Anther and pollen ontogenesis of Kielmeyera pumila Pohl (Calophyllaceae)

• Grant number: 25/14191-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: October 01, 2025
• End date: September 30, 2026
• Field of knowledge: Biological Sciences - Botany - Plant Morphology
• Principal Investigator: Letícia Silva Souto
• Grantee: Caroline Lanza Pivetta
• Host Institution: Centro de Ciências Humanas e Biológicas (CCHB). Universidade Federal de São Carlos (UFSCAR). Sorocaba , SP, Brazil

Abstract

This project aims to study anther and pollen ontogeny of Kielmeyera pumila Pohl, the structures responsible for producing and storing pollen grains. Anthers are formed through successive cell divisions and elongations, giving rise to different tissues with specific functions. Internally to these tissues is the sporogenous tissue, which, through meiotic and mitotic divisions, forms microspores, or pollen grains, that can be dispersed in different pollen units. The anther development is a conserved aspect in most angiosperms and can be used for different types of studies. However, ontogenetic studies are little explored among angiosperms, especially within the family Calophyllaceae. The genus Kielmeyera Mart. & Zucc. has approximately 50 species that are distributed throughout South America, in environments with some type of restriction. Its anthers and pollen grains show considerable variation between species. The pollen grains, commonly aggregated in Kielmeyera, do not follow the most common condition among angiosperms, i.e., being dispersed as monads, making the genus an ideal model for studying pollen groupings. Kielmeyera pumila is a native subshrub endemic to Brazil in which pollen grains can be released either as tetrads or polyads; thus, the species is key to understand the evolution of pollen release in the group. Therefore, this project aims to study the development of the anthers and pollen grains of K. pumila, making it possible to fill the gaps in knowledge regarding the formation of pollen clusters and set the foundation to future research in this genus and in other groups of angiosperms.