The evolutionary significance of multigermicity in the genusSpinacia (Chenopodiaceae)

Abstract

The presence of multigerm seedballs in the chenopodiacious genusSpinacia is noted. In the wild, colonising, and “weedy” dioecious species,S. turkestanica andS. tetrandra, the distribution of a multigerm seedball could effectively overcome the problem posed by isolation of the sexes. The hypothesis is tested assessing the extent of intra-seedball progeny hybridisations and seed production in the two wild species. The success in seed production by intra-seedball progeny crosses suggests that the distribution of such seedball progeny groups permits not only a percentage survival under isolation of these dioecious plants, but also the colonisation of areas outside that of the parent populations.