title: ASSESSMENT OF MOLECULAR GENETIC STABILITY BETWEEN LONG-TERM CRYOPRESERVED AND TISSUE CULTURED WASABI (Wasabia japonica) PLANTS.
abstract: BACKGROUND
  Maintaining the genetic integrity in long-term tissue cultured and cryopreserved plants is important for the conservation of plant genetic resources.
  
  
  OBJECTIVE
  In this study, the genetic stability of cryopreserved wasabi shoot tips stored for 10 years at -150 degree C was visualized using Amplified Fragment Length Polymorphism (AFLP) and Methylation Sensitive Amplified Polymorphism (MSAP).
  
  
  METHODS
  The study included plants derived from cryopreserved shoot tips after 10.5 years storage at -150 degree C (LN10yr), after 2 h storage at -196 degree C (LN2hr), cryopreservation controls (No LN cooling (TC)) and non-treated controls without LN cooling (LC). The donor plants for LN2hr, TC and LC were also maintained in vitro at 20 degree C for the same period.
  
  
  RESULTS
  Neither technique detected genetic variations in either control or cryopreserved plants. Some mutations were noted in plants maintained in tissue culture for 10 years. Comparison of genome stability for TC and LN2hr plants showed only a minor change in DNA. However, when comparing the LC and Ln10yr, many differences were found.
  
  
  CONCLUSIONS
  We conclude that cryopreservation is a superior conservation method compared to tissue culture in maintaining genetic stability for a long-term storage of wasabi germplasm.
authors.affiliation: Department of Science of Technology Innovation, Nagaoka University of Technology, Nagaoka, Niigata, Japan. maki@vos.nagaokaut.ac.jp.
authors.forename: S
authors.initials: S
authors.lastname: Maki
authors.affiliation: Department of Applied Chemistry and Biotechnology, Niihama National College of Technology, Niihama, Ehime, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Hirai
authors.affiliation: National Institute of Agrobiological Science, Tsukuba, Ibaraki, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Niino
authors.affiliation: Faculty of Life and Environment Science, Shimane University, Matsue, Shimane, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Matsumoto
mesh_terms: D054458:Amplified Fragment Length Polymorphism Analysis; D015925:Cryopreservation / Q000379:methods; D018744:DNA, Plant / Q000235:genetics*; D042822:Genomic Instability; D018520:Plant Shoots / Q000235:genetics*; D011110:Polymorphism, Genetic; D046509:Tissue Culture Techniques; D031228:Wasabia / Q000235:genetics*
chemical_list: D018744:DNA, Plant