Species delimitation in the subgenus Cereus mirabella (cereeae, cactaceae) using the cactaceae591 ortholog panel

• Grant number: 25/00918-5
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: May 01, 2025
• End date: April 30, 2026
• Field of knowledge: Biological Sciences - Genetics - Plant Genetics
• Principal Investigator: Fernando de Faria Franco
• Grantee: Milena Sviatek Ribeiro Rocha
• Host Institution: Centro de Ciências Humanas e Biológicas (CCHB). Universidade Federal de São Carlos (UFSCAR). Sorocaba , SP, Brazil

Abstract

Species delimitation is essential for evolutionary studies and biodiversity conservation. The unified species concept integrates different approaches (biological, ecological, etc.) as stages in lineage diversification. Phylogenies, which depict evolutionary relationships among species, benefit from next-generation techniques for robust inference. Traditional molecular markers often lack efficiency for non-model organisms, such as cacti, making taxon-specific target sequencing panels preferable. The family Cactaceae, iconic in the Americas, is valued for its cultural importance and ecological roles. Its rapid diversification and complex patterns challenge species recognition based on morphology alone. The subgenus Mirabella F.Ritter, including Cereus mirabella N.P.Taylor and Cereus albicaulis (Britton & Rose) Luetzelb., is found in the Brazilian Caatinga and Cerrado, with unresolved phylogenetic relationships. Taxonomic debates persist regarding the delimitation of Estevesia alex-bragae P.J.Braun as a synonym of C. mirabella or an independent taxon (C. alexbragae (P.J.Braun et Esteves) M.Köhler). Furthermore, morphological similarities between C. mirabella and C. albicaulis challenges the taxonomy. This study aims to apply a multilocus phylogenetic approach using target sequence capture with the Cactaceae591 panel to resolve these issues, by testing the reciprocal monophyly of C. mirabella, C. albicaulis, and C. alexbragae, and detect intraspecific lineages through tools like HybPiper, IQ-TREE, Astral, and GATK.