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101.
Summary Helianthus petiolaris is a wild species used in genetic improvement of sunflower, as a donor of cytoplasmic male sterility and of genetic resistance to diseases. Isozyme variation for ADH, ACP, EST, GDH, LAP, PGI, PGD and SKDH in this species was studied using starch gel electrophoresis. The patterns thus obtained were compared with zymograms of inbred lines, hybrids and open pollinated varieties of H. annuus. The same alleles for EST and SKDH isozymes were found in both species, while ACP showed an allele that has not been found in sunflower. The rest of the isozyme systems showed both common alleles and characteristic ones for each species. ACP, GDH and PGD were monomorphic in H. petiolaris, while ADH and LAP were monomorphic in H. annuus. The isozyme markers obtained here could be useful in breeding programs involving interspecific crosses, and studies on introgression and on genetic variation in other populations of this wild species.  相似文献   
102.
Molecular genetic mapping of peach   总被引:17,自引:0,他引:17  
E. Dirlewanger  C. Bodo 《Euphytica》1994,77(1-2):101-103
Summary A project to develop a linkage map of the peach (Prunus persica) genome is underway using an F2 population segregating for several morphological characters and pest resistance e.g., nectarine (g), weeping shape (pl) and aphid resistance (Rml). The RAPID technique was used to analyse 270 plants. Linkage analysis of the F2 population was performed using the MAPMAKER software. Eight linkage groups were established and RAPID markers flanking thepl gene were found.  相似文献   
103.
The existence of genetic variability for angular leaf spot (ALS) resistance in the common bean germplasm allows the development of breeding lines resistant to this disease. The BAT 332 line is an important resistance source to common bean ALS. In this work we determined the inheritance pattern and identified RAPD markers linked to a resistance gene present in BAT 332. Populations F1, F2,BCs and BCr derived from crosses between BAT 332 and cultivar Rudá were used. Rudá is a commercial cultivar with carioca type grains and susceptible to ALS. The resistance of BAT 332 to race 61.41 of the pathogen was confirmed. Segregation analysis of the plants indicated that a single dominant gene confers resistance. For identification of RAPD markers linked to the resistance gene, bulk segregant analysis (BSA) was used. Two RAPD markers,OPAA07950 and OPAO12950, linked in coupling phase at 5.10 and 5.83 cM of this gene, respectively, were identified. These molecular markers are important for common bean breeders and geneticists as source of genetic information and for marker assisted selection in breeding programs. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   
104.
Molecular mapping of powdery mildew resistance genes in wheat: A review   总被引:40,自引:3,他引:40  
Powdery mildew, caused by Blumeria graminis f. sp. tritici (syn. Erysiphe graminis f. sp. tritici), is one of the most important diseases of common wheat (Triticum aestivum L.) worldwide. Molecular mapping and cloning of genes for resistance to powdery mildew in hexaploid wheat will facilitate the study of molecular mechanisms underlying resistance to powdery mildew diseases and help understand the structure and function of powdery mildew resistance genes, and permit marker-assisted selection in breeding programs. So far, 48 genes/alleles for resistance to powdery mildew at 32 loci have been identified and located on 16 different chromosomes, of which 21 resistance genes/alleles have been tagged by restriction fragment length polymorphisms (RFLPs), random-amplified polymorphic DNAs (RAPDs), amplified fragment length polymorphisms (AFLPs), sequence characterized amplified regions (SCARs), sequence-tagged sites (STS) or simple sequence repeats (SSRs). Several quantitative trait loci (QTLs) for adult plant resistance (APR) to powdery mildew have been associated with molecular markers. The detailed information on chromosomal location and molecular mapping of these genes has been reviewed. Isolation of powdery mildew resistance genes and development of valid molecular markers for pyramiding resistance genes in breeding programs is also discussed.  相似文献   
105.
棉花抗黄萎病基因的QTL定位   总被引:33,自引:14,他引:33  
以高感黄萎病的陆地棉品种"邯郸208"与高抗黄萎病海岛棉品种"Pima90"的136个F2单株为作图群体,构建了一个包括17个连锁群、标记间平均间距18.61cM、全长1842.8cM的陆海种间分子标记遗传连锁图,该图约覆盖棉花基因组的36.8%。单因子方差分析和复合区间作图检测到与黄萎病抗性相关的3个QTL,分别位于第四连锁群和第七连锁群上,分别解释表型变异方差的15.39%、54.11%和57.18%。初步认为海岛棉"Pima90"对陆地棉"邯郸208"的黄萎病抗性由两个主效QTL和一个微效QTL共同控制。  相似文献   
106.
