Function of the pollen coat in different stages of the fertilization process

The weight of released proteins after four subsequent washings of pollen of Petunia hybrida L, in germination medium (containing 10% saccharose and 0.01 % boric acid) is calculated to be c. 18% of the original dry pollen weight. Although washed-and-dried pollen did germinate very badly after replacement in the germination medium, it produced normal pollen tube growth in the style and normal seed setting in the ovary. It is concluded that released pollen coat substances are not functional in the in vivo fertilization process. Another conclusion is that these eluted pollen coat substances have no role as recognition factors in the gametophytically-determined incompatibility system of Petunia.