Tsutomu Ishimaru

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Tsutomu Ishimaru

Tsutomu is seconded from the Japan International Research Center for Agricultural Sciences (JIRCAS) to International Rice Research Institute (IRRI) to implement IRRI-Japan collaborative research project, Climate Change Adaptation in Rainfed Rice Areas (CCARA). He is currently attempting to develop the lines with high-yielding potential and heat escape, which are suitable traits for rainfed lowland condition, using molecular marker-assisted selection (MAS).


  • Carbohydrate metabolism in the developing grain
  • Rice grain quality and fertility under high temperature stress
  • Genetic improvement of yield potential


  • PhD in Agriculture, The University of Tokyo, Crop Science laboratory (2004)
  • MSc, The University of Tokyo (2001)
  • BS, Kobe University (1999)


  • Plant Breeder, PBGB, IRRI (April 2011-present)
  • Plant Breeder, Japan International Research Center for Agricultural Sciences (JIRCAS) (2011-present)
  • Rice Physiologist, National Agricultural and Food Research Organization (NARO), National Institute of Crop Science (NICS) (2005-2010)
  • Post-doctoral fellow, The University of Tokyo, Breeding Science laboratory (2004-2005)


  • Crop Science Society of Japan
  • Japanese Society of Breeding


  1. Ishimaru et al. Quantifying rice spikelet sterility in potential heat-vulnerable regions: Field surveys in Laos and southern India. Field Crops Res., in press.
  2. Ishimaru et al. (2015) Laser microdissection-based gene expression analysis in the aleurone layer and starchy endosperm of developing rice caryopses in the early storage phase. Rice 8:22
  3. Hirabayashi et al. (2015) qEMF3, a novel QTL for early-morning flowering trait from wild rice, Oryza officinalis, to mitigate heat stress damage at flowering in rice (Oryza sativa L.). J. Exp. Bot., 66: 1227-1236
  4. Shi et al. (2014) Popular rice (Oryza sativa L.) cultivars show contrasting responses to heat stress at gametogenesis and anthesis. Crop Sci., doi:10.2135/cropsci201
  5. Fujita et al. (2013) NAL1 allele from a rice landrace greatly increases yield in modern indica cultivars. Proc. Natl. Acad. Sci. USA 110: 20431-20436

Tsutomu Ishimaru
Dr. Tsutomu Ishimaru

Senior Scientist - Plant Breeding

International Rice Research Institute
Los Baños, Laguna

+63 2 580 5600
ext 2729