Abstract
Salt tolerance of wheat is known to change with growth stage. Identifying the multiple parameters associated with salt tolerance during different growth stages is important for evaluating wheat genotypes and improving their salt tolerance. Thirteen wheat genotypes from Egypt, Germany, Australia and India were grown in soil and exposed to four salinity levels (control, 50, 100 and 150
mM NaCl). Tiller number, leaf number and leaf area per plant at vegetative stage; dry weight per plant at vegetative, reproductive and maturity stages; and yield components of main spike and total grain yield at maturity were determined. The results showed that tiller number was affected more by salinity than leaf number and leaf area at the vegetative stage. Salinity decreased dry weight per plant significantly at all growth stages. Spikelet number on the main stem decreased much more with salinity than spike length, grain number and 1000-grain weight at maturity. According to cluster analysis with multiple agronomic parameters at all growth stages, the Egyptian genotypes Sakha 8 and Sakha 93 and the Indian genotype Kharchia were ranked as the most tolerant to salinity. A change in salt tolerance with growth stages was observed for Sids 1, Gemmeza 7 and Westonia. Drysdale and Sakha 69 were ranked as moderate tolerant. The remaining genotypes showed the lowest tolerance to salinity at all growth stages. We conclude that an increase in tiller number per plant and spikelet number per spike will improve the salt tolerance of wheat genotypes in breeding programs. Cluster analysis with multiple agronomic parameters simultaneously to evaluate the salt tolerance facilitates the rankings of salt tolerance of wheat genotypes.