The influence of diel period on fish assemblage in the unstructured littoral of reservoirs     

M. ŘÍHA  J. KUBEČKA  M. PRCHALOVÁ  T. MRKVIČKA  M. ČECH  V. DRAŠTÍK  J. FROUZOVÁ  E. HOHAUSOVÁ  T. JŮZA  M. KRATOCHVÍL  J. PETERKA  M. TUŠER  M. VAŠEK 《Fisheries Management and Ecology》2011,18(4):339-347

Abstract Diel changes in littoral fish assemblage were studied in four reservoirs in the Czech Republic (Central Europe). The sampling was performed by beach seining in an unstructured littoral zone. Perch, Perca fluviatilis L., roach, Rutilus rutilus (L.), bream, Abramis brama (L.), carp, Cyprinus carpio L., ruffe, Gymnocephalus cernua (L.), pikeperch, Sander lucioperca (L.), eel, Anguilla anguilla (L.) and A. brama × R. rutilus hybrids exhibited higher densities at night. Only bleak, Alburnus alburnus (L.) exhibited higher densities during the day. The number of species was higher in night hauls, and mean body size of roach and bleak was also higher at night. Diel changes in fish densities resulted in the change in species composition between day and night. The study has implication for the sampling design to assess littoral fish assemblages using beach seine netting and recommends night sampling for a representative assessment or sampling during both diel periods for a robust assessment.  相似文献   

Physiological Role of Exogenously Applied Glycinebetaine to Improve Drought Tolerance in Fine Grain Aromatic Rice (Oryza sativa L.)     

M. Farooq  S. M. A. Basra  A. Wahid  Z. A. Cheema  M. A. Cheema  A. Khaliq 《Journal of Agronomy and Crop Science》2008,194(5):325-333

Rice performance under drought stress is mainly impeded by oxidative damage and hampered plant water status, which may be improved by exogenous use of osmoprotectants. In this study, the role of glycinebetaine (GB) to improve drought tolerance in rice (Oryza sativa L.) cultivar Super-basmati was evaluated. GB was used both as seed and foliar application. For priming, seeds were soaked in 50, 100 and 150 mg l⁻¹ aerated solution of GB for 48 h. At four-leaf stage, one set of plants was subjected to drought stress, while the other set kept at full field capacity. Drought was maintained at 50 % of field capacity by watering when needed. For exogenous application, 50, 100 and 150 mg l⁻¹ GB levels were applied at five-leaf stage. Drought stress greatly reduced the rice growth while GB application improved it both under well-watered and drought conditions. Drought tolerance in rice was strongly related to the maintenance of tissue water potential and antioxidant system, which improved the integrity of cellular membranes and enabled the plant to maintain high photosynthesis. Foliar treatments were more effective than the seed treatments, while among the GB treatment, foliar application with 100 mg l⁻¹ was the most effective.  相似文献   

Activation of Antioxidant System by KCl Improves the Chilling Tolerance in Hybrid Maize     

M. Farooq  T. Aziz  Z. A. Cheema  M. Hussain  A. Khaliq 《Journal of Agronomy and Crop Science》2008,194(6):438-448

As maize is a chilling-sensitive crop, low temperatures during the early stages of development can be injurious to crop growth and development. Prime mechanism behind chilling-induced damage is oxidative stress. This study was undertaken to improve the chilling tolerance in hybrid maize by seed priming with KCl. For priming, seeds of the maize hybrid Hycorn 8288 were soaked in 50, 100 and 150 mg l⁻¹ aerated solution of KCl for 24 h and then re-dried close to original weight. Primed and untreated seeds were sown at 27 °C (optimal temperature) and at 15 °C (chilling stress) under controlled conditions. Seed priming improved the performance of maize under both normal and stress conditions. It was found that the chilling tolerance in maize is well associated with the enhanced capacity of the anti-oxidative system. Priming with KCl significantly improved the chilling tolerance mainly by the activation of antioxidants including catalase, superoxide dismutase and ascorbate peroxidase enzymes. KCl treatments also improved the germination rate and time, root and shoot length, and fresh and dry weights of seedlings compared with control. Soluble sugars and α-amylase activity determined as general metabolic indicators of stress were also improved by seed priming with KCl. Other possible bases of chilling tolerance in maize included maintenance of high tissue water contents, reduced electrolyte leakage and carbohydrate metabolism. Seed treatment with 100 mg l⁻¹ KCl was the best treatment to improve the performance of hybrid maize both under normal and chilling stress conditions.  相似文献   

Agroforestry on alkali soil: effect of planting methods and amendments on initial growth,biomass accumulation and chemical composition of mesquite (Prosopis juliflora (SW) DC) with inter-space planted with and without Karnal grass (Diplachne fusca Linn. P. Beauv.)     

