Comparative osmotic adjustments in barley and tetraploid wheats

Five barley (Hordeum vulgare L.), five durum wheat (Triticum turgidum convar. durum L.) and one wild emmer wheat (Triticum turgidum convar. dicoccoides) genotypes from different origins and differing for drought tolerance and potential yield, were studied for their osmotic adjustment capacity at the same stage and under similar water stress conditions. Differences for water status parameters between barley and tetraploid wheat genotypes were noted and discussed. The lowest osmotic adjustment capacities were noted in drought susceptible varieties, while a high capacity was found in genotypes exhibiting a high yield stability across contrasting environments. Relative water content, leaf osmotic potential and accumulation of soluble sugars were found to be highly related with osmotic adjustment; they could be used as criteria for a rapid evaluation of osmotic adjustment in segregating populations.