Infrageneric relationships, synopsis and evolution of foliar and inflorescence parts in Luxemburgia (Ochnaceae)

• Grant number: 24/09427-1
• Support Opportunities: Scholarships in Brazil - Master
• Start date: December 01, 2024
• End date: September 30, 2026
• Field of knowledge: Biological Sciences - Botany - Plant Taxonomy
• Principal Investigator: José Rubens Pirani
• Grantee: Sophia Yukimi Honda Cáceres
• Host Institution: Instituto de Biociências (IB). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Luxemburgia constitutes the only Brazilian endemic genus of Ochnaceae, composed of ca. 20 species distributed mainly in campo rupestre vegetation in Minas Gerais. Taxonomically relevant characters in the genus are associated with leaves, especially venation patterns and stipules form, and inflorescences, mainly related to bracts and bracteoles traits. Nevertheless, as those attributes display significant inter and intraspecific variability, currently it is difficult to establish accurate patterns supporting a confident species delimitation. In addition, the infrageneric relationships within the genus are still not fully understood given the low resolution of the phylogenetic reconstructions made for the genus. Hence, the main goals of this study are: i) to quantify morphological variation (e.g. leaf venation, stipules, bracts and bracteoles length, persistence, number of cilia in the apex and/or margins) in all species, in order to properly assess their use for species circumscription; ii) to infer a robust phylogeny for Luxemburgia, including all described species and using nuclear and plastid DNA sequences obtained through the target capture technique. A combined analysis of molecular and morphological data will be performed to obtain an ancestral trait reconstruction aiming to propose robust hypotheses on the evolution of such characters in the group. The morphological and evolutionary data produced by this study will contribute to the knowledge about endemic lineages of Brazilian mountain floras.