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971.
Mary Elizabeth K. Gnanambal K. C. Ramya Devi P. Hareesh Chandra Edward J. K. Patterson 《Phytoparasitica》2011,39(2):121-127
The current study is based on the screening of novel insecticides from new sources that have not being exploited hitherto.
The major objectives of this research work were to extract marine molluscs, Lambis lambis, Trochus radiatus and Chicoreus ramosus, from Tuticorin coastal waters using different solvents to test their insecticidal properties and partially purify the active
components. The ethyl acetate extracts of L. lambis and T. radiatus showed 100% mortality of Sitophilus oryzae, at a concentration of 200 μg ml−1. The LC50 values for ethyl acetate extracts of L. lambis, T. radiatus and C. ramosus were found to be 67.08, 348.86 and 571.42 μg ml−1, respectively. With regard to bacterial metabolites, at a concentration of 200 μg ml−1 the ethyl acetate extract of A3 was able to elicit an activity of 40% and that of strain A1 – 20%. The LC50 values of the bacterial metabolites were also investigated. Upon chromatographic separation of active ethyl acetate extracts
of T. radiatus, the 100% methanol column-purified fraction was found to have an activity of 30% at a concentration of 10 μg against S. oryzae. The purity of the partially pure active compound was observed to be 72.78% on analysis with high pressure thin layer chromatography. 相似文献
972.
Manoj Kumar Solanki Nidhi Singh Rajesh Kumar Singh Pratiksha Singh Alok K. Srivastava Sudheer Kumar Prem L. Kashyap Dilip K. Arora 《Phytoparasitica》2011,39(5):471-481
Tomato root rot caused by Rhizoctonia solani is a major soilborne disease resulting in significant yield loss. The culture filtrates of six isolates of Trichoderma/Hypocrea species were evaluated for in vitro production of hydrolytic enzymes. Results demonstrated that all the six isolates were able to produce chitinase, β-1, 3 glucanase
and protease in the range of 76–235 μmol GlcNAc min-1 mg-1 protein, 31.90–37.72 nmol glucose min-1 mg-1 proteins and 63.05–86.22 μmol min-1 mg-1 proteins, respectively. Trichoderma/Hypocrea-based formulation(s) were prepared with chitin (1% v:v) and CMC (0.5% w:v) for root rot management in a greenhouse. Root dip
application with bioformulation(s) resulted in a significant reduction of the root rot index. In addition, bioformulations
increased plant growth attributing traits significantly relative to untreated control. Accumulation of total phenols, peroxidase,
polyphenoloxidase and phenylalanine ammonia lyase increased in chitin-supplemented Trichoderma/Hypocrea formulation-treated plants challenged with R. solani. The results suggest that chitin-fortified bioformulation(s) could be an effective system to control root rot of tomato in
an eco-compatible manner. 相似文献
973.
Firas Talas Heiko K. Parzies Thomas Miedaner 《European journal of plant pathology / European Foundation for Plant Pathology》2011,131(1):39-48
Fusarium head blight (FHB) is one of the most destructive diseases of wheat. Twelve small commercial wheat fields (size 1–3
hectares) were sampled in Germany for Fusarium populations at three spots per field with 10 heads each. PCR assays using generic primers confirmed 338 isolates as F.graminearum sensu stricto (s.s.) (64.9%) out of 521 Fusarium spp. that were further analyzed. Populations of F. graminearum s.s. in Germany contain three types of trichothecenes with a dominancy of 15-acetyldeoxynivalenol chemotype (92%) followed
by 3-acetyldeoxynivalenol chemotype (6.8%) and a few isolates of nivalenol chemotype (1.2%). All these isolates were genotyped
using 19 microsatellite loci. The 12 populations showed a high genetic diversity within the small scale sampling areas resulting
in 300 different haplotypes. Genetic diversity within populations (71.2%) was considerably higher than among populations (28.8%)
as shown by analysis of molecular variance. Gene flow (Nm) between populations ranged from 0.76–3.16. Composition of haplotypes
of one population followed over 2 years changed considerably. No correlation between genetic and geographical distance was
found. In conclusion, populations of F. graminearum s.s. in Germany display a tremendous genetic variation on a local scale with a restricted diversity among populations. 相似文献
974.
