Enhanced diagnostics of RNA and DNA viruses and control of viral synergism and yield losses in subsistence sweetpotato production

  • Untiveros, Milton (Osallistuja)
  • Wang, Linping (Osallistuja)
  • Chiunga, Evangelista (Osallistuja)
  • Tugume, Arthur (Osallistuja)
  • Zerbini, Murilo (Osallistuja)

Projekti: Tutkimusprojekti

Projektin yksityiskohdat

Kuvaus (abstrakti)

Sweetpotato is an important subsistence, food security and famine relief crop in sub-Saharan Africa. Its cultivation area grows faster than any other traditional subsistence crop. The annual global production is 126 million tons, of which 62 million tons are produced in East Africa, in the countries around Lake Victoria. The biggest producer is Uganda. Sweetpotato performs well in relatively poor soils, has high tolerance to drought and a good nutritional value (especially the orange-flesh varieties) and can be piece-meal harvested. It is a “women’s crop” grown for the family’s daily needs, and it shows also potential to develop to a cash crop.
In East Africa, viruses cause the only significant diseases in sweetpotato. Our studies on diversity and genetic variability of sweetpotato viruses in Uganda show that wild species act as reservoirs of RNA viruses infecting sweetpotato crops. Emerging data suggest that DNA viruses may also be common and very harmful, but have been little studied. The most severe diseases and yield losses are caused by mixed infection of Sweet potato chlorotic stunt virus (SPCSV) with other viruses, which results in synergistic interactions between the viruses, because the Class 1 RNase III enzyme produced by SPCSV eliminates antiviral defence. Breeding of SPCSV-resistant sweetpotato varieties has met limited success so far, but elucidation of the unique mechanism by which SPCSV eliminates antiviral defence in sweetpotato informs novel possibilities for virus control.
In this project, an international research and training network including institutes in Uganda, Tanzania, Peru, Brazil, United Kingdom and Finland will i) study the prevalence and genetic diversity of DNA viruses in sweetpotatoes and wild Ipomoea species in East Africa using small-RNA deep-sequencing and rolling circle amplification as broad-spectrum approaches in virus detection; ii) reveal how sweetpotato-infecting potyviruses express new genes suppressing antiviral defence; and iii) develop means to inhibit the RNase III enzyme of SPCSV to prevent infection or enhance recovery of plants from sweetpotato virus disease. At least three postgraduate students from developing countries will benefit from training, networking and mobility. The project is expected to progress efficiently owing to the established international network of the institutes with complementary expertise.
Todellinen alku/loppupvm01/09/201431/08/2018


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