For pollen fertility - Please , follow the method describrd in my publication
The biological value of pollen of some blackcurrantcultivars (Ribes nigrum L.) Acta Agrobotanica 06/2006; 59(1):147-154. DOI: 10.5586/aa.2006.015
However, flowers storage is very difficult. If you would like to use pollen for morphological study You may simply dry the flowers, or make the glycerogelly slides.