Development of seeds as self-organizing units: testing the predictions

Abstract

Differential development of seeds and their abortion in multi-ovulated fruits is explained by a process of self-organized movement of resource units into the developing ovules. This process involves movement of resource units would be autocatalytically favored and hence dominate over others at a rate defined by the sink-drawing ability of the ovules of a species. Such a process leads to varying levels of seed abortion that are independent of resource or pollen limitation and also predicts a positive relationship between the sink-drawing ability of a species and the extent of seed abortion in its fruits. We tested this prediction by (1) manipulating the sink-drawing ability of ovules in phaseolus vulgaris Linn., Vigna unguiculata Walp., Crotolaria medicaginea Lam., and Solanum seaforthianum Andr.; (2) analyzing the relationship between the in vivo sink-drawing ability and seed abortion in 15 species; and (3) using data from the literature. Our results seem to indicate that, as sink-drawing ability of ovules in a fruit or of a species increases, seed abortion also increases, supporting the self-organization model.