Genome sequences of two diploid wild relatives of cultivated sweetpotato reveal targets for genetic improvement

Sweetpotato, Ipomoea batatas (L.) Lam. (2n = 6x = 90), is an important food crop ranking seventh globally with 106.6 million tons produced in 2014 (FAOSTAT 2014). Sweet- potato provides a rich source of carbohydrates, dietary fiber, vitamins, and micronutrients, is low in fat and cholesterol1, and due to its resilience and adaptability, it serves an important role in food security for subsistence farmers in sub-Saharan Africa (SSA). Indeed, efforts by the International Potato Center (CIP) to replace the dominant β-carotene lacking white-fleshed varieties in SSA with provitamin A-rich orange-fleshed sweetpotato (OFSP)2 were considered a breakthrough achievement as vitamin A deficiency affects more than 40% of children under 5 years old in SSA and is a leading cause of blindness and premature death3. Awarding of the World Food Prize in 2016 to four scientists who pioneered biofortification with OFSP highlights the significance of these efforts and the importance of OFSP in shifting human health outcomes.

View PDF Report


Transcriptomic analysis of sweetpotato under dehydration stress identifies candidate genes for drought tolerance

Sweet potato (Ipomoea batatas [L.] Lam.) is an important subsistence crop in Sub‐ Saharan Africa, yet as for many crops, yield can be severely impacted by drought stress. Understanding the genetic mechanisms that control drought tolerance can facilitate the development of drought‐tolerant sweet potato cultivars. Here, we report an expression profiling study using the US‐bred cultivar, Beauregard, and a Ugandan landrace, Tanzania, treated with polyethylene glycol (PEG) to simulate drought and sampled at 24 and 48 hr after stress. At each time‐point, between 4,000 to 6,000 genes in leaf tissue were differentially expressed in each cultivar. Approximately half of these differentially expressed genes were common between the two cultivars and were enriched for Gene Ontology terms associated with drought response. Three hundred orthologs of drought tolerance genes reported in model species were identified in the Ipomoea trifida reference genome, of which 122 were differentially expressed under at least one experimental condition, constituting a list of drought tolerance candidate genes. A subset of genes was differentially regulated between Beauregard and Tanzania, representing genotype‐specific responses to drought stress. The data analyzed and reported here provide a resource for geneticists and breeders toward identifying and utilizing drought tolerance genes in sweet potato.

View PDF Report


DNA profiling of sweetpotato cultivars and clones

GT4SP Capacity Building & Training
WEBINAR: 30th November 2016
Time: 11.00am-12.30pm
Presenter: Mercy Kitavi

View Webinar presentation


Webinar: Marker Assisted Breeding as Next Generation Strategy

Check out Craig Yencho’s webinar on Marker-Assisted Breeding of Sweetpotato recently posted on our website and Youtube. The first few minutes are rough as it is a live connection from Nairobi to Raleigh and broadcast across SSA.

Watch Video Webinar