Seed Germination Behavior of Withania spp. under Different Temperature Regimes

摘要

The genus Withania comprises 23 species, among which only two [IV. somnifera (Ashwagandha) and W. coagulans (Ashutoshbooti)] have been reported from India. Withania spp. dried roots are widely used in traditional system of medicine. Optimal germination potential is essential for commercial growers to justify buying premium-priced seed and ensure acceptable performance of their crop. An experiment was initiated to determine seed germination potential and vigor index of W. somnifera and W. coagulans atthree constant (15°C, 20°C, and 25°C) and one alternating (15/35°C) temperature (10/14 h) regimes in Petri dishes, with daily 16 h light (180 lx)/8 h dark photoperiod. Highest germination percentage (92%) and seedling vigor index II (0.2583) were observed at 15/35°C, followed by 15°C (90.7% and 0.1207, respectively) in W. somnifera. Vigor index I was highest (344.5) at 15°C, followed by 15/35°C (319.7) in W. somnifera. In the case of W. coagulans, highest germination percentage (65%), seedlingvigor index I (499.9), and vigor index II (0.0609) were recorded at 15°C, followed by 20°C (germination = 55%, vigor index I = 450.01, and vigor index II = 0.0516). This information should help growers in raising a healthy nursery of W. somnifera at 15/35°C or 15°C and 15 or 20°C for W. coagulans.