全文获取类型
收费全文 | 16380篇 |
免费 | 0篇 |
专业分类
林业 | 3620篇 |
农学 | 1293篇 |
基础科学 | 137篇 |
2729篇 | |
综合类 | 706篇 |
农作物 | 2095篇 |
水产渔业 | 1779篇 |
畜牧兽医 | 1049篇 |
园艺 | 1110篇 |
植物保护 | 1862篇 |
出版年
2018年 | 2744篇 |
2017年 | 2702篇 |
2016年 | 1178篇 |
2015年 | 64篇 |
2014年 | 14篇 |
2013年 | 5篇 |
2012年 | 788篇 |
2011年 | 2122篇 |
2010年 | 2101篇 |
2009年 | 1252篇 |
2008年 | 1311篇 |
2007年 | 1574篇 |
2006年 | 28篇 |
2005年 | 96篇 |
2004年 | 100篇 |
2003年 | 150篇 |
2002年 | 58篇 |
2001年 | 4篇 |
2000年 | 40篇 |
1995年 | 1篇 |
1993年 | 12篇 |
1992年 | 7篇 |
1990年 | 1篇 |
1989年 | 5篇 |
1988年 | 11篇 |
1987年 | 1篇 |
1977年 | 4篇 |
1972年 | 1篇 |
1969年 | 1篇 |
1968年 | 4篇 |
1967年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 125 毫秒
991.
Nadia Korolev Mukhiddin Mamiev Tirza Zahavi Yigal Elad 《European journal of plant pathology / European Foundation for Plant Pathology》2011,129(4):591-608
Plots in two vineyards in the Golan Heights, Israel were treated with six botryticides during three growing seasons with 3
applications per season. Applications of fenhexamid, pyrimethanil and cyprodinil + fludioxonil were effective, resulting in
52–65% and 53–63% mean reduction in grey mould incidence and severity, respectively. Carbendazim, fluazinam and iprodione
were ineffective or slightly effective. Five hundred and sixteen B. cinerea isolates were collected from infected berries or trapped from the air in the vineyards, and profiles of sensitivity to benomyl,
fenhexamid, fluazinam, fludioxonil, iprodione and pyrimethanil were established for each of the isolates based on a mycelial
growth test. Seventy-four percent of the isolates were sensitive to the six tested fungicides, and the other 26% of the isolates
were classified into 10 phenotypes characterized by resistance to one or more fungicides. Resistant isolates showed fitness
parameters similar or reduced in comparison to sensitive isolates. Resistance to benzimidazoles and to dicarboximides was
the most frequent (up to 25%) and apparently pre-existed in the populations tested. Increased frequency of benzimidazole resistance,
but not dicarboximide resistance, was observed following the 3 years of applications of the fungicides. High level resistance
to pyrimethanil was present at a frequency of about 2% in both vineyards in the first 2 years of the sampling survey and reached
10% in the third year at Site 2. A few isolates were resistant to fenhexamid or fludioxonil (0.8 or 0.2%, respectively). No
strong resistance to fluazinam was detected, although numerous, less sensitive isolates, presumably possessing multi-drug
resistance traits, were recovered at higher frequency from the plots treated with fluazinam than from the untreated plots. 相似文献
992.
Piérri Spolti Luana Schneider Rosa M. V. Sanhueza Jean C. Batzer Mark L. Gleason Emerson Medeiros Del Ponte 《European journal of plant pathology / European Foundation for Plant Pathology》2011,129(1):21-29
Sooty blotch and flyspeck is caused by numerous species of fungi that colonize the surface of apple fruit and thereby lower
its market value. Although this disease poses a substantial threat to apple growers’ profitability in some regions, reliable
and cost-effective methods for epidemiological and disease control studies have not been validated, nor are they widely available.
We modified a standard area diagram to aid sooty blotch and flyspeck severity assessments and quantified its impact on accuracy
and precision of visual estimates. Samples of ‘Fuji’ and ‘Mutsu’ fruit were photographed both from the top and laterally.
Severity was assessed from a sub-sample of 160 images using image analysis software. Validation of the diagram was performed
by eight raters who independently assessed severity in two series of selected images representing the lateral view and the
top view, initially unaided and subsequently with the aid of the scale. Severity estimates ranged from 0.4% to 98% (most fruit
had <10% severity). Accuracy and precision of the estimates were significantly improved when using the diagrammatic scale;
concordance correlation coefficient values increased from 0.81 to 0.95. A strong tendency to underestimate severity for the
mid-range to high levels was minimized when using the aid, which also improved reproducibility of the estimates among raters.