Gurbachan Singh  I. P. Abrol  S. S. Cheema 《Agroforestry Systems》1988,7(2):135-160

Growth responses of mesquite (Prosopis juliflora (SW) DC.) during establishment stage to planting methods and amendments were studied in a highly alkali soil (Aquic Natrustalf, ESP 94), at the experimental farm of the Central Soil Salinity Research Institute, Karnal in July, 1984. Six combinations of planting methods and amendments with and without Karnal grass (Diplachne fusca Linn. P Beauv) in the inter-row space were compared in a four times replicated field experiment in randomised block design. The mean plant height (MPH), diameter at stump height (DSH), diameter at breast height (DBH), lopped biomass 16 months past planting and total biomass attained in 2 years period were significantly less when inter-row space was planted with Karnal grass. The MPH (cm), DSH and DBH (mm) attained in 2 years period were 319, 43.4 and 15.1 in with grass as compared to 405, 53.4 and 20.3 in without grass treatments. Similarly, the total biomass attained in 2 years was about 3 times more where inter-row space was not planted with grass. Growth was better when mesquite was planted by auger hole and pit methods than in trench plantation, when the original soil was treated with gypsum at 3 kg plant^–1 and then refilled. However, using trenches of dimensions 30 × 30 cm and filled with a mixture of original soil, 3 kg gypsum and 8 kg farm yard manure plant^–1 appeared to be promising method for establishing mesquite plantations on highly deteriorated alkali soils. The effect of amendments on growth decreased in the order gypsum + FYM, gypsum + rice husk, gypsum, control. In two years period, 37 percent mesquite died in the trenches in which the original soil was left unchanged. Effect of treatments on nutrient concentrations and total accumulations in different segments of mesquite is discussed. Karnal grass gave 25.3 t ha^–1 green forage yield in 8 cuts without amendment in a growth period of 26 months proving its great potential as a folder crop for the adverse sites. The inorganic chemical composition of the shoots, including trace elements Fe, Mn, Zn and Cu, is such as to make this species a highly promising plant for the exploitation of alkali soils. Growing Karnal grass with mesquite for a period of about 2 years reduced soil pH and EC significantly and improved organic carbon and available N contents. The grass improved water infiltration rates and moisture storage in the lower layers of the profile.  相似文献   

CUE-MATE诱导新疆褐牛同期发情试验   总被引：1，自引：1，他引：0  

李静  王海军  哈克木  扎克尔 《中国牛业科学》2009,35(6)

[目的]为了探索新疆褐牛同期发情处理的有效时间段和最佳处理方法.[方法]采用CUE-MATE孕酮栓+PGF2α法进行新疆褐牛同期发情试验,[结果]表明:同期发情主要集中在取栓后的2 d,平均发情率为72.5%,情期受胎率为66.7%;3月的同期发情率显著高于5月和7月(P＜0.05),达到90.8%,但情期受胎率低于5月和7月,为61.0%,差异不显著(P＞0.05);母牛卵巢上以有黄体的同期发情率最高,达到95.3%,其次是有卵泡的,无黄体、卵泡的最低,三者差异显著(P＜0.05);有卵泡的情期受胎率略高于有黄体的,差异不显著(P＞0.05),无黄体、卵泡的同期发情率和受胎率都最低,差异显著(P＜0.05);育成牛的同期发情率略高于经产牛,为92%,差异不显著(P＞0.05);育成牛的情期受胎率显著高于经产牛(P＜0.05),为73.9%.[结论]环境温度、营养水平及母牛卵巢上有无黄体、卵泡影响发情率的高低,CUE-MATE孕酮栓+PGF2α法可用于诱导新疆褐牛的同期发情.  相似文献   

利用水稻功能基因SSR标记鉴定水稻种质资源   总被引：36，自引：6，他引：36  

赵勇  杨凯  翁跃进 《中国农业科学》2002,35(4):349-353

 利用 16对水稻功能基因的SSR引物研究了 2 3份世界 5个国家不同来源的水稻种质资源的遗传多样性 ,共检测出 78个等位基因变异 ,每对引物可检测 2～ 10个等位基因变异 ,平均为 5 .2个 ,品种间遗传相似系数在0 .13～ 0 .6 4之间。UPGMA聚类分析表明 ,在相似系数 0 .13处可以将材料分为 2大类 ,来自巴西、日本和中国的粳稻全部聚为第Ⅰ类 ,巴西陆稻和原产科特迪瓦的陆稻聚在第Ⅰ类的第三小群 ;第Ⅱ类全为籼稻 ,来源于巴基斯坦的籼稻和 1个来源于韩国的籼稻分布在第Ⅱ类 ,说明水稻功能基因在不同亚种、不同产地来源和不同生态类型的水稻之间存在差异 ,也进一步证实水稻功能基因的SSR标记是研究水稻种质资源分类、地理分布、生态类型和系谱分析的有效工具。  相似文献   

Detection of antibodies to Mycobacterium johnei by counterimmunoelectrophoresis.     

