Natural occurrence of <Emphasis Type="Italic">Fusarium</Emphasis> species and fumonisin on maize grains in Ethiopia     

Hadush Tsehaye  May Bente Brurberg  Leif Sundheim  Dereje Assefa  Arne Tronsmo  Anne Marte Tronsmo 《European journal of plant pathology / European Foundation for Plant Pathology》2017,147(1):141-155

Fusarium species causing maize kernel rot are major threats to maize production, due to reduction in yield as well as contamination of kernels by mycotoxins that poses a health risk to humans and animals. Two-hundred maize kernel samples, collected from 20 major maize growing areas in Ethiopia were analyzed for the identity, species composition and prevalence of Fusarium species and fumonisin contamination. On average, 38 % (range: 16 to 68 %) of maize kernels were found to be contaminated by different fungal species. Total of eleven Fusarium spp. were identified based on morphological characteristics and by sequencing the partial region of translation elongation factor 1-alpha (EF-1α) gene. Fusarium verticillioides was the dominant species associated with maize kernels (42 %), followed by F. graminearum species complex (22.5 %) and F. pseudoanthophilium (13.4 %). The species composition and prevalence of Fusarium species differed among the areas investigated. Fusarium species composition was as many as eight and as few as four in some growing area. The majority of the maize samples (77 %) were found positive for fumonisin, with concentrations ranging from 25 μg kg^?1 to 4500 μg kg^?1 (mean: 348 μg kg^?1 and median: 258 μg kg^?1). Slight variation in fumonisin concentration was also observed among areas. Overall results indicate widespread occurrence of several Fusarium species and contamination by fumonisin mycotoxins. These findings are useful for intervention measures to reduce the impact of the main fungal species and their associated mycotoxins, by creating awareness and implementation of good agricultural practices.  相似文献   

Atlantic salmon (Salmo salar L.) as a net producer of long-chain marine ω-3 fatty acids     

Sanden M  Stubhaug I  Berntssen MH  Lie Ø  Torstensen BE 《Journal of agricultural and food chemistry》2011,59(23):12697-12706

The objective of the present study was to investigate the effects of replacing high levels of marine ingredients with vegetable raw materials and with emphasis on lipid metabolism and net production of long-chain polyunsaturated ω-3 fatty acids (EPA + DHA). Atlantic salmon were fed three different replacement vegetable diets and one control marine diet before sensory attributes, β-oxidation capacity, and fatty acid productive value (FAPV) of ingested fatty acids (FAs) were evaluated. Fish fed the high replacement diet had a net production of 0.8 g of DHA and a FAPV of 142%. Fish fed the marine diet had a net loss of DHA. The present work shows that Atlantic salmon can be a net producer of marine DHA when dietary fish oil is replaced by vegetable oil with minor effects on sensory attributes and lipid metabolism.  相似文献   

The role of precipitation,and petal and leaf infections in Sclerotinia stem rot of spring oilseed Brassica crops in Norway     

Andrea Ficke  Chloé Grieu  May Bente Brurberg  Guro Brodal 《European journal of plant pathology / European Foundation for Plant Pathology》2018,152(4):885-900

Sclerotinia stem rot (SSR) is the most important disease of oilseed Brassica crops in Norway. Fungicide applications should be aligned with the actual need for control, but the SSR prediction models used lack accuracy. We have studied the importance of precipitation, and the role of petal and leaf infection for SSR incidence by using data from Norwegian field and trap plant trials over several years. In the trials, SSR incidence ranged from 0 to 65%. Given an infection threshold of 25% SSR, regression and Receiver Operating Characteristics (ROC) analysis were used to evaluate different precipitation thresholds. The sum of precipitation two weeks before and during flowering appeared to be a poor predictor for SSR infection in our field and trap plant trials (P?=?0.24, P?=?0.11, respectively). Leaves from three levels (leaf one, three, five), and petals were collected at three to four different times during flowering from nine field sites over two years and tested for SSR infection with real-time PCR. Percentage total leaf and petal infection explained 57 and 45% of variation in SSR incidence, respectively. Examining the different leaves and petals separately, infection of leaf three sampled at full flowering showed the highest explanation of variation in later SSR incidence (R²?=?65%, P?<?0.001). ROC analysis showed that given an infection threshold of 45%, both petal and leaf infection recommended spraying when spraying was actually needed. Combining information on petal and leaf infection during flowering with relevant microclimate factors in the canopy, instead of the sum of precipitation might improve prediction accuracy for SSR.  相似文献