Author : Ishimaru, Tsutomu; Nagaoka, Ichiro; Kim, Daryong

Summary : As a consequence of extreme changes in climate, farming scale, and social structure, the requirements for rice yield potential and grain quality have been changing in Japan. To meet the demands of consumers, rice processing companies, and paddy farmers, “Tsukiakari” and “Niji-no-kirameki” were developed as high-yielding and highly palatable rice cultivars. The palatability of both cultivars is excellent and is as high as the leading Japanese cultivar, “Koshihikari.” The yield potential of the new cultivars is over 700 g m−2 (brown rice, 15% moisture basis), and their shorter culm lengths provide greater lodging tolerance. “Tsukiakari” has been mainly distributed in the northern and central regions of Honshu, whereas “Niji-no-kirameki” has been distributed in the central and western regions. An early maturity cultivar, “Tsukiakari,” is useful for separating harvest schedule from “Koshihikari.” “Niji-no-kirameki” has been replacing “Koshihikari” in heat-vulnerable regions due to its superior heat resilience during the ripening period. Establishing proper cultivation methods for “Tsukiakari” and “Niji-no-kirameki” through multiple environmental tests helps local farmers efficiently manage their farms and produce high-yielding and highly palatable crops. Superior characteristics of “Tsukiakari” and “Niji-no-kirameki” will be useful to develop new rice genotypes that highly meet the needs of the times. (authors' abstract)