全文获取类型
| 收费全文 | 808篇 |
| 免费 | 245篇 |
| 国内免费 | 67篇 |
专业分类
| 林业 | 12篇 |
| 农学 | 150篇 |
| 27篇 | |
| 综合类 | 381篇 |
| 农作物 | 99篇 |
| 水产渔业 | 81篇 |
| 畜牧兽医 | 323篇 |
| 园艺 | 31篇 |
| 植物保护 | 16篇 |
出版年
| 2025年 | 42篇 |
| 2024年 | 46篇 |
| 2023年 | 43篇 |
| 2022年 | 73篇 |
| 2021年 | 75篇 |
| 2020年 | 88篇 |
| 2019年 | 68篇 |
| 2018年 | 57篇 |
| 2017年 | 50篇 |
| 2016年 | 81篇 |
| 2015年 | 48篇 |
| 2014年 | 52篇 |
| 2013年 | 45篇 |
| 2012年 | 63篇 |
| 2011年 | 60篇 |
| 2010年 | 61篇 |
| 2009年 | 44篇 |
| 2008年 | 33篇 |
| 2007年 | 42篇 |
| 2006年 | 17篇 |
| 2005年 | 9篇 |
| 2004年 | 9篇 |
| 2003年 | 5篇 |
| 2002年 | 2篇 |
| 2001年 | 1篇 |
| 1962年 | 2篇 |
| 1956年 | 4篇 |
排序方式： 共有1120条查询结果，搜索用时 0 毫秒
1.
Thaise Pinto de Melo Marina Rufino Salinas Fortes Ben Hayes Lucia Galvão de Albuquerque Roberto Carvalheiro 《Zeitschrift für Tierzüchtung und Züchtungsbiologie》2020,137(2):139-154
The aim of this study was to identify candidate regions associated with sexual precocity in Bos indicus. Nellore and Brahman were set as validation and discovery populations, respectively. SNP selected in Brahman to validate in Nellore were from gene regions affecting reproductive traits (G1) and significant SNP (p ≤ 10–3) from a meta-analysis (G2). In the validation population, early pregnancy (EP) and scrotal circumference (SC) were evaluated. To perform GWAS in validation population, we used regression and Bayes C. SNP with p ≤ 10–3 in regression and Bayes factor ≥3 in Bayes C were deemed significant. Significant SNP (for EP or SC) or SNP in their ±250 Kb vicinity region, which were in at least one discovery set (G1 or G2), were considered validated. SNP identified in both G1 and G2 were considered candidate. For EP, 145 SNP were validated in G1 and 41 in G2, and for SC, these numbers were 14 and 2. For EP, 21 candidate SNP were detected (G1 and G2). For SC, no candidate SNP were identified. Validated SNP and their vicinity region were located close to quantitative trait loci or genes related to reproductive traits and were enriched in gene ontology terms related to reproductive success. These are therefore strong candidate regions for sexual precocity in Nellore and Brahman. 相似文献
2.
Genome‐wide association (GWA) mapping in potato requires high‐density genotyping. With the Illumina SolCAP potato single‐nucleotide polymorphism (SNP) array, a first tool for GWA mapping in potato became available. Thirty‐six tetraploid varieties and eight diploid breeding clones were genotyped for 8303 SNPs using this array. The objectives of our study were to examine in this set of germplasm: (i) the degree of polymorphism of the SolCAP SNPs in European germplasm, (ii) the population structure, (iii) temporal trends of genetic diversity and (iv) the genome‐wide extent of linkage disequilibrium (LD). Three‐quarters of the SNPs were polymorphic. In the principal coordinate analysis, a clear separation of tetraploid from diploid genotypes was observed, whereas no distinct subgroups among the tetraploid varieties were detected. The nonlinear trendline of the LD measure vs. the physical map distance decayed within 275 bp to an value of 0.10, indicating that theoretically, about 3 million equally distributed SNPs are required for GWA mapping in this diverse set of germplasm. As the LD decay changes with the population selected for GWA mapping, the number of required markers might be different in other germplasm. 相似文献
3.
Accurate assessment of genetic similarity is important for plant breeding, germplasm enhancement and conservation of plant genetic resources. A comparative analysis of genome diversity among a group of six-rowed spring barley (Hordeum vulgare L.) cultivars was carried out using sequence-specific amplified polymorphism (S-SAP) and single nucleotide polymorphism (SNP), with the results compared to the kinship coefficients derived from the pedigree data. Mean pair-wise GS values were estimated to be 0.0957 ± 0.144 (Kinship), 0.491 ± 0.189 (SNPs), and 0.602 ± 0.098 (S-SAPs). S-SAP and SNP-based genetic similarity (GS) values were normally distributed but kinship values had a non-normal and skewed distribution. Pair-wise correlation of GS values were lowest for the S-SAP and the SNP matrices (r =; 0.040, p<0.230) and highest for the SNP and pedigree matrices (r =; 0.240, p < 0.001). Analysis of molecular variance (AMOVA) attributed about 90.4% of observed variation to the cultivars within each of the malting and feed groups. Variance component between malting and feed groups was 6.6% for both SNP and S-SAP data suggesting lack of a significant genetic differentiation along this agronomic division. The remaining 3% of variation was attributed to genetic diversity within cultivars. Although both DNA-based marker systems were able to differentiate all barley cultivars, significant difference were observed in the pattern of genetic relationships obtained by the two marker systems and the pedigree data. 相似文献
4.
