Occurrence of a new recombinant begomovirus species infecting tomato in the Al‐Batinah region of Oman     

A. A. M. Al‐Shihi  A. J. Khan  S. Akhtar  A. T. M. Lima  F. M. Zerbini  R. W. Briddon 《Plant pathology》2014,63(5):1177-1184

Whitefly‐transmitted begomoviruses are the most important limiting factor for tomato cultivation in Oman, particularly in the Al‐Batinah region, the major agricultural area of the country. Commercial farms in the Al‐Batinah region were surveyed during January–March 2013. Samples of tomato showing leaf curl disease symptoms typical of begomoviruses were collected and analysed. Full‐length sequences of five clones were shown to have relatively low percentage identity values to known begomoviruses, with the highest (88·6%) to isolates of Tomato leaf curl Oman virus (ToLCOMV), a begomovirus previously reported in Oman, indicating that these represent a newly identified species, for which the name Tomato leaf curl Barka virus (ToLCBrV) is proposed. Four isolates of ToLCBrV were found associated with Tomato leaf curl betasatellite (ToLCB). The five isolates of ToLCBrV characterized in this study were shown to be recombinants, with ToLCOMV as the major parent, and a fragment of Croton yellow vein virus (CrYVV) spanning the 3′ half of the replication‐associated protein. The significance of these findings is discussed.  相似文献   

Characteristics of Aerococcus viridans isolated from bovine subclinical mastitis and its effect on milk SCC,yield, and composition     

Sun  Meng  Gao  Jian  Ali  Tariq  Yu  Dan  Zhang  Shiyao  Khan  Saeed U.  Fanning  Séamus  Han  Bo 《Tropical animal health and production》2017,49(4):843-849

Tropical Animal Health and Production - Aerococcus viridians (A. viridans), an environmental Gram-positive bacterium, has been documented to be associated with bovine mastitis. However, its exact...  相似文献   

Bovine and Caprine Brucellosis in Bangladesh: Bayesian evaluation of four serological tests,true prevalence,and associated risk factors in household animals     

Md. Shamim Ahasan  Md. Siddiqur Rahman  A. K. M. Anisur Rahman  Dirk Berkvens 《Tropical animal health and production》2017,49(1):1-11

A cross-sectional study was carried out to estimate the true prevalence of Brucella spp. and identify allied risk factors/indicators associated with brucellosis in the Dinajpur and Mymensingh districts of Bangladesh. A total 320 stratified random blood samples were collected and tested in parallel for Brucella antibodies using Rose Bengal (RBT), slow agglutination (SAT), and indirect and competitive ELISA. In addition, a structured questionnaire was administered to each household herd owner to gather information regarding potential risk factors. Both univariate and multivariate logistic regression analyses were used to identify potential risk factors or indicators at animal level. A Bayesian approach was used to estimate the true prevalence of brucellosis along with the test performances (Se and Sp). The estimated animal level true prevalence in cattle was 9.70 % (95 % CPI 5.0–16 %) and in goat 6.3 % (95 % CPI 2.8–11.0 %). The highest sensitivity was achieved by SAT ranges from 69.6 to 78.9 %, and iELISA was found to be more specific (97.4 to 98.8 %) in comparison with other tests. On the other hand, a significant level of (P?<?0.05) Brucella seropositivity was found in cattle that breed naturally compared with those that undergo artificial insemination. In goats, exotic breeds were significantly associated (P?<?0.05) with Brucella seroprevalence compared with indigenous breeds. Goats with a previous records of abortion and/or retained placenta were also found to have significant levels (P?<?0.05). Cows with previous abortion records showed higher odds (18 times) of being seropositive. None of the evaluated tests can be recommended to apply alone for the diagnosis of bovine and caprine brucellosis.  相似文献   

Responses of endophytic and rhizospheric bacterial communities of salt marsh plant (Spartina alterniflora) to polycyclic aromatic hydrocarbons contamination     

Su  Jianqiang  Ouyang  Weiying  Hong  Youwei  Liao  Dan  Khan  Sardar  Li  Hu 《Journal of Soils and Sediments》2016,16(2):707-715

Journal of Soils and Sediments - Plants and their root-associated microbes play important roles in the remediation of polycyclic aromatic hydrocarbons (PAHs) present in the sediments of...  相似文献   

