全文获取类型
收费全文 | 179篇 |
免费 | 0篇 |
国内免费 | 5篇 |
专业分类
林业 | 15篇 |
农学 | 5篇 |
基础科学 | 1篇 |
54篇 | |
综合类 | 6篇 |
农作物 | 27篇 |
水产渔业 | 8篇 |
畜牧兽医 | 62篇 |
园艺 | 1篇 |
植物保护 | 5篇 |
出版年
2022年 | 2篇 |
2021年 | 1篇 |
2020年 | 1篇 |
2019年 | 3篇 |
2018年 | 5篇 |
2017年 | 3篇 |
2016年 | 5篇 |
2015年 | 3篇 |
2014年 | 6篇 |
2013年 | 29篇 |
2012年 | 6篇 |
2011年 | 16篇 |
2010年 | 7篇 |
2009年 | 8篇 |
2008年 | 10篇 |
2007年 | 11篇 |
2006年 | 15篇 |
2005年 | 8篇 |
2004年 | 11篇 |
2003年 | 7篇 |
2002年 | 9篇 |
2001年 | 2篇 |
2000年 | 3篇 |
1999年 | 3篇 |
1998年 | 2篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1993年 | 3篇 |
1992年 | 1篇 |
1976年 | 1篇 |
1965年 | 1篇 |
排序方式: 共有184条查询结果,搜索用时 15 毫秒
81.
Yoshimasa Nakano Takeo Yamakawa Motoki Ikeda Junji Ishizuka 《Soil Science and Plant Nutrition》2013,59(4):929-932
The compatibility between rhizobia and host plants for nodulation was determined based on the genetic and physiological properties of both symbionts. It has been observed that soybean varieties carrying the Rj-gene were not nodulated effectively by certain strains or groups of rhizobia. Soybeans carrying the Rj 2-gene, Rj 2-varieties, were found to nodule ineffectively by the rhizobial strains belonging to the 3-24-44 and 122 serogroups (Caldwell 1966). In the same way, Rj 3- and Rj 4-varieties were found to nodule ineffectively by strains USDA 33 (Vest 1970) and USDA 61 (Vest and Caldwell 1972), respectively. 相似文献
82.
An experiment was conducted to identify the main nitrogenous compound transported in the xylem sap of soybean plants nodulated with Rhizobium fredii. Soybean (Glycine max L. Merr.) cultivars, wild type Bragg (nod+, fix+) and its nitrate tolerant, hypernodulating mutant ntsll16 (nod++, fix+) were used for this experiment. These soybean plants were inoculated with a slowgrowing rhizobium, Bradyrhizobium japonicum USDAllO or fast-growing rhizobia consisting of a mixture of R. fredii USDA191, USDA193, and USDA-194 and grown in a phytotron under natural light and controlled temperature conditions. Xylem sap was collected from Bragg and ntsll16 plants at the flowering and pod elongation stages. Acetylene reduction activity per plant or per nodule weight was not different between soybean lines and inoculums. The composition of the nitrogenous compounds in the xylem sap was compared between the symbionts, with B. japonicum and R. fredii. At the flowering stage, ureide-N and amide-N accounted for 53 to 70% and 20 to 27% respectively of the total N in the sap collected from the plants inoculated either with B. japonicum or R. fredii. At the pod elongation stage, ureide-N and amide-N accounted for 74 to 85%, and 7 to 19% of total sap N. With the growth of the soybean plants, the ratio of ureide-N in the xylem sap increased. These results suggest that in the case of wild soybean and the hypernodulating mutant line nodulated by R. fredii, ureide is transported as the main nitrogenous compound of fixed nitrogen in the xylem sap in the same way as in plants nodulated with B. japonicum. 相似文献
83.
84.
Papa Saliou Sarr Shigeru Araki Didier Aime Begoude Martin Yemefack Gabriel Ambroise Manga Takeo Yamakawa 《Soil Science and Plant Nutrition》2016,62(1):13-19
Pueraria is an herbaceous, perennial legume crop originating in Asia. Pueraria phaseoloides (Roxb.) Benth. (tropical kudzu) is frequently introduced into production systems and is used as green manure, a cover crop and a forage plant, making it important economically. We used P. phaseoloides as a trap crop to study and characterize soil rhizobia in Eastern Cameroon. Bacteria were isolated from fresh nodules collected from field-grown P. phaseoloides roots. The 16S-23S rRNA internal transcribed spacer (ITS) sequences from 30 bacterial isolates were amplified by polymerase chain reaction (PCR) and the reaction products were sequenced. Phylogenetic analysis revealed that all isolates were ascribed to the genus Bradyrhizobium and were grouped into three clusters of Bradyrhizobium sp. strains, one cluster of B. yuanmingense strains, and one cluster of B. elkanii strains. Acetylene reduction assay (ARA) results indicated that the B. yuanmingense strains had significantly higher nitrogen fixation potential and that they could be used as inoculants to enhance nitrogen fixation in Pueraria grown in Eastern Cameroon. 相似文献
85.
86.
