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   57篇
  免费   1篇
林业   14篇
农学   3篇
  5篇
综合类   2篇
农作物   2篇
水产渔业   7篇
畜牧兽医   19篇
园艺   2篇
植物保护   4篇
  2023年   1篇
  2022年   3篇
  2021年   4篇
  2019年   3篇
  2018年   2篇
  2017年   1篇
  2016年   2篇
  2015年   4篇
  2014年   1篇
  2013年   3篇
  2012年   2篇
  2011年   2篇
  2010年   1篇
  2009年   4篇
  2008年   8篇
  2007年   4篇
  2005年   2篇
  2004年   1篇
  1983年   1篇
  1982年   1篇
  1980年   3篇
  1979年   1篇
  1978年   2篇
  1975年   2篇
排序方式: 共有58条查询结果,搜索用时 15 毫秒
41.
Some important physicochemical and bioactive characteristics of disease free 10 wild grown bilberry (Vaccinium myrtillus) accessions were evaluated. External and internal fruit quality was assessed by standard parameters (fruit weight, fruit color, fruit firmness, soluble solids, pH and total acidity) and bioactive contents (total phenolics, total anthocyanins, total antioxidant capacity and, vitamin C) in fruit were also determined. The commercial grown northern higbush blueberry, Vaccinium corymbosum cv. Bluecrop also included in the study to make comparision with bilberry samples. The highbush blueberry cv. Bluecrop had distinctive external fruit characteristics, such as bigger and more attractive fruits. However, the wild grown bilberry accessions showed interesting characters in mesocarp, such as high total phenolic content, total anthocyanin and total antioxidant capacity. Total phenolic and total anthocyanin content was 327?mg gallic acid equivalent and 142?mg of cyanidin-3-glucoside equivalent in 100?g fresh fruit in cv. Bluecrop while it was between 576–624?mg gallic acid equaivalent and 296–324?mg of cyanidin-3-glucoside equivalent in 100?g fresh fruits of bilberry accessions. Moreover, wild accessions approximately had 2 folds higher antioxidant capacity than cv. Bluecrop. Results suggested that bilberry accessions may serve as a source of desirable genes to develop improved varieties that respond to the new needs of the market.  相似文献   
42.
Drought is becoming a major threat to rice farming across the globe owing to the depletion of water tables in rice-growing belts. Drought affects rice plants at multiple stages, causing damage at morphological and physio-biochemical levels, leading to severe losses that exceed losses from all other stresses. The amalgamation of conventional breeding methods with modern molecular biology tools and biometrical methods could help accelerate the genetic gain for drought tolerance in rice. Many drought-tolerance traits with genetic determinants have been identified and exploited for tolerance rice variety breeding. The integration of genome-wide association study and genomic selection tools with speed breeding shortened the breeding cycle and aided in rapid improvement of genetic gain. In this review, we emphasized the progress made through classical breeding as well as the limitations and usefulness of current genomic methods in improving drought tolerance. We briefly addressed methods for identifying genetic determinants for drought tolerance and deploying them through genomics-assisted breeding programmes to develop high-yielding drought-tolerant rice cultivars.  相似文献   
43.
44.
通过单因素实验确定包囊化清酒乳杆菌的最佳碳源为葡萄糖,最佳氮源为蛋白胨,最佳促生长因子为番茄汁,pH缓冲剂CaCO3最佳浓度为0.5%。在此基础上,采用响应曲面法建立了菌体浓度多元二次模型方程,探讨了4个因子的交互作用及其最佳水平范围,得到最佳培养基组成为:乳清粉60g/L,葡萄糖18.87g/L,蛋白胨21.98g/L,番茄汁98.62mL/L,CaCO34.39g/L,MgSO40.28g/L,MnSO40.18g/L。  相似文献   
45.
