Detecção de novas espécies virais em inhame (Dioscorea spp.) no Brasil por sequenciamento de nova geração

Abstract

The yam (Dioscorea spp.) has an important socio-economic role in tropical and subtropical regions of Asia, Africa and the Americas including the Caribbean. In Brazil, it is a significant source of income and food for the local populations and family agriculture, especially in the Northeast region of the country. The crop yield is very affected by both abiotic factors and biotic agents, including fungi, nematodes and viruses. Diseases caused by viruses are important because the vegetative propagation of yam provides the accumulation and spread of these pathogens on successive crops. To date, the reported viruses in this crop belong to nine genera: Aureusvirus, Badnavirus, Carlavirus, Comovirus, Cucumovirus, Fabavirus, Macluravirus, Potexvirus and Potyvirus. The objective of the present work was to analyze, through the Next Generation Sequencing (NGS), different viral species that infect the yam in fields located in the states of Pernambuco and Paraíba and in the Federal District. Leaf tissue samples of D. rotundata and D. alata were subjected to partial virus purification, the total RNA was extracted and submitted to NGS. The nucleotide reads obtained were assembled using CLC Genomics Workbench 6.5 program and the contigs using Geneious program. Based on the data obtained from NGS it was possible to detect three new virus species reported in this work. It was sequenced the complete genome of two new species, one belonging to the family Secoviridae, with the proposed name Dioscorea virus S (DVS), and another to Foveavirus genus of the family Betaflexiviridae, called Dioscorea virus F (DVF). For the third species described, belonging to the family Closteroviridae, it was done only the viral detection in the collected samples and proposed the name Dioscorea virus C (DVC).