Keisuke Tomioka Yuuri Hirooka Toshirou Nagai Hiroyuki Sawada Takayuki Aoki Toyozo Sato 《Journal of General Plant Pathology》2011,77(4):266-268
Severe blight of potted seedlings of monkshood caused by Plectosporium tabacinum was found in glasshouses in Kagawa Prefecture in southwest Japan in May 2001. Root rot and browning of stem bases were followed
by wilting and yellowing of leaves, then blighting of leaves, flower buds and stems. A fungus was isolated from diseased plants
and confirmed to cause the disease. The new disease was named “Plectosporium blight of monkshood”. 相似文献
975.
Shin-ichi Shimizu Takao Ito Takanori Miyoshi Yasunobu Tachibana Tsutae Ito 《Journal of General Plant Pathology》2011,77(6):326-330
Universal primers to detect Satsuma dwarf virus (SDV), including distantly related strains Citrus mosaic virus (CiMV), Navel orange infectious mottling virus (NIMV), and
Hyuganatsu virus (HV), were tested in a convenient one-step RT-PCR assay. SDV was the most broadly detected using uSDVup/uSDVdo
primers that specifically targeted a nucleotide sequence in the 3′-noncoding region that is conserved in both segmented RNAs
1 and 2 of SDV among the tested primers. Nucleotide sequence analysis confirmed that the amplified RT-PCR products could be
derived from RNAs 1 or 2 of SDV variants, some of which had interesting genetic diversity. 相似文献
976.
Shinpei Banno Hidenari Saito Hiroshi Sakai Toshihiko Urushibara Kentaro Ikeda Takeshi Kabe Isao Kemmochi Makoto Fujimura 《Journal of General Plant Pathology》2011,77(5):282-291
Verticillium longisporum and V. dahliae, causal agents of Verticillium wilt, are spreading through the cabbage fields of Gunma Prefecture. Using the V. longisporum-specific intron within the 18S rDNA and differences between ITS 5.8S rDNA sequences in Japanese isolates of V. longisporum and V. dahliae, we developed three quantitative nested real-time (QNRT) PCR assays. The QNRT-PCR quantification of V. longisporum or V. dahliae in cabbage field soil was consistent with the severity of Verticillium wilt disease in those fields. In field trials of resistant
cultivar YR Ranpo grown for three seasons in soil infested with the pathogen, disease severity and pathogen density in the
soil were significantly reduced in a field moderately contaminated by V. dahliae, but only slightly reduced in a highly contaminated field. These results suggest that continuous cultivation of a resistant
cultivar is an effective way to reduce the pathogen population. QNRT-PCR assays provide a powerful analytical tool to evaluate
the soil population dynamics of V. longisporum and V. dahliae for disease management. 相似文献
977.
Antonio Evidente Rossitza Rodeva Anna Andolfi Zornitsa Stoyanova Carmen Perrone Andrea Motta 《European journal of plant pathology / European Foundation for Plant Pathology》2011,130(2):173-182
Recently, a new fungal disease caused by Diaporthe angelicae (anamorph Phomopsis foeniculi) has been found with increasingly frequency on fennel (Foeniculum vulgare) in Bulgaria. Using a bioassay-guided isolation and purification procedure, different metabolites were isolated from the
fungal culture filtrates. They were identified by spectroscopic methods as nectriapyrone, a pentaketide monoterpenoid, and
altersolanols A and J and macrosporin, three octaketides anthracenones. Leaf puncture bioassay was applied on detached tomato
leaves to prove the phytotoxic activity of the fractions and of pure compounds. Nectriapyrone and altersolanols A and J showed
a modulated phytotoxicity, while macrosporin was not toxic. Altersolanol A was the most active compound. 相似文献
978.
