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Fusarium head blight caused by Fusarium graminearum Schwabe (telemorph Gibberella zeae (Schwein) Petch) is one of the most important wheat diseases causing head blight world – wide. Apart from reducing yield, it may produce mycotoxins (deoxynivalenol and zearalenone). Breeding for resistance is the most effective means of head blight control. Previously, correlation coefficient was determined for resistance in natural and artificial conditions (r = 0, 78 and r = 0, 82). The purpose of this ivestigation was to determine the reliability of the method of artificial spike inoculation comparing FHB resistance of wheat varieties under different environments in two years of testing. Two small-scale trials were conducted with 14 varieties in 2007 and 2008 and again with 16 varieties in 2008 and 2009. Both trials were conducted under conditions of artificial infection. Inoculum was prepared from four F. graminearum Schw. isolates. Their pathogenicity had been determined in the laboratory using the method by Mesterhazy (1984). The inoculum was produced on modified Bilay's liquid medium. Field trials were sprayed with a spore suspension of 5 x 105 spores / ml. The first inoculation was made when 50% of the spikes flowered. The inoculation was repeated twice at 2-3 days intervals. Three ratings were taken using the visual rating index (VRI). Considerable differences in resistance degree to fusarium head bligh were obtained among the tested wheat varieties (2007, 2008, 2009). Average infection severety for the 14 varieties tested in 2007 and 2008 was 25, 8 % and 25, 2 % rerspectvely. Correlation coefficient (r = 0, 72) between variety resistance to FHB in 2007 and 2008 was obtained. Resistance to fusarium head blight of the tested varieties ranged from 5, 7 % go 50, 3 %. Average infection of the 16 varieties tested in 2008 and 2009 was 23, 5 % and 35, 4 % respectively. Correlation coefficient (r = 0, 81) between variety resistance to FHB in 2008 and 2009 was obtained. The most resistant variety had an average VRI index 7, 2 %, and the most susceptible variety 48, 7 %. Resistance degree of the varieties tested to fusarium head blight coincided during the two years of testing. Aplication of artificial ear inoculaltion with F. graminearum Schw. proved as a reliable method under different environment conditions in 2007, 2008 and 2009. |
