A REPRODUCTIVE CALENDAR OF LILIUM-LONGIFLORUM THUNB CV GELRIA

The development and timing of different processes in the floral biolog y and sexual reproduction of Lilium longiflorum were studied and broug ht together into a chronological reproductive calendar. Care must be t aken when emasculating flowers later than 4 days before anthesis (DBA) , because the stomium of the anther was open from 8 DBA and the pollen grains appear to be mature from 3-2 DBA. The receptivity period of th e pistil lasts for a rather long period, but before wilting of an unpo llinated flower as determined by a change of the colour of the periant h from white into brown, the flower had already lost its receptivity. Because L. longiflorum pollen grains can easily be stored, the pistil receptivity should thus determine the pollination schedule. The relati onships between pollen tubes and pistil are discussed with respect to plant breeding.