S I Muhammed  R A Tadayon  A H Cheema 《The Veterinary record》1978,102(18):401-403

Counterimmunoelectrophoresis (CIE) was applied in the detection of antibodies to Mycobacterium johnei in 110 sheep, 11 goat and 31 cattle sera and compared to immunodiffusion (ID) test. One per cent Noble agar, 7 ml per slide of 5 cm x 10 cm; barbitone-tris buffer, mu = 0.03, pH 8.6; a constant current of 5 mA per slide and M johnei protoplasmic antigen at 4 mg per ml were found to impart high sensitivity to CIE and give rapid results. CIE detected 97 sheep, 11 goat and 31 cattle positive sera, a total of 139, as compared to 44, 11, 28 and 83 respectively, detected by ID. Strongly positive sera could be demonstrated within 30 minutes by CIE and the test was run for only 90 minutes while earliest reactions were not observed before 18 hours and some reactions took 144 hours to develop in ID test.  相似文献   

Cloning and Sequence Analysis of the Gene Encoding LipL32 of <Emphasis Type="Italic">Leptospira interrogans</Emphasis> Serovar Sejroe     

Amutha R  Chaudhury P  Garg AP  Vasan P  Cheema PS  Srivastava SK 《Veterinary research communications》2007,31(5):513-519

Leptospira, a member of the order Spirochaetales, is the causative agent of leptospirosis, an important zoonosis encountered worldwide. The Leptospira interrogans serovar Sejroe was grown in EMJH medium and its DNA was isolated using standard techniques. The LipL32 gene was amplified using the reported primer of Kirschneri of LipL32. The amplified product was found to comprise 756 base pairs. This amplified gene fragment of LipL32 lipoprotein was cloned in E. coli (DH5α) cells using pDrive plasmid as a vector. The recombinant cells were selected on LB agar medium containing ampicillin, X-gal and isopropyl-β-d-thiogalactopyranoside. Plasmid was extracted from the recombinant white colonies, and restriction endonuclease (RE) analysis was carried out using PstI and SalI. On partial sequence analysis, the product exhibited 756 base pairs, corresponding to 251 amino acids. The cloned gene could be further used for expression of recombinant protein for serodiagnosis of leptospirosis.  相似文献   

Shrimp Oil Extracted from Shrimp Processing By-Product Is a Rich Source of Omega-3 Fatty Acids and Astaxanthin-Esters,and Reveals Potential Anti-Adipogenic Effects in 3T3-L1 Adipocytes     

Indrayani Phadtare  Hitesh Vaidya  Kelly Hawboldt  Sukhinder Kaur Cheema 《Marine drugs》2021,19(5)

The province of Newfoundland and Labrador, Canada, generates tons of shrimp processing by-product every year. Shrimp contains omega (n)-3 polyunsaturated fatty acids (PUFA) and astaxanthin (Astx), a potent antioxidant that exists in either free or esterified form (Astx-E). In this study, shrimp oil (SO) was extracted from the shrimp processing by-product using the Soxhlet method (hexane:acetone 2:3). The extracted SO was rich in phospholipids, n-3 PUFA, and Astx-E. The 3T3-L1 preadipocytes were differentiated to mature adipocytes in the presence or absence of various treatments for 8 days. The effects of SO were then investigated on fat accumulation, and the mRNA expression of genes involved in adipogenesis and lipogenesis in 3T3-L1 cells. The effects of fish oil (FO), in combination with Astx-E, on fat accumulation, and the mRNA expression of genes involved in adipogenesis and lipogenesis were also investigated. The SO decreased fat accumulation, compared to untreated cells, which coincided with lower mRNA expression of adipogenic and lipogenic genes. However, FO and FO + Astx-E increased fat accumulation, along with increased mRNA expression of adipogenic and lipogenic genes, and glucose transporter type 4 (Glut-4), compared to untreated cells. These findings have demonstrated that the SO is a rich source of n-3 PUFA and Astx-E, and has the potential to elicit anti-adipogenic effects. Moreover, the SO and FO appear to regulate adipogenesis and lipogenesis via independent pathways in 3T3-L1 cells.  相似文献   

5种不同油茶无性系组织培养特性的研究     

戴小英  查小华  龚斌  宋晓琛  徐林初 《江西林业科技》2009,(4):10-12

本研究选取5种油茶优良无性系,在春季不同时间段采集当年生半木质化穗条作外植体,进行芽的诱导、增殖培养。本研究筛选出了各油茶无性系进瓶诱导的最佳时间,具有广谱性、适合无性系繁殖的增殖培养基：H改良＋BA 2.0 mg/L（以下单位同）＋IAA 1.0,同时选出了繁殖系数高、有效苗数量多、可应用于组培产业化发展的优良油茶无性系。  相似文献