Genetic diversity within a wild rocket [Diplotaxis tenuifolia (L.) DC.] germplasm collection and molecular characterization of selected accessions

• Autor(a) principal: Reis, João Pedro Martins dos
• Data de Publicação: 2022
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10400.1/19116
• topic: Diplotaxis tenuifolia; Diversidade genética; RAPD; ISSR; microssatélites; CAPS; Domínio/Área Científica::Ciências Médicas::Outras Ciências Médicas

Wild rocket (Diplotaxis tenuifolia (L.) DC) is a species known for its growing consumption as “baby leaf” crop. Downy mildew, a disease caused by the pathogen Hyaloperonospora sp., is one cause of production losses in D. tenuifolia cultivation. To preserve elevated quality standards and sustainable production of wild rocket, the characterization of genetic diversity present in a germplasm collection is an important step towards the identification of genetic resources, fundamental to plant breeding. The objectives of this work encompass the characterization of the genetic diversity within a germplasm collection of D. tenuifolia, including a set of E. sativa samples, and the unequivocal identification of a group of selected accessions, using molecular markers. Genetic diversity analysis, performed using 5 Inter Simple-Sequence Repeats (ISSR) and 7 Random Amplified Polymorphic DNA (RAPD) primers, resulted in 110 scorable polymorphisms. Wild rocket accessions exhibited intraspecific genetic similarity with values ranging between 0.697 and 0.994. Tighter clusters aggregate accessions with greater genetic similarity provided by the same producing company. The unequivocal identification of 90 accessions was performed using Simple-Sequence Repeats (SSR) and Single Nucleotide Polymorphisms (SNP) markers, the latter analyzed as Cleaved Amplified Polymorphic Sequences (CAPS). These loci were mined from the D. tenuifolia genomic assembly (UAlgDiploT.01), uploaded to the genomic databases. Twenty SSR and 19 SNP loci (selected by the presence of a TaqI restriction region in the SNP site), were retrieved for analysis. From this, five SSR and nine SNP loci were selected, giving rise to 70 SSR alleles analyzed by capillary gel electrophoresis and 36 CAPS polymorphisms. The molecular characterization of selected accessions resulted in the identification of specific fingerprints for the accessions, excluding 1 trio and 6 pairs of wild rocket accessions, exhibiting full similarity (100%). Thus, confirming the presence of duplicate accessions provided by different breeding and commercial companies.