Carpejani, Adriano Aygnes creator Pena, Guilherme Ferreira creator Vieira, Felipe Sakamoto creator Tiago, Poliana Vicente creator Rossi, Ana Aparecida Bandini creator text periodical abstract or summary bl. continuing eng Abstract In view of the economic and environmental importance of Bertholletia excelsa Bonpl. for the Amazon and the reducing natural habitat area of this species, the present study proposes to examine genetic variability among accessions of Brazil nut from the Amazon rainforest. Seventeen native Brazil nut genotypes were sampled from Sinop-MT and the genomic DNA were amplified using 15 inter-simple sequence repeat (ISSR) markers. The percent polymorphism and the polymorphism information content (PIC) of each primer were determined. The primers amplified 84.62% of the polymorphic bands and 15.38% of the monomorphic bands. The PIC for each primer ranged from 0 to 0.68. The Unweighted Pair Group Method with Arithmetic Mean (UPGMA) was the most efficient in group representation, as it showed the highest cophenetic correlation coefficient (CCC = 0.92), the lowest stress (12.31%) and the lowest distortion (1.51%). The use of ISSR markers was an efficient tool in the study of genetic diversity among Brazil nut genotypes, and the genetic diversity found can be used for conservation and pre-breeding programs for this crop. Keywords: ISSR, brazil nut, conservation. Publicação on-line; Bibliography p. 6-8; (50 ref.); 5 tables; 1 illlus.; Summary (En) MARCADOR MOLECULAR BERTHOLLETIA EXCELSO CASTANHA DO PARÁ CONSERVAÇÃO Rio de Janeiro-RJ Instituto de Florestas - UFRRJ 1994 2025-0458 1415-0980 / ISSN 2179-8087 0nline BR2026001906 v. 27(4) p. 1-8; (2020) https://www.scielo.br/j/floram/a/5d3yyMyvHP9jrpcHQxhyXtm/?format=pdf&lang=en https://www.scielo.br/j/floram/a/5d3yyMyvHP9jrpcHQxhyXtm/?format=pdf&lang=en BR-BrBNA 260611 20260611165133.0 eng