Effect of dormancy breaking treatments on germination, vigour and physio-biochemical changes in seeds of Rauvolfia serpentina (L.) benth. ex kurz-endangered medicinal species

Rauvolfia serpentina (L.) Benth. ex Kurz is an endangered medicinal species which produces large proportion of non-viable seeds. In addition, the viable seeds show dormancy because of adverse influence of the stony endocarp, seed coat induced dormancy and non-deep physiological dormancy rendering the seed mediated propagation unsatisfactory. The present study indicates the effect of dormancy breaking treatments on germination and underlying physio-biochemical changes in Rauvolfia serpentina (L.) Benth. ex Kurz. Untreated seeds did not show germination, whereas, the maximum germination percentage (36.67%) was observed in seeds subjected to GA₃ 200 ppm for 48 hrs, which was closely followed by GA₃ 100 ppm for 48 hrs (28.89%), KNO₃ 1% for 48 hrs (23.33%) and chilling at 5°C for 4 weeks as well as thiourea 0.5% for 48 hrs (22.22%). Henceforth, above seed treatments can pave the way for breaking dormancy; inducing gerinamtion and improving vigour of seeds of Rauvolfia serpentina which otherwise remained ungerminated. Physio-biochemical responses of seeds to these pre-sowing treatments have also been discussed.