全文获取类型
收费全文 | 117篇 |
免费 | 4篇 |
专业分类
林业 | 9篇 |
农学 | 6篇 |
基础科学 | 2篇 |
31篇 | |
综合类 | 7篇 |
农作物 | 4篇 |
水产渔业 | 1篇 |
畜牧兽医 | 29篇 |
植物保护 | 32篇 |
出版年
2023年 | 2篇 |
2022年 | 2篇 |
2021年 | 3篇 |
2020年 | 2篇 |
2019年 | 1篇 |
2018年 | 1篇 |
2017年 | 2篇 |
2016年 | 2篇 |
2015年 | 3篇 |
2014年 | 1篇 |
2013年 | 5篇 |
2012年 | 5篇 |
2011年 | 12篇 |
2010年 | 2篇 |
2009年 | 8篇 |
2008年 | 7篇 |
2007年 | 9篇 |
2006年 | 6篇 |
2005年 | 12篇 |
2004年 | 7篇 |
2003年 | 7篇 |
2002年 | 1篇 |
2001年 | 2篇 |
1999年 | 4篇 |
1998年 | 1篇 |
1997年 | 2篇 |
1996年 | 1篇 |
1994年 | 1篇 |
1992年 | 2篇 |
1991年 | 1篇 |
1989年 | 1篇 |
1984年 | 1篇 |
1982年 | 1篇 |
1977年 | 1篇 |
1975年 | 2篇 |
1952年 | 1篇 |
排序方式: 共有121条查询结果,搜索用时 15 毫秒
101.
Graham J. King F. H. Alston I. Battle E. Chevreau C. Gessler J. Janse P. Lindhout A. G. Manganaris S. Sansavini H. Schmidt K. Tobutt 《Euphytica》1991,56(1):89-94
Summary A recently initiated collaborative project involving apple breeders in seven European countries is described. The objective is to improve the European apple crop by molecular-aided breeding to increase efficency and reduce the time-scale in breeding for resistance, tree habit and fruit quality. The strategy adopted provides a model for similar studies in fruit, forest and other woody species. The project is based on progenies from a small number of crosses involving many important agronomic genes. Replication of these reference progenies by vegetative propagation will enable studies to be carried out simultaneously in each country. By developing a range of molecular markers, including isozymes, RFLPs and sequence-tagged DNA probes, an integrated molecular map is being constructed for use in a wide range of breeding and genetic studies. Construction of a database recording many mapped molecular markers will enable efficient exploitation of data in future genetic, breeding and physiological studies of apple. Aspects of the adopted strategy, techniques and management are discussed in the context of mapping genes in perennial crop genomes. 相似文献
102.
B. A. Vinatzer A. Patocchi S. Tartarini L. Gianfranceschi S. Sansavini C. Gessler 《Plant Breeding》2004,123(4):321-326
A polymerase chain reaction (PCR)‐based method was developed to isolate microsatellite markers from large‐insert genomic DNA clones of bacterial artificial chromosome (BAC) libraries. The method is fast and economic since it does not require subcloning. It was applied to isolate a microsatellite marker from a BAC clone of the chromosomal region containing the apple scab resistance gene Vf. The Vf gene of Malus floribunda 821 is the most widely used source of scab resistance in apple breeding. A second microsatellite was found on the extremity of a BAC clone flanking the Vf locus. The two microsatellites allowed the identification of the presence of the Vf gene in the scab‐resistant accessions M. micromalus SA573‐3, ‘Golden Gem’, M. prunifolia 19651 and MA 16 not previously known to carry this gene. They were also used to verify the correctness of the published genealogical tree of the Vf cultivar ‘Florina’, in which a probable mistake was identified. This analysis shows the importance of genotyping the Vf locus when choosing scab‐resistant germplasm as parents in breeding programmes. 相似文献
103.
Di Guardo G Di Cesare A Otranto D Casalone C Iulini B Mignone W Tittarelli C Meloni S Castagna G Forster F Kennedy S Traversa D 《Veterinary parasitology》2011,183(1-2):31-36
This study reports the occurrence of Toxoplasma gondii in the brain of three striped dolphins (Stenella ceoruleoalba) found stranded on the Ligurian Sea coast of Italy between 2007 and 2008. These animals showed a severe, subacute to chronic, non-purulent, multifocal meningo-encephalitis, with the cerebral parenchyma of two dolphins harbouring protozoan cysts and zoites immunohistochemically linked to T. gondii. Molecular, phylogenetic and mutation scanning analyses showed the occurrence of Type II and of an atypical Type II T. gondii isolates in one and two dolphins, respectively. In spite of the different molecular patterns characterizing the above T. gondii genotypes, the brain lesions observed in the three animals showed common microscopic features, with no remarkable differences among them. The role of T. gondii in causing the meningo-encephalitis is herein discussed. 相似文献
104.
