Preliminary studies on seed dormancy of Schleichera oleosa (Lour.) Merr.

Schleichera oleosa is a tropical deciduous tree species distributed in south-east Asia. The aim of the present study was to investigate the nature of seed dormancy of Schleichera oleosa that have low germination under laboratory conditions. Seeds were treated by scarification, Gibberellic acid (GA), and combined treatment of scarification and GA before allowing them to imbibe in moist paper. Maximum water uptake was observed in seeds that were soaked in GA after scarification. The moisture content of seed coat remained unchanged during imbibition that suggests the water-impermeable nature of seed coat. Scarification accelerated germination, but it could not fully eliminate dormancy. The highest germination was found in the combined treatment of scarification and GA application. Dry storage at room temperature for 9 months broke dormancy and allowed germination of untreated seeds at 28C. The results indicate that Schleichera oleosa seeds exhibit both physical (for its water-impermeable seed coat) and physiological dormancy and need afterripening for 9 months to overcome the dormancy. The ecological perspective of dormancy of this tropical seed has been discussed.