RESUMEN
In this study, the processes of pollination ecology of Fritillaria delavayi were investigated to document its reproductive characteristics. Some individuals of F. delavayi could produce seeds under bagging without emasculation (11%), but the rate was significantly lower than that of the natural control (87%). It is suggesting that pollination of F. delavayi largely depends on pollen vectors. Bombus sushikini was the only effective pollinator of F. delavayi and the visitation frequency was 0.003 time xXflower(-1) x min(-1). Flowering of F. delavayi in whole population lasted for 35 d and single flower for 11 d. Pollen viability and stigma receptivity lasted for 9 d and were relatively long compared with other Fritillaria genus plants. Consequently, bumblebee pollination and long floral longevity seem to be important for reproductive assurance of F. delavayi in harsh alpine environments.