Hyssopus officinalis is a valuable aromatic and medicinal plant because of its content in essential oils. To increase, quantitatively and qualitatively, the genetic variability we used mutagen treatment with 5-25 kR.
Studying the behaviour of some morphological characteristics in generation M1 (I-III vegetation years) - treated plant height, the bush diameter, the branching degree, number of inflorescence, their length, number of flowers and verticille - we noticed diminishing compared to the population of origin (De Ciorani). An exception is only the population treated with 5 kR, which presented some stimulating effects.
The biosynthesis of essential oils in herba was, on the contrary, stimulated in the mutagenized plants, the increase related to the control being of 103-158% in the second vegetation year of 62-114% in the third.
The applied mutagen treatment diversified the initial biological material, a proof in this respect being the different values of the morphological and biochemical parameters analysed, on the one hand between the experimental variants and between these and the original population on the other.