Since 1989 we used a plant test system by the classification of chromosomal aberrations in the root tip meristems of young spruce trees (Picea abies (L.) Karst.) for an early detection of environmental influences on forest tree species. The results obtained from different natural sites and from fumigation experiments recommended this test system to be an easy and sensitive screening method for damages caused by environmental mixtures on spruce trees, for nonaccumulating compounds as ozone, too. In the connection with these studies of the structural chromosome alterations further techniques were performed to get information about the heterochromatin behaviour of the chromosomes. Therefore C-banded preparations were done and as a further dividing tissue female gametophyte tissue was used. First results of the use of the interphase nuclei for cytogenetic studies and the first steps to explore the pattern of the heterochromatic parts of the interphase nuclei are also presented here.
