Effects of potato-onion intercropping on root morphology of tomato through volatile organic compounds

Abstract

Facilitative interactions occur between the plants in intercropping systems, however, the underlying allelopathy mechanisms are poorly understood. We determined the effects of potato-onion (Allium cepa var. agrogatum Don.) intercrop on root morphology of tomato (Lycopersicon esculenum L.) through volatile organic compounds (VOCs). There were four treatments as (i) Tomato/tomato without VOCs interaction (-TT), (ii) Tomato/tomato with VOCs interaction (+TT, control), (iii) Potato-onion/tomato without VOCs interaction (-OT) and (iv) Potato-onion/tomato with VOCs interaction +(OT) in glasshouses. As compared to tomato, VOCs from potato-onion significantly increased the number of root tips total length but decreased the root diameter of tomato, however significantly the increase the tomato root length (0-0.5 mm mean diameter). These results indicated that the tomato root morphology has influenced by aboveground secreted VOCs from neighboring plants in potato-onion intercropping system.