Scientists from Japan and the International Rice Research Institute (IRRI) have discovered a rice gene that in preliminary testing increased production by 13–36 per cent in modern long-grain indica rice varieties—the world’s most widely grown types of rice.
“We discovered the gene, SPIKE, in an Indonesian tropical japonica rice variety,” announced rice breeder Nobuya Kobayashi of the National Agriculture and Food Research Organization—Institute of Crop Science in Japan. Dr. Kobayashi is a former IRRI scientist seconded from the Japan International Research Center for Agricultural Sciences (JIRCAS).
Tropical japonica rice is mainly grown in East Asia and accounts for only about 10 per cent of global rice production. Incorporating SPIKE into indica varieties that are very popular and widely used across 70 per cent of global rice-growing areas could significantly contribute to food security.
IRRI breeders had earlier observed traits related to higher yield potential—such as large panicles, large leaves, a vigorous root system, and thick stems—in several Indonesian tropical japonica rice varieties. At the time, however, the specific gene responsible for higher yield among these varieties had not been identified.
The discovery of SPIKE, which is published today in the scientific journal Proceedings of the National Academy of Sciences of the United States of America (PNAS), means that breeders can now start incorporating the gene into popular indica rice varieties. The gene can improve plant architecture without altering grain quality or growth periods.
“Using a new approach of combining molecular identification of the SPIKE gene and conventional breeding, we have developed rice, with the SPIKE gene, that has higher yield when compared with an equivalent rice without the gene,” Dr Kobayashi said.
The function of the SPIKE gene was validated by IRRI scientists.
“Our work showed that SPIKE is indeed one of the genes responsible for the yield increase that breeders have spent many years searching for,” said Inez Slamet-Loedin, head of IRRI’s Genetic Transformation Laboratory.
Breeders at IRRI are now using SPIKE to boost the yield potential of leading local rice varieties.
