Sustainable Strategies to Combat the Papaya Ringspot Virus

View the project final report

Commodities

• Fruits: papaya

Practices

• Pest Management: genetic resistance, integrated pest management

Viral diseases impose severe limitations on papaya production worldwide, including growing regions of southern Florida, Puerto Rico and Hawaii. The most significant of these is papaya ringspot virus (PRSV), which dramatically reduces marketable yield and can lead to plant stunting or death. All types of papaya are susceptible to PRSV, except where resistance has been genetically engineered. The virus cannot be directly controlled, so disease management focuses on regular chemical sprays to reduce abundance of the aphid vector. The challenges of controlling pathogenic plant viruses with the associated risks to pesticide applicator, the environment, and consumers are common across most food crops. Innate genetic resistance is therefore the best defense against viral pathogens. In the case of transgenic papaya, such resistance has been achieved through expression of the viral coat protein gene. Unfortunately, the utility of resistant varieties has been attenuated by negative public perception of "GMOs" and limited availability and diversity of resistant germplasm. As a result, new solutions are required to enable papaya production that is both profitable and sustainable. Therefore, we propose to develop solutions by 1) evaluating the use of transgenic, PRSV-resistant papaya border rows to shelter high-value plantings of susceptible varieties, and 2) generating broad-spectrum virus resistance through a novel gene editing approach in papaya that excludes methods using foreign DNA. Through these efforts, we hope to contribute to enhanced grower profitability, improved resiliency, and reduced chemical inputs.

• Evaluate the use of PRSV-resistant border plantings to protect susceptible papaya varieties.
• Generate virus resistance papaya accessions through consumer-friendly biotechnology.