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101.
植物内生固氮菌研究进展 总被引:2,自引:0,他引:2
综述了植物内生固氮菌生物多样性、生物学特性 ,生理特性 ,与寄主植物的相互作用及应用前景等方面的研究进展。 相似文献
102.
云南重楼植物内生真菌的分离及抗菌活性筛选 总被引:8,自引:1,他引:7
从云南重楼[Paris polyphylla Smithvar.yunnnanensis(Franch.)Hand.Mazz.]块状茎中分离出166株内生真菌,对其进行形态分类鉴定归于4目,6科,20个属,体现了云南重楼植物内生真菌的生物多样性特征。同时,选择与人类和植物相关的37株病原微生物作为抗菌活性筛选指示菌,进行了云南重楼植物内生真菌抗菌活性的初步研究。结果表明,4株内生真菌对细菌、植物致病真菌、皮肤致病真菌多种病原微生物具有显著抑制生长的作用。 相似文献
103.
104.
Tian X.L. Cao L.X. Tan H.M. Zeng Q.G. Jia Y.Y. Han W.Q. Zhou S.N. 《World journal of microbiology & biotechnology》2004,20(3):303-309
The populations of endophytic fungi and actinomycetes from four rice cultivars in the Panyu district (Site 1) and Wushan district
(Site 2) in Guangdong province, South China, were studied. The preponderant endophytic fungi and actinomycetes isolated belonged
to Fusarium and Streptomyces respectively. The incidence of Streptomycetes griseofuscus ranged from 36.1 to 69% out of all the different rice cultivars from the two sites. It is the commonest population of endophytic
actinomycetes, and constituted the greatest part of all the antagonistic communities. The distributions of endophytic fungi
and actinomycetes in roots and leaves were different, endophytic fungi from leaves were diverse, some were organ-specific.
More diverse endophytic actinomycetes were isolated from roots than from leaves. The endophytic fungi isolated from rice in
Site 2 were more diverse than that in Site 1. The diversity of the endophytic actinomycetes, however, was less than that in
Site 1. Acid soil in Site 2 is ideal for the growth and colonization of fungi while the alkaline soil in Site 1 is better
for the growth and colonization of actinomycetes. The results suggested that differences in the chemical composition of soil
could influence the endophytic microbial communities of rice plants. The endophytic fungi and actinomycetes isolated from
poor-growing seedlings and susceptible rice cultivars were more abundant than that the disease-resistant counterparts. In
the dual culture and activity detection of the metabolites, 41.2% of all the isolated endophytic fungi showed antagonism to
rice pathogens. Fifty percent of all the isolated endophytic actinomycetes were antagonistic to those pathogens. The percentage
of Streptomyces griseofuscus and hygroscopicus reached 55.4 and 21.4% of all the active actinomycetes.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
105.
Dark septate endophytic fungi (DSE) may have an important functional relationship with host plants, but these functions and
the colonization process remain unknown. We made microscopic observations of the growth of an endophytic hyphomycete in Chinese
cabbage roots to understand its colonization process. This hyphomycete was Heteroconium chaetospira, a suspected DSE. Three weeks post inoculation, some hyphae became irregularly lobed and formed microsclerotia within host
epidermal cells of healthy plants. In stunted plants, hyphae formed closely packed masses of fungal cells within host epidermal
cells, but conidiophores rarely broke through the cell walls to produce conidia.
Received: December 7, 2000 / Accepted: November 20, 2001 相似文献
106.
IMRAN A. SIDDIQUI S. SHAHID SHAUKAT GHAZALA H. KHAN & M. J. ZAKI 《Journal of Phytopathology》2002,150(6):321-329
Argemone mexicana L. (Papaveraceae), a tropical annual weed, is known to be phytotoxic to many crop species. This study was designed to examine the possible impact of A. mexicana on root‐infecting fungi, changes in fungal community structure and the growth of tomato. A. mexicana decaying shoots in soil provided a marked decrease in the infectivity of Fusarium solani and Rhizoctonia solani but Macrophomina phaseolina remained unaffected. Plant height and shoot growth of tomato plants increased markedly though high concentration of A. mexicana (5% w/w) was deleterious to tomato plants. General species diversity of soil fungal communities increased in the amended soils over the controls and greater increase in diversity occurred at higher concentrations of decaying A. mexicana. Likewise, equitability and richness components of diversity increased in treatments compared to controls but declined with increasing sampling period. Aspergillus nidulans, Cephaliophora irregularis, Drechslera halodes, Paecilomyces lilacinus and Trichoderma viride were isolated exclusively from the amended soils. Aqueous extract of A. mexicana when applied in soil greatly suppressed all three of the above root‐infecting fungi, and at lower concentration actually enhanced plant growth. The influence of different levels of N‐fertilization with NH4NO3 on the modification of the effect of decaying A. mexicana on root‐infecting fungi was also investigated. N‐fertilization to some extent alleviated the phytotoxicity to tomato plants while suppressing the root‐infecting fungi. A. mexicana in conjunction with Pseudomonas aeruginosa, a plant growth‐promoting rhizobacterium, significantly suppressed root‐infecting fungi with concomitant increase in plant growth. Whereas P. aeruginosa was reisolated from the rhizosphere and inner root tissues of tomato, its population slightly declined in the amended soil but not to an extent that could reduce the biocontrol and growth promoting potential of the bacterium. 相似文献
107.
