Stress-physiological investigations and chromosomal analyses on cloned Norway spruce trees exposed to various levels of ozone in open-top chambers

Antioxidants and pigments in needles as well as chromosomal aberrations in root tip meristems of young clonal Picea abies trees were investigated after exposure to different ozone concentrations (charcoal filtered, non-filtered, non-filtered +25ppb, non-filtered +50ppb) in open-top chambers for three months. The same analyses were conducted after keeping the trees under ambient conditions for one year. Ozone treatments induced a dose dependent increases in chromosomal aberrations (up to nearly 10%) which could be found even after one year. Antioxidants and pigments in needles varied between sample times but differences among ozone treatments were not observed.