P-212 - High Throughput Sequencing for Improved Virus Detection in Strawberry

Over 10 million tons of strawberries are produced annually across the world with 1.3 million tons produced annually in the United States alone. To protect global crop production, clean plant programs and certification testing are needed for the prevention of both endemic and exotic diseases. Graft bioassays have been a mainstay in strawberry certification programs to detect viral infections for decades; however, they may fail to detect viruses that do not produce symptoms in single infections or viruses that take longer than the testing period to produce symptoms. High throughput sequencing (HTS) has the potential to streamline the testing process and identify pathogens more effectively by providing a snapshot of the entire microbial profile including previously unknown viruses and viruses that would go undetected in a bioassay. In this study, virus detection in strawberry plants through HTS was compared to graft indexing for virus detection. Each donor plant was grafted onto two replicates of UC 4, 5 ,10, and 11 strawberry indicator plants and monitored for symptom expression for eight weeks and again after plants overwintered. The donor leaves were also used for TNA extraction and HTS detection of viral sequences. Symptoms did not consistently develop on indicator plants. Preliminary results indicate HTS is more effective at detecting viral infections. Out of the donor plants that tested positive for at least one virus through HTS, 16% and 27% had symptomless grafted indicator plants after eight weeks and after natural dormancy respectively.