ABSTRACT
The conventional hypothesis of gametophytic self-incompatibility in the angiosperms involves one to four multiallelic incompatibility loci and the positive inhibition of incompatible pollen tubes. However, this concept does not accommodate recent experimental data indicating that there may be many loci. An alternative hypothesis which incorporates many loci and complementary pollen-style interactions suggests that there may be no S gene, as previously thought, and that gametophytic self-incompatibility is perhaps merely one aspect of extensive pollen-style interactions.
ABSTRACT
Pollinations were made on either the tip or the basal portions of the stigmatic surface in Dianthus chinensis. These two treatments provided, respectively, either good or modest opportunity for pollen tube competition. The pollen used came from a single clone. Technical and statistical methods were used to reduce greatly the influence of variation in seed weight. Seeds resulting from the two contrasting treatments were planted, and it was found that there were statistically significant differences in germination time and seedling weight between treatments. These results suggest that the quality of the F1 generation can be significantly modified by competition between pollen tubes from a single plant.
