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131.
N. K. Krishna Kumar M. Aradya A. A. Deshpande N. Anand P. R. Ramachandar 《Euphytica》1996,89(3):319-324
Summary A preliminary evaluation for resistance to chili thrips, Scirtothrips dorsalis Hood of 41 and 194 pepper (Capsicum annuum L.) germplasms during 1987 and 1988, respectively, indicated chili accessions may be a promising source of resistance. In contrast, all sweet pepper accessions tested were highly susceptible. A number of chili accessions produced a moderate yield, in spite of a high thrips infestation indicating tolerance to S. dorsalis. Rating for thrips damage was more reliable and efficient than estimating thrips numbers in screening pepper accessions for resistance to thrips. Highly significant, positive correlation between ratings at the seedling stage and final rating for thrips damage indicated the feasibility of screening pepper accessions at the seedling stage. Comparing the similarities in rating among accessions resulted in 40 distinct groups. The variance-covariance matrix of the data from these 40 groups was subjected to principal component analysis. This accounted for 56 and 18 per cent of the variation across the two principal axes, respectively. Projection of chili and sweet pepper accessions along these two axes revealed three distinct clusters. About 80 per cent of chili accessions formed the first cluster, 58 per cent of the sweet pepper accessions formed the second cluster and a third cluster exhibited intermediate ratings for thrips damage. The significance of these findings in relation to geographical divergence and resistance to thrips among pepper accessions is discussed. 相似文献
132.
133.
The objectives of this study were to determine genetics of Al tolerance and whether the Al tolerance observed is governed by the same gene. The lines ‘L‐7903’ and ‘L‐4602’ have been developed through breeding programme as Al‐tolerant lines. These lines showed maximum root regrowth and minimum accumulation of Al and callose as compared to sensitive genotypes (‘BM‐4’ and ‘L‐4147’). Al tolerance in the parents, F1, F2 and backcross generations was estimated using the regrowth of the primary root after staining and scoring of fluorescent signals. The F1 hybrids responded similarly to the tolerant parents, indicating dominance of Al tolerance over sensitivity. The segregation ratios obtained for Al tolerance and sensitivity in the F2 and backcross generations were 3 : 1 and 1 : 1, respectively. Test of allelism confirmed the same gene was conferring Al tolerance in both genotypes (‘L‐7903’ and ‘L‐4602’) as the F1 was also tolerant and no segregation of tolerant : sensitive was recorded. These results indicated that Al tolerance is a monogenic dominant trait that can be easily transferred to agronomic bases through backcross breeding technique. 相似文献
134.
Identification of a diverse mini‐core panel of Indian rice germplasm based on genotyping using microsatellite markers 下载免费PDF全文
Kapil K. Tiwari Anshuman Singh Sasmita Pattnaik Maninder Sandhu Sukhdeep Kaur Sourabh Jain Sushma Tiwari Shweta Mehrotra Mahender Anumalla Rashmita Samal Jyoti Bhardwaj Neha Dubey Vikrant Sahu Gayle A. Kharshing Patu K. Zeliang Kadiri Sreenivasan Pankaj Kumar Swarup K. Parida Sevanthi V. A. Mithra Vandana Rai Wricha Tyagi Pawan K. Agrawal Atmakuri R. Rao Arunava Pattanayak Girish Chandel Ashok K. Singh Ishwari S. Bisht Kangila V. Bhat Gundimeda J. N. Rao Jitendra P. Khurana Nagendra K. Singh Trilochan Mohapatra 《Plant Breeding》2015,134(2):164-171
Identification of a small core germplasm set representing the available genetic diversity is essential for its proper evaluation and subsequent utilization in rice improvement programmes. For constituting a small diverse mini‐core panel of Indian rice germplasm, a representative set of 6912 accessions drawn based on their geographic origin from the whole rice germplasm collection available in the National Gene Bank was genotyped using 36 microsatellite markers. Automated fragment analysis of amplicons yielded a total of 435 alleles, with an average 12.4 and range of 3–29 alleles per locus. Polymorphism information content (PIC) ranged from 0.08 (RGNMS190) to 0.86 (RM552) with an average of 0.528. Based on genotyping data, a mini‐core consisting of 98 genotypes was identified. Ninety‐four per cent of the alleles present in the core set were present in the mini‐core. The identified small but diverse panel will be useful for further intensive trait‐specific evaluation and utilization in allele mining. 相似文献
135.
Development of kunitz trypsin inhibitor (KTI)-free soybean is crucial for soy-food industry as the heat inactivation employed to inactivate the anti-nutritional factor in regular soybean incurs extra cost and affects protein solubility. In the presented work, a null allele of KTI from PI542044 was introgressed into cultivar ‘JS97-52’ (recurrent parent) through marker assisted backcrossing. Foreground selection in BC1F2, BC2F2 and BC3F2 was carried out using the null allele-specific marker in tandem with SSR marker Satt228, tightly linked with a trypsin inhibitor Ti locus. Background selection in null allele-carrying plants through 106 polymorphic SSR markers across the genome led to the identification of 9 KTI-free lines exhibiting 98.6% average recurrent parent genome content (RPGC) after three backcrosses, which otherwise had required 5–6 backcrosses through conventional method. Introgressed lines (ILs) were free from KTI and yielded at par with recurrent parent. Reduction of 68.8–83.5% in trypsin inhibitor content (TIC) in ILs compared to the recurrent parent (‘JS97-52’) was attributed to the elimination of KTI. 相似文献
136.
