STIGMA RECEPTIVITY OF 2 PROTEA CULTIVARS IN RELATION TO THE DEVELOPMENT OF HYBRIDIZATION TECHNIQUES

Stigma receptivity of two Protea cultivars was investigated by observi ng seed set, pollen tube growth and the opening and closing of the sti gmatic groove. Both cultivars were found to be protandrous. Peak stigm a receptivity, measured by seed set, was found to occur during the per iod of two to six days after anthesis in Fl repens (L.) L. cv. Sneyd a nd at three days in P. eximia (Salis. ex Knight) Fourcade cv. Fiery Du chess. Peak stigma receptivity in P. repens Sneyd, measured by pollen tube growth, was found to occur during the period of two to six days a fter anthesis when the maximum mean number of pollen tubes per ovary w as 2.5. Peak stigma receptivity in Fl repens Sneyd, based on the width of the stigmatic groove, was found to be at three to six days after a nthesis, and in FI eximia Fiery Duchess at five to seven days. Pollen tubes reach the ovary after four days and the maximum pollen tube numb er in the ovary occured at seven days after anthesis. It is proposed t hat Protea spp. be hand-pollinated two to six days after anthesis in o rder to obtain maximum seed set. For studies on pollen tubes in the ov ary, inflorescences should not be harvested before seven days after po llination.