Preliminary Studies on Seed Dormancy of Premna latifolia Roxb.

Background: Premna latifolia Roxb. (Lamiaceae) is a deciduous tree distributed in Africa to China, throughout Indochina and Malaysia, to Australia and the Pacific. The various parts of the plant (leaves, stem bark and root) is reported to have numerous medicinal properties. The lack of understanding and consideration of dormancy and germination traits of a species could result in unsuccessful restoration programme. The aim of the present study was to investigate the nature of seed dormancy of P. latifolia that have low germination in natural conditions.

Materials and Methods: To determine the type of seed dormancy, water imbibition and germination test were performed. Seeds were treated by mechanical scarification, Gibberellic acid (GA) and combined treatment of scarification and GA before allowing them to imbibe in moist paper.

Results: All the treated (mechanically scarified, GA treated, mechanically scarified + GA treated) and untreated (control) seeds imbibed water for 4 days, however the maximum imbibition occurred in scarified seed + GA3 500ppm for 24 h (40.3%) followed by mechanically scarified seeds (38.7%). Higher germination was observed in scarified seeds + GA3 500ppm for 24 h (44%) followed by GA3 500ppm for 24 h (29.3%). Whereas, lowest germination was observed in untreated seeds (6.6%).

Conclusion: Seeds possess non -deep physiological dormancy which requires scarification and treatment of GA to enhance germination.