Phytotoxicity studies of Canarium zeylanicum Blume on lettuce and radish.

We did a preliminary investigation of the allelopathic activity of 60 invasive and medicinal plants in Sri Lanka on Lactuca sativa (lettuce) and Raphanus sativus (radish). Out of 60 plants, 14 significantly reduced lettuce seedling lengths than distilled water, and 55 plants reduced radish seedling growth. In consideration of all the parameters tested, Cardiospermum halicacabum and Canarium zeylanicum Blume showed the highest phytotoxicity. C. zeylanicum (family Burseraceae), an endemic plant in Sri Lanka was selected for the isolation of phytotoxic compounds. The whole tree has a distinct fragrance bears edible seeds and has potential health benefits. This plant is used for medicinal purposes and its bark contains 3-hydroxy-12-methoxy-8,11,13-podocarpatrien-3-one and acetyl aleuritolic acid. This is the first report of the aforementioned two compounds from C. zeylanicum. These compounds exhibited phytotoxicity against lettuce. [ABSTRACT FROM AUTHOR]