Association of an allele-specific marker with dehydration stress tolerance in foxtail millet suggests SiDREB2 to be an important QTL

Dehydration-responsive element binding (DREB) genes assist in improving stress tolerance of plants by activating the expression of several stress-responsive genes. Therefore, development of functional markers for useful alleles utilizing DREB genes is crucial for crop improvement strategies. Earlier we reported a synonymous single nucleotide polymorphism (SNP) associated with dehydration tolerance at 558(th) bp (an A/G transition) in the SiDREB2 gene of foxtail millet (Setaria italica L.) and developed an allele-specific marker (ASM) for SiDREB2. In the present study, we validated this ASM using a set of 122 foxtail accessions, of which 45 were investigated in an earlier study. The QTL associated with SiDREB2 contributed to similar to 20 % of the total phenotypic variation (PV) for relative water content (RWC) and this signified the importance of this QTL for dehydration tolerance in foxtail millet.