Drylands are extensively spread in southern Tunisia where there are sizeable underground saline water that can to be used for sustainable production of salt-tolerant plants. Barley is a relatively salt-tolerant plant, compared to other Poaceae species. In order to identify salt-tolerant barley genotypes, we evaluated and compared the effect of salinity on eight genotypes. We have used two levels of saline irrigation water (6 and 12 g NaCl.L-1) along with a non-saline control. Our results showed that for all genotypes, plant height was significantly reduced at 12 g NaCl.L1. However at this level of stress, leaf surface was reduced in some genotypes. It is worth to note that high salinity did not reduce leaf surface in both Tunisian varieties Manel and Rihane as well as in the introduced PK30118. These improved genotypes showed a strong decrease in their chlorophyll content, assessed by SPAD measurement. Yield parameters analysis showed that the local population Ardhaoui, Pak1, PK30109 and PK30046 exhibit a high number of ears/m2, independently of the salinity level of the irrigation water. The Tunisian improved cultivars as well as PK30118 and PK30130 were severely affected when irrigated with a 12 g NaCl.L-1. The thousand grains weight parameter was affected for all study genotypes at severe salinity except the local genotype Ardhaoui. The global yield analysis showed that in the absence of salinity, improved cultivars Manel, Rihane and the Pakistani lines PK30118 and PK30130 showed the highest yields. The lowest yield reduction at moderate stress was observed with Pak1 and with Ardhaoui with the severe stress. In general, our results showed that, only a severe salinity stress significantly affected barley lines confirming the salt tolerance of this specie. Moreover, our results indicated that salt sensitive genotypes are unable to restrict leaf expansion when submitted to salinity. On the whole, Manel and Rihane can be used only under non-saline conditions. The genotypes Pak1 and PK30046 can be also used under moderate salinity, while Ardhaoui can be used under both moderate and severe saline conditions.