Federica Di Cesare Daniela Gioeni Giuliano Ravasio Alberto Pellegrini Lorena Lucatello Vittoria Bisutti Roberto Villa Petra Cagnardi 《Journal of veterinary pharmacology and therapeutics》2019,42(4):392-400
This study aimed to define the pharmacokinetic profiles of dexmedetomidine and methadone administered simultaneously in dogs by either an oral transmucosal route or intramuscular route and to determine the bioavailability of the oral transmucosal administration relative to the intramuscular one of both drugs, so as the applicability of this administration route in dogs. Twelve client‐owned dogs, scheduled for diagnostic procedures, were treated with a combination of dexmedetomidine hydrochloride (10 μg/kg) and methadone hydrochloride (0.4 mg/kg) through an oral transmucosal route or intramuscularly. Oral transmucosal administration caused ptyalism in most subjects, and intramuscular administration caused transient peripheral vasoconstriction. The results showed reduced and delayed absorption of both dexmedetomidine and methadone when administered through an oral transmucosal route, with median (range) Cmax values of 0.82 (0.42–1.49) ng/ml and 13.22 (2.80–52.30) ng/ml, respectively. The relative bioavailability was low: 16.34% (dexmedetomidine) and 15.5% (methadone). Intramuscular administration resulted in a more efficient absorption profile, with AUC and Cmax values for both drugs approximately 10 times higher. Dexmedetomidine and methadone administered simultaneously by an oral transmucosal route using injectable formulations were not well absorbed through the oral mucosa. Nevertheless, additional studies on these drugs combination using alternative administration routes are recommended. 相似文献
105.
Papetti A Pruzzo C Daglia M Grisoli P Bacciaglia A Repetto B Dacarro C Gazzani G 《Journal of agricultural and food chemistry》2007,55(2):278-284
Some beverages and foods protect tooth surfaces against Streptococcus mutans colonization. Adhesion of S. mutans is a crucial step in the initiation and development of dental caries. In this study, we showed that barley coffee (BC), a beverage made from roasted barley, interferes with S. mutans adsorption to hydroxyapatite (HA), and we identified its antiadhesive components. The effects of sublethal concentrations (sub-MICs) of BC on the adhesion of S. mutans to saliva-coated HA beads were assessed using three experimental approaches: (A) Beads were pretreated with BC before adding bacteria, (B) BC and bacteria were added to the beads simultaneously, and (C) streptococci grown in the presence of sub-MICs of BC were added to the beads. All treatments induced variable but significant inhibition of S. mutans sucrose-dependent and -independent adherence to HA. Similar results were obtained with other oral streptococci. BC components were fractioned by dialysis and gel filtration chromatography; the <1000 Da molecular mass (MM) fraction, which contains polyphenols, zinc, and fluoride ions, and the >1000 kDa MM fraction, which consists of a potent brown antioxidant, melanoidin, both displayed antiadhesive properties. High-MM melanoidin was not detected in unroasted barley, indicating that it forms during the roasting process. Results suggest that BC consumption may influence the colonization of tooth surfaces by cariogenic bacteria. 相似文献
106.
Accinelli C Koskinen WC Becker JM Sadowsky MJ 《Journal of agricultural and food chemistry》2007,55(7):2677-2682
Veterinary antimicrobial agents have been detected in a number of environmental samples, including agricultural soils. In this study, we investigated the persistence and sorption of the sulfonamides sulfamethazine (SMZ) and sulfachloropyridine (SCP) in soil and their potential effects on soil microorganisms. The sulfonamides dissipated more rapidly from the silt loam soil as compared to the sandy soil. Average half-lives of SMZ and SPC among the two soils were 18.6 and 21.3 days, respectively. The presence of liquid swine slurry (5% v/w) decreased sulfonamide persistence in the silt loam soil. The lower persistence of the antimicrobials in liquid swine slurry-amended soil was likely due to higher microbial activity, as compared to unamended soil, and/or to the greater bioavailability of the sulfonamides to degrading microorganisms, as estimated by sorption isotherms. Concentrations of SMZ and SPC up to 100 microg g-1 had no effect on antimicrobial degradation rates and soil microorganisms. These studies suggest that higher sulfonamide concentrations would be necessary to affect the main processes controlling their environmental fates in soil, but at the concentrations normally found in the environment, there would be little or no effects. 相似文献
107.
