Combined drought and salinity stress, prevalent in arid and semi-arid regions of the world, is known to have more damaging effects on wheat crops as compared to the individual drought and salinity stress conditions. Different hexaploid Triticum aestivum subspecies including ssp. compactum, ssp. spelta, and ssp. sphaerococcum have not been well explored for abiotic stress tolerance. While ssp. compactum and ssp. sphaerococcum are free threshing, ssp. spelta is a hulled type. All these subspecies are autogamous and can be crossed with ssp. aestivum to produce fertile offsprings. Hence, it will be useful to identify and utilize the potential genotypes of these subspecies to develop stress tolerant wheat cultivars. Thus, more than 20 genotypes of these species have been screened in hydroponic system under controlled, drought stressed, salinity stressed, and combined drought and salinity stressed growth conditions. The tolerance level of these genotypes was estimated in terms of growth parameters, photosynthetic rates, relative water content and electrical conductivity under different stress conditions. A huge genetic variation in stress tolerance was observed within and among all the studied species. A significant correlation was identified between the stress tolerance and different parameters. The obtained results directed that these neglected hexaploid wheat subspecies can be a potential source of combined drought and salinity stress tolerance.

Acknowledgements: The authors acknowledge the TUBITAK 1001 (No. 123R072) project for the funding provided to conduct this research work.