A species ofMycosphaerella with aPseudocercospora anamorph was collected on overwintered fallen leaves of Japanese beech,Fagus crenata. Based on comparison of morphology withMycosphaerella species on Fagaceae, the fungus was newly described asMycosphaerella buna. ThePseudocercospora anamorph derived from a single ascospore of the fungus was morphologically identical to an endophytic anamorph isolated from
asymptomatic living leaves of Japanese beech.
Contribution No. 150, Laboratory of Plant Parasitic Mycology, Institute of Agriculture and Forestry, University of Tsukuba 相似文献
108.
用共聚焦激光扫描显微镜观测GFP标记的内生固氮菌Klebsiella oxytoca SA2侵染水稻根 总被引:9,自引:0,他引:9
用高效绿色荧光蛋白(green fluorescent protein,GFP)突变体EGFPmut2的基因标记内生固氮菌--产酸克雷伯氏菌(Klebsiella axytoca (Fluegge)Lautrop)SA2,用标记菌接种限菌培养条件下生长的水稻(Oryza sativa L.)幼苗,在接种后1、2、4 、8、12、16和21d,用共聚焦激光扫描显微镜对水稻鲜根进行光学切片,显示了标记菌从水稻根成熟区表面向根内入侵的过程。定殖在根表面的标记菌主要从侧根伸出的位置侵入侧根皮层,从邻近发生侧根的位置进入内皮层和维管柱。SA2还能从初生根成熟区无侧根伸出的位置侵入皮层向维管柱迁移。SA2入侵水稻根引发了水稻根局部的过敏反应以阻滞细菌地下海主侵,表现为侵入根内的细菌周围的根细胞细胞壁变厚,在蓝光下发出很强的黄绿荧光。 相似文献
109.
Dayle E. Saar Neil O. Polans Paul D. Sørensen Melvin R. Duvall 《Plant Molecular Biology Reporter》2001,19(3):249-260
PCR primers with broad applicability are useful in many molecular-based studies; however, their universality can compromise
results when DNA contaminants also are amplified. Eighty-one templates ofDahlia (Asteraceae), primarily extracted from native Mexican populations, were tested for the presence of fungal contaminants; out
of these, almost 1 in 7 templates (13.6%) was contaminated. In a second survey across 12 angiosperm families using material
collected in Illinois, fungal DNA contaminated over 60% of the templates analyzed. Endophytic fungi often are symptomless
symbionts living within the above-ground tissues of their angiosperm hosts and are not affected by surface sterilization techniques.
Recent studies have revealed their widespread occurrence and broad host range. We also present field strategies for obtaining
plant material to reduce the possibility of collecting infected leaves and a simple screening test for detecting fungal DNA
in angiosperm templates. 相似文献
110.
Endophytic fungi, especially from mangrove plants, are rich source of secondary metabolites, which plays a major role in various pharmacological actions preferably in cancer and bacterial infections. To perceive its role in antidiabetic activity we isolated and tested the metabolites derived from a novel strain Alternaria longipes strain VITN14G obtained from mangrove plant Avicennia officinalis. The crude extract was analyzed for antidiabetic activity and subjected to column chromatography. The isolated fractions were screened in vitro for α-glucosidase and α-amylase inhibitory activities. The cytotoxicity of the isolated fractions was studied on L929 cell lines. Following which, the screened fraction 2 was allowed for structure elucidation using gas chromatography-mass spectrometry, one-dimensional, two-dimensional nuclear magnetic resonance spectroscopy, ultraviolet, and Fourier-transform infrared analysis. The binding energies of the isolated fraction 2 with glycolytic enzymes were calculated by molecular docking studies using AutoDock Vina. The isolated fraction 2 identified as 2,4,6-triphenylaniline, showed no significant difference in α-amylase inhibition rates and a significant difference of 10% in α-glucosidase inhibition rates than that of the standard drug acarbose. Further, the cytotoxicity assay of the isolated fraction 2 resulted in a cell viability of 73.96%. Supportingly, in silico studies showed 2,4,6-triphenylaniline to produce a stronger binding affinity toward the glycolytic enzyme targets. The compound 2,4,6-triphenylaniline isolated from A. longipes strain VITN14G exhibited satisfactory antidiabetic activity for type 2 diabetes in vitro, which will further be confirmed by in vivo studies. Successful outcome of the study will result in a natural substitute for existing synthetic antidiabetic drugs. 相似文献