Abu Shamim Mohammad Nahiyan Louisa Robinson Boyer Peter Jeffries Yoh-ichi Matsubara 《European journal of plant pathology / European Foundation for Plant Pathology》2011,130(2):197-203
The diversity of Fusarium populations in asparagus (Asparagus officinalis L.) decline fields in Japan was estimated by PCR-SSCP (single-stranded conformational polymorphism) analysis of the ITS2
regions of the nuclear rRNA genes. This method was used to rapidly and objectively identify pathogens associated with roots
of plants showing symptoms of asparagus decline collected from fields in five regions across Japan. Over 651 fusarial isolates
were obtained, and were easily differentiated into three principal species. Fusarium oxysporum f. sp. asparagi was most frequently isolated from the domestic five regions (68%), whereas Fusarium proliferatum (28.6%) was less frequent. Fusarium solani was found much rarely (2.5%). The frequency of isolation of Fusarium proliferatum increased gradually from the north to the south of Japan, though considerable differences were found between fields in each
region, as well as regional differences among the Fusarium populations. Most of the fusarial isolates were highly pathogenic in vitro. These results reveal that Fusarium oxysporum f. sp. asparagi and Fusarium proliferatum are important biotic factors which lead to asparagus decline in Japan. 相似文献
979.
Warrick R. Nelson Tonja W. Fisher Joseph E. Munyaneza 《European journal of plant pathology / European Foundation for Plant Pathology》2011,130(1):5-12
Three haplotypes of the recently discovered bacterium species “Candidatus Liberibacter solanacearum” are described and related to geographic ranges. The first two are associated with Zebra Chip/Psyllid
Yellows of potatoes and other solanaceous plants, vectored by the tomato/potato psyllid Bactericera cockerelli in North and Central America and New Zealand. The third is associated with diseased carrots in Finland and vectored by the
carrot psyllid Trioza apicalis. The haplotypes are described by SNPs on the 16s rRNA, 16s/23s ISR and 50s rplJ and rplL ribosomal protein genes. These SNPs
are inherited as a package across the three genes. Haplotype “a” has been found primarily from Honduras and Guatemala through
western Mexico to Arizona and California, and in New Zealand. Haplotype “b” is currently known from eastern Mexico and northwards
through Texas to south central Washington. These haplotypes show some range overlap in Texas, Kansas and Nebraska. The haplotypes
are not yet known to elicit biological differences in the plant or insect hosts. These apparently stable haplotypes suggest
separate bacterial populations of long standing. 相似文献
980.
Odile Carisse Catherine Meloche William W. Turechek 《European journal of plant pathology / European Foundation for Plant Pathology》2011,130(3):349-365
The spatial pattern of apple scab was characterized using 10 years of disease incidence and lesion density data collected
in managed orchards located in Quebec, Canada. Distributional analyses indicated that scab incidence was better characterized
by the beta-binomial than the binomial distribution in 53 and 65% of the data sets at the leaf and shoot scales, respectively.
Median values of the beta-binomial parameter θ, a measure of small-scale aggregation, were near 0 (0.003 and 0.028) at both
sampling scales, indicating that disease incidence was close to being randomly distributed (low degree of aggregation). For
lesion density, the negative binomial distribution fitted the data better than the Poisson distribution in 86% of the data
sets at the leaf scale. The median value of the index of dispersion k was 0.068, indicating that aggregation was present. For all apple scab measurements, the power law models provided a good
fit to the data. The estimated slope and intercept parameters were significantly greater than 1 and 0, respectively, suggesting
that spatial heterogeneity changed systematically with disease incidence. Results of a covariance analysis showed that spatial
heterogeneity of scab incidence at both scales and lesion density was not dependent upon shoot type but that spatial heterogeneity
of scab incidence and lesion density at the leaf scale was influenced by the sampling period. A hierarchical analysis showed
that scab incidence at the tree scale increased as a saturation-type curve with respect to incidence at the leaf or shoot
scales. A similar relationship was observed for incidences at the shoot and leaf scales. An effective sample size model based
on the binary power law parameters (Madden and Hughes, Phytopathology 89:770–781, 1999) gave the best fit to the leaf and shoot data, respectively. The incidence-lesion density relationship at both scales was
well described by a complementary log-log (CLL) and log transformation model ( Radj2 = 0.97 and Radj2 = 0.94 ) \left( {R_{{adj}}^2 = 0.97\,and\,R_{{adj}}^2 = 0.94} \right) , however, the models tended to underestimate lesion density. The information of the spatial relations of apple scab within
and between hierarchical scales acquired from this study can be used in developing and evaluating practical disease management
strategies and to improve apple scab assessments for fungicide or cultivar susceptibility trials. 相似文献