부산대학교 도서관

Although there are reports of isolation of mycoherbicidal pathogens attacking the widespread broomrapes (Orobanchespp.) that parasitize legumes and vegetables, none is in use or available. This is despite there being no good method of controlling broomrapes in most crops other than by preplant fumigation with methyl bromide. Two highly parasitic fungi, Fusarium arthrosporioidesstrain E4a (CNCM I-164) and F. oxysporumstrain E1d (CNCM I-1622), were isolated from nearly 100 organisms found on diseased, juvenile, emerging Orobancheflower stalks. A near-axenic polyethylene envelope system for culturing broomrape on tomato roots was used to ascertain pathogenicity of these strains. Both organisms fulfilled Koch's postulates for being primary pathogens. Their DNAs were analyzed and fingerprinted by restriction fragment length polymorphism and random amplified polymorphic DNA, showing that they are indeed different from each other and from many other Fusariumspp. and other formae speciales of F. oxysporumincluding a strain that attacks O. cumanaon sunflowers. Both strains infect O. aegyptiaca, O. cernua,and O. ramosa,but not O. cumana.They did not infect any of the vegetable and legume crops tested and thus seem specific to Orobanche.Tomato plant roots dipped into a fungal spore and mycelial suspension and planted in broomrape-infested soil were protected for 6 weeks, as were tomato transplants in pot experiments. About 90% control was also achieved by posttransplant soil drench with fungal suspensions in pot experiments. These pathogens may be effective as seed, transplant, or soil-drench treatments of high-value vegetable and other crops.