The global meeting place for people interested in all things related to SWEETPOTATO

Share your research and experience, ask and answer questions, meet your peers.

tax-image

Breeding

We continue to strengthen sweetpotato breeding in Africa to ensure continuous production of high yielding, disease-resistant, nutritious varieties adapted to local agro-climatic conditions and the preferred trait combination for producers, processors and consumers. Our accelerated breeding approach is based on having more sites at the earliest breeding stages.  At least one of those sites will be a stress environment of interest, for example where virus pressure is high.  With the accelerated breeding approach we have reduced the time from crossing to having a variety ready to release from 7-8 years to 4-5 years.

 

Sweetpotato Genebank

 

CIP’s extensive sweetpotato collection was begun in 1985 and the CIP genebank at present holds samples of over 8000 accessions (about a thousand of which are wild) from the Americas, Asia and Africa.  The Center’s scientists use this diverse reservoir of genetic material to provide healthy planting material for farmers, and to breeders developing sweetpotato varieties with wider adaptability, pest resistance, and tolerance to abiotic stresses such as climate change. Researchers also improve varieties providing the particular qualities needed for processing and increased table use according to cultural preferences, and monitor and improve the nutritional properties of the crop, with special emphasis on increasing vitamin A content.

 

Germplasm Collection(s)

 

Global sweetpotato genetic diversity is maintained in a number of gene banks around the world. These contain various types of germplasm, ranging from wild relatives to cultivated varieties, including farmers’ landrace varieties, old varieties, currently important cultivars, and breeding materials. Because sweetpotato is a clonally propagated crop, typically sweetpotato germplasm is in clonal form (maintained in tissue culture, frozen, or as living plants in a greenhouse or field gene bank). Sweetpotato genetic resources may also be maintained as populations of seed; typcially the case for wild relatives and populations from breeding programs. There are many sweetpotato gene banks around the world, typically with information about sources and characteristics of the germplasm in them. We provide here information and links to gene banks and to sources of information about sweetpotato germplasm, including guidelines on sweetpotato germplasm characterization and gene bank management.

Weevils damage large proportions of sweetpotato harvests  in Sub-Saharan Africa and induce the accumulation of toxic compounds in the healthy-looking parts of damaged storage roots. Through biotechnology, we are working on two strategies that will eventually be combined into widely-cultivated sweetpotato varieties.

 

Through biotechnology, we have introduced new genes that produce anti-weevil proteins in the sweetpotato storage root. In parallel, we are testing a new strategy to weaken specific genes of the weevils to block their development. These two strategies will eventually be combined into widely-cultivated sweetpotato varieties in SSA.

 

With conventional breeding, thousands of genes are shuffled and recombined to obtain a desired trait. In comparison, modern biotechnology adds as little as one single gene to provide the desired trait to an existing well-performing variety. As a result, the level of genetic modification is only a tiny fraction of that produced through conventional breeding.

 

 

 

 

Annual Sweetpotato Speedbreeders’ meetings are held to learn the latest methods and share findings. The scope of the Breeding CoP group is being expanded to include more research concerning marker-assisted breeding and sweetpotato genomics.

 

There are sweetpotato support platforms that backstop national program breeders in 14 SSA countries and co-supervise PhD candidate breeders. Annual Sweetpotato Speedbreeders’ meetings are held to learn the latest methods and share findings. The scope of the Breeding CoP group is being expanded to include more research concerning marker-assisted breeding and sweetpotato genomics.

Developments in genomics, which involves high-throughput DNA sequencing coupled to new analytical tools to identify genes associated with key traits, promise to make sweetpotato breeding much more efficient.

 

Sweetpotato is a hexaploid crop with two non-homologous ancestral genomes hypothesized. Knowledge of genome sequences is indispensable for basic biological research and long-term crop improvement. However, the polyploidy and the high degree of heterozygosity of the sweetpotato genome make it infeasible for whole genome sequencing.

 

As an alternative, we are in the process of generating high-quality genome sequences of diploid and highly homozygous accessions of Ipomea trifida and I. triloba, the two closest wild relatives and putative wild ancestors of the cultivated sweetpotato. The resulting two high-quality draft genomes will serve as references for cultivated sweetpotato and as the foundation for next generation breeding technologies for sweetpotato improvement.

Subtopics
More content to read up on Breeding