Enhancement of seed germination in Macaranga peltata for use in tropical forest restoration

Abstract

We used pre-sowing treatments viz., soaking seeds in concentrated sulphuric acid (CSA), gibberellic acid (GA), combined treatment of CSA + GA and mechanical scarification to overcome seed dormancy and enhance synchronous germination of Macaranga peltata seeds. We analysed percent seed germination data by logistic regression and confirmed that except in GA treatment, time and acid concentration together were crucial for enhancing germination. The combination treatment of CSA and GA resulted in higher percent germination (up to 74%) than either treatment used separately, but produced defective seedlings (26%). Mechanical scarification of seed coat had the greatest impact in enhancing germination (78%) and reducing imbibition time (6 days) against the control (0%). Germination studies and SEM analysis confirmed that seed germination in M. peltata was inhibited by seed coat dormancy.