Sensitivity of Lasiodiplodia theobromae from Brazilian papaya orchards to MBC and DMI fungicides     

Alba Valéria da Silva Pereira  Ricardo Brainer Martins  Sami Jorge Michereff  Marcelo Bezerra da Silva  Marcos Paz Saraiva Camara 《European journal of plant pathology / European Foundation for Plant Pathology》2012,132(4):489-498

Stem rot caused by Lasiodiplodia theobromae is an important postharvest disease of papaya in Brazil, responsible for reducing the quality and quantity of fruits. Fungicide use is one of the main disease management measures. However, there are no estimates available of pathogen sensitivity to commonly employed fungicides. Therefore, the EC₅₀ from 120 isolates of L. theobromae from northeastern Brazil, representative of six populations of the pathogen, was estimated in vitro for fungicides of the methyl benzimidazole carbamates—MBC (benomyl and thiabendazole) and demethylation-inhibiting—DMI (imazalil, prochloraz, tebuconazole) groups. Mycelial growth on fungicide-free media and virulence on papaya fruits of the MBC-sensitive and non-sensitive isolates were compared. For MBCs, 8.4% of isolates were non-sensitive to fungicides. For the remaining 91.6%, the mean EC₅₀ ranged from 0.002 to 0.13 μg ml⁻¹ and 0.36 to 1.27 μg ml⁻¹ for benomyl and thiabendazole, respectively. For DMIs, the mean EC₅₀ range for imazalil was 0.001 to 2.27 μg ml⁻¹, 0.04 to 1.75 μg ml⁻¹ for prochloraz, and 0.14 to 4.05 μg ml⁻¹ for tebuconazole. The EC₅₀ values of non-sensitive isolates were significantly (P≤0.05) higher those for the sensitive isolates for each of the DMI fungicides. Differences (P≤0.05) were found in the levels of sensitivity to DMI fungicides among the isolate populations associated with orchards. The populations from two orchards were less sensitive to DMIs. No solid evidence was found for fitness costs relating to MBC non-sensitive isolates because mycelial growth in fungicide-free media and virulence on papaya fruits were similar to those of sensitive isolates.  相似文献   

Investigation of serum amino acid and serum amyloid A concentrations in chickens with amyloid arthropathy     

Sevimli A  Yalcin M  Cangul IT  Aydin S 《The Veterinary quarterly》2012,32(1):17-23

  相似文献   

Development of EST‐SSR markers for diversity and breeding studies in opium poppy     

Hatice Şelale  Ibrahim Çelik  Visam Gültekin  Jens Allmer  Sami Doğanlar  Anne Frary 《Plant Breeding》2013,132(3):344-351

All publicly available opium poppy expressed sequence tag (EST) sequences, totalling 20 885, were assembled into unigenes and examined for simple sequence repeats (SSRs). Nearly 19% of the 14 957 unigenes contained SSRs with 4% harbouring more than one SSR. Average density of the SSRs was 1 SSR per 3.6 kb of non‐redundant EST sequence. Trinucleotide SSRs were most frequently identified (39%), and many of the most prevalent motifs were AT‐rich. Flanking primers were designed for 86% of the SSRs and 67 primer pairs were tested on 37 opium poppy accessions and seven related species. All markers were transferable to the related species. Polymorphism information content (PIC) values for the markers were intermediate for comparisons within opium poppy (average of 0.27) and slightly higher for comparisons across species (average of 0.29). The markers were found to be useful for diversity analysis as they successfully distinguished among Turkish opium poppy accessions and land races.  相似文献   

Phosphate solubilizing bacteria and fungi in desert soils: species,limitations and mechanisms     

Fuad Ameen  Sami A. AlYahya  Saleh AlNadhari  Hadi Alasmari  Fahad Alhoshani  Milton Wainwright 《Archives of Agronomy and Soil Science》2019,65(10):1446-1459

Desert soils are infertile, and the ability to improve them by P-fertilization is limited by the solubility of phosphate. We aimed to understand the function of phosphate solubilizing bacteria and the mechanisms behind phosphate solubilization in desert soils. Vegetated and barren desert soils, mine spoil and a fertile temperate grassland loam were sampled. Bacteria and fungi were isolated and identified, and their phosphate-solubilizing abilities were measured in vitro. The release of plant available PO₄, SO₄, NO₃ and NH₄ from desert soils did not compare with that of a grassland soil. Desert soils had substantially lower solubilization than grassland, 162 and 99–121 µg PO₄-P g^?1 dry soil, respectively. Phosphate-solubilizing bacteria and fungi were inhabiting the soils. Si addition increased phosphate solubilization of fungi by 50%. The isolated microbes were shown, using ³¹P nuclear magnetic resonance (NMR) analysis, to rapidly take-up both intracellular and extracellular phosphate during the phosphate solubilizing process. Desert soil had potentially active microbial populations that are capable to solubilize inorganic phosphorus; S and Si as the limiting factors. Acidification as the main mechanism to solubilize mineral phosphate was not as evident in our desert soils as in former studies dealing more fertile soils.  相似文献   

Effect of the maturation process on the phenolic fractions, fatty acids, and antioxidant activity of the Chétoui olive fruit cultivar     

Damak N  Bouaziz M  Ayadi M  Sayadi S  Damak M 《Journal of agricultural and food chemistry》2008,56(5):1560-1566

