Isolation of Thielaviopsis basicola from soil with umbelliferous root tissue as baits

Root tissue of 31 cultivars and varieties representing 12 species and 12 genera of the Umbelliferae were tested and evaluated as baits for Thielaviopsis basicola (Berk. & Br.) Ferr. in soil. The relative ability of root tissue of each species to selectively bait T. basicola from soil was measured as degree of invasion of the root tissues by T. basicola and freedom of the tissue from decay by other organisms. Root tissue of carrot as bait was superior to root tissue of other species tested. The mechanism(s) in carrot which permits selective isolation of T. basicola from soil is not restricted to carrot but can be found in varying degrees in at least five other species in the Umbelliferae.