Institute of Crop Science, NARO

Rice Physiology Unit

Our prime aim is to raise the yield potential of rice plant to ensure higher rice production. We study the physiological factors, such as photosynthesis and plant canopy structures of high yielding varieties. Based on these physiological studies, we try to dissect the genetic basis and elucidate the components of high yield in order to facilitate the development of rice breeding materials with enhanced yield potential. We also aim to develop better management options for farmers to ensure a high yield for new NARO-bred varieties, and to develop plant types and crop management system that will enhance a stable and sustainable rice production. In particular, we are developing a management system that can cope with higher temperatures due to climate change. Furthermore, we try to elucidate the physiological factors associated with reduced absorption and accumulation of radiocesium in order to contribute to the recovery efforts and reconstruction of agriculture in areas which was severely affected by the 2011 earthquake and tsunami in eastern Japan.


Unit Leader


Unit Members

Research Topics
Hitoshi OGIWARA Senior Researcher Climate Change, Direct seeding
Junko ISHIKAWA Senior Researcher Molecular Physiology
Yumiko ARAI Senior Researcher Crop physiology and management system
Masaki OKAMURA Researcher High yielding Physiology

Research Publications

  • Analiza G. Tagle, Daisuke Fujita, Leodegario A. Ebron, Mary Jeanie Telebanco-Yanoria, Kazuhiro Sasaki, Tsutomu Ishimaru, Yoshimichi Fukuta, Nobuya Kobayashi (2016) : Characterization of QTL for unique agronomic traits of new-plant-type rice varieties using introgression lines of IR64. Crop Journal 4:12-20.
  • Shigeto Fujimura, Junko Ishikawa, Yuuki Sakuma, Takashi Saito, Mutsuto Sato, Kunio Yoshioka (2014) : Theoretical model of the effect of potassium on the uptake of radiocesium by rice. Journal of Environmental Radioactivity 138 :122-131.
  • Yumiko Arai-Sanoh, Toshiyuki Takai, Satoshi Yoshinaga, Hiroshi Nakano, Mikiko Kojima, Hitoshi Sakakibara, Motohiko Kondo, Yusaku Uga (2014) : Deep rooting conferred by DEEPER ROOTING 1 enhances rice yield in paddy fields. Scientific Reports 4, Article number: 5563.