Fabiana Firetti

By Fabiana Firetti

In neotropical ecosystems, genetic variability and diversity of plant species seem to be generated and maintained by sexual reproduction. However, apomixis appears as an alternative reproductive strategy in many plant families. Apomixis comprises the development of a new organism from an unreduced and unfertilized egg cell. Traditionally, it is considered a dead end of evolution due to the lack of genetic variability; however, processes such as de novo mutation, gene conversion, mitotic recombination and epigenetic drift may work as important sources of genetic variation during apomictic reproduction. Moreover, plant species show facultative apomixis, which allows the formation of sexual and asexual offspring. As a result, natural apomict populations show greater genotypic variability than expected from a clonal population. Also, asexual reproduction is considered one of the important attributes promoting diversity in angiosperms. Here, I review the occurrence of apomixis in several plant families that are well represented in neotropics and I infer the relation between apomixis and diversity of species. Many plant families that are common in the neotropical region show facultative apomixis associated with polyploidy and hybridization events. Apomixis seems to play a key role in the establishment of new evolutionary lineages in a wide variety of environmental conditions.

Part of the book: Vegetation