Prostanoids-induced dispersion in the melanophores of a carp Labeo rohita (Ham.)     

M. Ovais  Fraz Ahmed  Md. Mubashshir  Safia Sumoona 《Fish physiology and biochemistry》2014,40(1):75-81

Effects of three prostaglandins (i.e., prostanoids) and one of its precursors, arachidonic acid, were examined on the melanophores of the fish Labeo rohita (Ham.). PGE₁, PGE₂, PGF_2α and arachidonic acid elicit a concentration-related dispersion in the fish melanophores. In vitro analysis of melanophores was performed through incubation of the isolated fish scales in different agonists and antagonists solutions. Dispersal effect of prostanoids may be mediated directly through the typical receptors or indirectly through release of neurotransmitter substance(s) from the melanophore nerve endings. Denervation of fish melanophores rendered them insensitive to prostanoid (PGF_2α). Propranolol and verapamil completely inhibited the dispersal effects of PGF_2α; theophylline and indomethacine blocked the effects of higher concentrations of PGF_2α. During dispersing influence of PGF_2α, a free flux of Ca²⁺ ions was required and the indirectly released substance(s) from melanophore nerve endings would be the catecholamines of adrenergic and purinergic in nature.  相似文献   

Effects of organic selenium supplemented diet on growth performance and antioxidant response in Cirrhinus mrigala     

Parishmita Handique  Hemanta Pokhrel  Binod Kalita  Raktim Sarmah  Abdul Malik Ahmed  Kaustabh Bhagawati  Arnab Narayan Patowary 《Aquaculture Research》2020,51(5):1973-1979

The present study was conducted to evaluate the …effect of dietary selenium on growth performance and antioxidant enzymes activity in Cirrhinus mrigala for a period of 45 days. Four numbers of experimental diets were prepared, T_c for Control (0 mg organic selenium/kg of diet), T₁ (2.5 mg organic selenium/kg of diet), T₂ (5.0 mg organic selenium/kg of diet) and T₃ (10 mg organic selenium/kg of diet). The water quality parameters (temperature, DO, pH, conductivity, hardness, ammonia, nitrate and nitrite) were found to be insignificant (p > .05) among all the treatments. Superoxidase dismutase (SOD) was found to be significantly highest in T₂ (6.10 ± 0.07) when compared with the other treatments. Similarly, catalase (CAT) activity in T₁ (13.21 ± 0.13) was significantly (p < .05) different with that of Control, T₂ and T₃. Present study also revealed that 2.5mg organic selenium/kg supplemented diet (T₁) showed highest results in net weight gain (15.55 ± 1.36 g), net weight gain percentage (185.88 ± 8.98%) and SGR (2.35 ± 0.06 g) compared with other experimental diet.  相似文献   

黄瓜游离小孢子培养诱导成胚和植株再生   总被引：4，自引：0，他引：4  

詹艳  陈劲枫 《园艺学报》2009,36(2):221-226

 以10个不同基因型黄瓜为试材进行游离小孢子培养,通过对成胚条件的系统研究,从‘7447’和‘Poinsett97’中获得了子叶形胚和再生植株。研究结果表明：基因型和小孢子发育时期是限制黄瓜游离小孢子成胚的关键因子。不同品种间胚状体产量差异显著,每皿产胚1.5～33.4个。单核靠边期是进行黄瓜游离小孢子培养的最佳时期。低温预处理有利于胚状体的诱导,4 ℃预处理2～4 d为宜,以处理2 d时胚状体产量最高。外源激素在诱导胚状体时并非必需,但低浓度的外源激素（0.5 mg·L^-1 2,4－D、0.2 mg·L^-1 6－BA）更能促进小孢子成胚。NLN和B5两种基础培养基在诱导胚状体上无显著差异。子叶形胚易分化成苗,而其它类型的胚状体不能获得再生植株。  相似文献   

Optimizing supplemental irrigation: Tradeoffs between profitability and sustainability     

Theib Oweis  Ahmed Hachum 《Agricultural Water Management》2009,96(3):511-516

Water production functions are used to model yield response to various levels of supplemental irrigation (SI), to assess water productivity coefficients, and to identify optimum irrigation under various input-output price scenarios. The SI production function is taken as the difference between the total water production function (irrigation + rain) and that of rainwater. Theoretical analysis of the unconstrained objective function shows that the seasonal depth of SI to maximize profit occurs when the marginal product of water equals the ratio of unit water cost to unit product sale price. Applying this analysis to wheat in northern Syria, the production functions of SI under different rainfall conditions are developed. Coupled with current and projected water costs and wheat sale prices, the functions are used to develop an easy-to-use chart for determining seasonal irrigation rates to maximize profit under a range of seasonal rainfall amounts.Results show that, for a given seasonal rainfall, there is a critical value for the ratio of irrigation cost to production price beyond which SI becomes less profitable than rainfed production. Higher product prices and lower irrigation costs encourage the use of more water. Policies supporting high wheat prices and low irrigation costs encourage maximizing yields but with low water productivity. The resulting farmer practice threatens the sustainability of water resources. Balancing profitability versus sustainability is a challenge for policy makers. Our analysis can help national and local water authorities and policy makers determine appropriate policies for water valuation and allocation; and assist extension services and farmers in planning irrigation infrastructure and farm water management.  相似文献   

