Essential oils of Schinus terebinthifolius and S. molle (Anacardiaceae): Mitodepressive and aneugenic inducers in onion and lettuce root meristems

Essential oils constitute an important group of plant products and include a mixture of volatile low-molecular-weight terpenes. The present study aimed to determine the phyto- and cytotoxicity of essential oils from leaves of Schinus molle and Schinus terebinthifolius on lettuce and onion. These essential oils affected germination, initial growth, and mitotic and metaphasic indexes of the target species. Compared to negative controls, essential oils of S. molle and S. terebinthifolius reduced the mitotic index of onion by 21.05% and 82.03%, respectively. Similar results were observed for lettuce. The volatiles also induced chromosomal abnormalities such as spindle disturbance at late prophase, sticky metaphase, c-mitosis, micronucleus, and nuclear buds. Although the essential oils of both species shared the same major compound (α-pinene), more pronounced effects were observed in S. terebinthifolius treatments. The results suggest that major and minor compounds of these essential oils act in synergy, causing the inhibitory effects observed on onion and lettuce.