Study of Some Mechanisms of Tolerance and Avoidance of Water Deficit in Barley (Hordeum vulgare L.)

Abstract

Some mechanisms of drought tolerance and avoidance have been studied in eight barley genotypes. These include three local cultivars (Ttichedrett, Beldi, Saida) and five introduced (Malouh, Seg09, Mari29, Awblack, Beecher) which were grown under three different water supply (100% FC, 60% FC, 30% FC). The increase in intensity of the water deficit reduces differently the relative water content among tested genotypes. Thus, in the treatment of 60% FC, this reduction varies between 1% (Beldi) and 6% (Tichedrett, Beecher), while in the lot of 30% FC it reaches the limits of 3% (Beldi) and 18% (Seg09). The results show that plants grown under water deficit (60% CC, 30% FC) accumulate significantly soluble sugars (r = 0.54**) and K+ (r = 0.26**) compared to control plants (100% CC). Thus, under 30% FC, the accumulation of soluble sugars reached values of 195% and 208% observed at Mari29 and Awblack. The accentuation of the water deficit causes a significant reduction of the RWL particularly after 120 mn (r = -0.27**) which is accompanied by an increase of the stomatic resistance (r = 0.53**). To limit dehydration under the water deficit, tested genotypes were distinguished into three groups by adopting avoidance, tolerance or by combining the two strategies.

Keywords

• barley
• drought
• tolerance
• transpiration
• osmotic adjustment