Characterization of nine Mlo family genes and analysis of their expression against pathogen infections in Vitis flexuosa     

Md. Zaherul Islam  HaeKeun Yun 《Euphytica》2016,211(3):379-394

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Characterisation of globally diverse blast-resistant upland rice (Oryza sativa L.) germplasms based on morpho-physiological and yield attributes     

Mst Tuhina-Khatun  M. Y. Rafii  M. Y. Wong  Md Aktar-Uz-Zaman 《Acta Agriculturae Scandinavica, Section B - Plant Soil Science》2016,66(5):417-431

Upland rice is a valuable base population for protecting against genetic erosion and broadening the gene pool of rice germplasms, and rice is also the staple food of more than 100 million people across the world. Therefore, an experiment was conducted to elucidate the performances of 27 globally diverse blast-resistant upland rice genotypes in terms of morphological, physiological and yield trait characteristics and to determine the correlations between and assess the diversity among these characteristics. All of the genotypes were evaluated in a randomised complete block design with three replications. Analysis of variance revealed 18 traits with significant to highly significant variations among themselves. The BRRI dhan42, BRRI dhan43, Ja Loy, C, Choke Tang and Chirikata 2 genotypes matured early, and the Chirikata 2, C, Choke Tang, BRRI dhan43 and Padi Beleong genotypes were best in terms of yield. The greatest heritability was recorded for the numbers of filled grains/panicle and the yield/plant, which demonstrated that these traits can be successfully transferred to the offspring if selection for these characteristics is performed in a hybridisation programme. The 27 genotypes were grouped into six clusters based on the contributing morphological, physiological and yield characteristics. The first four principal components accounted for 40, 59, 70 and 79% of the total variation, respectively, which indicated abundant genetic differences between these genotypes. The Chirikata 2, C, Choke Tang and BRRI dhan43 were selected as the best genotypes and could be used as valuable resources for high-yielding, early maturing, blast-resistant cultivars and parental sources for hybridisation programmes for challenging environments in the future.  相似文献   

Moringa oleifera Lam. leaf extract as bioregulator for improving growth of maize under mercuric chloride stress     

Amina Bibi  Sultan Mehmood  Kalsoom Bibi  Saad Ullah Khan  Adnan Khattak 《Acta Agriculturae Scandinavica, Section B - Plant Soil Science》2016,66(6):469-475

The contamination of agriculture soils with heavy metals is increasing due to both natural and anthropogenic activities. This has resulted in lowering the yield and quality of agriculture crops. The aim of the present investigation was to determine the effect of Moringa oleifera (M. oleifera) aqueous leaf extract (MALE) on growth and Hg phytoextraction potential of maize cv. Azam under mercuric chloride (HgCl₂)-induced stress. Soil was contaminated with different concentrations of HgCl₂ (1 and 0.5?mg/kg). The MALE was applied at 5% and 2.5% as seed soaking prior to sowing of seeds in the pots. The M. oleifera leaf was a good source of macronutrients (Na, K, Ca and Mg) and micronutrients (Fe, Zn, Mn, Co and Ni) as well as natural phenolics. The induced HgCl₂ stress significantly reduced seed germination (%), shoot dry weight, root dry weight, chlorophyll content and carotenoids content. The HgCl₂-induced stress was associated with accumulation of phenolics and Hg in roots. The accumulation of Hg in roots was significantly correlated with phenolics content (r?=?.8007, p?=?.000). The exogenous application of MALE significantly ameliorated adverse effects of HgCl₂ stress on maize plants. The accumulation of Hg in roots was significantly increased by MALE. It is inferred from findings of the present investigation that MALE served as bioregulator and can be applied to reduce adverse effects of HgCl₂ on maize. Moreover, MALE can enhance the Hg phytoremediation potential of maize.  相似文献   

Effects of salicylic acid on growth and accumulation of phenolics in Zea mays L. under drought stress     

Farzana Latif  Sultan Mehmood  Adnan Khattak  Asif Ullah Khan  Safiullah Khan 《Acta Agriculturae Scandinavica, Section B - Plant Soil Science》2016,66(4):325-332