Global Bibliometric Analysis of the Research in Biochar     

Ahmed S F Ahmed  Sai Vanga  Vijaya Raghavan 《Journal Of Agricultural & Food Information》2013,14(3):228-236

Global interest in studying biochar stems from its ability to sequester carbon in soil and render nutrients and moisture more readily available to root systems. Therefore, a bibliometric analysis was conducted to investigate global scientific publications related to biochar research, providing insight into the number of articles published, journal platforms, subjects, citations, and overall trends. The primary databases employed were the Web of Science and Science Citation Index. A total of 1,697 articles published between 2000 and 2015 were evaluated. This systematic bibliometric analysis will assist research groups and individuals to understand global biochar research trends and focus future research. The influence of biochar on soil, plants, and the environment continues to require greater attention.  相似文献   

Identification of glycinin and beta-conglycinin subunits that contribute to the increased protein content of high-protein soybean lines     

Krishnan HB  Natarajan SS  Mahmoud AA  Nelson RL 《Journal of agricultural and food chemistry》2007,55(5):1839-1845

Seed protein concentration of commercial soybean cultivars calculated on a dry weight basis ranges from approximately 37 to 42% depending on genotype and location. A concerted research effort is ongoing to further increase protein concentration. Several soybean plant introductions (PI) are known to contain greater than 50% protein. These PIs are exploited by breeders to incorporate the high-protein trait into commercial North American cultivars. Currently, limited information is available on the biochemical and genetic mechanisms that regulate high-proteins. In this study, we have carried out proteomic and molecular analysis of seed proteins of LG00-13260 and its parental high-protein lines PI 427138 and BARC-6. Sodium dodecyl sulfate polyacrylamide gel electrophoresis analysis revealed that the high-protein lines accumulated increased amounts of beta-conglycinin and glycinins, when compared with Williams 82. High-resolution two-dimensional electrophoresis utilizing pH 4-7 and pH 6-11 ampholytes enabled improved resolution of soybean seed proteins. A total of 38 protein spots, representing the different subunits of beta-conglycinin and glycinin, were identified by matrix-assisted laser desorption ionization time-of-flight mass spectrometry. High-protein was correlated with an increase in the accumulation of most of the subunits representing beta-conglycinin and glycinin. Comparisons of the amino acid profiles of high-protein soybean lines revealed that the concentration of sulfur amino acids, a reflection of protein quality, was not influenced by the protein concentration. Southern blot analysis showed the presence of genotypic variation at the DNA level between PI 427138 and BARC-6 for the genes encoding group1 glycinin, beta-conglycinin, Bowman-Birk inhibitor (BBI), and the Kunitz trypsin inhibitor (KTI). LG00-13260 inherited the allelic variants of the parental line PI 427138 for glycinin, beta-conglycinin, and KTI, while BBI was inherited from the parental line BARC-6. The results of our study indicate that high-seed protein concentration is attributed to greater accumulation of specific components of beta-conglycinin and glycinin subunits presumably mediated by preferential expression of these genes during seed development.  相似文献   

Correction to: Impact of leaf infestation by herbivorous insects on the elemental uptake of citrus trees     

Semhi  Khadija  Clauer  Norbert  Al-Raeesi  Ali Ahmed 《植物病害和植物保护杂志》2019,126(1):77-77

Journal of Plant Diseases and Protection - In the original publication, the article title was incorrectly published as ‘Impact of leave infestation by herbivorous insects on the elemental...  相似文献   

Chemical Constituents of Lagenaria siceraria Mesocarp and Its Xanthine Oxidase and Alpha-Amylase Inhibitory Activities     

Dildar Ahmed  Parsa Dar  Raza Chaudhery  Rashid Masih 《International Journal of Fruit Science》2017,17(3):310-322

