A chemical analysis of the Sorghum bicolor root exudate lead to the identification of the quinone sorgoleone 1 and the corresponding dihydroquinone 2 as the major components. An in vitro essay have shown that at the concentration of 20 mM this exudate caused a 13.1% reduction on the radicular growth of Lactuca sativa L. In a recirculating hydroponic culture system, the exudate produced by the roots of four plants of sorghum caused a 62.4% reduction on the lettuce leaf area after 33 days of planting.
allelophathy; Sorghum bicolor; sorgoleone; Lactuca sativa