Abstract:
Nitrate reduction mutants (/i/Y-mutants) were selected from 33 isolates of Fusarium oxysporum isolated
from asparagus plantings showing reddish brown rot symptoms in Malaysia. These nitrate reduction
mutants were used in complementation tests for vegetative compatibility. Nine vegetative compatibility
groups (VCGs) were identified, but most (19) isolates fell into 4 VCGs that were found at more than one
location. There was no strong interrelationship between VCG and location. However, seven isolates were
identified as vegetatively self-incompatible based bn their inability to form heterokaryons between
complementary/fiY-mutants.
