Isozyme Variability in Field Populations of Phytophthora cinnamomi in Australia

Abstract

Isozyme characteristics of 280 isolates from populations of Phytophthora cinnamomi in native veg- etation in six locations in south-eastern Australia were examined at 19 enzyme loci. No new enzyme genotypic arrays were identified as compared with earlier samplings. This work indicates that the low variability for P. cinnamomi in Australia obtained in earlier work, from separate isolates in a wide range of locations, is paralleled in detailed population samples in south-eastern Australia. At one location, A₁ and A₂ mating types coexisted in soil samples. The lack of recombinants in these population samples suggests an absence of sexual reproduction in the field.