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41.
A large set of candidate nucleotide-binding site (NBS)-encoding genes related to disease resistance was identified in the sorghum (Sorghum bicolor) genome. These resistance (R) genes were characterized based on their structural diversity, physical chromosomal location and phylogenetic relationships. Based on their N-terminal motifs and leucine-rich repeats (LRR), 50 non-regular NBS genes and 224 regular NBS genes were identified in 274 candidate NBS genes. The regular NBS genes were classified into ten types: CNL, CN, CNLX, CNX, CNXL, CXN, NX, N, NL and NLX. The vast majority (97%) of NBS genes occurred in gene clusters, indicating extensive gene duplication in the evolution of S. bicolor NBS genes. Analysis of the S. bicolor NBS phylogenetic tree revealed two major clades. Most NBS genes were located at the distal tip of the long arms of the ten sorghum chromosomes, a pattern significantly different from rice and Arabidopsis, the NBS genes of which have a random chromosomal distribution. 相似文献
42.
The availability of the complete genome sequences has facilitated access to essential information to identify proteins. The determination of Arabidopsis genome sequence has had a great impact to annotate data. The genome sequencing of Sorghum bicolor has been only recently completed and hither to the global response to abiotic stresses in this important crop remains largely unexplored. We used 2-D gel electrophoresis based proteomic approach refined with MALDI-TOF to analyze drought-stress response proteins in sorghum. Major changes in protein complement of sorghum were observed in hydroponic cultures at 96 hours under drought stress. Six most highly expressed proteins were excised for functional identification. Here, we developed a method to obtain functional distances between GO terms and analyzed distance values to allocate shortest path (SP) in GO hierarchy. The shortest paths for expressed proteins were noted for most informative common ancestor (MICA) terms, viz. binding, catalytic activity and primary metabolic process. We observed the expressed proteins belonged to the functional group of signal transduction mechanisms, carbohydrate transport and metabolism. These identified functions of proteins suggest a different mechanism of drought-stress tolerant in sorghum. The novel approach applied in this study may have great importance in further identifying proteins involved in abiotic and biotic stress conditions in crops. 相似文献
43.
The corn planthopper, Peregrinus maidis (Ashmead) (Homoptera: Delphacidae) causes serious economic losses in corn and sorghum. The insect occurs mostly at humid
low elevations in the tropics and coastal areas of subtropical and temperate regions of all continents, the Caribbean Islands,
and islands in the Atlantic, Indian, and Pacific Oceans. This review provides a detailed compilation on the chronological
progress made in basic and strategic aspects of research on the interactions between P. maidis and various host plants. The nature of damage by P. maidis and its economic impact, ecobiology in relation to host diversity, abiotic, and seasonal interactions; and life tables and
alary polymorphism are discussed. Host plant resistance studies indicate that very few sources of resistance to P. maidis have been identified in maize, sorghum, or pearl millet, warranting a need to standardize rapid and reliable screening methods.
The behavioral responses vis-à-vis mechanisms of resistance show the predominance of antixenosis for colonization and/or oviposition
with variable degrees of antibiosis affecting life cycle parameters of P. maidis on maize and sorghum. The role of morphological traits, physiological mechanisms, and biochemical factors governing resistance
are described. Population dynamics based on density-dependent and density-independent interactions are also discussed. In
addition, aspects of P. maidis on chemical control, biological control, and trophobiosis interactions are listed. Future thrusts on research approaches
are also discussed. Genetic engineering techniques involving lectin genes in the development of transgenic plants, and the
molecular mapping of genes conferring resistance to both P. maidis and its transmitted virus diseases may stimulate further research and lead to better understanding of P. maidis—host plant interactions.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
44.
