Morpho-physiobiochemical dissection reveals insight into salt-induced differential responses in genetically modified Solanum melongena L. (Bt Brinjal) varieties using an indigenous hydroponic system

Salinity is a major abiotic constraint of crop production in many countries, including Bangladesh, where a significant amount of cultivable areas are diversely affected by rising salt concentrations. Therefore, it is of paramount importance to figure out the possible solutions to cope with this abiotic stress. So, the development of tolerant genotypes of various crop species can be the best alternative to enhance crop production as well as to improve the livelihoods of poor marginal farmers. With this in mind, the impact of different NaCl levels (50 mM, 100 mM, and 150 mM) on four different Bt Brinjal (Bacillus thuringiensis) genotypes (BARI Bt Begun-1, BARI Bt Begun-2, BARI Bt Begun-3, and BARI Bt Begun-4) was evaluated using morpho-physicochemical analyses at growth, harvesting, and postharvest stages by establishing a new indigenous cost-effective hydroponic system. Our results show that excess salt (> 100 mM) has a detrimental effect on plant growth and development and most of the traits measured across different growth stages. Based on the different measured traits, BARI Bt Begun-1 and BARI Bt Begun-2 varieties outperformed in terms of better morpho-physiological, biochemical, photosynthetic, and antioxidant capacity under salt stress when compared to BARI Bt Begun-3 and BARI Bt Begun-4. Therefore, we conclude that BARI Bt Begun-1 and BARI Bt Begun-2 are moderately tolerant varieties, while BARI Bt Begun-3 and Begun-4 were susceptible varieties to salinity stress. The identified salt-responsive contrasting varieties can serve as valuable genetic materials in comparative genomics for breeding salt-tolerant Brinjal varieties and the newly established hydroponic system could be utilized in translational research programs.