Genetic parameters of flax genotrophs. V. Behaviour of nuclear DNA in parental and F1 generations

Abstract

The nuclear DNA difference between large (L) and small (S) genotrophs, induced in the flax variety 'Stormont Cirrus' (PL), was investigated using Feulgen photometry. L and S genotrophs were crossed, respectively, to the PL genotype and the parental, and F1 generations were grown in greenhouse (T1) and field (T2) temperatures. Results demonstrate that (i) the DNA values show increased reversion in the crosses, compared with the parents at T1 and less reversion in the crosses, than in the parents, at T2; (ii) more reversion occurs in the PL maternal crosses than in the PL paternal crosses; and (iii) the PL genotroph possess a nuclear and a cytoplasmic factor which plays a direct part in determining nuclear DNA changes in the chromosomes of the stable genotype.Key words: rDNA, DNA amounts, genotrophs, temperature effects.