T.P. Lanyasunya Hongrong Wang S.T. Kariuki E.A. Mukisira S.A. Abdulrazak N.K. Kibitok J.O. Ondiek 《Animal Feed Science and Technology》2008,144(3-4):185-195
To evaluate the potential of Commelina benghalensis as a forage for ruminants, effects of plant maturity on chemical composition, rumen degradability as well as its increased dietary inclusion level on intake, digestibility and N balance in sheep fed Sorghum almum were investigated with forage obtained from the wild, re-established and harvested at 6, 10 and 14 weeks of growth. Composite herbage samples were analyzed for dry matter (DM), chemical components, total extractable phenolics (TEP) and amino acid content. In sacco rumen degradability measurements used six individually confined wethers (8 ± 0.5 months of age; 21 ± 2.6 kg live-weight (LW)) fitted with rumen cannulae and fed a ration of 3:1 fresh S. almum and Medicago sativa hay (about 1:2 on a DM basis). In sacco bags containing 5 g each of dry herbage were inserted into the rumen and withdrawn sequentially after 0, 12, 24, 36 and 48 h. Metabolizable energy (ME) was estimated from 24 h in vitro gas production. In the digestibility study, 12 wethers fitted with rumen canula were housed in metabolic crates and allotted to four treatment diets (i. e., D0, D10, D20 and D30) constituted from fresh S. almum and pre-wilted C. benghalensis in a randomized complete block design. The control diet (D0) was 3 kg fresh S. almum (≈535.5 g DM/wether/d about 30 g/kg LW), whereas D10, D20 and D30 were D0 +300, 600 or 900 g of wilted C. benghalensis (≈34, 68 or about 102 g DM/wether/d), respectively. The study lasted for 21 d. Dry matter, fibre and TEP content increased (P<0.001) with maturity of the forage, whereas those of CP and EE decreased (P<0.0001) over the same period. Amino acids (AA) also declined with maturity (P<0.05). Rumen degradability of DM and OM were unaffected, but DM intake increased linearly (P<0.0001) at a decreasing rate (Q: P<0.05) and DM digestibility (DMD) and N intake increased linearly (P<0.01 and P<0.0001, respectively) as level of C. benghalensis in the diet increased. Results indicate that advancing maturity affected chemical composition, but not rumen degradability, of C. benghalensis and also demonstrated that inclusion of C. benghalensis in S. almum diet improved intake, digestibility and N intake, suggesting its potential use as a feed supplement. 相似文献
45.
Marcia Reed Rodrigues Coelho Marjon de Vos Newton Portilho Carneiro Ivanildo Evódio Marriel Edilson Paiva Lucy Seldin 《FEMS microbiology letters》2008,279(1):15-22
The diversity of nitrogen-fixing bacteria was assessed in the rhizospheres of two cultivars of sorghum (IS 5322-C and IPA 1011) sown in Cerrado soil amended with two levels of nitrogen fertilizer (12 and 120 kg ha(-1)). The nifH gene was amplified directly from DNA extracted from the rhizospheres, and the PCR products cloned and sequenced. Four clone libraries were generated from the nifH fragments and 245 sequences were obtained. Most of the clones (57%) were closely related to nifH genes of uncultured bacteria. NifH clones affiliated with Azohydromonas spp., Ideonella sp., Rhizobium etli and Bradyrhizobium sp. were found in all libraries. Sequences affiliated with Delftia tsuruhatensis were found in the rhizosphere of both cultivars sown with high levels of nitrogen, while clones affiliated with Methylocystis sp. were detected only in plants sown under low levels of nitrogen. Moreover, clones affiliated with Paenibacillus durus could be found in libraries from the cultivar IS 5322-C sown either in high or low amounts of fertilizer. This study showed that the amount of nitrogen used for fertilization is the overriding determinative factor that influenced the nitrogen-fixing community structures in sorghum rhizospheres cultivated in Cerrado soil. 相似文献
46.
Visual stimuli influence the orientation behaviour of the sorghum midge, Contarinia sorghicola Coq. (Diptera: Cecidomyiidae). Yellow, red and white colours are attractive to the midge while blue and black are least attractive. Sorghum panicles covered with blue- or black-coloured bags in a headcage showed maximum midge damage, while the reverse was true for panicles covered with yellow, red, and white coloured bags.
Panicles at half-anthesis with viable pollen and receptive stigmata suffered higher damage than those at the pre- and post-anthesis. Physical removal of anthers and stigmata significantly reduced the oviposition by the sorghum midge. Reduced oviposition/adult emergence was also recorded in male sterile sorghum lines (2219A and 296A) or through chemically- (Ethrel) (2-Chloro ethyl-phosphonic acid) induced male sterility in panicles of the sorghum cultivar, Swarna. Chemical stimuli from viable pollen and receptive stigmata and to a limited extent physical stimuli, govern the oviposition behaviour of the sorghum midge.
