Sorensen J.L.,University of Aalborg |
Sorensen J.L.,University of Aarhus |
Akk E.,Estonian Research Institute of Agriculture |
Thrane U.,Technical University of Denmark |
And 4 more authors.
International Journal of Food Microbiology | Year: 2013
Fusarielins constitute a relative unexplored group of secondary metabolites, which have been isolated mainly from unidentified Aspergillus and Fusarium strains. In the present study we show that the ability to produce fusarielins is restricted to a few Fusarium species. Among the 15 analyzed species fusarielins were identified only in extracts from Fusarium graminearum and Fusarium tricinctum. The influence of different carbon sources on fusarielin biosynthesis was examined and the results showed that disaccharides and dextrin in combination with arginine as sole nitrogen source increased fusarielin production. When arginine was replaced with nitrate the fusarielins were produced on a wider selection of carbon sources including all monosaccharides. Production of fusarielins in F. graminearum was also influenced by pH, cultivation time, temperature and fructose concentration with the optimal conditions being: pH. 6, 25°C, 26. days and 60. mg fructose/mL. Wheat spikes were inoculated with F. graminearum to determine whether fusarielins are produced in infected cereals and fusarielin H was detected in all samples ranging from 392 to 1865. ng/g (mean: 989. ng/g) indicating that fusarielins are produced during infection. The study shows that even though fusarielins are produced by a narrow list of Fusarium species, they potentially can be present in infected cereals. © 2012 Elsevier B.V.
Adamonyte G.,Lithuanian Academy of Sciences |
Kastanje V.,Estonian Research Institute of Agriculture
Folia Cryptogamica Estonica | Year: 2011
Forty three species and infraspecific taxa of myxomycetes were recorded in different ecotopes of the Saaremaa island, the West Estonian Archipelago, during the 17 th Symposium of the Baltic Mycologists and Lichenologists in 2008. Among them, thirteen species were found for the first time in Estonia: Arcyria abietina, Comatricha ellae, Craterium leucocephalum, Diderma effusum, Didymium nigripes, Echinostelium apitectum, Licea minima, L. operculata, Physarum robustum, P. viride, Stemonaria irregularis, Stemonitopsis amoena, and Trichia munda.
Sepp M.,University of Tartu |
Saue T.,University of Tartu |
Saue T.,Estonian Research Institute of Agriculture
International Journal of Biometeorology | Year: 2012
Biology-related indicators do not usually depend on just one meteorological element but on a combination of several weather indicators. One way to establish such integral indicators is to classify the general atmospheric circulation into a small number of circulation types. The aim of present study is to analyse connections between general atmospheric circulation and potato crop yield in Estonia. Meteorologically possible yield (MPY), calculated by the model POMOD, is used to characterise potato crop yield. Data of three meteorological stations and the biological parameters of two potato sorts were applied to the model, and 73 different classifications of atmospheric circulation from catalogue 1.2 of COST 733, domain 05 are used to qualify circulation conditions. Correlation analysis showed that there is at least one circulation type in each of the classifications with at least one statistically significant (99%) correlation with potato crop yield, whether in Kuressaare, Tallinn or Tartu. However, no classifications with circulation types correlating with MPY in all three stations at the same time were revealed. Circulation types inducing a decrease in the potato crop yield are more clearly represented. Clear differences occurred between the observed geographical locations as well as between the seasons: derived from the number of significant circulation types, summer and Kuressaare stand out. Of potato varieties, late 'Anti' is more influenced by circulation. Analysis of MSLP maps of circulation types revealed that the seaside stations (Tallinn, Kuressaare) suffer from negative effects of anti-cyclonic conditions (drought), while Tartu suffers from the cyclonic activity (excessive water). © 2011 ISB.
Saue T.,Estonian Research Institute of Agriculture |
Saue T.,University of Tartu |
Kadaja J.,Estonian Research Institute of Agriculture
Boreal Environment Research | Year: 2011
The main objective of this research is to generate and analyse values of meteorologically possible yields (MPY, maximum yield achievable under given meteorological conditions) of potato for the middle and the end of the 21st century, at three Estonian locations. An early and a late potato varieties are analysed as examples. Climate change is evaluated under four different emission scenarios by 18 different GCMs; resultant changes are introduced into a dynamical potato growth model POMOD. The climate-driven changes without considering the effect of CO2 concentration change are determined. A negative impact of climate warming on early potato growth in Estonia is confirmed. Moderate climate change scenarios will have a positive influence on growth of the late potato variety, whereas stronger changes will cause the decline of agrometeorological resources. A more positive or less negative effect of climate change is detected for northern Estonia. © 2011.
Runno-Paurson E.,Estonian University of Life Sciences |
Runno-Paurson E.,Jogeva Plant Breeding Institute |
Remmel T.,University of Tartu |
Ojarand A.,Estonian Research Institute of Agriculture |
And 2 more authors.
European Journal of Plant Pathology | Year: 2010
The characteristics of populations of Phytophthora infestans from organic farms, small conventional farms and large conventional farms were determined from isolates collected in northern Estonia in 2004 and 2005. For the population as a whole 41% were A2; all virulence factors to the 11 R genes from Solanum demissum were found; and more than 70% had high or intermediate resistance to metalaxyl. Isolates from organic farms tended to have more complex pathotypes than isolates from either large or small conventional farms, but there was a higher proportion of metalaxyl resistant isolates from large conventional farms than from small conventional farms or from organic farms. © 2010 KNPV.