Characterization of Egyptian <Emphasis Type="Italic">Phytophthora infestans</Emphasis> population using simple sequence repeat markers     

Ramadan A. Arafa  Nour Elden K. Soliman  Olfat M. Moussa  Said M. Kamel  Kenta Shirasawa 《Journal of General Plant Pathology》2018,84(2):104-107

The plant pathogenic oomycete, Phytophthora infestans, is the causal agent of late blight disease in tomato and potato. For characterizing Egyptian P. infestans isolates by DNA marker analysis, 40 isolates of P. infestans were collected from different locations in Egypt during two growing seasons (2012/2013 and 2013/2014). The 40 isolates were grouped into seven genotypes, in which 24 alleles were detected. The identified genotypes were not completely associated with geographic location and sample collection years. These results provide genetic and geographical information for developing a program to manage late blight disease.  相似文献   

Comparative effect of drought duration on growth,photosynthesis, water relations,and solute accumulation in wild and cultivated barley species          下载免费PDF全文

Maroua Mejri  Kadambot H. M. Siddique  Tark Saif  Chedly Abdelly  Kamel Hessini 《植物养料与土壤学杂志》2016,179(3):327-335

Drought is a major factor limiting crop production worldwide. Barley is a well‐adapted cereal that is largely grown on dry marginal land where water and salinity are the most prevalent environmental stresses. This study was carried out to investigate the effects of drought stress and subsequent recovery on growth, photosynthetic activity, water relations, osmotic adjustment (OA), and solute accumulation of wild (Hordeum maritimum) and cultivated barley (H. vulgare L.). In a pot experiment, 60 d old seedlings were subjected to drought stress for 0, 7, 14, 21, or 28 d, and then re‐watered to recover for up to 21 d. Plants were harvested at the end of each of these drought/recovery treatments. Drought significantly reduced fresh and dry weights at the whole‐plant level, photosynthetic activities, and solute and water potentials, while increasing leaf Na⁺ and K⁺ concentrations. The adverse effects of drought on growth were more marked in cultivated barley than in wild barley and the reverse was true for photosynthetic activities. During recovery, all wild barley seedlings completely recovered. For cultivated barley seedlings, rehydration had a beneficial effect on growth and photosynthesis, independent of treatment duration, but complete recovery did not occur. The reduction in leaf solute potential at full turgor in drought‐stressed barley, relative to the control, suggests active OA which was more significant in wild barley than in cultivated barley. OA was mainly due to the accumulation of inorganic (K⁺ in cultivated barley and Na⁺ in wild barley) and organic (soluble sugars and proline) solutes. The results suggest that OA is an important component of the drought‐stress adaptation mechanism in wild barley, but is not sufficient to contribute to drought tolerance in cultivated barley. In the latter species, the results show that even short periods (as little as 7 d) of water deficit stress had considerable long‐term effects on plant growth.  相似文献   

First report of Corythauma ayyari (Drake) (Hemiptera: Tingidae) on Arabian and Spanish jasmine in Tunisia          下载免费PDF全文

D. Haouas  E. Guilbert  M. Ben Halima‐Kamel 《EPPO Bulletin》2015,45(1):144-147

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Erratum to: Natural Volcanic Tuff-Based Geopolymer for Zn Removal: Adsorption Isotherm,Kinetic, and Thermodynamic Study     

Kamel K. Al-Zboon  Bashar M. Al-smadi  Sajedh Al-Khawaldh 《Water, air, and soil pollution》2017,228(4):164

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First record of the grapevine aphid,Aphis illinoisensis Shimer,in Tunisia     

M. Kamel‐Ben Halima  L. Mdellel 《EPPO Bulletin》2010,40(2):191-192

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Compost enhances plant resistance against the bacterial wilt pathogen Ralstonia solanacearum via up-regulation of ascorbate-glutathione redox cycle     

Sahar A. Youssef  Kamel A. H. Tartoura 《European journal of plant pathology / European Foundation for Plant Pathology》2013,137(4):821-834

