Between Phenolic Compounds and Polymorphic Profiles: A Robust Strategy for Genetic Studies in Caryocar Brasiliense

Objective: This study aimed to optimize a leaf DNA extraction protocol based on the CTAB method, with adaptations to mitigate the effects of phenolic compounds, and to evaluate the efficiency of ISSR markers in the genetic discrimination of natural populations of the species. Theoretical Framework: Caryocar brasiliense Cambess., commonly known as pequizeiro, is a native species of the Brazilian Cerrado with ecological, economic, and cultural relevance. The genetic characterization of its populations is essential for conservation strategies and genetic improvement programs. However, the presence of secondary compounds in the leaves hinders the extraction of high-quality DNA, compromising molecular analyses. Method: Samples from five regions in northern Minas Gerais were analyzed, with experimental adjustments to the extraction buffer, deproteinization time, and the number of pellet washing steps. For molecular analysis, 20 ISSR primers were tested, of which 11 produced satisfactory amplification. Results and Discussion: The samples showed high variability in DNA concentration and purity, with A260/A280 ratios ranging from 0.68 to 2.16, demonstrating the effectiveness of the protocol even in partially degraded leaves. The introduction of BSA (25 mg/mL) in PCR reactions significantly increased amplification efficiency, especially with primer UBC 840, resulting in polymorphic and informative profiles, particularly in the Mirabela-MG population. The results confirm that the optimized protocol is effective in obtaining high-quality DNA, being suitable for genetic studies in C. brasiliense. The combination of an adjusted extraction technique and the application of ISSR markers, supported by additives such as BSA, represents a robust and economically viable approach for the genetic characterization of the species, supporting conservation, management, and the valorization of Cerrado genetic resources.