EXAMINATION OF MITOCHONDRIAL-DNA RESTRICTION-FRAGMENT-LENGTH-POLYMORPHISMS, DNA FINGERPRINTS, AND RANDOMLY AMPLIFIED POLYMORPHIC DNA OF COLLETOTRICHUM-ORBICULARE

Twenty-four isolates of Colletotrichum orbiculare, three isolates of C . magna, and two putative isolates of Glomerella cingulata var. orbicu lare, representing diverse geographical and cucurbit host origins, veg etative compatibility groups, and races were examined for mitochondria l and nuclear DNA restriction fragment length polymorphisms (RFLPs) an d randomly amplified polymorphic DNA (RAPD), Six isolates of C orbicul are from cocklebur, a noncucurbit host, also were examined. Four mitoc hondrial DNA (mtDNA) haplotypes, designated A, Al, B, and C, were obse rved among the isolates examined. Twenty-two isolates, representing th ree vegetative compatibility groups and two races pathogenic to cucurb its, had an identical mtDNA RFLP haplotype (haplotype A) with each of seven restriction enzymes. Six cocklebur isolates (nonpathogenic on cu curbits) had an mtDNA RFLP haplotype identical to the pathogenic isola tes with six of the seven restriction enzymes examined; however, restr iction enzyme PvuII detected a single additional restriction site in t he mtDNA of the cocklebur isolates (haplotype Al). Three nonpathogenic isolates of C magna had a third mtDNA RFLP haplotype (haplotype B). T wo nonpathogenic isolates of C orbiculare from honeydew melon and two nonpathogenic isolates of Glomerella cingulata var. orbiculare from cu cuzzi gourd had a fourth mtDNA RFLP haplotype (haplotype C). DNA finge rprinting, which was conducted with the synthetic oligonucleotide prob e (CAT)5 or a human minisatellite DNA probe, identified these same fou r haplotypes. Five RAPD primers also resolved the four RFLP groups. On e RAPD primer resolved two groups among isolates within mtDNA RFLP hap lotype A that correlated with host origin, vegetative compatibility gr oup, and race. Thus, one RAPD primer differentiated the two races of C orbiculare. Overall, there was a strict correspondence between mtDNA RFLP haplotype, DNA fingerprint group, and RAPD group among the isolat es examined.