Source: International Atomic Energy Agency – IAEA
Phillipe Nikiema, a researcher at Burkina Faso’s Environmental Institute of Agricultural Research explains his results on the new sorghum lines resistant to Striga to fellow colleagues at the Joint FAO/IAEA Plant Breeding and Genetics Laboratory in Siebersdorf, Austria. (Photo: A. Ghanim/IAEA).
Farmers in Africa will soon benefit from new sorghum varieties resistant to Striga — also known as witchweed — one of the most devasting parasitic weeds that impact crop yields on the continent. Improved sorghum lines with resistance to Striga have been developed using gamma ray irradiation, with the support of the IAEA and the Food and Agriculture Organization of the United Nations (FAO). “This important achievement is of great significance, especially as we prepare for the International Year of Plant Health 2020,” said Qu Liang, Director of the FAO/IAEA Division of Nuclear Techniques in Food and Agriculture.
“For African farmers, the availability of Striga-resistant sorghum varieties will be a major breakthrough: it will improve livelihoods for rural communities and contribute to food security,” said Abdelbagi Ghanim, a plant breeder and geneticist at the Joint FAO/IAEA Division. Striga infestation is a scourge that continues to pose a huge challenge for crop productivity, reducing national and regional capacity for food production, he added.
Striga is present in parts of Africa, Asia, and Australia, with the greatest crop losses in Africa’s savannahs. FAO estimates that annual crop loss due to Striga across Africa exceeds US $7 billion, impacting over 300 million people. Up to 50 million hectares of crop land are Striga infested, Ghanim said. “Striga is a major biological constraint to cereal production in most of sub-Saharan Africa and semi-arid tropical regions of Asia.” Crops such as sorghum, millet, maize and upland rice face the biggest threat from this parasitic weed.
Plant mutation breeding is the process of exposing plant seeds, cuttings or cell cultures to radiation, such as gamma rays, and then planting the seed or cultivating the irradiated in vitro material in a sterile medium that generates a plantlet. The mutated plants, after selection for improved agronomic traits over several generations, are then multiplied, evaluated and released as improved varieties.
Plant mutation breeding does not involve genetic transformation, but rather uses a plant’s own genetic resources and mimics the natural process of spontaneous mutation, the motor of evolution. By using radiation, scientists can significantly shorten the time it takes to breed new and improved plant varieties.
This technique focuses on the use of radiation in combination with biotechnologies to develop favourable crop traits. New varieties of plants are bred to thrive in harsh conditions such as heat and drought), or to improve their nutritional value, to resist diseases or pests, to grow in saline soils, or to use water and nutrients more efficiently.