首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   65篇
  免费   1篇
  17篇
农作物   7篇
水产渔业   18篇
畜牧兽医   8篇
园艺   5篇
植物保护   11篇
  2023年   1篇
  2021年   2篇
  2020年   2篇
  2019年   3篇
  2018年   6篇
  2017年   4篇
  2016年   4篇
  2015年   2篇
  2014年   3篇
  2013年   6篇
  2012年   3篇
  2010年   4篇
  2009年   1篇
  2008年   4篇
  2007年   5篇
  2006年   6篇
  2004年   2篇
  2003年   2篇
  2002年   2篇
  2001年   4篇
排序方式: 共有66条查询结果,搜索用时 140 毫秒
11.
A feeding trial on yellow tail cichlid Pseudotropheus acei (Regan 1922) was undertaken to asses the effect of dietary Spirulina meal as a natural carotenoid source. Four experimental diets were formulated to progressively replace 0% (C), 2.5% (SP2.5), 5% (SP5) and 10% (SP10) of fish meal weight. Ten fish per tank (initial weight 3.75?±?0.02?g) were randomly distributed into twelve 80?l fiberglass tanks connected to a closed recirculation system (temperature 26.7?±?0.06°C). The diets were tested in triplicate for 12?weeks. The specific growth rate of fish fed all Spirulina diets were significantly higher compared to diet C. Feed intake (FI) tended to increase with dietary Spirulina level, and fish fed diet SP10 had significantly higher FI values compared to diet C. No significant differences in feed conversion ratio were observed among these groups. Although the protein efficiency ratio of fish fed diet C was lower than that of all Spirulina diets, no significant differences were observed among these groups (P?>?0.05). The total egg production and hatching rate (%) of eggs derived from all fish fed with Spirulina diets was significantly higher compared those from fish fed diet C. The yellow and blue coloration of yellow tail cichlid fed the diet containing Spirulina meal was enhanced and inclusion of dietary Spirulina meal was elevated carotenoids in skin. Results of the present study indicated that Spirulina meal has the potential to enhance the growth, reproductive performance and coloration on yellow tail cichlid.  相似文献   
12.
Plant growth–promoting rhizobacteria (PGPR) have been reported to stimulate the growth and yield of grain crops, particularly when nutrient supply is poor. However, the mechanisms underlying stimulation of plant growth may vary depending not only on growth conditions and crop management but also on plant and bacterial species. The present study assessed the effect of an inoculation with single or multiple PGPR strains on phosphorus (P)‐solubilization processes in the soil and on grain yield in wheat. Single inoculation with Bacillus subtilis OSU‐142, Bacillus megaterium M3, or Azospirillum brasilense Sp245 increased grain yield by 24%, 19%, and 19%, respectively, while a mixed inoculation with OSU‐142, M3, and Sp245 increased grain yield by 33% relative to noninoculated plants. Single inoculations with Paenibacillus polymyxa RC05 or Bacillus megaterium RC07 were less effective. Single or mixed treatments with OSU‐142, M3, and Sp245 increased the concentrations of the labile and moderately labile P fractions in rhizosphere soil. The growth‐stimulating effect of OSU‐142, M3, and Sp245 was also reflected by higher P concentrations in most plant organs. Among all inocula tested, the highest plant P acquisition was obtained in the presence of M3 and accompanied by the highest microbial P levels and the highest phosphatase activities in the rhizosphere soil. In conclusion, seed inoculation with mixed PGPR strains may effectively substitute for a part of P‐fertilizer application in extensive wheat production, and in particular M3 appears to improve the solubilization of inorganic soil P.  相似文献   
13.
