Differential physio-chemical responses of wild and cultivar Sesamum species exposed to drought and recovery.

• Sesamum indicum , a commercial oilseed crop shows less productivity during severe and recurrent drought exposure. But its wild relative S. radiatum is considered as a potential candidate for drought-resistance. • Upon exposure to drought (15 days), the wild taxa sustained cellular turgor, regulated lipid peroxidation through enhanced accumulation of osmolytes, and higher activity of antioxidants than the cultivar. • The wild taxa recovered at a faster rate upon rewatering, and can be used to improve the drought-tolerance of sesame, thereby to combat the forthcoming climate crisis. Drought is one of the most significant abiotic stresses that affect plant performance, lowers agricultural output, and, in extreme cases, results in crop loss. The major challenge faced by farmers is to ensure the production of crop varieties under extreme environmental conditions. Sesame (Sesamum indicum L.) is a traditionally important major cash crop for small and marginal farmers in some developing countries since it requires less intensive care and investment. Although sesame is considered as a resilient crop, it remains sensitive to severe drought. In this study, the morpho-physiological, biochemical, and antioxidant responses of wild and cultivar species of Sesamum viz., S. radiatum , and S. indicum subjected to different irrigation treatments such as mild (75 % Field capacity), moderate (50 % FC) and severe (25 % FC) drought and subsequent recovery (rewatered to 100 % FC) were evaluated in comparison with control groups. Present findings revealed that both species displayed differential responses to the drought stress and subsequent recovery. In particular, the wild taxa demonstrated better drought tolerance, probably due to their higher leaf-relative water content, decreased lipid peroxidation, enhanced accumulation of osmolytes, and increased activities of enzymatic and non-enzymatic antioxidants. On the other hand, the cultivar presented reduced leaf-relative water content, increased lipid peroxidation, higher electrolyte leakage, and reduced antioxidant activities, mostly at 25 % FC. Present data suggests that the cultivar was strictly exacerbated, mostly during severe water deficits; however, the wild species could re-adjust to the water deficit circumstances and recover completely. The current study implies the potential of wild species that can be used to improve the drought tolerance of commercial sesame by utilizing the same in breeding programs. [ABSTRACT FROM AUTHOR]