Effects of differential drying rates on seed germination in Bombacopsis quinata seeds

The seeds of Bombacopsis quinata bear resemblance to recalcitrant seeds that can not be dried and conservation of such seeds is difficult. The present study focuses to understand the germination behaviour of B. quinata seeds, when the seeds are desiccated to lower moisture contents at different rates.

The seed when slow dried under ambient conditions for 24, 48 and 72 hrs equilibrated to 35.3, 17.1 and 14.6% moisture content respectively. The percentage germination did not show any significant decrease. When the seeds were rapidly dried over silica gel for 24, 48 and 72 hrs they attained 14.8 %, 11.4 and 9.4% moisture content respectively. The rapid drying resulted in progressive loss of viability reaching a low of 12% germination after 72 hrs of drying. However, seeds maintained high viability when they were slow dried for 48 hrs followed by rapid drying for 24hrs. Increase in mean germination time was observed in the desiccated seeds. The increase was more in seeds dried over silica gel as compared to slow dried seeds under ambient conditions. About 83% of the seeds showed polyembryony which was not affected by desiccation.