Journal of General Plant Pathology

, 73:8

A case study of infection of rice roots by deleterious fungi and minor pathogenic Pythium species in a paddy field


    • Faculty of Bioresource SciencesAkita Prefectural University
  • Keisuke Tubaki
    • Tokyo University of Agriculture
  • Tsutomu Matsumoto
    • Akita Prefectural College of Agriculture
  • Shin-ichi Fuji
    • Faculty of Bioresource SciencesAkita Prefectural University
  • Hideki Naito
    • Faculty of Bioresource SciencesAkita Prefectural University

DOI: 10.1007/s10327-006-0312-x

Cite this article as:
Furuya, H., Tubaki, K., Matsumoto, T. et al. J Gen Plant Pathol (2007) 73: 8. doi:10.1007/s10327-006-0312-x


Roots of rice plants grown in paddy fields in a transplant culture system were collected seven times between 8 and 22 weeks after transplanting, for two crop seasons. Rice seedlings grown in a potting medium amended with the collected roots were significantly shorter than those grown in the same medium either without the addition of the roots or amended with pasteurized, collected roots indicating that seedlings were inhibited by heat-labile microorganisms on the collected rice roots. Ninety-five and 172 pure cultures of Pythium spp. and fungi, respectively, were isolated from the rice roots collected 5 or 7.5 weeks after transplanting in the fields. Among these microorganisms, Pythium aristosporum inhibited seedling growth in greenhouse experiments, and Acremonium sp., Alternaria sp., Epicoccum nigrum, Fusarium sp., Massarina sp., Penicillium spp., Rhinocladiella sp., Stemphylium sp., Trichocladium sp., and several unidentified fungi inhibited seminal root growth in in vitro experiments. These microorganisms might be involved in the inhibition of seedling growth in soils amended with the rice roots collected from the paddy field. Thus, roots of rice plants at the middle stage of growth transplanted into paddy fields can harbor pathogenic or deleterious fungi or Pythium sp(p). The effects of these microorganisms on rice growth in paddy fields are discussed.

Key words

Transplant culture systemsSoil-borne minor diseases

Copyright information

© The Phytopathological Society of Japan and Springer-Verlag Tokyo 2007