DAMAGES OF WOODEN PLANTS AT CELLULAR-LEVE L OF MERISTEMS

Abnormal development and suppressed growth of apical meristems within the growing points of shoots and roots of wooden plants required inves tigations of their mitotic activity and caryological situation. It has been shown that species of spruce are mitotically highly active throu ghout the whole year and in particular during their morphological stat e of dormancy. As consequence of this continous sensitivity they may b e affected by pollutants (especially herbicides) via active cell regio ns in the meristems of shoots and roots. Senescence of initial cells s eems not to be the result only of physiological affections but is even forced by genetic alterations. Observed modifications in the chromoso me structure of mitotic active cells within growing points of shoots a nd roots of P. pungens and P. engelmannii confirm this assumption.