The morphology of tongue in straw-coloured fruit bat from tropical forests was evaluated in relation to frugivorous diets and in comparison with other species that consumes other food types. Gross, stereomicroscopy, scanning electron microscope and histological methods were used. The tongue was relatively long with round tip, which closely fitted into oral cavity. Five types of mechanical papillae included crown-like and trifid filiform papillae. Also bulky, cone-shaped papillae and long conical papillae were identified. These mechanical types also showed variations in shape, size and number of processes of papillae. Transitional forms of these mechanical papillae were present. Fungiform papillae with taste pores were interposed amongst filiform types in apex and body; three ovoid-shaped vallate papillae were in triangular arrangement on root and displayed taste pores. Some bulky, cone-shaped papillae surrounded the vallate papillae. Histologically, mechanical filiform types showed highly keratinized stratified squamous epithelium and dense connective tissue core with secondary papillae. Taste buds appeared in fungiform and vallate papillae. Neutral and acidic secretions were identified in lingual glands of root. The presence of prominent filamentous processes of filiform papillae and conical papillae of the tongue in conjunction with gustatory papillae ensures adaptation to copious fruit diets. The gross morphometric and histometric parameters of the tongue did not differ remarkably from previous values obtained for some fruit bats with comparable weight. This investigation showed similarities with fruit bats such as large flying fox and Egyptian fruit bat and reflect common diet and feeding habits but varied from insectivorous and nectivorous bats.  相似文献   
46.
47.
This study investigated the effects of arbuscular mycorrhizal (AM) colonisation by Glomus clarum on growth and fruit yield of pepper (Capsicum annum cv. 11B 14) grown at high salinity. The experiment was conducted in pots containing a mixture of perlite and sand (1:1, v/v) under glasshouse conditions. Treatments were: (1) no added NaCl without arbuscular mycorrhizae (NS-AM), (2) no added NaCl with arbuscular mycorrhizae (NS + AM), (3) added 50 mM NaCl without arbuscular mycorrhizae (S1-AM) and (4) added 100 mM NaCl without arbuscular mycorrhizae (S2-AM), (5) added 50 mM NaCl with arbuscular mycorrhizae (S1 + AM) and (4) added 100 mM NaCl with arbuscular mycorrhizae (S2 + AM). The NaCl treatments reduced pepper shoot and root dry matter, and fruit yield compared with the non-saline treatments. The concentrations of N, P and K, in the leaves were significantly reduced by salinity stress, however, mycorrhizal colonisation of the salt-stressed plants restored leaf nutrient concentrations to the levels in non-stressed plants in most cases. AM inoculation improved pepper growth under salt or saltless conditions and reduced cell membrane leakage.  相似文献   
48.
Detection of infectious hypodermal and hematopoietic necrosis virus (IHHNV) in shrimp is complicated by the fact that certain virus-related sequences are integrated into the genome of Penaeus monodon in some parts of the world, which has been reported so far from Africa and Australia. In this study, we evaluated the highly specific and sensitive diagnostic primer sets for detection of infectious IHHNV and integrated virus-related sequence in 177 samples of P. monodon from India. A nested primer set, IHHNV648F/R and IHHNV309F/R was used to specifically detect infectious IHHNV and not the virus-related sequences. IHHNV was detected in 67.4% postlarvae (PL) and 34% adult samples using this primer set. The OIE recommended primers IHHNV392F/R and IHHNV389F/R gave positive reaction for 86.7% PL and 67% adult samples, while the primer pair 77012F and 77353R gave positive reaction with 46.7% PL and 20% adult samples. These primers were found to detect virus-related sequence integrated into the shrimp genome. The analysis of virus-related sequence by MG831F/R primers showed that 33.7% PL and 31.7% adult shrimp possessed Type A virus-related sequence. 22.8% PL and 10.5% adults had both IHHNV and Type A virus-related sequence. Cloning and sequencing 832 bp virus-related sequence from P. monodon from India revealed presence of five shrimp DNA markers between 439 and 825 bp. This study is the first conclusive report on the presence of Type A virus-related sequence in P. monodon from India.  相似文献   
49.
50.
The counter-immunoelectrophoresis test (CIEPT) was compared with the rose bengal plate test (RBPT) and the serum agglutination test (SAT) in the diagnosis of brucellosis in 241 sheep. The total number of animals positive by one or more of the tests used was 106. Sixty animals were positive by all tests, while 87, 79 and 80 were positive by CIEPT, RBPT and SAT respectively. Based on the assumption that animals with an SAT titre of 40 I.U./ml or above were true positives, the CIEPT had a sensitivity of 82.5% and a specificity of 78.3% compared to 96.5% and 87% respectively, demonstrated by the RBPT. CIEPT might be used in flocks without clinical evidence of ram epididymitis if a test to supplement RBPT were required; but it would only partially replace SAT. Sera positive in RBPT but negative in CIEPT would have to be tested by SAT. With this combination, only about 22% of sera positive in RBPT would need to be further tested by SAT.  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