Virulence spectrum of the Erysiphe graminis DC. ex Merat f. sp. tritici Em. Marchal population in Southeastern part of Yugoslavia in 1986 and 1987

Stojanovic, S.; Ponos, B.

Virulence spectrum of the Erysiphe graminis DC. ex Merat f. sp. tritici Em. Marchal population in Southeastern part of Yugoslavia in 1986 and 1987

1990

Stojanovic, S. | Ponos, B. (Institut za strna zita, Kragujevac (Yugoslavia))

Powdery mildew is a frequent and economically important wheat disease in Yugoslavia. Thus, the selection programs include improving of new varieties which would have good resistance beside other positive characteristics. But, the greatest difficulties in this task are made by parasite population changes. That is the reason for studying of Erysiphe graminis tritici virulence spectrum in the southeastern part of Yugoslavia in 1986 and 1987. Isogenic wheat lines with genes Pm 1, Pm 2, Pm 3a, Pm 3b, Pm 3c and Pm 4a were used in this investigations. Results showed wide virulence spectrum of this fungi in Yugoslavia. Analysis of 375 isolates originating from 76 localites and different wheat varieties estimated 38 different virulence genes combinations. Beside wide variability, the population is virulent because most isolates had three or four virulence genes. But, the greatest part of population is composed from rather few genotypes, with virulence formula 2, 3b, 4a/1, 3a, 3c; 1, 2, 3b, 4a/3a, 3c and 1, 3b, 4a/2, 3a, 8c. Their presence in localities and years investigated didn't change much pointing to parasite stability in time and space.

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