Sajad Majeed Zargar Bodo Raatz Humira Sonah MuslimaNazir Javid A. Bhat Zahoor Ahmad Dar Ganesh Kumar Agrawal Randeep Rakwal 《Journal of Crop Science and Biotechnology》2015,18(5):293-308
Recent advances in sequencing technology have brought several novel platforms for marker development and subsequent genotyping. The high-throughput and cost effective marker techniques have changed the entire scenario of marker applications. The huge genotypic data obtained with next generation sequencing (NGS) also demands analytical tools, statistical advances, and comprehensive understanding to cope with breeding applications. In the present review, we discussed different available marker techniques, their strengths, and limitations. Emphasis was given on software tools, analytical pipelines, workbenches, and online resources available for marker development. Comparison of SNP genotyping involving complexity reduction techniques like GBS, RRL, RAD, and array-based platforms were presented in a view to describe suitability for specific purposes. We found that genotyping by whole genome re-sequencing has great potential, and could be a routine application in the near future with continuously decreasing cost of sequencing. Microsatellites, still a valuable option for breeders, have also advanced with NGS. Here a catalogue of tools for microsatellite evaluation in short sequence reads was provided. The most common applications of molecular marker like QTL mapping, genome-wide association mapping (GWAS), and genomic selection were highlighted. The present review will be helpful for the effective utilization of available resources and for the planning of crop improvement programs employing molecular marker techniques. 相似文献
137.
138.
Growth vigour plays an important role in the establishment of a normal crop. The F2 population of a cross between high‐ and low‐growth vigour varieties of chickpea segregated into 15 high : 1 low growth vigour. The results for recombinant inbred lines and BC1P2 showed a good fit to the expected 3 : 1 ratio. The results indicated that growth vigour is controlled by two genes with duplicate dominant epistasis. No gene has so far been identified for growth vigour in chickpea. Correlation between growth vigour and other characters showed that high growth vigour had significant negative correlation with days to first flower, days to 50% flowering, days to first pod and days to maturity. 相似文献
139.
Effect of Water Stress on Physiological Attributes and their Relationship with Growth and Yield of Wheat Cultivars at Different Stages 总被引:1,自引:0,他引:1
The effects of water stress on physiological attributes of drought‐sensitive (Kalyansona) and drought‐tolerant (C‐306) wheat cultivars were studied in a pot experiment. Water stress was imposed by withholding irrigation at boot and anthesis stages. Leaf water potential, leaf osmotic potential and leaf turgor potential (measured with pressure chamber and osmometer), as well as leaf diffusive resistance, leaf transpiration rate and leaf‐to‐air transpiration gradient (measured with a steady‐state porometer) were measured diurnally. Growth and yield parameters were recorded after harvesting of the crop. Triplicate data were analysed using a completely randomized design and correlations amongst these parameters were computed. Water stress was found to reduce diurnal leaf water potential and leaf osmotic potential in both the genotypes but leaf osmotic potential was significantly higher in the drought‐tolerant cultivar C‐306 than in the drought‐sensitive cultivar Kalyansona. Positive turgor was recorded in both the genotypes under water stress and non‐stress conditions. Water‐stressed plants showed significantly lower turgor potential than control plants. In diurnal observations, water‐stressed plants exhibited significantly higher leaf diffusive resistance in both genotypes at both stages. The diffusive resistance of C‐306 was predominantly higher than that of Kalyansona. Water stress decreased leaf transpiration rate at both stages but the reduction was higher at the anthesis stage. The leaf‐to‐air temperature gradient was much higher in C‐306 than in Kalyansona at the boot stage but at the anthesis stage genotypic variation was non‐significant. The capacity to maintain cooler foliage was lower at the anthesis stage than at the boot stage in both the cultivars. Shoot dry weight, number of grains, test weight, grain yield, biological yield and harvest index decreased to a greater extent when water stress was imposed at the anthesis stage, while imposition of water stress at the boot stage caused a greater reduction in plant height and number of tillers. Similarly, water stress caused a smaller reduction in growth, yield and yield attributes in C‐306 than in Kalyansona. In general, the correlation coefficient of grain and biological yield with water potential and its components was positive and highly significant. Similarly, turgor potential was also correlated positively and significantly with grain yield at both the stages, but with biological yield it was significant only at the anthesis stage. A negative and significant correlation was obtained for diffusive resistance and leaf‐to‐air temperature gradient with grain yield at the boot and anthesis stages. The rate of transpiration was also positively and significantly correlated to grain and biological yields at both the stages. Amongst the yield attributes, number of leaves and number of tillers were positively correlated at the anthesis stage, whereas leaf area and shoot dry weight were significantly correlated with grain and biological yields at both the stages. 相似文献
140.
Field studies on differentially irrigated wheat ( Triticum aestivum L.) crops were conducted at Pantnagar for two years to evaluate the use of thermal infrared radiation to detect crop water stress. Data show that the stress-degree-day index (mid day canopy-air temperature difference) is influenced by environmental variability other than soil moisture. Improvement in the stress-degree-day (SDD) index was achieved by including the measurements of vapor pressure deficit and approach was termed as plant water stress index (PWSI). Observations indicated that daily variation in SDD values due to meteorological changes was removed through PWSI. Better correlation was found between soil-induced leaf water potential and plant water stress index than between total leaf water potential and plant water stress index. It is concluded that remote sensing of thermal infrared radiation offers a promising technique which can be incorporated into irrigation management programme. 相似文献