Smart breeding for Striga-resistant rice
BBSRC/GCRF-funded research into the genetics of rice and the parasitic weed Striga has yielded new understanding about how the plants interact. The findings can be used to breed elite Striga-resistant rice and to develop a tool to help rice farmers plant the best rice varieties for their area.
|>3 billion||Number of people who rely on rice to survive|
|20-100%||Proportion of rice yield which can be lost to Striga parasites|
|$7 billion||Financial losses caused by Striga parasites each year|
Striga asiatica and Striga hermonthica are parasitic weeds that feed by attaching to the roots of crops. They cause severe yield losses in crops such as rice, one of the world’s most important crops, with a devastating impact on the people who rely on the crop for food. Because Striga species evolve rapidly, breeding Striga-resistant rice has proved elusive to crop scientists, until now.
A team of researchers led by Professor Julie Scholes at the University of Sheffield and Dr Mathias Lorieux at the International Centre for Tropical Agriculture, Colombia are using CRISPR/Cas9 gene editing technology to discover multiple resistance genes with different modes of action. Breeders will then be able to ‘stack’ these resistance genes in rice to give the plants multiple layers of resistance, so even if Striga evolves to overcome one resistance gene, the crop will still be protected. By stacking resistance genes in high-yielding rice varieties, breeders can create elite rice with both Striga resistance and high yield.
This principle will ultimately allow smart breeding to produce rice with the best combination of genes depending on the specific Striga variants in different regions of sub-Saharan Africa.
Header image: Flowering S. asiatica on rice in Tanzania, by AfricaRice.