EFFECT OF DNA PREPARATION FROM LAVER (PORPHYRA-YEZOENSIS) THALLI ON REPRODUCIBILITY OF RAPD (RANDOM AMPLIFIED POLYMORPHIC DNA) PATTERNS

Laver (Porphyra yezoensis) DNAs were extracted from thalli with five d ifferent procedures and used for RAPD (random amplified polymorphic DN A) analysis as templates. Restriction enzyme-digestive DNAs were obtai ned with all procedures examined. However, RAPD patterns generated wit h these DNAs appeared highly irreproducible and were considerably diff erent from each other. When DNAs purified with CsCl gradient centrifug ation were used for RAPD analysis as templates, highly reproducible RA PD patterns were obtained, suggesting that unpurified DNAs extracted f rom thalli with all five extraction procedures contained an excess of RNA, polysaccharides and/or other materials which affected the RAPD re producibility. Thus, results indicated that purification of DNA is ess ential to produce reproducible RAPD patterns of Porphyra DNA.