Anther development, microsporogenesis and microgametogenesis of Kielmeyera coriacea Mart. & Zucc. (Calophyllaceae)

• Grant number: 24/22551-3
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: March 01, 2025
• End date: February 28, 2026
• Field of knowledge: Biological Sciences - Botany - Plant Morphology
• Principal Investigator: Letícia Silva Souto
• Grantee: Biancca Yokomizo Girardi
• Host Institution: Centro de Ciências Humanas e Biológicas (CCHB). Universidade Federal de São Carlos (UFSCAR). Sorocaba , SP, Brazil

Abstract

The androecium, the male reproductive part of angiosperm flowers, is formed by stamens that are composed by filaments and anthers. The anther is the most apical portion of the stamen and usually presents four microsporangia, where several microspores are produced and develop in pollen grains. The pollen grains can be dispersed in distinct ways, three of them present in the genus Kielmeyera-namely, monads, tetrads or polyads. In general, the angiosperms present non-compartmentalized anthers and pollen grains dispersed in monads, however, locellate anthers and pollen grains dispersed in groups (tetrads and polyads) are common in Kielmeyera. Anatomic studies of anthers in the genus are limited, though are extremely important to understand the group evolution. With the aim of studying the anther and pollen grain development of a species dispersing the pollen grains in tetradsi, Kielmeyera coriacea Mart. & Zucc. was chosen. For that, flower buds and flowers were collected from a population of the state of São Paulo in October 2024. The samples were fixed in FAA and stored in 70% alcohol. The flowers and flower buds will be dissected to remove the anthers that will be included in methacrylate resin, cut in microtome and stained with toluidine blue. This will allow us to determinate how the anther wall and the locelli are formed, how the pollen grains are formed and at what point in the development the changes that lead to the non-separation of the pollen grain tetrads occur. Hence, we expect to contribute to a better understanding of the anther evolution in the genus and the family.