The most significant focal points of the embryo transfer technology are as follows: the selection of donors, the response of the selected donor to the superovulation protocol and the obtained number of the transferable embryos. For this purpose, it is suggested that donor selection can be done by anti‐Müllerian hormone (AMH) levels, and embryo production is evaluated. AMH is secreted by the granulosa cells of primordial, pre‐antral and antral follicles below 4 mm in the ovary, independent of FSH. Therefore, the aim of this study was to investigate the relationship between serum AMH levels and the number of corpus luteum (CL), total embryos and transferable embryos that were shaped after a uniform superovulation protocol. For this reason, 48 Simmental cows, which were located at General Directory of Agricultural Enterprises (region, province, etc. instead of the general directorate), were used as donors for the embryo transfer. Blood samples were taken at random, regardless of the stage of animal's sexual cycle. AMH levels were measured by enzyme‐linked fluorescent assay (ELFA) method of the miniVIDAS® (bioMérieux SA) using AMH Bovine Test Kit. According to the statistical analyses of the obtained data, AMH levels were positively correlated with CL and total embryos (p < .05). No significant correlations between AMH and transferable embryos were approved (p > .05). It was also determined that each 200 pg/ml increase in serum AMH level resulted in one increase in CL number. Overall, considering the positive correlation between AMH level and the obtained number of CL and total embryos after a superovulation treatment, it was concluded that measuring blood AMH level prior to any further costly implementation may be an effective method in donor selection.  相似文献   
14.
In 2009 a greenhouse experiment was conducted to determine the effects of boron (B) and plant growth-promoting rhizobacteria (PGPR) on wheat (Triticum aestivum spp. vulgare cv ‘Bezostiya’) and barley (Hordeum vulgare cv ‘Tokak’) on plant growth, freezing injury, and antioxidant enzyme capacity. Results showed that boron (0, 1, 3, 6, 9 kg B ha?1) and PGPR application (Bacillus megaterium M3, Bacillus subtilis OSU142, Azospirillum brasilense Sp245 and Raoultella terrigena) at which 50% of leaves were injured (LT50) values and ice nucleation activities in both plants were found statistically significant. Boron application with all PGPR strains decreased LT50 values in wheat and barley plants under noncold stress (NCS) and cold stress conditions (CS). There were statistically significant differences between bacterial inoculation and B fertilizer in terms of root and shoot dry weight under NCS and CS conditions. Reactive oxidative oxygen species (ROS) and antioxidant enzyme activities (SOD, POD, CAT) were negatively affected CS conditions and decreased with reduced temperatures of media, but B and PGPR applications alleviated the low-temperature deleterious effects in both plants species tested. The lowest ROS and antioxidant enzyme (SOD, POD, CAT) of wheat and barley were observed with 6 kg B ha?1 with R. terrigena.  相似文献   
15.
Slope length effects on microbial biomass and activity of eroded sediments   总被引:2,自引:0,他引:2  

Purpose  

Due to climatic and topographic conditions, soil erosion is a major problem in Turkey; approximately 86% of the land is suffering from some degree of erosion. This study investigated the relationship between bare soil slope length and the erosion-induced degradation of soil quality and the loss of carbon (C) and nitrogen (N) from the microbial biomass in eroded sediment in the Western Black Sea Region of Turkey.  相似文献   
16.
17.
During 2003 and 2005, plant growth promoting effects of Pseudomonas BA-8 and Bacillus OSU-142 were tested alone or combinations on sweet cherry (Prunus avium L.) cv. 0900 Ziraat in terms of yield, growth, nutrient composition of leaves in the province of Konya, Turkey. The presence of Pseudomonas BA-8, Bacillus OSU-142 and BA-8 + OSU-142 stimulated plant growth and resulted in significant yield increase. Floral and foliar applications of BA-8, OSU-142 and BA-8 + OSU-142 in sweet cherry significantly increased yield per trunk cross-sectional area (16.3, 10.9 and 21.7%), fruit weight (4.15, 5.37 and 1.24%) and shoot length (11.3, 11.8 and 29.6%), respectively, compared with the control. In addition, N, P and K contents of sweet cherry leaves with BA-8, OSU-142 and BA-8 + OSU-142 treatments, Fe and Zn contents of leaves with BA-8 + OSU-142 treatment and Mn content of the leaves of sweet cherry with BA-8 and OSU-142 applications significantly increased. Nitrogen, P and K contents in leaves were determined to be increased from 2.00, 0.17 and 0.43% in the control to 2.19, 0.20 and 0.54% by BA-8 application, to 2.32, 0.24 and 0.54% by OSU-142 application and to 2.43, 0.22 and 0.51% by BA-8 + OSU-142 application, respectively. Co-inoculation of BA-8 + OSU-142 increased Fe and Zn contents of leaves up to 50.5 and 35.5% compared with the control, respectively. Manganese content of leaves significantly also increased by BA-8 (26.6%) and OSU-142 (27.0%) applications compared with the control. The results of the present study suggested that Pseudomonas BA-8 and Bacillus OSU-142 alone or in combination have a great potential to increase the yield, growth and nutrition of sweet cherry plant.  相似文献   
18.
