Neutral Genetic Diversity of Brazilian Native Flora: Current Approaches and Gaps

Understanding genetic diversity is crucial for plant adaptation in a changing world. The neutral genetic variation (NGD) is correlated to adaptation capacity, which is crucial for long-term conservation of threatened species. Brazil, a megadiverse nation with habitats encompassing a great variety of ecosystems, harbors a wealth of plant biodiversity, yet studies on NGD remain scarce. This work analyzed published data on NGD in native Brazilian plant populations, identifying 731 papers through a systematic search on the Scopus database. Results indicated microsatellite markers as the most used for population studies, followed by ISSR. The SNP marker is still underutilized, possibly due to its higher costs and labor-intensiveness. Fabaceae, Bromeliaceae, and Arecaceae were the most studied families. Moreover, the two most studied species were Euterpe edulis and Hancornia speciosa, both economically important species. Notably, trees and herbs dominated the studies with a focus on the Atlantic Forest biome. However, Cerrado and Amazon biomes were also well represented, underscoring the importance of broader investigation across all Brazilian ecosystems. These findings reveal a critical gap in knowledge, where traditional molecular markers are most used and few economically important species are intensively studied. The number of threatened species studied is negligible, and most are not endemic. With looming climate and landscape changes, more comprehensive studies of NGD of threatened flora in Brazil are vital. The lack of genetic diversity information of native species may threaten any conservation efforts in the long term.