Association Mapping For Salinity Tolerance Related Traits in a Structured Barley Population

Document Type : Original Article

Abstract

ASTRUCTURED barley population of 103 wild barley accessionand 19 spring barley cultivars was used to identify quantitativetrait loci (QTLs) for salt tolerance traits by means of an associationmapping approach using 660 DArT markers. In this investigationbarley accession and spring barley cultivars were employed in a twoyeargreenhouse project having a completely randomized designinvolving four irrigation water treatments having different salinitiesand twice replicated. Measurement parameters included grain yieldper plant, straw weight, relative water content, chlorophyll content,Na+, K+ and salt tolerance %. Several statistical models werecompared, the K-model was less spurious background associations,in this model 61 QTLs were detected under both of control and saltstress conditions (1000, 3000 and 5000 ppm NaCl of waterirrigation) over whole barley genome for yield, straw weight, relativewater content, chlorophyll content , Na+, K+ and salt tolerance %.Among of these QTLs, 21 detected under control, phenotypicvariations explained by these QTLs, were ranged from 8.02 in N+ to25.67% of the total variation in K+. 40 QTLs were identified undersaline conditions and the phenotypic variation explained by eachmain effect QTLs (M-QTL) ranged from 4.65 % in chlorophyllcontent at 3000 ppm condition to 28.13 % in ST at 5000 ppmcondition. The genomic regions that harbor QTLs for Na+, salttolerance and related traits on chromosome 1H, 2H and 7H in ourstudy can be used for targeting candidate gene (s) for salt toleranceof barley.

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