Gamma irradiation effects on durum wheat (Triticum durum Desf.) under various conditions.

The effects on morphological and physiological characters of durum wheat (Triticum durum Desf.) plants issued from seeds upon irradiation with low doses of cobalt gamma rays (i.e., 0, 10, 20 and 30 Gy), were studied. The study is carried out in the Experimental Research Station of Ecole Supérieure d'Agriculture du Kef (North West Tunisia) in 2008/2009. In Petri dishes, the 20 Gy dose caused an increase of the speed and Germination Capacity (GC) of the seeds as compared to non irradiated ones. Plants from these treated seeds maintained on Knops' culture medium (culture medium used to study plant growth in test tubes), improved root system in terms of length, volume and weight when compared to the plants issued from the non treated seeds. This irradiation dose (20 Gy) also improved in a significant way the above ground system growth of the plants. Under glass house conditions with a water stress, the plants issued from seeds treated with 20 Gy, had higher water content and membrane stability as compared of those from the non irradiated ones. Furthermore, seed irradiation with this dose had a positive effect on the chlorophyll content and maximum quantum yield of the irradiated plants. These results suggest that ionizing irradiation may be considered as an alternative in improving root growth of the plant and therefore controlling drought.