Prezygotic barriers in Alstroemeria aurea (Alstroemeriaceae).

SOUTO, C.; M., AIZEN & A. PREMOLI

Ascona, Suiza

Workshop; Evolutionary ecology of the prezygotic stage; 2003

Prezygotic barriers may represent effective mechanisms to avoid the deleterious effects of inbreeding.  We report the existence of distance-dependent prezygotic barriers in self-compatible Alstroemeria aurea, a clonal herb native to temperate forests of the southern Andes.   Here we analyzed the effects of physical distance (1, 10, and 100 m ) and genetic similarity (10 electrophoretic loci) between donor and recipient ramets on pollen performance.  The proportion of pollen tubes that reach the base of the style increased strongly with crossing distance, an effect that could be attributed directly to the degree of genetic relatedness between donors and recipients.  We propose that the existence of prezygotic barriers might contribute to the high degree of genetic mixing exhibited by some clonal species.