Yuichi SAEKI Hiroko OGURO Isao AKAGI Takeo YAMAKAWA Akihiro YAMAMOTO 《Soil Science and Plant Nutrition》2009,55(5):627-633
The soybean-nodulating Sinorhizobium fredii strain has been reported to possess three copies of rRNA gene operons. In the present study, we investigated the diversity of the 16S–23S rDNA internal transcribed spacer (ITS) regions of S. fredii strains. Based on the sequences of the ITS regions, we divided the sequences of the S. fredii strains into two groups, type A and type B. A dot-matrix analysis indicated that the region flanked by tRNA-Ile and tRNA-Ala is longer in type A than in type B, whereas type B sequences possess longer regions upstream of tRNA-Ile and downstream of tRNA-Ala than those of the type A sequence. Restriction fragment length polymorphism of polymerase chain reaction product (PCR-RFLP) of the ITS region in the cloned plasmids as templates could reconstruct the PCR-RFLP pattern from the total DNA as a template. The results of Southern hybridization using the insert sequence between tRNA-Ile and tRNA-Ala in type A as a probe indicated differences in the copy numbers of the type A ITS regions among the strains tested. These results indicated that S. fredii strains possess the type A and type B sequences of the ITS regions at ratios of 3:0, 2:1, 1:2 or 0:3. These S. fredii strains may be useful biological materials for the study of intraspecific variations. 相似文献
87.
Although the fungicidal properties of phosphite have been recognized, its potential as a fertilizer is still being debated. The information on how phosphite affects the growth and quality of plants in relation to phosphate (Pi) also remains unknown. This study was conducted to investigate the effect of phosphite in relation to Pi on growth and quality parameters of lettuce (Lactuca sativa L.). The results showed that addition of phosphite to the nutrient solution at different rates ranging from 0.05 to 2 mM significantly increased total P, water‐extractable Pi, and phosphite in both shoots and roots, but did not improve plant growth under various Pi supplies (0.05, 0.1, 0.15, and 0.3 mM as Pi levels for approximately 50%, 80%, 90%, and 100% of the maximum plant growth, respectively), indicating that phosphite was well absorbed by roots and mobile inside the plants, but did not provide any P nutrition. Also, no stimulating effect of any Pi–phosphite combination was observed. The effect of phosphite on plant growth was strongly dependent on the level of Pi supply. In general, application of phosphite up to 2 mM did not influence the growth of Pi‐sufficient plants. However, plants fertilized with Pi for about 90% of maximum growth were still vulnerable to phosphite at 2 mM. The negative effect of phosphite was found even at concentrations as low as 0.2 mM, when plants were supplied with Pi adequate for about 80% of maximum growth or less. At 0.05 mM, phosphite had marginal effects on plant growth under all the Pi levels. Although phosphite itself had little influence on the ascorbate and mineral concentrations of lettuce, its application to Pi‐deficient plants may decrease the mineral concentrations of plants brought about by the inhibitory effect of phosphite on root growth and hence nutrient uptake. Since phosphite is an effective fungicide for lettuce, care should be taken on Pi supplies prior to application of phosphite products to minimize the harmful effects. 相似文献
88.
Kurihara Takeo Hashimoto Kazumasa Nakano Shoji Matsuyama Yukihiko Ito Atsushi Kanematsu Masaei Okamura Kazumaro 《International Aquatic Research》2018,10(4):349-359
International Aquatic Research - In the inner area of the Sea of Ariake, rearing experiments were conducted to examine how the survival rates of juveniles of three bivalve species (Anadara... 相似文献
89.
We investigated the effects of integrated organic and inorganic fertilizers on the growth and yield of indica rice variety Manawthukha and japonica rice variety Genkitsukushi. In a split-plot design, the two rice varieties were assigned as main plot factors, and the integrated treatments were the subplot factors, including no-N fertilizer(N_0), 50% chemical fertilizer(CF)(CF_(50)), 100% CF(CF100), 50% CF + 50% poultry manure(PM)(CF_(50)PM_(50)), 50% CF + 50% cow manure(CM)(CF_(50)CM_(50)), and 50% CF + 50% compost(CP)(CF_(50)CP_(50)). CF100 was equivalent to N at 85 kg/hm~2. Manure was applied based on the estimated mineralizable nitrogen(EMN) level, which is dependent on total N(%) of each manure type. Manawthukha rice plants were taller with higher tiller number and dry matter content. However, higher soil-plant analysis development(SPAD) values were measured in Genkitsukushi throughout the crop growth period, resulting in higher seed-setting rate(%) and greater yield. At the same N level, CF_(50)PM_(50) application in both rice varieties resulted in higher SPAD values, plant height and tiller number than CF_(100). CF_(50)PM_(50) containing total N more than 4% supplied synchronized N for the demands of the rice plants, resulting in maximum dry matter, yield and yield components. CF_(50)CM_(50) and CF_(50)CP_(50) treatments containing total N less than 4% resulted in lower yields which were similar to CF_(100). These results indicated that integrating organic and inorganic fertilizers enhanced growth parameters and yields of Manawthukha and Genkitsukushi, while reducing the dose of chemical fertilizer. 相似文献
90.
Toriumi H Tsumagari S Kuwahara Y Ichikawa Y Takeishi M Sakai T 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2003,65(2):243-247
In ultrasonographic diagnosis of ovarian disorders and the estrous cycle in sows, transverse observation of the uterus yielded more characteristic findings than observation of sagittal sections. Transverse ultrasonography revealed that the low progesterone (P) type uterus showed a round structure, while the high P type uterus showed a flattened structure. These results corresponded well with rectal palpation findings: the low P type uterus had a hard, pipe-like structure and the high P type a soft, balloon-like structure. For gilts, we employed a minimum convex type transrectal prostate probe that had an approximately 18 cm insertion handle. The images of the uterus obtained thereby were a similar to those obtained from sows. The above results suggest that it should be possible to diagnose and treat many ovarian disorders in sows and gilts based only on the ultrasonograhic findings. In short, ultrasonograhic findings of a round structure of the uterine wall might be an indication for PMSG (pregnant mare serum gonadotropin) treatment, while findings of a flattened structure might be an indication for PGF(2) (alpha) administration. 相似文献