108.
Francesco Tafuri Maurizio Patumi Cesare Marucchini Mario Businelli 《Pest management science》1982,13(6):665-669
Gas-chromatographic analyses of extracts of soil samples from plots, treated with a 50% atrazine wettable powder at dose rates of 2 and 4 kg a.i. ha?1, showed the presence of a new atrazine degradation product. This product was isolated, concentrated and purified by column chromatography and high-performance liquid chromatography. The chromatographic properties of this material were identical with those of a product isolated from a 0.02% methanolic solution of 2-amino-4-chloro-6-isopropyl-amino-1,3,5-triazine that had been stored under laboratory conditions. A combined gas-liquid chromatographic/mass spectrometric assay identified the new product in soil as 2-isopropylamino-4-methoxy-6-methylamino-1,3,5-triazine. 相似文献
109.
M. G. Chacón N. E. Adler F. Jarrin W. G. Flier C. Gessler G. A. Forbes 《European journal of plant pathology / European Foundation for Plant Pathology》2006,115(2):235-245
Thirty-nine isolates of Phytophthora infestans were collected from the wild host Solanum ochranthum in the highland tropics of Ecuador and characterized with a set of phenotypic and molecular markers (mating type, metalaxyl sensitivity, the allozyme loci Gpi, and Pep, mitochondrial DNA haplotype, RFLP, and SSR), as well as for pathogenicity on various hosts. Three groups of isolates (A, B, and C) were identified based on their multilocus genotypes and variable abilities to cause disease on different hosts. Group A had a combination of alleles for the Gpi (86/100), Pep (96/100) and mtDNA (Ia) loci, as well as an RFLP fingerprint, that have not been reported for P. infestans in Ecuador, or elsewhere. Group B shares many marker characteristics with the US-1 lineage described in Ecuador on tomato, pear melon (S. muricatum), and S. caripense, but has SSR alleles not present in typical US-1 isolates. Group C for all markers tested is identical to the EC-1 lineage described on cultivated and wild potatoes in Ecuador. All isolates from S. ochranthum were able to re-infect their host of origin in the detached leaf assay; however, we did not draw clear conclusions as to the relative aggressiveness of the three groups on this host. Isolates of group A were the most specialized and were generally non-pathogenic or weakly pathogenic on all hosts other than S. ochranthum. Groups B and C infected tuber-bearing hosts, including the cultivated potato but were generally non-pathogenic on other non-tuber bearing hosts. Solanum ochranthum was infected by isolates coming from tuber-bearing Solanum hosts (i.e., the EC-1 lineage of P. infestans) and some US-1 isolates from non-tuber bearing hosts. Thus, in nature this species might be a potential reservoir of inoculum of different pathogen populations able to infect the cultivated hosts potato, tomato and pear melon (S.␣muricatum). Unlike potato and tomato in Ecuador, each of which is primarily attacked by a highly specialized pathogen population, S. ochranthum appears to harbour at least three pathogen groups of␣different genetic make-up. The unresolved issue of potential host specificity in isolates found on S.␣ochranthum could complicate efforts to use this species in tomato improvement. 相似文献
110.
Caterina L. Matasci Mauro Jermini Davide Gobbin Cesare Gessler 《European journal of plant pathology / European Foundation for Plant Pathology》2010,127(4):501-508
The genetic structure of a Plasmopara viticola population was characterized on five single vines, one for each cultivar Regent, Merlot, Isabella, Müller-Thurgau and Solaris,
using four neutral specific polymorphic microsatellite markers. Five-hundred and seventy samples were collected at four dates
in the period between the 10th of July and the 23rd of August 2006. On average over all five cultivars, 67% of the genotypes
present on the single selected vines derived from primary infections and caused 37% of the lesions genotyped. Fifty-three
percent of these genotypes occurred only once on the vine throughout the survey period, while 14% were able to asexually reproduce
on the selected single vine throughout the survey period, causing 23% of the lesions. Thirty-three percent of the genotypes
on the single vine derived from other vines, 28% from vines of other cultivars in the other rows, and 5% from vines of the
same cultivar in the same row. New primary infections appear all along the sampling dates. The overwhelmingly quantitative
role of primary infections at vineyard scale was known, however here we observed the phenomenon also at the single vine scale
and the reduced contribution of secondary lesions to the populations present on more resistant cultivars compared to the susceptible
cultivars. As the sampling extended almost to defoliation, the results are judged to be representative of a typical P. viticola epidemic. 相似文献