Evaluating Salt Tolerance of 14 Barley Accessions from Southern Tunisia Using Multiple Parameters

Abstract

Barley "Ardhaoui" (Hordeum vulgare L.) is a local landraces cropped in southern Tunisia characterized by its resistance to drought and salinity. Salt tolerance of barley changes according to the growth stages. In order to study the salinity tolerance of (Hordeum vulgare L.), fourteen barely accessions, were grown in soil and exposed to four salinity levels (5, 7, 13 and 20 dS/m).To evaluate its salt tolerance using multiple parameters, fourteen barley accessions from two regions in the southern Tunisia (costal and mountainous regions) were grown in soil and exposed to four salinity levels (5, 7, 13 and 20 dS/m). Plant growth parameter, total biomass at final harvest, straw yield and yield compound associated with salt tolerance during the different growth stages were determined. The results showed negative effects of salinity on the growth and the development of the barley. However, the salt sensitive accessions showed a greater reduction in tiller number (e.g. by about 80 %) than tolerant ones (e.g. by about 57 %) at 20 dS/m. These decrease on the growth of leaves, tillers and the aerial part constitute a strategy developed by the barely in vegetative phase to reduce the salt stress. Tiller and spikelet numbers were more affected by the salinity at 13 and 20 dS/m the different results showed significant correlation between the spikes numbers and the tiller number (r = 0.872). The salinity affected negatively these two parameters, which both initiate during early growth stages. So, the salinity has a greater influence on final grain yield than on yield components in the later stages. The studied parameters showed significant differences (p<0.05) between the barely accessions.The cluster analysis using agronomic parameters at all growth stage showed that the accessions "Ettalah" and "Elhezma" were ranked as the most tolerant to salinity. However, "Boughrara" and "Edwiret Elgdima" accessions were ranked as moderate and presented a change of their degree of tolerance with the different growth stage. The remaining accessions showed the lowest tolerance to salinity. A highest tolerance was observed on the accessions from plain zones compared at those of mountainous zones.The response differences between accessions of local population of barley "Ardhaoui" reflecting an important internal genetic variability against the salinity. This variability could be more explored and used for the barley breeding program.

Identification of barley landrace genotypes with contrasting salinity tolerance at vegetative growth stage

“…However, the most tolerant ones showed minimal percentages decrease. These results corroborate those obtained by Ben Khaled et al (2012).…”

“…However, within barley, the most sensitive stages towards salinity seem to be the earlier growth stages (Adjel et al 2013). Indeed, the vegetative stage which is characterized by its high tillering capacity appears to be a very important stage to evaluate genotypes response towards salinity (Ben Khaled et al 2012). Thus salt tolerance at vegetative stage is considered as an important indicator of barley salt tolerance at later growth stages.…”

Variable Levels of Tolerance to Water Stress (Drought) and Associated Biochemical Markers in Tunisian Barley Landraces

“…In southern Tunisia, where precipitation is very low, barley is the predominant cereal due to its tolerance to drought stress. In this region, there are many landraces, such as those included in the “Ardhaoui”, “Beldi”, “Djebali”, “Djerbi”, “Frigui”, “Sfira” or “Souihlis” landrace groups, which are well-known for their stress tolerance [ 18 , 19 , 20 , 21 , 22 ].…”

“…Given that crop landraces are generally well adapted to the agroclimatic conditions of the region where they evolved and may contain a large genetic variation [ 24 ], they represent an interesting source for the selection of drought-tolerant materials. Barley landraces from Tunisia are genetically variable [ 18 , 25 ] and therefore are amenable to selection for drought tolerance, as long as diversity exists for this trait. In this respect, Ben Khaled et al [ 18 , 26 ] found genetic variation for salinity tolerance among different landrace accessions of the “Ardhaoui” barley, which is autochthonous of southern Tunisia and is grown in areas with low precipitation.…”

Salt tolerance in barley originating from harsh environment of North Africa

“…Here, a characterization based on the vegetative, yield and its related traits was investigated, which showed a high intra-specific diversity among the North African genotypes regarding salt tolerance. The existence of a large amount of genetic diversity has been already reported on barley (Royo and Aragues, 1999;Ben Khaled et al, 2012), rice (Mahmood et al, 2009) and wheat (El-Hendawy et al, 2005).…”