Inflorescências - Terminologia/classificação e tendências evolutivas em Magnoliophyta (Angiospermae).

RUA G.H.; REINHEIMER R.

Gramado, Brasil

Congreso; Os avanços da Botânica no início do século XXI; 2006

Sociedade Botânica do Brasil

Statements about homology of inflorescence parts has been largely influenced by typology-based comparative-morphology. In the last years a new source of evidence became available from developmental genetics. Once flowering is triggered, flowering SAM can either produce floral structures or remain indeterminate, depending on the expression of meristem-identity genes. Evidence from defective mutants of some model plants points to a simple genetic switch controlling the indeterminate/determinate developmental fate of a SAM. Moreover, both timing effects and bi-directional development seem to play a crucial role in determining the ultimate inflorescence form. Homology correspondences between different inflorescence parts might be reassessed, in order to adjust descriptive terms, such as ‘synflorescence’, ‘florescence’, and ‘paraclade’, to such current evidence. Although morphological-comparative analyses are an unavoidable step to construct primary homology hypotheses regarding inflorescence parts, such hypotheses must be further tested through developmental, genetic, and phylogenetic tools.