Maturity is one of the most important factors associated with the quality evaluation of fruit and vegetables. This work aims to investigate the effect of the maturation process of the olive fruit on the phenolic fraction and fatty acid of irrigated Chétoui cultivar. The phenolic composition was studied by using reverse-phase high-performance liquid chromatography followed by LC-MS and GC-MS analyses and fatty acids by GC. Oleuropein was the major phenolic compound at all stages of ripeness. Unexpectedly, both phenolic compounds hydroxytyrosol and oleuropein exhibited the same trends during maturation. Indeed, the oleuropein levels decreased during the ripening process and were not inversely correlated with the concentrations of hydroxytyrosol. The antioxidant capacity of olive extracts was evaluated by measuring the radical scavenging effect on 1,1-diphenyl-2-picrylhydrazyl and the beta-carotene linoleate model system. The IC 50 and AAC values of the olive extracts decreased from 3.68 to 1.61 microg/mL and from 645 to 431, respectively. There was a correlation between the antioxidant activity and the oleuropein concentration. The fatty acid composition was quantified in olive fruit during maturation and showed that fatty acids were characterized by the highest level of oleic acid, which reached 65.2%.  相似文献   

Artificially cold‐induced quiescent egg viability of the tropical copepod Acartia bilobata (Copepoda,Calanoida)          下载免费PDF全文

Yen‐Ju Pan  Anissa Souissi  Jiang‐Shiou Hwang  Sami Souissi 《Aquaculture Research》2017,48(4):1974-1979

  相似文献   

Changes in fatty acids profile,monosaccharide profile and protein content during batch growth of Isochrysis galbana (T.iso)          下载免费PDF全文

Asma Gnouma  Irina Sadovskaya  Anissa Souissi  Khaled Sebai  Amel Medhioub  Thierry Grard  Sami Souissi 《Aquaculture Research》2017,48(9):4982-4990

To investigate the nutritional value of the marine micro‐alga Isochrysis galbana Tahitian Isochrysis strain (T.iso) as an alternative feed for aquaculture during culture age, its biochemical composition was studied under autotrophic and controlled culture conditions at different growth stages: exponential phase, early and late stationary phases and decay phase. Analysis showed that C14:0, C16:0, C16:1, C18:4 (n‐3) and C22:6 (n‐3) were the most abundant fatty acids in this alga at different growth stages. The highest values of monounsaturated fatty acids were recorded at the late stationary and the decay phases. However, the highest levels of polyunsaturated fatty acids were observed at the early stationary phase. At all growth stages, I. galbana (T.iso) contained arabinose, xylose, mannose, galactose and glucose. Glucose represented the main sugar, and its content per dry alga biomass weight increased with increasing age of the culture and reached about fourfold in the decay phase. The maximum protein content was also observed during this last phase.  相似文献   

Prevalence and genotypes of infectious salmon anaemia virus (ISAV) in returning wild Atlantic salmon (Salmo salar L.) in northern Norway     

Abdullah Sami Madhun  Stig Mhle  Vidar Wennevik  Egil Karlsbakk 《Journal of fish diseases》2019,42(8):1217-1221

  相似文献   

Transmission Efficiency of <Emphasis Type="Italic">Potato Leafroll Virus</Emphasis> by Four Potato Colonizing Aphid Species in Tunisian Potato Fields     

Wafa Khaled  Ibtissem Ben Fekih  Sabrine Nahdi  Rebha Souissi  Sonia Boukhris-Bouhachem 《Potato Research》2018,61(1):89-96

This study investigated the transmission efficiency of Potato leafroll virus (PLRV) by four potato colonizing aphid species, Myzus persicae, Macrosiphum euphorbiae, Aphis gossypii and Aphis fabae, reported from leaves and yellow water trap. Physalis floridana was used as a test plant for virus transmission. DAS-ELISA was used for virus screening of samples as well as virus detection on the test plant after transmission experiment. A 2-h period was sufficient for the tested aphids to acquire PLRV virions. However, a difference in the transmission potential occurred according to the aphid species. The highest potential was recorded for M. persicae and M. euphorbiae, at 90 and 80%, respectively. For the first time, the study revealed the PLRV transmission efficiency of A. fabae, estimated at 50%. The lowest potential rate of 30% was recorded for A. gossypii. This study highlights the PLRV transmission capacities of four potato colonizing aphids suspected to play a key role in the spread of PLRV in potato seed production sites.  相似文献   

Effect of Nephthyl Acetic Acid Foliar Spray on Amelioration of Drought Stress Tolerance in Maize (Zea mays L.)     

Sami Ullah  Jehan Zada  Sajjad Ali 《Communications in Soil Science and Plant Analysis》2016,47(12):1542-1558

The present study aimed to determine the effect of nephthyl acetic acid (NAA) on the physiological mechanism of drought tolerance in selected maize (Zea mays L.) varieties under induced drought stress at the vegetative stage. Maize seeds were sown in plastic pots (14 cm lower inside diameter, 18.5 cm upper inner diameter, 15.6 cm height, and 0.5 cm thickness) filled with 3 kg of air-dried soil and sand (3:1) in triplicate in the greenhouse of the Botany Department, Bacha Khan University, Charsadda in 2014. Results showed that the activities of antioxidant enzymes and proline accumulation were associated with the dry mass production and consequently with the drought tolerance of the maize varieties. It has been concluded that the inhibitory effects of water stress were ameliorated by exogenous application of NAA and were found to be significant for antioxidant enzymes at the vegetative stage in both varieties.  相似文献