Tropentag, October 6 - 8, 2009 in Hamburg "Biophysical and Socio-economic Frame Conditions for the Sustainable Management of Natural Resources"

Screening for Variability in Salt Tolerance within a Georgian Wheat Germplasm Collection

¹Leibniz-Institute of Plant Genetics and Crop Plant Research (IPK), Resources Genetics and Reproduction, Germany
²Institute of Botany of Georgian Academy of Science, Georgia
³University of Hohenheim, Dept. of Plant Production and Argoecology in the Tropics and Subtropics, Germany
⁴Leibniz-Institute for Plant Genetics and Crop Plant Research (IPK), Genebank, Germany

Abstract

Bread wheat Triticum aestivum L. possesses a genetic variation for the ability to survive and reproduce under salt stress conditions. Durum wheat (T. durum Desf.) is in general more sensitive in comparison to bread wheat, however, exceptions can be found showing the same extent of salt tolerance. Endemic wheats in general are characterised by a high adaptability to their environment. In Georgia several wheat species were already cultivated since the Neolithic and Early Bronze Age and the region is known for the abundance of endemic species. The level and variability of salt tolerance were assessed in a germplasm collection of 144 winter and spring wheat accessions from Georgia comprising Triticum aestivum L., T. durum Desf., T. dicoccon Schrank, T. polonicum L. and Georgian endemics: T. carthlicum Nevski, T. karamyschevii Nevski, T. macha Dekapr. et Menabde, T. timopheevii (Zhuk.) Zhuk. and T. zhukovskyi Menabde et Ericzjan. The accessions were tested for salt tolerance at the germination stage using four sodium chloride (NaCl in H₂O) concentrations (0, 175, 210 and 350 mmol l^-1). Large variability in salt tolerance within the Georgian germplasm was found among the different wheat species. The genetic background of the endemic hexaploid winter wheat T. macha comprises a higher potential for salt tolerance traits than T. aestivum. In general, the accessions of the tetraploid species responded to the lower sodium concentration with similar germination scores as the hexaploid wheat accessions, but germination and growth were severely reduced when the genotypes were subjected to the highest concentration of NaCl. The endemic wheat T. timopheevii was among the most tolerant tetraploid materials. Therefore, the Georgian endemic wheats represent promising donors for salt tolerant traits for future breeding efforts for salinity tolerance in wheat.

Keywords: Georgian germplasm, germination stage, salt tolerance, Triticum

Contact Address: Annette Weidner, Leibniz-Institute of Plant Genetics and Crop Plant Research (IPK), Resources Genetics and Reproduction, Corrensstr. 3, Gatersleben, Germany, e-mail: weidneripk-gatersleben.de