Abstract

Leeks (Allium porrum L.) are increasingly included in the rotation or inter-planting with tobacco in many provinces of China and worldwide. Therefore, we examined the possible allelopathic potential of leek seeds on the germination, seedling emergence and root elongation of flue-cured tobacco of different cultivars. The effects of imbibed leek seeds, their aqueous leachates and extracts of the seed on the germination and root elongation of the seeds of four test flue-cured tobacco cultivars, K 326, Yunyan 85, Zhongyan 100 and NC 89, under both aseptic and soil conditions, were investigated. Inhibitory effects were evident in all of the bioassays of these tobacco seeds. The leachates of the leek seeds and the aqueous seed extract were highly inhibitory, but the seeds themselves were less inhibitory. The observations indicate a release of inhibitory substances from the leek seeds leading to the observed inhibitory effects. The results of this study may be very useful for the management of crop rotations/systems involving leek as a component.

Key words: Allium porrum L., allelopathy, flue-cured tobacco, inhibitory effects, seed germination, seed extract.