Utilization of Organic Solvents for Pollen Preservation and Pre-flowering Pollen Collection in Cryptomeria japonica

Abstract

The pollen of Cryptomeria japonica (sugi), an economically important conifer species, was treated with various organic solvents—acetone, ethanol, chloroform, and hexane—to evaluate their effectiveness in pollen handling and preservation. When pollen was soaked in acetone or ethanol for 24 h at 4°C, its germination rate was significantly lower than that of the control (p < 0.01). In contrast, treatment with hexane did not significantly affect pollen germination (p > 0.05). Further storage of sugi pollen in hexane at 4°C decreased germination rate from 67.0% to 37.8% within one week, maintaining 36.2% viability after one month. Furthermore, hexane enabled the collection of viable pollen from male flowers harvested in December and February, before flowering. These findings suggest that the use of hexane offers a novel approach for the collection and temporary preservation of coniferous sugi pollen.