Among‐ and Within‐flower Comparisons of Pollen Tube Growth Following Self‐ and Cross‐pollinations in Dianthus Chinensis (Caryophyllaceae)

We compared the rate of pollen tube growth following self‐ and cross‐pollinations both among and within flowers of two clones of Dianthus chinensis L. For among‐flower comparisons, both styles of a flower were pollinated with either self‐ or cross‐pollen. Within‐flower comparisons were made between the two styles of the same flower, one of which was self‐pollinated and the other cross‐pollinated. Comparisons between flowers indicated that self‐pollen grew slower than cross‐pollen in both clones. However, differences in the growth rate of pollen tubes from self‐ and cross‐pollinations were greater when comparisons were made between the two styles of the same flower than when pollinations were made in different flowers. These results suggest the existence of interstyle interactions in pollen tube growth.