Effet de l'irradiation des semences d'orge (Hordeum vulgare) sur la croissance des jeunes plantules et la résistance au Drechslera teres

Abstract

Barley seeds of two cultivars (Smash and Thibaut) and one line (74-F-6) with water contents adjusted between 12.8 and 13.3%, were irradiated with various doses (1–160 Gy) of 60Co γ rays. Doses of 1–40 Gy favored an increased length of the first leaf. In general, doses of 15 and 20 Gy decreased barley susceptibility to Drechslera teres f. maculata by 25 and 21%, respectively. This reduction was a function of the line or cultivar used. The best response was obtained with cv. Smash. Seedling growth stimulation and host susceptibility to D. teres were significantly correlated (r = −0.68). The stimulatory effect of γ rays on growth could be used at low levels, to provide adequate field resistance to net blotch caused by D. teres f. maculata. Key words: barley, Hordeum vulgare, seeds, γ ray, net blotch, Drechslera teres.