Screening wild progenitors of wheat for salinity stress at early stages of plant growth: insight into potential sources of variability for salinity adaptation in wheat

Abstract

Wild relatives of wheat have served as a pool of genetic variation for understanding salinity tolerance mechanisms. Two separate experiments were performed to evaluate the natural diversity in root and shoot Na+ exclusion and K+ accumulation, and the activity of four antioxidant enzymes within an extensive collection of ancestral wheat accessions. In the initial screening experiment, salinity stress (300 mm NaCl) significantly increased Na+ concentration in roots and leaves and led to a significant decline in root and shoot fresh weights, dry weights, and K+ contents. Principal component analysis of the 181 accessions and 12 species identified three first components accounted for 63.47% and 78.55% of the variation under salinity stress. We identified 12 accessions of each species with superior tolerance to salinity for further assessment of their antioxidant defence systems in response to salinity. Both mild (250 mm NaCl) and severe (350 mm NaCl) levels of salinity significantly increased activities of four enzymes, indicating an enhanced antioxidant-scavenging system for minimising the damaging effects of H2O2. Some of the wild relatives—Aegilops speltoides (putative B genome), Ae. caudata (C genome), Ae. cylindrica (DC genome) and Triticum boeoticum (Ab genome)—responded to salinity stress by increasing antioxidants as the dominant mechanism to retain oxidative balance in cells. Further evaluation of salt-tolerance mechanisms in these superior wild relatives will help us to understand the potential of wheat progenitors in the development of more salt-tolerant varieties.

iPASTIC: An online toolkit to estimate plant abiotic stress indices

“…Information on experimental setup, growth conditions, salinity treatments, and collection of aboveground biomass yield under control (Yp) and saline (Ys) conditions for each seedling plant is in Ahmadi et al. (). Detailed information on the tested genotypes is in Appendix .…”

“…A greenhouse pot experiment was conducted in 2015-2016 at the Crop Production and Breeding Department, Imam Khomeini International University, Qazvin, Iran. Information on experimental setup, growth conditions, salinity treatments, and collection of aboveground biomass yield under control (Yp) and saline (Ys) conditions for each seedling plant is in Ahmadi et al (2018b). Detailed information on the tested genotypes is in Appendix S1.…”

Effect of Water Deficit Stress on Seedling Biomass and Physio-Chemical Characteristics in Different Species of Wheat Possessing the D Genome

“…Therefore, these new resources can provide an ideal opportunity for producing new varieties. Wild wheats are a valuable source of genes related to water deficit stress and other abiotic and biotic stresses [15,[29][30][31][32]. For example, Aegilops tauschii Coss.…”

Assessment of genetic diversity inTriticum urartuThumanjan ex Gandilyan accessions using start codon targeted polymorphism (SCoT) and CAAT-box derived polymorphism (CBDP) markers

“…Hence, distribution of this germplasm in the different parts of Iran, suggest that this area is an ideal source of diversity for discovering useful genes to transfer into modern wheat. Several studies reported that T. urartu is an ideal source of genes related to seed quality, tolerance to both biotic [especially for leaf rust and powdery mildew diseases] and abiotic [especially for drought, salinity and cold] stresses tolerance [4][5][6][7][8][9][10][11][12].…”