Effects of High Boron on the Nutrients Uptake of Aegilops Genotypes Differing in Their B Tolerance Level

Wheat wild relatives are considered as an important source of tolerance to several abiotic stress conditions. Their genetic diversity can be effectively utilized to develop breeding lines and modern wheat cultivars with greater stress tolerances. Despite their great potential, Aegilops species have not been completely explored for such tolerances. Boron (B) toxicity is one of the crucial abiotic stress conditions that negatively affect the wheat productivity in arid and semi-arid regions of the world. Other than several symptoms, high B is known to impede the uptake and translocation of macro and micronutrients in plants. Thus, the hypothesis is that the plants showing less effect of B toxic growth conditions on nutrients uptake and translocation can be more tolerant to B toxicity. To test this hypothesis, we have used 19 Aegilops genotypes differing in their B toxicity tolerance level along with a B toxicity tolerant cultivar, Bolal and estimated their root-shoot nutrient concentrations under B toxic growth condition. Further, the association between their root-shoot nutrient concentrations and level of B toxicity tolerance was evaluated. To understand the underlying mechanism, experimental genotypes were grown under three different B growth conditions in hydroponic system including Control (3.1 μM B); toxic (10 ppm B), and highly toxic (100 ppm B) boron treatment. The macro and micronutrient concentrations in the roots and shoots of the genotypes showed large variations and were observed to be differentially affected by high B stress.