Comprehensive evaluating of wild and cultivated emmer wheat (Triticum turgidum L.) genotypes response to salt stress

Emmer wheat as the progenitor of common wheat, holds the genetic potentiality for improvement of wheat yield, quality and stress tolerance such as drought and salt. To comprehensively evaluate the salt tolerance of emmer wheat, a total of 30 traits including growth, physiology and photosynthesis related as well as K+ and Na+ content of 30 wild emmer and 14 durum wheat accessions were systematically investigated and compared between normal and saline conditions. Salt tolerance index (STI) based on multiple regression analysis of these traits was calculated and five wild emmer accessions showed high salt tolerance, which could be used as valuable resource for wheat salt tolerance improvement. Furthermore, wild emmer genotypes showed wider trait performance variation compared to durum wheat, indicating the higher genetic diversity in wild emmer wheat. Then, shoot Na+ content, shoot K+/Na+ ratio, root length and root surface area were identified as suitable indexes for salt tolerance evaluation. Na+ exclusion mechanism was found to be playing an important role in response to salt stress in emmer wheat. The salt tolerance in emmer wheat was systematically characterized here, which not only provided the elite germplasm for wheat improvement, but also provided the efficient method and some useful indexes for salt tolerance assessing.