Extrafloral nectaries in four species of Sapindaceae: structure and diversity

• Grant number: 22/06272-1
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: August 01, 2022
• End date: July 31, 2023
• Field of knowledge: Biological Sciences - Botany - Plant Morphology
• Principal Investigator: Diego Demarco
• Grantee: Danielle Maximo Fonseca e Silva
• Host Institution: Instituto de Biociências (IB). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Sapindaceae is one of the largest families of the order Sapindales, standing out from the others due to the presence of latex and extrastaminal nectariferous disk. Although there is a great diversity of nectaries in the order and a significant volume of studies on them, there is no information about the extrafloral nectaries of Sapindaceae, with the exception of morphological and topological data, which indicate a high structural diversity for the family. Previous observations suggest that the extrafloral nectaries of Paullinia, Serjania, and Urvillea have an anatomical structure different from all other nectaries of the order; therefore, this project aims to describe, for the first time, the extrafloral nectaries in species of these three genera, aiming to investigate their structure and nectar composition. For the structural study, young shoots will be fixed, embedded, and sectioned in a rotary microtome. For the analysis of the main chemical classes of the nectar, several histochemical tests will be performed, in addition to the use of glycosuria. The results of this study will allow classifying the type of the extrafloral nectary of Sapindaceae and identifying its structural diversity in relation to the other nectaries of the order. (AU)