In this study, the effects of cypermethrin on antioxidant status, oxidative stress biomarkers, behavior, and mortality in the freshwater mussel Unio elongatulus eucirrus were examined. Cypermethrin was applied at concentrations of 5, 10, 20, 40, 80, and 160 μg/L, for 1, 24, 48, 72, and 96 h. With increasing cypermethrin concentrations, the mussels showed significantly (P < 0.05) increased lipid peroxidation (MDA), which might be associated with decreased levels of reduced glutathione (GSH) and catalase (CAT) activity in the digestive glands and gills of the mussels. Negative correlations were observed between the MDA and the GSH and CAT levels after cypermethrin exposure, indicating a protective role of GSH and CAT against lipid peroxidation, and suggesting the use of these antioxidants as a potential biomarker of toxicity associated with contaminant exposure in freshwater mussels. In addition, at 5 μg/L, cypermethrin had no effect on the duration of the active and rest periods. All higher concentrations caused inhibition of the filtration activity by reducing the active periods and lengthening the rest periods. The active periods shortened as the cypermethrin concentrations increased, the reduction being 90% of the control at 160 μg/L. Rest periods were longest (237% longer than the control) at 160 μg/L. The 48, 72, and 96 h LC50 values of cypermethrin for mussels were determined as 96.50, 77.96, and 59.20 μg/L, respectively (P < 0.05). The results indicate that the insecticide cypermethrin has a harmful effect not only on nontarget aquatic arthropods and fish, but also on mollusks, although the sensitivity of mussels is less than that of fish. Being a general toxicant for aquatic life, cypermethrin should be used with great caution in agriculture to protect natural waters from contamination.  相似文献   
19.
The aim of this study was to determine the spermatological characteristics in male L. abu during the spawning season. Semen was collected weekly by abdominal massage from 26 males in March. In collected semen, volume, motility, duration of motility, concentration and pH were determined. In the L. abu sperm, volume (μl), motility (%), duration of motility (s), concentration (×109/ml), and pH values were found 45.76 ± 3.55, 54.25 ± 2.93, 330.15 ± 37.92, 4.27 ± 0.40 and 7.87 ± 0.05, respectively. A correlation was found between semen volume and semen pH. Semen volume and the duration of sperm motility were higher in the 2nd and 3rd sampling dates than in the 1st and 4th sampling dates (P < 0.05; P < 0.01, respectively). Neither sperm motility nor sperm concentration was affected by sampling dates. Major changes in semen pH were observed in the 4th sampling date (P < 0.001). The Pearson correlation test presented significant relationships with the duration of motility, semen volume, and motility. Semen pH values were significantly correlated with the sperm concentration and semen volume. Sperm concentration was inversely correlated with semen volume. Sperm motility and duration significantly correlated with total weight. Total length significantly correlated with the duration of motility and total weight. In conclusion, these characteristics represent a valuable baseline dataset for establishing a semen quality standard and provide background information that may be useful for assisted breeding programs in this species.  相似文献   
20.
The yield response of a wheat (Kirik) and a barley (Tokak 157/37) cultivar to inoculation with Azospirillum brasilense Sp246 and Bacillus sp. OSU‐142 was studied in relation to three levels of N fertilization (0, 40, and 80 kg ha–1) under field conditions in Erzurum, Turkey, in 1999 and 2000. Seed inoculation with A. brasilense Sp246 significantly affected yield and yield components, both in wheat and barley. On average of years and N doses, inoculation with A. brasilense Sp246 increased spike number per m2, grain number per spike, grain yield, and crude protein content by 7.2, 5.9, 14.7, and 4.1 % in wheat and by 6.6, 8.1, 17.5, and 5.1 % in barley, respectively, as compared to control. Inoculation with Bacillus sp. OSU‐142 significantly increased kernel number per spike in wheat, but no significant effect was determined in the other characteristics. Grain yields and yield components were also higher at all levels of nitrogen fertilizer in the inoculated plots as compared to the control. However, these increases diminished at high fertilizer levels. These results suggest that application of the growth promoting bacteria A. brasilense Sp246 may have the potential to be used as a biofertilizer for spring wheat and barley cultivation in organic and low‐N input agriculture.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号