Rice seedlings release allelopathic substances

Rice (Oryza sativa L,) seedlings inhibited the growth of hypocotyls and roots of cress (Lepidium sativum L.) seedlings when both seedlings were grown together. Two growth inhibiting substances were found in the culture solution in which rice seedlings were hydroponically grown for 14 d. One growth inhibitor was further purified. This suggests that the rice seedlings may produce growth inhibiting substances, acting as allelochemicals to other plants, and release them from their roots into the environment.