Sweetpotato Genome Fully Decoded, Revealing Complex Hybrid Origin
Scientists have fully decoded the sweetpotato genome, revealing its complex hybrid origin from multiple wild ancestors and paving the way for improved crop breeding and food security.
Scientists have achieved a major milestone by fully decoding the sweetpotato genome, a breakthrough announced on September 14, 2025. This accomplishment unravels the genetic secrets of a crop that feeds millions worldwide, especially in regions like sub-Saharan Africa and the Philippines, where sweetpotato is vital for food security and resilience against climate extremes.
The sweetpotato's DNA is exceptionally complex, containing six sets of chromosomes—a condition known as hexaploidy. Unlike humans, who inherit two chromosome sets, sweetpotato's genome posed a formidable challenge to researchers, likened to reconstructing six shuffled encyclopedias. Led by Professor Zhangjun Fei at the Boyce Thompson Institute, the team used advanced DNA sequencing and phasing techniques to separate and organize the plant's 90 chromosomes into their original sets. This is the first time the complete, phased genome of a sweetpotato variety, specifically 'Tanzania,' has been mapped in such detail.
Hybrid Origins and Genetic Mosaic
The research revealed that sweetpotato's genome is a mosaic, stitched together from multiple wild ancestors. About one-third of its DNA comes from Ipomoea aequatoriensis, a wild species native to Ecuador, while another significant portion resembles a Central American species, Ipomoea batatas 4x. However, some ancestral contributors remain unidentified, and their genetic sequences are intricately intertwined within the same chromosomes. This unique architecture classifies sweetpotato as a segmental allopolyploid—a hybrid that behaves genetically as if it originated from a single species, but in reality, it is the product of multiple species merging and recombining over time.
Implications for Crop Improvement and Food Security
The sweetpotato's polyploid nature provides it with remarkable adaptability and disease resistance, crucial traits for subsistence farmers facing climate variability. Multiple versions of key genes act as genetic backups, enabling the plant to survive drought, resist pests, and thrive in diverse environments. This new genomic clarity empowers breeders to more efficiently identify genes responsible for yield, nutritional content, and resilience, accelerating the development of improved sweetpotato varieties.
In the Philippines, local researchers at Visayas State University (VSU) have contributed to related studies, highlighting how soil phosphorus levels trigger molecular mechanisms that enhance root development. These findings offer practical strategies for farmers, such as smarter fertilizer management, which can lead to higher yields and more sustainable agriculture. The sweetpotato's resilience and productivity are now better understood at both the genetic and physiological levels, promising benefits for food security and rural livelihoods.
Future Directions and Global Impact
While this breakthrough provides unprecedented insight into sweetpotato genetics, scientists emphasize that decoding additional varieties from different regions will be necessary to capture the full spectrum of genetic diversity. The methods developed for sweetpotato may also help unlock the genomes of other complex crops, such as wheat, cotton, and banana, which are essential for global food systems. As climate change intensifies, these advances in crop genomics are critical for breeding resilient, high-yielding plants to meet the world's growing food needs.