[nfluence of UV radiation (2.537 A) on Nicotiana rustica L. I. growth and contents in lipo-soluble pigments

Abstract

The effect of short radiation. (2.537 A) has been studied on the growth and contents of lipo-soluble pigments in Nicotiana rustica L. plants.

It has been proved that increasing dosage of UV slow the growth and preferably cause some damage to the leaves, with typical folding back on the hedges and the appearance of dark spots. When the treatment is stoped and the plants leaved under natural light, it becomes visible the phenomena of «photoreactivation», although the plant tends to recover provided only sub-lethal doses had been administered.

In general the farther UV decreases the contents of chlorophyle b more than the chlorophylla.

The synthesis of carotenes seems not to be affected by the treatment with farther UV, since the radiated plants have a high contents of them. On the other hand it is noticeable an interference in the synthesis of xantophill, since from the 3rd sample the contents decreases in the radiated plants.