The present study was conducted to identify natural products in the bioactive fractions of Lagenaria siceraria mesocarp. Column chromatography and gas chromatography-mass spectrometry (GC-MS) was used for separation and identification of phytochemicals. Methanolic extract and its fractions displayed alpha-amylase and xanthine oxidase inhibitory activities comparable to standard drugs. GC-MS analysis of the fractions and column eluates revealed the presence of a variety of chemical compounds, including 4-(methoxymethyl)phenol, 2,2?-methylenebis{6(1,1-dimethylethyl)-4-ethyl}phenol, methyl 2-hydroxy-3-phenylpropanoate, oxacyclododecane-2,8-dione, N-(2-(4-hydroxyphenyl)ethyl] acetamide, 2,3-Epoxycarane, 4-(propan-2-yl)benzaldehyde, octadec-1-ene, 4a-methyl-1-methylidene-1,2,3,4,4a,9,10,10a-octahydrophenanthrene, 2,6-di(propan-2-yl)naphthalene, methyl 3-(4-hydroxy-3,5-dimethylphenyl)propanoate, 4,8a-dimethyl-6-(prop-1-en-2-yl)-3,5,6,7,8,8a-hexahydronaphthalen-2(1H)-one 1,3-dihydro-2-benzofuran, methyl N-hydroxybenzenecarboximidoate, linoleic acid, and palmitic acid. Many of these compounds are being reported for the first time from this plant, the presence of which may explain, at least partly, its medicinal efficacy. The fruit possesses significant anti-enzymatic properties against alpha-amylase and xanthine oxidase, and the most active compounds of mesocarp of the fruit appear in ethyl acetate fraction of its methanolic extract.  相似文献   

Genomewide association study reveals novel quantitative trait loci associated with resistance towards Septoria tritici blotch in North European winter wheat          下载免费PDF全文

Nana Vagndorf  Nanna Hellum Nielsen  Vahid Edriss  Jeppe Reitan Andersen  Jihad Orabi  Lise Nistrup Jørgensen  Ahmed Jahoor 《Plant Breeding》2017,136(4):474-482

Fungal diseases are a major constraint for wheat production. Effective disease resistance is essential for ensuring a high production quality and yield. One of the most severe fungal diseases of wheat is Septoria tritici blotch (STB), which influences wheat production across the world. In this study, genomewide association mapping was used to identify new chromosomal regions on the wheat genome conferring effective resistance towards STB. A winter wheat population of 164 North European varieties and breeding lines was genotyped with 15K single nucleotide polymorphism (SNP) wheat array. The varieties were evaluated for STB in field trials at three locations in Denmark and across 3 years. The association analysis revealed four quantitative trait loci, on chromosomes 1B, 2A, 5D and 7A, highly associated with STB resistance. By comparing varieties containing several quantitative trait loci (QTL) with varieties containing none of the found QTL, a significant difference was found in the mean disease score. This indicates that an effective resistance can be obtained by pyramiding several QTL.  相似文献   

Intensive organic vegetable production increases soil organic carbon but with a lower carbon conversion efficiency than integrated management     

Yi Zhao  Shuxia Wu  Roland Bol  Mansoor Ahmed Bughio  Wenliang Wu  Yecui Hu  Fanqiao Meng 《植物养料与土壤学杂志》2020,183(2):155-168

Intensive vegetable production in greenhouses has rapidly expanded in China since the 1990s and increased to 1.3 million ha of farmland by 2016, which is the highest in the world. We conducted an 11‐year greenhouse vegetable production experiment from 2002 to 2013 to observe soil organic carbon (SOC) dynamics under three management systems, i.e., conventional (CON), integrated (ING), and intensive organic (ORG) farming. Soil samples (0–20 and 20–40 cm depth) were collected in 2002 and 2013 and separated into four particle‐size fractions, i.e., coarse sand (> 250 µm), fine sand (250–53 µm), silt (53–2 µm), and clay (< 2 µm). The SOC contents and δ¹³C values of the whole soil and the four particle‐size fractions were analyzed. After 11 years of vegetable farming, ORG and ING significantly increased SOC stocks (0–20 cm) by 4008 ± 36.6 and 2880 ± 365 kg C ha^?1 y^?1, respectively, 8.1‐ and 5.8‐times that of CON (494 ± 42.6 kg C ha^?1 y^?1). The SOC stock increase in ORG at 20–40 cm depth was 245 ± 66.4 kg C ha^?1 y^?1, significantly higher than in ING (66 ± 13.4 kg C ha^?1 y^?1) and CON (109 ± 44.8 kg C ha^?1 y^?1). Analyses of ¹³C revealed a significant increase in newly produced SOC in both soil layers in ORG. However, the carbon conversion efficiency (CE: increased organic carbon in soil divided by organic carbon input) was lower in ORG (14.4%–21.7%) than in ING (18.2%–27.4%). Among the four particle‐sizes in the 0–20 cm layer, the silt fraction exhibited the largest proportion of increase in SOC content (57.8% and 55.4% of the SOC increase in ORG and ING, respectively). A similar trend was detected in the 20–40 cm soil layer. Over all, intensive organic (ORG) vegetable production increases soil organic carbon but with a lower carbon conversion efficiency than integrated (ING) management.  相似文献