Response of Durum Wheat (Triticum turgidum L. subsp. durum) to Root Exudate Autotoxicity and Osmotic Stress Depends on Variety Combination

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Imen Bouhaouel
Soumaya Nasraoui
Khaoula Boudabbous
Olfa Ayed-Slama
Hajer Slim Amara


The problem of autotoxicity is known in cereal crop residues, and is one of the major reasons for reduced growth/yield under continuous monoculture practice. However, investigation on the autotoxic effects of wheat root exudates is scarce. This is the first report on autoinhibition activity of durum wheat roots during seedling establishment stage. Nine variety combinations were tested according to two experimental protocols, ‘seed-to-seed’ and ‘seed-after-seed’, under water stress applied at different osmotic pressures (0, 50, 100, 150, and 200 g l-1) using the polyethylene glycol ‘PEG6000’. Comparing the two protocols, our finding showed that durum wheat root exudates cause autotoxicity. Coleoptile growth seems to be more sensitive to high PEG6000 concentrations (100, 150, and 200 g l-1) than that of radicle. The magnitude of the inhibitory action depended on the combination of donor and receiver plants, which may be of the same or different varieties. Notably, Nasr-Karim, Maali-Maali, and Maali-Khiar were the most affected combinations by root exudate autotoxicity and water stress effect, while combinations with the same variety, such as Sculpture-Sculpture, Khiar-Khiar, and Nasr-Nasr were the least affected.

Durum wheat, autotoxicity, root exudates, variety combinations, water stress, PEG6000

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Bouhaouel, I., Nasraoui, S., Boudabbous, K., Ayed-Slama, O., & Amara, H. S. (2021). Response of Durum Wheat (Triticum turgidum L. subsp. durum) to Root Exudate Autotoxicity and Osmotic Stress Depends on Variety Combination. Asian Journal of Research in Biosciences, 3(2), 6-13. Retrieved from
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