Diversidade fenotípica e metagenômica de Spondias tuberosa: subsídios para a bioeconomia da Caatinga

Abstract

Spondias tuberosa Arr. Câm., commonly known as umbuzeiro, is a species native to the Brazilian Caatinga biome and holds great potential for regional bioeconomic development. Its fruits are of notable nutritional, sociocultural, and commercial importance to communities in the semi-arid region. However, integrated studies on the phenotypic and microbiological diversity of this species remain scarce, particularly in natural populations from the state of Sergipe. This dissertation aims to investigate the phenotypic variability of fruits and natural populations of umbuzeiro, and to functionally characterize the microbiomes associated with their endocarps, with the goal of identifying relevant traits for conservation strategies, genetic improvement, and sustainable biotechnological applications. The study is structured into three scientific chapters. The first one chapter presents a systematic review of the role of endophytic microorganisms in fruits and seeds of fruit-bearing species, highlighting their functions in plant growth promotion, biological control, resistance induction, and postharvest conservation. The review includes 59 studies selected according to PRISMA criteria, revealing that bacterial genera such as Bacillus and Pseudomonas, as well as fungi like Trichoderma and Penicillium, are most frequently associated with beneficial functions. Despite significant advances in studies on fruit microbiota, substantial gaps remain in the understanding of seed-associated microbial communities, especially in tropical native species. The second chapter addresses the phenotypic characterization of fruits and natural populations of S. tuberosa in extractive areas of Sergipe. Morphological and biometric traits such as fruit weight, soluble solids content, firmness, diameter, and length were evaluated. The analyses revealed wide intra and inter-population variability, highlighting genotypes with agronomic promise and commercial potential. Chromatic attributes, particularly luminosity, proved to be the most consistent descriptors for differentiating the origin of umbuzeiro fruits and endocarps. The Gararu population exhibited a more uniform and distinct phenotype, Poço Verde showed greater internal cohesion, whereas Canindé displayed greater variability among matrices, with matrix nine standing out due to its relevant phenotypic characteristics, such as size and sweetness, which make it distinct from the others. The third chapter employs functional metagenomic approaches to explore the composition and biotechnological potential of the microbiota found in fruit endocarps. DNA extraction, sequencing, and bioinformatic analyses were conducted to identify key microbial groups. Results revealed a diverse microbial community, with bacteria harboring genes related to nitrogen fixation, phosphate solubilization, auxin production, and ACC deaminase activity. These microbial functions support the potential use of S. tuberosa as a source of natural bioinputs in low-impact agricultural systems. The findings of this dissertation contribute significantly to the recognition of umbuzeiro as a strategic resource for fostering the bioeconomy of the Caatinga biome. The integration of morphological and molecular data provides scientific and technical foundations for public policies aimed at biodiversity conservation, the development of cultivars adapted to semi-arid conditions, and the sustainable use of native microbial resources. Ultimately, the dissertation emphasizes the value of combining traditional knowledge with modern science to strengthen sustainable and inclusive agricultural practices.