Prolonged Seed Dormancy in Phyllanthus emblica L. Can Be Overturned by Seed Scarification and Gibberellin Pre Treatment

Abstract

Phyllanthus emblica L. is an important constituent of Ayurvedic medicine and a fresh fruit species in the market in Sri Lanka. Therefore, it has a high potential to be established as a commercial fruit crop. The seeds of P. emblica are semi orthodox and exhibit a long dormancy period hindering the natural sexual propagation. Therefore, it still remains as an underutilized fruit crop in Sri Lanka due to its lack of quality planting material and poor propagation techniques. Long term dormancy also causes a big challenge in germinating seeds to create populations in breeding programs. In order to promote P. emblica from its underutilized status, what seems most feasible is to develop a method to break up the seed dormancy artificially. In order to do so, the methods of breaking the dormancy of P. emblica seeds have to be studied. Therefore, the aim of this study was to identify a method to break up the seed dormancy of P. emblica. The seeds were extracted from 21 trees belonging to three different districts in Sri Lanka. The selected viable seeds were subjected to four different pre treatments: none treated seeds (i.e. control), seeds scarified, seeds scarified and treated with 1% gibberellin and seed coat removed and followed by seeds treated with 1% gibberellin. From the four treatments, seed dormancy was overturned with a germination percentage of 43% by the seed pre treatment where the seeds were scarified and treated with 1% gibberellin and no other pre treatment methods were successful in breaking the dormancy. This suggests that the natural germination potential of P. emblica seeds is very low and it can be overridden by seed scarification and gibberellin pre treatment.