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191.
Alamin Alfatih Jie Wu Sami Ullah Jan Zi-Sheng Zhang Jin-Qiu Xia Cheng-Bin Xiang 《Plant, cell & environment》2020,43(11):2743-2754
Plants frequently suffer from environmental stresses in nature and have evolved sophisticated and efficient mechanisms to cope with the stresses. To balance between growth and stress response, plants are equipped with efficient means to switch off the activated stress responses when stresses diminish. We previously revealed such an off-switch mechanism conferred by Arabidopsis PARAQUAT TOLERANCE 3 (AtPQT3) encoding an E3 ubiquitin ligase, knockout of which significantly enhances resistance to abiotic stresses. To explore whether the rice homologue OsPQT3 is functionally conserved, we generated three knockout mutants with CRISPR-Cas9 technology. The OsPQT3 knockout mutants (ospqt3) display enhanced resistance to oxidative and salt stress with elevated expression of OsGPX1, OsAPX1 and OsSOD1. More importantly, the ospqt3 mutants show significantly enhanced agronomic performance with higher yield compared with the wild type under salt stress in greenhouse as well as in field conditions. We further showed that OsPQT3 expression rapidly decreased in response to oxidative and other abiotic stresses as AtPQT3 does. Taken together, these results show that OsPQT3 is functionally well conserved in rice as an off-switch in stress response as AtPQT3 in Arabidopsis. Therefore, PQT3 locus provides a promising candidate for crop improvement with enhanced stress resistance by gene editing technology. 相似文献
192.
Rice blast disease is one of the most devastating diseases of rice
(Oryza sativa L.) caused by the fungus Magnaporthe oryzae (M. oryzae), and
neck blast is the most destructive phase of this illness. The underlying molecular
mechanisms of rice blast resistance are not well known. Thus, we collected 150
rice varieties from different ecotypes in China and assessed the rice blast
resistances under the natural conditions that favoured disease development in
Jining, Shandong Province, China in 2017. Results showed that 92 (61.3%) and
58 (38.7%) rice varieties were resistant and susceptible to M. oryzae,
respectively. Among the 150 rice varieties screened for the presence of 13 major
blast resistance (R) genes against M. oryzae by using functional markers, 147
contained one to eight R genes. The relationship between R genes and disease
response was discussed by analysing the phenotype and genotype of functional
markers. The results showed that the rice blast resistance gene Pita was
significantly correlated with rice blast resistance. Our results provided a basis for
the further understanding of the distribution of 13 major R genes of rice blast in
the germplasm resources of the tested rice varieties, and were meaningful for rice
disease resistance breeding. 相似文献
193.
Increasing temperatures resulting from climate change dramatically impact rice crop production in Asia. Depending on the specific stage of rice development, heat stress reduces tiller/panicle number, decreases grain number per plant and lower grain weight, thus negatively impacting yield formation. Hence improving rice crop tolerance to heat stress in terms of sustaining yield stability under high day temperature (HDT), high night temperature (HNT), or combined high day and night temperature (HDNT) will bolster future food security. In this review article, we highlight the phenological alterations caused by heat and the underlying molecular-physiological and genetic mechanisms operating under different types of heat conditions (HDT, HNT, and HDNT) to understand heat tolerance. Based on our synthesis of HDT, HNT, and HDNT effects on rice yield components, we outline future breeding strategies to contribute to sustained food security under climate change. 相似文献
194.
195.
Background and Aims
Anoxic conditions are seldom considered in root iron plaque induction of wetland plants in hydroponic experiments, but such conditions are essential for root iron plaque formation in the field. Although ferrous ion availability and root radial oxygen loss capacity are generally taken into account, neglect of anoxic conditions in root iron plaque formation might lead to an under- or over-estimate of their functional effects, such as blocking toxic metal uptake. This study hypothesized that anoxic conditions would influence root iron plaque formation characteristics and translocation of Zn and Cd by rice seedlings.Methods
A hydroponic culture was used to grow rice seedlings and a non-disruptive approach for blocking air exchange between the atmosphere and the induction solution matrix was applied for root iron plaque formation, namely flushing the headspace of the induction solution with N2 during root iron plaque induction. Zn and Cd were spiked into the solution after root iron plaque formation, and translocation of both metals was determined.Key Results
Blocking air exchange between the atmosphere and the nutrient solution by N2 flushing increased root plaque Fe content by between 11 and 77 % (average 31 %). The N2 flushing treatment generated root iron plaques with a smoother surface than the non-N2 flushing treatment, as observed by scanning electron microscopy, but Fe oxyhydroxides coating the rice seedling roots were amorphous. The root iron plaques sequestrated Zn and Cd and the N2 flushing enhanced this effect by approx. 17 % for Zn and 71 % for Cd, calculated by both single and combined additions of Zn and Cd.Conclusions
Blocking of oxygen intrusion into the nutrient solution via N2 flushing enhanced root iron plaque formation and increased Cd and Zn sequestration in the iron plaques of rice seedlings. This study suggests that hydroponic studies that do not consider redox potential in the induction matrices might lead to an under-estimate of metal sequestration by root iron plaques of wetland plants. 相似文献196.
