Caracterização genômica do DNA repetitivo e diversidade genética em Syagrus coronata (Mart.) Becc

• Autor(a) principal: SANTANA, Jackeline Terto da Silva
• Data de Publicação: 2022
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UFRPE
• Texto Completo: http://www.tede2.ufrpe.br:8080/tede2/handle/tede2/9503
• topic: Syagrus coronata; Ouricuri; Genoma; Marcador molecular; Diversidade genética; FITOTECNIA::MELHORAMENTO VEGETAL

Syagrus coronata (Mart.) Becc., popularly known as ouricuri and licuri, is a member of Arecaceae and has great socioeconomic and ecological importance. Despite being a species widely distributed in the Caatinga and Atlantic Forest, the urban expansion and intensification of agricultural practices have contributed to the accentuated population decline, requiring measures that can help the conservation of its genetic resources. Genomic studies involving the characterization of the repetitive fraction and determination of the genome size have been carried out for species of Arecaceae. However, for S. coronata there is a need to study the organization of repetitive DNA. Therefore, the objective of this study was: 1) to estimate the genome size and characterize the repetitive DNA in S. coronata by flow cytometry and k-mer approach using the RESPECT method and 2) to analyze the genetic diversity of populations of S. coronata in two biomes using microsatellite markers and chloroplast DNA. The genome size was estimated at 2.27 ± 0.026 Gbp/1C using flow cytometry and 2.76 Gbp using the k-mer approach. The repetitive fraction of the genome corresponded to 60.39%, where retrotransposons LTR sequences were more abundant (37.62% for Ty1/Copia and 12.2% for Ty3/Gypsy). Other repetitive elements were identified: transposons (3.91%), ribosomal DNA (0.56%) and satellite sequences (1.32%). There was high diversity in the number and length of monomers in the satellite sequences. The results of genetic diversity in six different localities of the Caatinga and Atlantic Forest biomes revealed the formation of only one population group, indicating that there is little genetic differentiation between the studied localities. Most of the genetic variation was present within the samples (98.3% for SSR data and 56.68% for SNPs), which indicates the presence of gene flow within the population. For species conservation purposes, in situ conservation is mainly suggested since the high diversity found within populations indicates wide distribution in different localities.