Effective techniques to break seed dormancy in Rhodomyrtus tomentosa (Aiton) Hassk. for seed germination enhancement

Abstract

Rhodomyrtus tomentosa is a valuable plant for medical and pharmaceutical uses. The plant reproduces through seeds; however, the seeds become dormant, resulting in low germination rates. The industrial demand for this plant is expanding, making sustainable propagation a major challenge. The present study aims to evaluate different techniques for breaking the dormancy of R. tomentosa seeds. A randomized design was used to evaluate different techniques for breaking the dormancy of R. tomentosa seeds, including de-operculum, chemical scarifications, and exogenous gibberellic acid (GA₃), in both laboratory conditions at ambient temperature (25 ± 2 °C) and field conditions. The characteristics of R. tomentosa fruit and seeds were assessed. The average mass, width, and length of fruits were 1.90 g, 13.78 g, and 15.27 g, respectively. The average seed/ripe fruit contained 57 seeds, and the mass of 1000 seeds was 2.64 g. Seed viability (100 %) was achieved in the treatment with 0.075 % tetrazolium at 45 °C for 3 h, but a germinated seed was only 13.00 %. The study of breaking seed dormancy in laboratory conditions revealed that de-operculum significantly enhanced seed germination up to 83.00 % within 15 days, compared with control treatment of 13.00 % within 34 days (p ≤ 0.01). In contrast, 10 % KNO₃ for 24 h under field conditions resulted in the highest seed germination rate of 91.00 % within 34 days, while de-operculum treatment showed 63.00 % of seed germination within 15 days. In addition, the seed water imbibition rate between control and de-operculum seeds was evaluated. The results demonstrated that the control seeds absorbed water more slowly than the de-operculum seeds, indicating that de-operculum promoted faster germination. The findings concluded that breaking seed dormancy is important for R. tomentosa seed germination. De-operculum and KNO₃ were discovered to be effective ways of breaking seed dormancy in R. tomentosa.