Climate Change Requires Novel Sweetpotato Breeding Approaches

Camilo Parada Rojas

2018-2021 FFAR Fellow

North Carolina State University

  • Next Generation Crops

Fields of rotten sweetpotatoes are not an uncommon occurrence in growing regions that experience hurricanes. A week before harvest, heavy rain can sweep through the area, flooding fields and promoting infection by opportunistic soil pathogens. Higher humidity and temperatures can increase plant susceptibility to these pathogens. While hurricanes may be temporary, the looming threat of more intensified and frequent severe weather events is looming. These severe weather events can have a long-term impact on pathogen populations, plant susceptibility, farm productivity and profitability.

Plant pathogen persistence in the soil can lead to diseases that will plague the fields each year if left unmanaged. This can increase production costs and force farmers to rotate to less profitable crops, resulting in a negative economic impact in rural communities. A warming climate can also increase the overwintering survival of several plant pathogens. Even a moderate increase in temperature can increase a pathogen’s geographic range, infection rate and disease severity. There are several approaches a farmer can take to prevent catastrophic losses caused by disease including selecting sites with good drainage, adopting a crop rotation schedule and applying pesticides. However, a cost effective and environmentally friendly strategy to fight pathogens is the deployment of resistant crops.

Humans achieve immunity to pathogens through exposure or vaccination. In contrast, plants lack the capacity to acquire immunity through exposure and rely on innate immunity coded in their genome. One example of innate immunity in plants are resistance genes that can trigger immune responses in plants. Conventional breeding techniques make it difficult to select for desirable traits such as disease resistance. In sweetpotatoes, breeding for resistance is even more challenging due to the limited number of breeding programs, unknown genetic basis of resistance and  complex genome. Desirable advanced breeding techniques will accelerate identification of disease-resistant material. I want to be part of the solution to this problem. 

My research aims to accelerate breeding using next-generation sequencing technologies that facilitate cataloging resistant genes in sweetpotato cultivars. This catalog of resistance genes will represent a game changing tool for breeders to improve the resilience of sweetpotato in the face of a changing climate. These resources will benefit farmers in the US and accelerate breeding efforts globally. The North Carolina sweetpotato industry accounts for 60 percent of the sweetpotato supply in the US and 80 percent of international sweet potato exports. The North Carolina SweetPotato Commission, representing growers, packers and processors, is my FFAR fellowship sponsor.

The FFAR Fellows program has inspired me to become a leader in my field and promote spaces where students can engage with each other. In my department, we call this space the Plant Pathology Student Only Seminar (PPSOS), a program highly valued during pandemic times, where we can share our experience and research goals with each other. The FFAR Fellows program has without hesitation been one of the best experiences in my graduate school life!