In this paper, the basic principle of chromosome walking is presented and we used an actin gene of radiata pine (Pinus radiata) as an example to conduct upstream and downstream chromosome walking for EST sequences. The full genomic sequence (2154 bp)
of the actin gene, including promoters 5′ UTR, CDS and 3′ UTR, was identified by chromosome walking. PCR amplification and DNA band sequencing
from 200 unrelated radiata pine trees revealed a total of 21 SNPs for the actin gene, three in the promoter region, 15 in CDS and 4 in 3′ UTR. The results of this experiment provide a technical framework
for SNPs discovery in none coding regions of candidate genes.
__________
Translated from Acta Botanica Boreali-Occidentalia Sinica, 2007, 27 (8): 1571–1576 [译自: 西北植物学报] 相似文献
5.
Peirong Li Tongbing Su Huiping Wang Xiuyun Zhao Weihong Wang Yangjun Yu Deshuang Zhang Changlong Wen Shuancang Yu Fenglan Zhang 《Plant Breeding》2019,138(3):309-324
Single‐nucleotide polymorphisms (SNPs) are rapid, economical and reliable genotyping tools. Non‐heading Chinese cabbage (Brassica rapa L. subsp. chinensis Makino) is now an economically important vegetable crop worldwide. In this study, 1,167 SNPs were evaluated for 7polymorphism among 70 representative non‐heading Chinese cabbage inbred lines using a Kompetitive Allele Specific PCR (KASP) genotyping assay. On the basis of identified polymorphisms and the results of a principal component analysis, we selected 50 core SNPs that were balanced sufficiently to provide adequate information for genetic identification. The core SNPs were used for construction of a neighbour‐joining dendrogram that separated the 70 inbred lines into four main groups and several subgroups corresponding to Caixin, Heiyebaicai, Huangxinwu, Naibaicai, Taitsai, Pak‐choi, and Wutatsai. This categorization was superior to that achieved using a dataset of 479 polymorphic SNPs. To confirm the utility of the core SNP markers in genetic identification, we tested their stability and resolution using 162 commercial hybrid cultivars. The SNPs, which represent a cost‐effective, accurate marker set for germplasm analysis and cultivar identification, are suitable for molecular marker‐assisted breeding in non‐heading Chinese cabbage. 相似文献
6.
7.
8.
9.
Akito Kaga Takehiko Shimizu Satoshi Watanabe Yasutaka Tsubokura Yuichi Katayose Kyuya Harada Duncan A. Vaughan Norihiko Tomooka 《Breeding Science》2012,61(5):566-592
Genetic variation and population structure among 1603 soybean accessions, consisted of 832 Japanese landraces, 109 old and 57 recent Japanese varieties, 341 landrace from 16 Asian countries and 264 wild soybean accessions, were characterized using 191 SNP markers. Although gene diversity of Japanese soybean germplasm was slight lower than that of exotic soybean germplasm, population differentiation and clustering analyses indicated clear genetic differentiation among Japanese cultivated soybeans, exotic cultivated soybeans and wild soybeans. Nine hundred ninety eight Japanese accessions were separated to a certain extent into groups corresponding to their agro-morphologic characteristics such as photosensitivity and seed characteristics rather than their geographical origin. Based on the assessment of the SNP markers and several agro-morphologic traits, accessions that retain gene diversity of the whole collection were selected to develop several soybean sets of different sizes using an heuristic approach; a minimum of 12 accessions can represent the observed gene diversity; a mini-core collection of 96 accession can represent a major proportion of both geographic origin and agro-morphologic trait variation. These selected sets of germplasm will provide an effective platform for enhancing soybean diversity studies and assist in finding novel traits for crop improvement. 相似文献
10.
Rosa Gagliardi Silvia Llambí M. Victoria Arruga 《Journal of veterinary science (Suw?n-si, Korea)》2015,16(3):273-280
The fields of pharmacogenetics and pharmacogenomics have become increasingly promising regarding the clinical application of genetic data to aid in prevention of adverse reactions. Specific screening tests can predict which animals express modified proteins or genetic sequences responsible for adverse effects associated with a drug. Among the genetic variations that have been investigated in dogs, the multidrug resistance gene (MDR) is the best studied. However, other genes such as CYP1A2 and CYP2B11 control the protein syntheses involved in the metabolism of many drugs. In the present study, the MDR-1, CYP1A2 and CYP2B11 genes were examined to identify SNP polymorphisms associated with these genes in the following four canine breeds: Uruguayan Cimarron, Border Collie, Labrador Retriever and German Shepherd. The results revealed that several SNPs of the CYP1A2 and CYP2B11 genes are potential targets for drug sensitivity investigations. 相似文献