Embriology of Nymphaea l. (Nymphaeales: Nymphaeaceae): implications for the early evolution of angiosperms

• Grant number: 14/01529-8
• Support Opportunities: Regular Research Grants
• Start date: December 01, 2014
• End date: November 30, 2016
• Field of knowledge: Biological Sciences - Botany - Plant Morphology
• Principal Investigator: Nelson Sabino Bittencourt Junior
• Grantee: Nelson Sabino Bittencourt Junior
• Host Institution: Instituto de Biociências, Letras e Ciências Exatas (IBILCE). Universidade Estadual Paulista (UNESP). Campus de São José do Rio Preto. São José do Rio Preto , SP, Brazil

Abstract

Understanding the diversification of Nymphaeales has a considerable interest to propose models of early evolution of the angiosperms, since recent phylogenetic studies based on molecular data have shown that Nymphaeales seems to be the second diverging clade, after Amborella, in the angiosperm phylogeny. Reproductive features are sources of the major traits that separate the angiosperms from the other seed plants. Therefore, investigating the reproductive biology of basal lineages of angiosperms is critical to establish its ancestral character states, and to understand the origin and early evolution of this group. In this project the andro- and gyno- sporo-gametogenesis, as well as the embryo and endosperm development will be investigated in some members of the Nymphaeaceae aiming to verify if the plesiomorphism of the Nuphar/Schisandra type gynogametophyte and cellular diploid endosperm in flowering plants would be supported by new data from non-investigated taxa belonging to the Nymphaeales. Moreover, we aim not only to contribute for a better understanding of the evolutionary origin of the endosperm and its possible homology with the embryo, but also to reveal new embryological data that would be used in the phylogenetic design of the family and/or the circumscription of infra-familiar taxonomic categories. The species selected to this study are Nymphaea caerulea, N. amazonum and Victoria amazonica. Flower buds, flowers at anthesis, and fruits in a range of developmental stages will be collected and processed to obtain permanent slides of microtomic serial histological sections that will be submitted to ordinary toluidine blue O staining and histochemical procedures for analysis in light microscope. (AU)