Comparisons of Isolates of Fusarium avenaceum from White Lupin and Other Crops by Pathogenicity Tests, DNA Analyses and Vegetative Compatibility Tests

Isolates of Fusarium avenaceum\ mostly from crops of white lupin or wheat\ were tested for pathogenicity on white lupin and wheat plants and compared by DNA tests and\ in a limited study\ vegetative compatibility[ Most of the 79 isolates were pathogenic on both plant species after inoculation on shoot bases[ Disease severity was greater at higher incubation temperatures that ranged from 04:09>C to 14:19>C "day:night tempera! tures#[ Isolates from lupin crops tended to be more patho! genic\ on average\ on lupins than on cereals[ Polymerase chain reaction "PCR#!restriction fragment length poly! morphism "RFLP# analysis of the internal transcribed spacer region of the rDNA distinguished two groups of isolates that occurred in di}erent proportions among isolates from lupins and cereal crops[ Random ampli_ed polymorphic DNA "RAPD#!PCR analyses indicated considerable genetic variation among isolates\ but there was some similarity among groups of isolates from popu! lations in the same _eld[ Genetic diversity was con_rmed by a high degree of vegetative incompatibility among 19 isolates using nitrate nonutilizing mutants[ There were no relationships among pathogenicity\ RFLP group\ RAPD group and vegetative compatibility group[