In addition to strengthening evidence that a standard area diagram can be used reliably in sooty blotch and flyspeck studies,
we expanded its application to disease assessment in the peduncle region, which enhances the usefulness of the method for
evaluating efficacy of management practices. 相似文献
993.
Rasa Jomantiene Yan Zhao Ing-Ming Lee Robert Edward Davis 《European journal of plant pathology / European Foundation for Plant Pathology》2011,130(1):97-107
Phytoplasmas infecting sour cherry and lilac in Lithuania were found to represent two lineages related to clover phyllody
phytoplasma (CPh), a subgroup 16SrI-(R/S)C (formerly 16SrI-C) strain exhibiting rRNA interoperon sequence heterogeneity. 16S
rDNAs amplified from the cherry bunchy leaf (ChBL) and lilac little leaf (LcLL) phytoplasmas were identical or nearly identical
to those of operon rrnA and operon rrnB, respectively, of CPh. There was no evidence of 16S rRNA interoperon sequence heterogeneity in either LcLL or ChBL phytoplasma.
Based on collective RFLP patterns of 16S rDNA, ChBL was classified in subgroup 16SrI-R, and LcLL was classified in new subgroup
16SrI-S. The ribosomal protein (rp) gene sequences from LcLL phytoplasma were identical to those of CPh, and strain LcLL was
classified in rp subgroup rpI-C. By contrast, rp gene sequences from ChBL phytoplasma differed from those of subgroup rpI-C;
based on RFLP patterns of rp gene sequences, ChBL was classified in new rp subgroup rpI-O. Single nucleotide polymorphisms
(SNPs), designated here by a new SNP convention, marked members of rp subgroup rpI-C, and distinguished LcLL and CPh from
ChBL and other non-rpI-C phytoplasmas in group 16SrI. The results raise questions concerning phytoplasma biodiversity assessment
based on rRNA genes alone and encourage the supplemental use of a single copy gene in phytoplasma identification and classification,
while drawing attention to a possible role of horizontal gene transfer in the evolutionary history of these lineages. 相似文献
994.
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
995.
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
996.
Otmar Spring Thines Marco Stefanie Wolf Reinhard Zipper 《European journal of plant pathology / European Foundation for Plant Pathology》2011,131(3):519-527
Sequencing of partial cox2 (part of the mitochondrial cytochrome-c-oxydase (COX) gene) was performed with samples from the oomycete genus Pustula, the white blister rusts of Asteraceae and related families. Sequence comparison uncovered several single nucleotide polymorphisms
(SNPs) between P. spinulosa and host specific strains of Pustula isolated from Senecio vulgaris, Tragopogon pratensis and cultivated sunflower, Helianthus annuus. Based on these differences, specific primers were designed for PCR-based detection of white blister rust strains pathogenic
to sunflower. The specificity of the primers was confirmed by cross testing with DNA from various oomycetes occurring in the
same locality. The limit of detection for DNA of P. helianthicola was 10 pg. This allowed detection with DNA from single sporangia and single oospores. The PCR-based experiments allowed detection
of the presence of sunflower white blister rust in soil samples from fields on which infected plants had been cultivated several
months before. Moreover, the molecular tools were successfully applied to trace the pathogen in asymptomatic tissue of infected
plants, demonstrating the systemic nature of Pustula on sunflower. 相似文献
997.
Monique L. Sakalidis Jane D. Ray Vincent Lanoiselet Giles E. StJ. Hardy Treena I. Burgess 《European journal of plant pathology / European Foundation for Plant Pathology》2011,130(3):379-391
Members of the Botryosphaeriaceae, in particular Lasiodiplodia theobromae, Neofusicoccum parvum, N. mangiferum and Botryosphaeria dothidea, commonly cause stem cankers, dieback and stem end rot of mangoes worldwide. In the current study, eight taxa of Botryosphaeriaceae
were identified as canker-associated fungi, pathogens, potential pathogens or endophytes of mangoes in the Kimberley, Australia.
These include Neoscytalidium novaehollandiae, Ne. dimidiatum, Pseudofusicoccum adansoniae, P. ardesiacum, P. kimberleyense, Lasiodiplodia sp. 1, L. iraniensis and L. pseudotheobromae. The pathogenicity of a selection of these species toward fruit and branches was tested. All were pathogenic to mango in comparison
to the control, with Lasiodiplodia spp. being the most pathogenic. It appears that either geographic isolation or the unique growing conditions in the Kimberley
may have provided an effective barrier to the acquisition or establishment of known botryosphaeriaceous pathogens. Wounds
caused by mechanical pruning may provide an entry point for infection, whilst severe pruning may increase plant stress. 相似文献
998.
