Physiological and Biochemical Effects of Drought Stress in Stevia (Stevia rebaudiana Bertoni)

Abstract

Drought has been limiting the productivity of agricultural crops by increasing alarmingly in recent years. This situation has increased the importance of research on the determination of plants resistant to arid conditions. In this study, two cultivars (Yalova and STF-4) of Stevia rebaudiana Bertoni plant were investigated physiological and biochemical responses of under drought stress. Plants were grown in controlled greenhouse conditions for 3 months and then exposed to drought for 3 weeks. The plants harvested after three weeks were measured leaf length, osmotic potential, relative water content (RWC), chlorophyll fluorescence (Fv/Fm), proline amount, hydrogen peroxide (H2O2) amount and lipid peroxidation level. In both cultivars of S. rebaudiana plant, when compared to the plants in the control group under drought stress, while a decrease in leaf length was detected, the highest decrease was found in Yalova cultivar (25.7%). However, both cultivars maintained their water status under drought stress. While Fv/Fm value was not affected by drought in STF-4 cultivar, Yalova cultivar decreased compared to the control. In the amount of proline was a difference between the cultivars. While STF-4 cultivar under arid conditions no change was observed in the amount of proline, increase of 42.9% occurred in Yalova cultivar. On the other hand, drought stress significantly increased the lipid peroxidation level in leaves. While this increase was 41.2% in Yalova cultivar, it was 21.1% in STF-4 variety. Differential response to drought stress between the two cultivars, was observed in H2O2 content. The amount of H2O2 under drought stress, while decreased by 42.7% in Yalova cultivar it increased by 5.5% in STF-4 variety. As a result, in the light of the measured parameters the STF-4 cultivar of S. rebaudiana plant was revealed that more drought tolerant.

Effect of Drought and UV-B Stress on Leaf Morphology of Ash-Leaved Maple and Sycamore Maple

“…exposed to harmful UV-B radiation were studied. In addition, the effects of drought stress on Echinacea purpurea L. (Mizgin et al, 2020), physiological and biochemical responses of drought stress on Stevia rebaudiana Bertoni (Yalçın et al, 2021), Borago officinalis L. (Torun and Eroğlu, 2021) and Seseli resinosum Freyn and Sint (Torun and Aydın, 2021), physiological and antioxidant responses and tolerance reactions of drought stress, morphological, physiological, and biochemical responses of Ostrya carpinifolia Scop. (Yılmaz et al, 2022) were investigated.…”