Relative water content and malondialdehyde as physio-biochemical indicators for evaluating water deficit tolerance of Triticum dicoccoides, tetraploid progenitor of wheat

Triticum dicoccoides, the immediate tetraploid progenitor of durum (T. durum) and bread wheat (T. aestivum) is known to endure harsh environmental conditions. The present study was aimed at exploring the responsiveness of Triticum dicoccoides accessions to early vegetative stage water deficit stress. Relative water content (RWC) and malondialdehyde (MDA) content were evaluated from the leaves of field-grown rain-fed plants. Significant genotypic variation was observed in wild accessions along with cultivated durum PDW 291 and bread wheat PBW 621 included in the set. The relative water content ranged from 75.50% (acc 7054) to 83.78% (acc 5251). The average content of malondialdehyde was recorded as 30.85 nmole g⁻¹ FW. Fourteen of the twenty-six T. dicoccoides accessions accumulated MDA less than the cultivated wheats. Overall, T. dicoccoides accessions 4655, 4667, 5251, 7054, 7079 and 14004 may be shortlisted to identify distinct allelic variants/stress-responsive loci for subsequent deployment in the wheat breeding program.