Population Structure of Heterobasidion annosum in Pure Pine Stands in Ukraine : Root and Butt Rots

Uppsala

International Union of Forest Research Organizations, Swedish University of Agricultural Sciences

1994

S. 340-347

16 Lit. Ang.

Bandaufführung

73681

The distribution of naturally occurring clones of Heterobasidion annosum was investigated in pure Scots pine plantation in Eastern Kharkov region, (70-year-old stand) and Central Ukraine (Gitomir region, 33- and 42-year-old stands). The total area investigated was 1,1ha. Clones were identified on the basis of reaction zone formation between paired heterokarvons (somatic incompatibility test). In all 50 different clones were identified among 125 tested heterokaryons on the three plots. The number of clones per hectare on plots was 21 and 73 in the 70- and 42-year-old stands, respectively. The mean number of pines infected by one clone was 2,3. The mean linear size of individual clones, expressed as the longest distance between points of isolation of two compatible heterokaryons, was 12,6m in the 70-year-old stand and 8,5m in the 42-year-old stand. The size of largest clone found in the oldest stand was 21m. The rate of vegetative spread of clones in the 42-year-old stand varied between 5 and 39cm per year (mean 18 cm/year).