title: Morphological and biochemical responses of Oryza sativa L. (cultivar MR219) to ion beam irradiation.
abstract: OBJECTIVE
  Heavy ion beam, which has emerged as a new mutagen in the mutation breeding of crops and ornamental plants, is expected to result in the induction of novel mutations. This study investigates the morphological and biochemical responses of Oryza sativa toward different doses of carbon ion beam irradiation.
  
  
  METHODS
  In this study, the dry seeds of O. sativa were irradiated at 0, 20, 40, 60, 80, 100, and 120 Gy, followed by in-vitro germination under controlled conditions. Morphological and biochemical studies were conducted to investigate the morphological and physiological responses of O. sativa towards ion beam irradiation.
  
  
  RESULTS
  The study demonstrated that low doses (10 Gy) of ion beam have a stimulating effect on the height, root length, and fresh weight of the plantlets but not on the number of leaves. Meanwhile, doses higher than 10 Gy caused reductions in all the morphological parameters studied as compared to the control samples. The highest total soluble protein content [(2.11 ± 0.47) mg/g FW] was observed in plantlets irradiated at 20 Gy. All irradiated plantlets were found to have 0.85% to 58.32% higher specific activity of peroxidase as compared to the control samples. The present study also revealed that low doses of ion beam (10 and 20 Gy) had negligible effect on the total chlorophyll content of O. sativa plantlets while 40 Gy had a stimulating effect on the chlorophyll content. Plantlets irradiated between 40 to 120 Gy were shown to be 0.38% to 9.98% higher in total soluble nitrogen content which, however, was not significantly different from the control samples.
  
  
  CONCLUSIONS
  Carbon ion beam irradiation administered at low to moderate doses of 10 to 40 Gy may induce O. sativa mutants with superior characteristics.
authors.affiliation: Division of Human Biology, International Medical University (IMU), 57000 Kuala Lumpur, Malaysia; Department of Science, Faculty of Engineering and Science, Universiti Tunku Abdul Rahman, 53300 Setapak, Kuala Lumpur, Malaysia; Agrotechnology and Bioscience Division, Malaysian Nuclear Agency, Bangi, 43000 Kajang, Selangor, Malaysia; Radiation-Applied Biology Division, Quantum Beam Science Directorate, Japan Atomic Energy Agency, 1233 Watanuki-machi, Takasaki, Gunma 370-1292, Japan.
authors.forename: Anna Pick Kiong
authors.initials: AP
authors.lastname: Ling
authors.forename: Ying Chian
authors.initials: YC
authors.lastname: Ung
authors.forename: Sobri
authors.initials: S
authors.lastname: Hussein
authors.forename: Abdul Rahim
authors.initials: AR
authors.lastname: Harun
authors.forename: Atsushi
authors.initials: A
authors.lastname: Tanaka
authors.forename: Hase
authors.initials: H
authors.lastname: Yoshihiro
mesh_terms: D002734:Chlorophyll / Q000378:metabolism*; D004307:Dose-Response Relationship, Radiation; D018506:Gene Expression Regulation, Plant / Q000502:physiology / Q000528:radiation effects*; D020450:Heavy Ions; D009154:Mutation / Q000502:physiology / Q000528:radiation effects*; D012275:Oryza / Q000166:cytology / Q000502:physiology / Q000528:radiation effects*; D010940:Plant Proteins / Q000378:metabolism*; D011829:Radiation Dosage
chemical_list: D010940:Plant Proteins; D002734:Chlorophyll