Author(s): Nidal Odat
Soil salinity limits crop productivity by affecting the growth, physiology, and expression of stress-responsive genes. To evaluate which varieties of cultivated barley from Jordan are salt tolerant, five cultivars of barley (Hordeum vulgare L.) of different varieties and morphotypes (i.e., two-and six-rowed barley) were evaluated in terms of their germination, growth traits, and gene expression of Cu/Zn- and Fe-SODs to three levels of salinity (100, 200 or 300 NaCl mM). Germination and root length were significantly affected by moderate and high levels of salinity (200 and 300 mM NaCl) mainly in the varieties Athroh, Mutah, Acsad176, Rum, and to lesser extent in Yarmouk variety, possibly as a consequence of osmotic stress and/or ionic toxicity. Analysis of quantitative real-time PCR (qRT-PCR) showed differential expressions of both Cu/Zn- and Fe-SOD genes between varieties and genotypes (i.e., the sixrowed barleys-Athroh, Acsad176, and Rum-and two-rowed barley-Yarmouk and Mutah). Moreover, both genes were up-regulated by salinity of 300 mM NaCl in the Athroh, Yarmouk, and Acsad176 varieties. Altogether, the result revealed that responses to salinity in all traits of germination, root growth, and gene expression were dependent on the variety and genotype of studied barley. Accordingly, these results have helped us to distinguish between salttolerant and salt-susceptible genotypes of cultivated barley of Jordan that shall be useful to local farmers and breeders of barley.
