Repetitive DNA of Higher Plants

Jerusalem artichoke DNA, extracted from resting rhizomes, was analysed by the reassociation kinetics of sheared denatured fragments. Various fractions were isolated according to their reassociation rates. The slowest fractions consist of unrepeated or single-copy DNA which makes up 55 per cent of the total DNA. The total sequence length of the haploid genome is estimated as corresponding to 0.23×1012 daltons. Among the fractions of repeated DNA isolated, two were relatively homogeneous with an average complexity of 2×108 and 109 daltons respectively.