Ergosterol as a Biochemical Indicator of Fungal Infection in Spruce and Fir Needles from Different Sources

Different fungi are discussed to play a certain role in recent spruce decline in addition to different abiotic factors such as SO2, photooxidants (ozone) or unfavourable climatic conditions. Thus, ergosterol as a specific fungal sterol was used as a biochemical indicator for fungal infection in differently damaged spruce and fir needles. With its aid it could be demonstrated that the important needle pathogens Rhizosphaera kalkhoffii Bubak, Lophodermium piceae and Sirococcus Type II contain unsaponified ergosterol comparable with the ergosterol content of different edible mushrooms. Furthermore it could be shown that all necrotic and also certain bleached and green needles exhibit fungal infection. However, fungal invasion seems to be a secondary reaction after the needle is predamaged by different factors.