The interactions between the pathogen Ralstonia solanacearum and potato Solanum tuberosum plants were studied to investigate the reactive oxygen species metabolic system and ascorbate (ASC)-glutathione (GSH) redox cycle in response to compost application. Single potato eyepieces were germinated and grown in pots containing sandy soil with or without compost at a rate of 7.5 g kg^?1 soil. Non-compost- and compost-treated plants (CTP) were inoculated with R. solanacearum 25 days after planting and then analyzed after 10 days, unless otherwise stated. The present results revealed that pathogen infection caused a remarkable decrease in plant growth related parameters and productivity and an increase in disease incidence. However, under these conditions compost had substantially improved plant growth and decreased disease incidence and bacterial population. R. solanacearum resulted in significant enhancement in the activities of NADPH oxidase, lipoxygenase, the production rate of superoxide and hydroxyl radicals, levels of hydrogen peroxide, membrane lipid peroxidation, and protein oxidation indicating the induction of oxidative stress in potato roots. However, the pathogen-mediated enhancement in indices of oxidative stress was considerably decreased by compost application, which enhanced the activities of ascorbate peroxidase (APX, EC 1.11.1.11), monodehydroascorbate reductase (MDHAR, EC 1.6.5.4), dehydroascorbate reductase (DHAR, EC 1.8.5.1) and glutathione reductase (GR, EC 1.6.4.2) in infected potato plants, implying a better ROS-scavenging activity. Data also indicated that there were general increases in ASC and GSH content in infected compost treated plants, but non-compost treated ones significantly had lower levels of such redox metabolites. In addition, significantly higher ratios of ASC/DHA (dehydroascorbate) and GSH/GSSG (glutathione disulphide) were generally found in CTP than in non-compost treated-ones. The obtained results suggest that compost provides effective protection against the Ralstonia bacterial pathogen via up-regulation of the capacity of the ASC-GSH cycle and modulation of the cellular redox status, thereby eliminating ROS damage and sustaining membrane stability.  相似文献   

Assessment of Training Needs for Egyptian Extension Specialists (SMSs) in Organic Farming Field: Use of the Borich Needs Model     

Adel I. M. A. Elhamoly  G. F. Koledoye  A. Kamel 《Journal Of Agricultural & Food Information》2014,15(3):180-190

This study identified and prioritized the in-service training needs of Egyptian extension specialists in organic farming. The Krejcie and Morgan sampling table was used to sample 77 agricultural extension specialists (SMSs). Based on the Borich needs assessment model, 16 competencies were used to assess the training needs of SMSs in organic farming using the perceived levels of importance. The training needs were analyzed and ranked using mean weighted discrepancy scores (MWDS). “Appropriate amounts of bio-fertilizers” (MWDS = 39.59) and “Steps of utilizing bio-fertilizers” (MWDS = 32.97) were the top two competencies. The Ministry of Agriculture can use these findings as the basis of training programs for SMSs.  相似文献   

Evaluation of a commercial intravaginal thermometer to predict calving in a Hungarian Holstein-Friesian dairy farm     

Ali Ismael Choukeir  Levente Kovács  Luca Fruzsina Kézér  Dávid Buják  Zoltán Szelényi  Mohamed Kamel Abdelmegeid  András Gáspárdy  Ottó Szenci 《Reproduction in domestic animals》2020,55(11):1535-1540

In this study, the utility of a commercial intravaginal thermometer was evaluated as an automated method for the prediction of calving in a total of 257 healthy pregnant Holstein–Friesian female cattle. The accuracy and the sensitivity of predicting calving within 48 hr before calving were also evaluated. The intravaginal temperature changes from 72 hr before and up to calving were significantly (p ≤ .001) affected by parity, season (summer vs. autumn), the time of day (8 a.m. or 8 p.m.) and the 6-hr time intervals (38.19°C: first interval 0 to 6 hr before calving vs. 38.78°C: twelfth interval 66 to 72 hr before calving), while the gender (p = .943), and the weight of the calf (p = .610), twinning (p = .300), gestation length (p = .186), foetal presentation (p = .123), dystocia (p = .197) and retention of foetal membranes (p = .253) did not affect it significantly. The sensitivity of the SMS of expecting calving within 48 hr and the positive predictive value were 62.4% and 75%, respectively, while the sensitivity and the positive predictive value for the SMS of expulsion reached 100%. It can be concluded that the investigated thermometer is not able to predict calving within 48 hr accurately; however, imminent calving can be accurately alerted.  相似文献   

Molecular characterization of pathogenic Escherichia coli isolated from diarrheic and in-contact cattle and buffalo calves     

Awad  Walid S.  El-Sayed  Amr A.  Mohammed  Faten F.  Bakry  Noha M.  Abdou  Nadra-Elwgoud M. I.  Kamel  Mohamed S. 《Tropical animal health and production》2020,52(6):3173-3185

Tropical Animal Health and Production - Escherichia coli field isolates from calves were characterized and categorized into the most significant diarrheagenic pathotypes using polymerase chain...  相似文献   

Pyrenophora teres growth and severity of net blotch on barley under salt stress     

Ben Alaya  Amani  Rabhi  Fatma  Hessini  Kamel  Djébali  Naceur 《European journal of plant pathology / European Foundation for Plant Pathology》2021,161(3):709-722

European Journal of Plant Pathology - Pyrenophora teres causes one of the most destructive barley diseases in semi-arid production areas worldwide. With the burgeoning issue of soil salinization,...  相似文献