S. H. Tams    E. Bauer    G. Oettler    A. E. Melchinger    C.-C. Schön 《Plant Breeding》2006,125(4):331-336
Significant relative midparent heterosis (MPH%) for grain yield in triticale (×Triticosecale Wittm.) has generated interest in the development of hybrid cultivars. The objectives of this study were to (i) examine the association between parental genetic distance (GD) and specific combining ability (SCA), (ii) investigate the existence of genetically distant heterotic groups in elite germplasm, and (iii) draw conclusions for future hybrid breeding in winter triticale. Genetic distance between 61 lines was estimated, based on 93 polymorphic simple sequence repeat (SSR) marker loci and 10 AFLP (amplified fragment length polymorphism) primer‐enzyme combinations (PEC). Agronomic data of 206 F1 crosses and their 61 parental lines grown in six German environments were published recently in a companion study. Correlations were made between SCA for grain yield, number of spikes/m2, 1000‐kernel weight and number of kernels per spike with GD estimates of the 56 female and five male parents (testers). Principal co‐ordinate analyses (PCoA) based on SSR data revealed no distinct subgroups in the germplasm. Correlations between GD and SCA were low for all traits (|r| ≤ 0.31), which hampers the prediction of SCA from molecular data. A multi‐stage procedure is recommended for future hybrid breeding in triticale by applying a pragmatic approach for the grouping of germplasm following the early history of hybrid breeding of maize.  相似文献   
107.
Genetic relationships among 18 accessions, including 16 of Ananas and two of Pseudananas, were investigated using RAPD molecular markers. The procedure for DNA extraction was adapted from the method of Dellaporta et al. (1983) where an incubation in proteinase K and a purification step were included. From the total of 148 markers scored,132 (89.2%) were polymorphic. The similarity matrix was used for cluster analysis. The phenogram developed from the RAPD bands showed that for most of the cases, the accessions within a species grouped together. Nevertheless, a moderate infraspecific genetic variation was observed. For example, DNA data grouped all A. comosus accessions with a mean similarity coefficient of 0.85. Comparable results were obtained with all other species investigated. The highest genetic divergence was found withinA. lucidus where the mean similarity coefficient among accessions was0.75. A similar level of genetic polymorphism was observed among species,therefore, a definition about which species were involved in the constitution of A. comosus genotypes was not possible. These results agree with the breeders standpoint suggesting that all Ananas species belong to the primary gene pool of pineapple. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   
108.
Cultivar identification and genetic map of mango (Mangifera indica)   总被引:2,自引:0,他引:2  
Amplified Fragment Length Polymorphism (AFLP) information was used for identification of mango (Mangifera indica L.) cultivars, for studying the genetic relationship among 16 mango cultivars and seven mango rootstocks and for the construction of a genetic linkage map. Six AFLP primer combinations produced 204 clear bands and on the average 34 bands for each combination. The average Band-Sharing between cultivars and rootstocks was 83% and 80%, respectively. The average Band-Sharing for mango is 81%. The probability of obtaining a similar pattern for two different mango cultivars and rootstocks is 6 × 10−3and 2 × 10−3, respectively. A preliminary genetic linkage map of the mango genome was constructed, based on the progeny of a cross between ‘Keitt’ and ‘Tommy-Atkins’. This linkage map consists of 13 linkage groups and covers 161.5 cm defined by 34 AFLP markers. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   
109.
Results on the inheritance of 6 enzyme systems: LDH, PGM, FDH, SKD, SOD, AAT from seeds of Vicia faba and the linkage relationships among these isozyme loci are presented. The allozymes at each one of these loci behaved in a codominant manner and segregated in the expected Mendelian ratio. Linkage tests between these loci showed that they segregate independently.  相似文献   
110.
Over the past decade microsatellites or simple sequence repeats (SSRs) have attracted a considerable amount of attention from researchers. The aim of the present paper was to analyse expressed sequence tag-derived SSR (EST-SSR) marker variability in wheat and to investigate the relationships between the number and type of repeat units and the level of microsatellite polymorphism. Two hundred and forty-one new EST-SSR markers available in a public database () were characterized in eight durum wheat cultivars (Svevo, Ciccio, Primadur, Duilio, Meridiano, Claudio, Latino, Messapia), two accessions of Triticum turgidum var. dicoccoides (MG4343, MG29896), one accession of T. turgidum var. dicoccum (MG5323) and in the common wheat cv. Chinese Spring. Of these, 201 primer pairs (83.4%) amplified PCR products successfully, while the remaining 40 (16.6%) failed to amplify any product. Of the EST-SSRs analysed, 45.2% of the primer pairs amplified one or two PCR products. Multiple discrete PCR products were observed among both di- and trinucleotide EST-SSR markers (31.2 and 40.5%, respectively). Markers based on dinucleotide microsatellites were more polymorphic than those based on trinucleotide SSRs in the 12 wheat genotypes tested (68.9 and 52.7%, respectively). An average of 2.5 alleles for dinucleotide and 2.0 alleles for trinucleotide SSRs was observed. The data reported in the present work indicate the presence of a significant relationship between motif sequence types and polymorphism. The primer set based on the AG repeat motif showed the lowest percentage of polymorphism (55.0%), while the primer set based on the AC repeat motif showed t he highest percentage (85.0%). Among trinucleotide SSRs, the AGG microsatellite markers showed the highest percentage of polymorphism (70.0%), and the ACG motif the lowest value (25.0%). The characterization of these new EST-SSR markers and the results of our studyon the effect of repeat number and type of motifs could have important applications in the genetic analysis of agronomically important traits, quantitative trait locus discovery and marker-assisted selection.  相似文献   
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