Enhancement of Seed Germination in Trema orientalis (L.) Blume—Potential Plant Species in Revegetation of Mine Wastelands

Abstract

Natural forest succession takes a long time to accumulate sufficient nutrients to support plant growth and enhance soil microbial activity. Human intervention in selecting native pioneer plant species is therefore required to accelerate sustainable restoration. Trema orientalis (L.) Blume, a fast growing pioneer plant species, has the ability to grow in nutrient deficient soils and proves to have reclamation potential in mine wastelands. However, its use has been limited due to low germination percentages and nonsynchronous seed germination. In the present study we tested the effect of sulphuric acid (H₂SO₄), hydrochloric acid (HCl), gibberellic acid (GA₃), and potassium nitrate (KNO₃) in varying concentrations and time durations on germination percentages and seed germination synchrony. We found that all treatments had a significant effect in predicting seed germination probabilities. Logistic regression analysis revealed that treatment solution and concentration had a significant effect on seed germination. Treatment with concentrated H₂SO₄ for 15 min increased germination up to 92% within 20 days with the least imbibition time (8 days) and highest Seedling Vigor Index (491). The scanning electron microscope images of seeds treated with H₂SO₄ showed complete dissolution of the honeycomb-like network of deposits on the seed coat surface removing the physical barrier and enhancing germination.

Keywords:

• chemical scarification
• dormancy
• native plants
• seed germination
• seed coat

Acknowledgments

The authors thank M/s Fomento Resources Pvt. Ltd., Goa, for providing financial assistance. The authors also thank the National Centre for Antarctic Ocean Research (NCAOR), Goa, for assisting with the SEM imaging.