Mohammad Reza Amirjani 《Archives Of Phytopathology And Plant Protection》2013,46(2):228-243
Salinity is a major yield-reducing factor in coastal and arid irrigated rice production systems. Rice seedlings (Oryza sativa cv. Tarom Atri) were exposed to different NaCl concentrations for 8 days after germination. Plants height, fresh and dry weight, relative water content, pigment and carbohydrate content, photosynthetic efficiency and lipid peroxidase and antioxidant enzyme activity of rice seedlings grown under salt stress were investigated. Seedling grown under 25and 50 mM salt were shorter than the control. They could, however, develop their secondary leaves. Seedlings grown in the nutrient solution supplied with 100 and 200 mM extra salt could not develop their secondary leaves. Fresh weight ofseedlings grown under salt stress reduced up to 42.2% of the non-treated seedlings. Chlorophylls and carotenoids contents decreased significantly in the salt-treated seedlings. Carotenoid contents in NaCl-treated seedlings were decreased to 39.3%. No significant changes occurred in the photochemical efficiency of control and stressed plants. Increasing concentrations of NaCl resulted in increase and decrease of Na+ and K+ ions, respectively. NaCl salinity caused an increase in both peroxide content and lipid peroxidation. Seedlings which recovered for 24 h showed lower peroxide and malondialdehyde content. 相似文献
197.
Wenjing Song Huwei Sun Jiao Li Xianpo Gong Shuangjie Huang Xudong Zhu Yali Zhang Guohua Xu 《Annals of botany》2013,112(7):1383-1393
Background and Aims
Although ammonium (NH4+) is the preferred form of nitrogen over nitrate (NO3−) for rice (Oryza sativa), lateral root (LR) growth in roots is enhanced by partial NO3− nutrition (PNN). The roles of auxin distribution and polar transport in LR formation in response to localized NO3− availability are not known.Methods
Time-course studies in a split-root experimental system were used to investigate LR development patterns, auxin distribution, polar auxin transport and expression of auxin transporter genes in LR zones in response to localized PNN in ‘Nanguang’ and ‘Elio’ rice cultivars, which show high and low responsiveness to NO3−, respectively. Patterns of auxin distribution and the effects of polar auxin transport inhibitors were also examined in DR5::GUS transgenic plants.Key Results
Initiation of LRs was enhanced by PNN after 7 d cultivation in ‘Nanguang’ but not in ‘Elio’. Auxin concentration in the roots of ‘Nanguang’ increased by approx. 24 % after 5 d cultivation with PNN compared with NH4+ as the sole nitrogen source, but no difference was observed in ‘Elio’. More auxin flux into the LR zone in ‘Nanguang’ roots was observed in response to NO3− compared with NH4+ treatment. A greater number of auxin influx and efflux transporter genes showed increased expression in the LR zone in response to PNN in ‘Nanguang’ than in ‘Elio’.Conclusions
The results indicate that higher NO3− responsiveness is associated with greater auxin accumulation in the LR zone and is strongly related to a higher rate of LR initiation in the cultivar ‘Nanguang’. 相似文献198.
Olumoye E. Oyetunji Cecilia O. Peluola Francis E. Nwilene Gbenga Akinwale Abou Togola Tolulope A. Agunbiade 《Archives Of Phytopathology And Plant Protection》2013,46(11):1292-1303
The effect of fungi–termite interaction on three rice varieties was conducted in a screen house at the Africa Rice Center (AfricaRice) Ibadan, Nigeria. Of the 10 fungi species (Fusarium verticilloides, Trichoderma sp., Aspergillus niger, Aspergillus flavus, Macrophoma sp., Neurospora sp., Botryodiplodia theobromae, Penicillum sp., Rhizopus sp. and Sclerotium rolfsii) isolated from termites, soil and rice plants, F. verticilloides, Trichoderma sp. and B. theobromae were used for the interaction study. Each fungus was inoculated singly and in combinations with termite into the root of each rice variety in potted soil. Leaf samples were taken to measure the chlorophyll content which is a major parameter to estimate effect of termite–fungi interaction. The chlorophyll content of the inoculated rice plants was significantly reduced when compared with the control. Fungi interaction with termite had significant reduction on the chlorophyll content. The synergistic relationship between the fungi and the termite was discussed. 相似文献
199.
Masaru Matsumoto Myo Zaw Seint San Aye 《Archives Of Phytopathology And Plant Protection》2013,46(13-16):777-784
A modified baiting technique was conducted for selective isolation, fungal DNA diagnosis and fungal cell lipid assay derived from Myanmar isolates of Rhizoctonia spp., causal agents of rice sheath diseases by trapping selective plant stem segments. Bait plant materials of rice, mat rush and cotton were successfully used to isolate R. solani AG1-IA, R. oryzae and R. oryzae-sativae. Moreover, the three plant materials were also effectively used to detect genomic DNA derived from all Rhizoctonia spp. obtained from Myanmar. Rice segment was the most successful materials for detection of fungal cell lipids including palmitic, stearic and linoleic acids. The results of this experiment demonstrate that bait plant materials of rice, mat rush and cotton were the best useful tools for not only direct isolation, but also fungal DNA diagnosis and cell lipid assay of Myanmar soil environmental conditions. 相似文献
200.