The accumulation of total soluble and cell wall-bound phenolics and total soluble proteins in Zea mays plants exposed to drought stress and foliar spray of salicylic acid (SA) at 10^?4?mol/L and 10^?5?mol/L was investigated. Drought stress was imposed at the four-leaf stage for 10 days (30–35% field capacity). Dehydration of maize leaves was accompanied by the accumulation of both total soluble and cell wall-bound phenolics, reduction in leaf relative water content (LRWC), and shoot and root growth attributes. Foliar spraying of SA further augmented the content of total soluble and cell wall-bound phenolics and total soluble proteins content under drought stress. SA ameliorated the adverse effects of drought stress on LRWC, shoot fresh weight, shoot dry weight, root fresh weight, root dry weight, root length and root area. The accumulation of both soluble and cell wall-bound phenolics by foliar spray of SA may be a mechanism related to SA-induced drought stress tolerance in maize. It was concluded that foliar spraying of SA at 10^?5?mol/L can be highly economical and effective for modifying the effects of drought stress on maize at the four-leaf stage.  相似文献   

Comparative Studies on the Use of Binary and Ternary Combinations of Various Acidifying Agents for the Reduction of Soil pH     

Tanzeela Fazal  Bushra Ismail  Asad Muhammad Khan  Rafaqat Ali Khan  Amir Abbas Shah Naqvi  Farrukh Siyar Hamid 《Communications in Soil Science and Plant Analysis》2016,47(1):11-18

The present study deals with the effects of addition of sulfur along with other acidifying agents for their ability to lower and maintain the pH in a given range for a longer period of time. The chemicals were subjected to batch test individually and in combinations. Treatments were applied to three soils of different textures: sandy clay loam, clay loam, and silt loam. A 1:1 soil/water paste along with the added amendment was maintained at room temperature for 2 months. Most of the chemical treatments lowered the pH significantly. Combinations containing S/Al₂(SO₄)₃/H₂SO₄, S/Al₂(SO₄)₃/H₂O₂, and S/H₂O₂/H₂SO₄ were found to be very effective in lowering the pH. The soil pH remained acidic for 2 months, indicating the suitability of chemically amended soil for the plantations requiring acidic soil pH.  相似文献   

Residue,tillage and N-fertilizer rate affected yield and N efficiency in irrigated spring wheat     

Asad Shah  M. Jamal Khan  Muhammad Asim 《Journal of plant nutrition》2016,39(14):2056-2071

Yield and nitrogen (N)-content in wheat was studied under applied treatments of crop residues (legume vs. cereal), tillage depths (deep vs. shallow) and N-fertilizer rates (0, 40, 80, 120 and 160 kg ha^?1) at wheat-maize cropping systems. Experiments were conducted at Agronomy Research farm, the University of Agriculture, Peshawar Pakistan, during winter season 2009–2010 and 2010–2011 crop growth seasons. Well-chopped crop residues (5 t ha^?1) on dry matter basis of legume (Vigna unguicuata) and cereal (Zea mays) were applied to soil and subsequently plowed with mold-board plow as deep tillage (DT) and cultivator as shallow tillage (ST) treatment (main plot treatments). A month after residue and tillage application, seedbed was prepared and wheat was planted with drill in rows 25 cm apart in middle of November each year. Phosphorus and potassium were applied uniformly 80 and 40 kg ha^?1, respectively during seedbed preparation. N-fertilizer rates were applied in two splits: half 15 days after sowing (DAS) and other half 45 DAS (sub-plot treatment). Uniform cultural practices were applied during crop growth and development. Legumes residues amendments showed better responses than cereal but lower than no-residue treatment for N-content in leaf blade before anthesis (LBA), after anthesis (LAA), straw N-content (SNC), grain N-content (GNC), grain N-uptake (GNU), crop N-removal (CNR), recovery efficiency of added nitrogen (REAN), N-use efficiency (NUE), grain N-uptake (GNU) and grain yield. Likewise, shallow tillage proved better than deep tillage system for LBA, LAA, SNC, GNC, GNU, CNR, REAN, NUE, GNU and grain yield. Increased N-fertilizer from control onwards showed significant (p > 0.05) increments in LBA, LAA, SNC, GNC, GNU, CNR, N-uptake and grain yield. Treatments interaction was also found significant (p > 0.05). Study suggested, regardless of the given treatments, GNU and grain yield were in strong positive linear relationship. Legume residue incorporated shallow out yielded GNU and NUE of spring wheat in wheat-maize cropping system. It is concluded that LR and ST with 120 kg N ha^?1 ensures production of good wheat quantity and quality.  相似文献