Assessment of Durum Wheat (<i>Triticum turgidum</i> var.<i> durum</i>) Cultivars for <i>in vitro </i>Salt Tolerance

In vitro</em> salt tolerance of 28 cultivars of durum wheat with native and exotic origins was investigated, using MS medium containing sodium chloride. The resulting calli were subjected to 8 salinity levels including 0, 0.3, 0.6, 0.9, 1.2, 1.5 and 1.8 percent NaCl (w/v). Donor plants of explant (immature embryo) were grown in a recirculating hydroponics and pots in a greenhouse as well as in the field. Assessment of calli was conducted after 0, 8 and 16 days after subculture of calli into the NaCl-contained medium. Callus growth rate, relative callus growth rate and percentages of callus necrosis were measured, using a 8 × 28 factorial experiment layout in a completely randomized design with 3 observations per treatment and 3 replications. Results of analysis of variances showed that among the criteria, relative growth rate of callus was the most reliable, while callus growth rate as not being quantitatively measured, was less devoted. Results of this study revealed that 'PI 40100' and 'Dipper-6' were superior genotypes for in vitro</em> salt tolerance. The high relative callus growth rate and less callus necrosis of these cvs. may indicate their superior genetic potential for in vitro</em> salinity tolerance.