Karyotype and genome size of Brazil nut (Bertholletia excelsa, Lecythidaceae). A technical note

• Published in: Tree genetics & genomes Vol. 21; no. 5; p. 23
• Main Authors: Mondin, Mateus, Chiriboga-Arroyo, Fidel, Martins, Karina, Kettle, Chris J., Silva, Gabriel Fernando
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.10.2025; Springer Nature B.V
• Subjects: Bertholletia excelsa; Biodiversity; Biomedical and Life Sciences; Biotechnology; Chromosomes; Conservation; Flow cytometry; Forestry; Forests; Genomes; Integrated software; Karyotypes; Lecythidaceae; Life Sciences; Nuts; Plant Breeding/Biotechnology; Plant Genetics and Genomics; Rainforests; Seeds; Short Communication; Sustainability management; Tree Biology; Trees; Brazil; Asia; Chromosome structure; Amazon basin; Ericales; Sustainability; Chromosome number; Nuez boliviana; Rainforest
• ISSN: 1614-2942; 1614-2950
• DOI: 10.1007/s11295-025-01709-6

Bertholletia excelsa (Lecythidaceae), commonly known as the Brazil nut, stands as a pivotal species in sustainable rainforest management, offering a multinational solution for long-term rainforest stewardship in the Amazon. Despite its economic and ecological significance, fundamental genetic data such as genome size and detailed chromosomal analysis still need to be included. Here, we present the first report on the genome size estimation of B. excelsa , determined through flow cytometry analysis to be 654.87 Mbp, with a confirmed chromosome count of 2n = 34. A tentative classification of chromosome morphology reveals a predominance of submetacentric chromosomes, indicating a potential karyotypic asymmetry. Furthermore, we provide insights into chromosome size estimation in Mbp, serving as a crucial reference for future genome assembly efforts. Notably, B. excelsa becomes only the second species within the Lecythidaceae family with a characterized genome size. Our findings underscore the wide variation in genome sizes within the family, emphasizing the importance of comprehensive genetic characterization efforts for neotropical and tropical species. This study contributes with genetic data essential for the next steps towards the genome-wide studies with positive potential implications for the conservation and sustainable management of B. excelsa and highlights avenues for further research in rainforest biodiversity conservation.