Maria Teresa Melillo Paola Leonetti Antonella Leone Pasqua Veronico Teresa Bleve-Zacheo 《European journal of plant pathology / European Foundation for Plant Pathology》2011,130(4):489-502
Nitric oxide (NO) has been shown to be an essential regulatory molecule in plant response to pathogen infection in synergy
with reactive oxygen species (ROS). At the present, nothing is known about the role of NO in disease resistance to nematode
infection. We used a resistant tomato cultivar with different sensitivity to avirulent and virulent populations of the root-knot
nematode Meloidogyne incognita to investigate the key components involved in oxidative and nitrosative metabolism. We analyzed the superoxide radical production,
hydrogen peroxide content, and nitric oxide synthase (NOS)-like and nitrate reductase activities, as potential sources of
NO. A rapid NO accumulation and ROS production were found at 12 h after infection in compatible and incompatible tomato-nematode
interactions, whereas the amount of NO and ROS gave different results 24 and 48 h after infection amongst compatible and incompatible
interactions. NOS-like arginine-dependent enzyme rather than nitrate reductase was the main source of NO production, and NOS-like
activity increased substantially in the incompatible interaction. We can envisage a functional overlap of both NO and ROS
in tomato defence response to nematode invasion, NO and H2O2 cooperating in triggering hypersensitive cell death. Therefore, NO and ROS are key molecules which may help to orchestrate
events following nematode challenge, and which may influence the host cellular metabolism. 相似文献
999.
Guruprasad B. Kulkarni Shrishailnath S. Sajjan T. B. Karegoudar 《European journal of plant pathology / European Foundation for Plant Pathology》2011,131(3):355-369
An indole-3-acetic acid (IAA) producing fungal strain was isolated from chickpea grown rhizospheric soil samples. Based on
morphological and Internal Transcribed Spacer (ITS) region sequence analysis the new isolate was identified as Fusarium delphinoides. The Fusarium delphinoides strain produces and secretes IAA in-vitro as identified by HPLC and Mass spectrometry. The IAA production is dependent on tryptophan (Trp) as a nitrogen source in
the medium. The IAA production is influenced by growth conditions such as pH of the medium, concentration of Trp and the nature
of the carbon source. Additional nitrogen sources repress Trp dependent IAA production. Glucose and Trp served as the best
carbon and nitrogen sources respectively. Pathogenicity of Fusarium delphinoides towards the plants was tested by electrolyte, nutrient leakage analysis and also by scoring the disease symptoms. Two cultivars
of chickpea (ICCV-10 and L-550) and two cultivars of pigeon pea (Maruti and PT-221) were assessed for the pathogenicity by
inoculating with spores of Fusarium delphinoides. The inoculation induced symptoms of Fusarium wilt as in the case of Fusarium oxysporum f. sp. ciceris (FOC), a known pathogen causing Fusarium wilt in chickpea. Electrolyte and nutrient leakage from the infected plants were used to assess the resistance, tolerance
(moderately resistance) and susceptibility of the plants to the infection. Based on the results, both the pigeon pea cultivars
(Maruti and PT-221) were rated as resistant, and ICCV-10 was rated as a tolerant cultivar of chickpea. However, chickpea cultivar
L −550 was found to be a susceptible host for infection by Fusarium delphinoides. These results suggest that Fusarium delphinoides, which belongs to the Fusarium dimerum species group, is an IAA producing plant pathogen and causes wilt in chickpea. Further, along with pathogenicity tests, electrolyte
and nutrient leakage analysis can be used to assess the pathogenicity of pathogenic fungi. 相似文献
1000.
Ferenc Viranyi Otmar Spring 《European journal of plant pathology / European Foundation for Plant Pathology》2011,129(2):207-220
This review summarises the progress in research on sunflower downy mildew as reported in publications of the past 10 to 15 years,
the period since the last comprehensive review on Plasmopara halstedii. Particular attention is paid to subjects that showed much progress and may be of particular interest to sunflower pathologists,
mycologists or molecular biologists. Accordingly, single sections are devoted to the problems of taxonomic and phylogenetic
aspects, host specificity, the host—pathogen interaction including resistance phenomena, as well as epidemiology and disease
management. Reflecting the progress achieved in some fields and illuminating the deficits in others should stimulate the reader's
interest in this very significant pathosystem. 相似文献