Virome analysis of sweetpotato in three Brazilian regions using high-throughput sequencing

Sweetpotato (Ipomoea batatas (L.) Lam.) is a highly nutritious food crop that suffers severe yield losses due to viral diseases. These are unintentionally spread mainly by vegetative propagation techniques commonly used by farmers. Virus indexing of vine cuttings (slips) coupled with tools specifically developed for identification of the main viruses is therefore essential to avoid disease outbreaks. In this work, we assessed the viral diversity in sweetpotatoes collected in some of the main producing areas in Brazil. The cuttings were grafted onto Ipomoea setosa Ker Gawl. prior to being subjected to ELISA for ten different viruses. Total DNA and RNA were also extracted from sweetpotato and I. setosa leaves for high-throughput sequencing (HTS) on an Illumina platform. Using this HTS strategy, nine viral species known to infect sweetpotatoes were identified, being seven of those species also identified in grafted I. setosa, two species identified exclusively in sweetpotato and two exclusively on I. setosa. From the ten different viruses tested by ELISA, six were identified in the samples evaluated. The generated data will be useful for virus indexing of sweetpotato as well as for virus resistance screening in sweetpotato breeding programs.

Automated summary

This study assessed the viral diversity in sweetpotatoes in Brazil using grafting and high-throughput sequencing techniques. Multiple viral species infecting sweetpotatoes were identified, and the generated data will be valuable for virus indexing and resistance screening in sweetpotato breeding programs.