方大口鲇(Si-lurus meridionalis)、黄颡鱼(Pseudobagrus fulvidraco)、斑点叉尾(Ictalurus punctatus)核DNA的ITS2片段,并构建UPMGA,NJ,ME和MP系统树。结果显示:根据遗传距离,斑点叉尾和黄颡鱼的亲缘关系最近(D=0.0661),接下来是黄颡鱼和南方大口鲇(D=0.1100),南方大口鲇和长吻(D=0.1184),斑点叉尾和南方大口鲇(D=0.1266),黄颡鱼和长吻(D=0.1490),斑点叉尾和长吻的亲缘关系是最远的(D=0.1503)。结果表明:长吻最早分化,其次是南方南方大口鲇和黄颡鱼,而斑点叉尾分化最晚。  相似文献   
45.
46.
杨属ITS序列的分子进化特点分析   总被引:4,自引:1,他引:4  
本文通过对杨属5组代表种并以柳属中旱柳的ITS序列作为参照,用成对比较的方法对杨属21个植物样品的ITS序列比较发现,杨属ITS序列的碱基替换情况是转换数大于颠换数,ITS-1序列中碱基发生转换和颠换的数目基本相似,而ITS-2序列中碱基发生转换的数目远远大于颠换。用朱克斯和坎托一参数模型和木村二参数模型对杨属ITS序列的替换率计算,无论是ITS-1还是ITS-2序列都没有达到数理统计上的明显差异。但由于ITS-2序列碱基的变化转换大大高于颠换,所以二参数模型计算所得结果大于一参数模型;采用相对速率测验法,对杨属各组分子进化相对速率进行了检测,结果分析得知,杨属5组的ITS序列分子进化速率有差异。杨属各组的ITS-1序列比较说明,大叶杨组、青杨组、黑杨组的进化速率都小于白杨组,而胡杨组则是进化速率最快的,大叶杨组的进化速率小于青杨组、胡杨组和黑杨组,黑杨组和胡杨组大于青杨组;ITS-2序列比较发现白杨组是进化速率最慢,其次是大叶杨组、青杨组,而黑杨组则稍大于胡杨组;总ITS序列比较是大叶杨组和黑杨组相对较慢,胡杨组最快;但就总的碱基替换分析,除了黑杨组和大叶杨组在ITS-1区间及青杨组、胡杨组和白杨组在ITS-2区间进化速率有显著差异外,其余组间都无显著的差异,尤其是在整个ITS序列区段碱基替换的差异都无显著差异。  相似文献   
47.
Intelligent Transportation System (ITS) is the most effective method to solve the modern traffic problems. Intelligent vehicle plays a very important role on ITS, and it influences the success of ITS directly. Intelligent Transportation System (ITS) is briefly introduced. Then it is given that advanced vehicle control system and electrics stability program (ESP) in the key technology of intelligent transportation system. The control algorithm for vehicle movement is discussed and the test result is given.  相似文献   
48.
Pea would benefit from the plasticity and adaptability of its cross-incompatible relatives Pisum fulvum and Lathyrus sativus L., and we have tested reciprocal sexual crossings by manually cross-pollinating plants of genotypes of these three species. Studies of in situ germination of pollen grains on stigmata showed that pollen tubes were generally unable to germinate or could not reach the ovary. A few putative hybrid pods were nevertheless harvested, with one grain per pod germinated in vitro, then micropropagated for flow cytometry, isoenzyme, molecular (ribosomal ITS PCR-RFLP) and genomic in situ hybridization (GISH) studies. One such grain was recovered from an inter-generic cross of P. sativum x L. sativus and four from an inter-specific P. sativum x P. fulvumcross. A strong cross-incompatibility was shown between pea and grass pea, where the putative hybrid turned out to be pea. Conversely, with the interspecific, P. sativum x P. fulvum cross, flow cytometry and isoenzymes with leaf tissues strongly suggested hybridity, while molecular approaches and GISH confirmed the production of inter-specific hybrids, and without the need for a wild type P. sativum accession as a bridging cross.  相似文献   
49.
Ectomycorrhiza (EM) community structure was analyzed at one bare heap site (BHS), one heap site with organic cover (HS-OH) and one reference site (RS) in the former uranium mining area near Ronneburg (Thuringia, Germany). Twenty-three EM morphotypes were distinguished, and 14 of them were additionally characterized by polymerase chain reaction (PCR), restriction fragment length polymorphism (RFLP) and internal transcribed spacer (ITS) sequence analysis. Colonization of birch by the different morphotypes was quantified, and the EM diversity at the different sites was investigated. Compared to RS, total EM colonization was reduced by 6% (P=0.851) at HS-OH and by 58% (P<0.001) at BHS. Likewise, EM diversity was reduced by 16% (P=0.229) at HS-OH and 52% (P<0.001) at BHS. The Sørensen similarity between EM samples from RS was nearly independent from the sampling date, whereas at HS-OH and especially BHS, the Sørensen similarity decreased with increasing time between the samplings. All EM fungal species dominating at the two heap sites were also present at RS. Thus, fungi with high tolerance against uranium and other stress factors at the heap sites (e.g. heavy metals, nutrient limitation, drought) were selected among all EM fungi of the area. Highly adapted fungi with a distribution restricted to the contaminated soils were not detected.Electronic Supplementary Material Supplementary material is available for this article at .  相似文献   
50.
Sequences of the internal transcribed spacers (ITS) of nuclear ribosomal DNA were analysed to precise their length (637–643 bp) and resolve phylogenetic relationships among eight Mediterranean species of the genus Hedysarum (Fabaceae). The infra-specific variability levels of the ITS sequences of spontaneous population of H. coronarium proved a lack of polymorphism both in the length and in the sequences examined in this species. Hence, a consensus ITS sequence characterising each Hedysarum species has been investigated for analysis of inter-specific polymorphisms. The level of variation of ITS sequence was high enough to make the ITS1 and ITS2 a useful tool for phylogenetic reconstruction. However, ITS2 seems to be relatively more polymorphic and more informative than ITS1 regarding length or GC percent. The phylogenic relationships in the genus Hedysarum based on ITS1 and ITS2 sequences taken independently or together, are discussed in the context of current work in molecular biosystematics. Results exhibited the distinctiveness of the two H. spinosissimum subspecies (i.e. H. spinosissimum ssp. capitatum and H. spinosissimum ssp. spinosissimum). In addition, the great similarity of the ITS sequences between H. coronarium (the only cultivated species of the genus) and H. carnosum suggests the usefulness of the latter in selection programmes to improve pastoral production in semi-arid areas.  相似文献   
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