Sorghum cultivars IS 12573C, S-GIRL-MR1 and IS 2816C showed antixenosis to adult midges. However, these cultivars became susceptible under no-choice conditions in the headcage. DJ 6514 and IS 12666C were attractive to the adult midges, but showed antixenosis to oviposition under natural and no-choice conditions. Genotypes with short florets showed antixenosis for oviposition. Ovary and anther breadth and tannin content of grain showed negative associations with oviposition. Cultivar antixenosis to adult midges and oviposition is an important component of resistance to the sorghum midge. 相似文献
Panicles at half-anthesis with viable pollen and receptive stigmata suffered higher damage than those at the pre- and post-anthesis. Physical removal of anthers and stigmata significantly reduced the oviposition by the sorghum midge. Reduced oviposition/adult emergence was also recorded in male sterile sorghum lines (2219A and 296A) or through chemically- (Ethrel) (2-Chloro ethyl-phosphonic acid) induced male sterility in panicles of the sorghum cultivar, Swarna. Chemical stimuli from viable pollen and receptive stigmata and to a limited extent physical stimuli, govern the oviposition behaviour of the sorghum midge.
Sorghum cultivars IS 12573C, S-GIRL-MR1 and IS 2816C showed antixenosis to adult midges. However, these cultivars became susceptible under no-choice conditions in the headcage. DJ 6514 and IS 12666C were attractive to the adult midges, but showed antixenosis to oviposition under natural and no-choice conditions. Genotypes with short florets showed antixenosis for oviposition. Ovary and anther breadth and tannin content of grain showed negative associations with oviposition. Cultivar antixenosis to adult midges and oviposition is an important component of resistance to the sorghum midge. 相似文献
47.
C. HOWARTH 《Plant, cell & environment》1989,12(5):471-477
Abstract The capacity to synthesize heat shock proteins (HSPs) during seed germination of sorghum (Sorghum bicolor) and pearl millet (Pennisetum americanum) has been examined. HSP synthesis is detectable in a thermotolerant genotype of sorghum during the first hour of imbibition of the seed under high temperature stress. A non-coordinate control of HSP synthesis during germination was revealed. Genotypic differences were manifest in the stage of germination at which the ability to synthesize HSPs was first apparent and this related to the thermosensitivity of that genotype. 相似文献
48.
49.
C. Grenier P. J. Bramel-Cox M. Noirot K. E. Prasada Rao P. Hamon 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2000,101(1-2):190-196
A large collection, such as the sorghum [Sorghum bicolor (L.) Moench] landrace collection held at the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT),
represents a challenge for the maintenance of both the accessions of and the information documented for the germplasm collection.
The accessibility and knowledge of the landrace collection are the essential factors for an efficient utilization of the genetic
resources by both breeders and farmers. Different sampling strategies, either random or non-random, were proposed to obtain
subsets of reduced size (core collection). Three subsets were established; a random sampling within a stratified collection
(logarithmic strategy: L); a sample based upon morpho-agronomic diversity (principal component score strategy: PCS); and a
sample based upon an empirical knowledge of sorghum (taxonomic strategy: T). Comparisons of these three samples for morpho-agronomic
characterization and passport information were assessed to determine their impact on phenotypic diversity. For their overall
diversity, the three subsets did not differ, as shown with the two-dimensional representation of the morpho-agronomic diversity
and the Shannon-Weaver diversity indices. When comparisons for morpho-agronomic and passport data were considered, the PCS
subset looked similar to the entire landrace collection. The L subset showed differences for characters associated with the
photoperiod reaction that was considered in the stratification of the collection. The T subset was the most distinct from
the entire landrace collection as it over-represented the landraces selected by farmers for specific uses and covered the
widest range of geographical adaptation and morpho-agronomic characteristics.
Received: 5 October 1999 / Accepted: 3 November 1999 相似文献
50.
Assessment of genetic diversity within and among germplasm accessions in cultivated sorghum using microsatellite markers 总被引:6,自引:0,他引:6
Y. Djè M. Heuertz C. Lefèbvre X. Vekemans 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2000,100(6):918-925
Microsatellite markers are increasingly being used in crop plants to discriminate among genotypes and as tools in marker-assisted
selection. Here we evaluated the use of microsatellite markers to quantify the genetic diversity within as well as among accessions
sampled from the world germplasm collection of sorghum. Considerable variation was found at the five microsatellite loci analysed,
with an average number of alleles per locus equal to 2.4 within accessions and 19.2 in the overall sample of 25 accessions.
The collection of sorghum appeared highly structured genetically with about 70% of the total genetic diversity occurring among
accessions. However, differentiation among morphologically defined races of sorghum, or among geographic origins, accounted
for less than 15% of the total genetic diversity. Our results are in global agreement with those obtained previously with
allozyme markers. We were also able to show that microsatellite data are useful in identifying individual accessions with
a high relative contribution to the overall allelic diversity of the collection.
Received: 10 August 1999 / Accepted: 27 August 1999 相似文献