Cells, Genes & Molecules

Range-wide genetic structure of an endemic herb from the Amazonian Savannas

The study assesses neutral and adaptive genetic structure and genetic diversity in Brasilianthus carajensis (Melastomataceae), an endemic herb from Amazonian Savannas.

Rare and narrowly distributed plants are particularly sensitive to loss and fragmentation of their natural habitats. This can ultimately result in reduced genetic diversity and a weakened ability to adapt to a changing environment. Conserving threatened endemic species is essential to maintain their evolutionary potential and minimise their extinction risk. Novel genomic technologies (such as RAD sequencing) have revealed themselves as a promising tool that can help to inform future conservation management, highlighting strategies that may work best for particular species and/or populations.

Brasilianthus carajensis (A) bush and (B) flower. Image credit: Pedro L. Viana.

In a recent study published in AoBP, Silva et al. evaluated the genetic health of a narrowly distributed herb (Brasilianthus carajensis) from the Amazonian Savannas. Using Next-Generation Sequencing technologies they were able to take a detailed glance at a representative portion of the plant’s genome, assessing genetic diversity, genetic composition and adaptations to local environmental conditions. The results of this study provide clear guidance on how to avoid the loss of unique genetic variation in this unique plant. The study identified three neutral and six adaptive genetic clusters, which could be considered as management units and adaptive units, respectively. The recent creation of the Campos Ferruginosos National Park appears to protect a portion of each of the identified management units in this study and so there appears to be no immediate threat to these. On the other hand, not all adaptive units are currently protected, and some lie in the vicinity of large-scale mining operations. As such, the authors suggest that samples from each adaptive unit could either be relocated or preserved in a seed bank. The authors conclude by stating that their study exemplifies how assumption-free genetic clustering methods and environmental association tests can be employed to inform management decisions to prevent the loss of unique genetic variation and maximize species resilience to future environmental change. This approach is particularly useful to inform management of rare and endangered species for which it is difficult or impossible to assess local adaptations using traditional common garden experiments.

This article was published as part of a Special Issue of AoBP entitled The Ecology and Genetics of Population Differentiation in Plants.

Researcher highlight

Dr. Rodolfo Jaffé grew up in Caracas, Venezuela and in 2005 moved to Germany to conduct a PhD in bee molecular ecology at Martin Luther University, Halle. He then completed a first postdoctoral appointment at the University of Western Australia, Australia and a second at the University of São Paulo, Brazil. He is currently a Senior Researcher at Vale Institute of Technology, Brazil, where he uses inter-disciplinary approaches, comprising genomics, spatial analyses, and biostatistics, to understand how the human-led degradation of natural habitats influences biodiversity and ecosystem services.