Historical Studies of Cupressus sempervirens L. Affected by Diplodia pinea f.sp. Cupressi and Seiridium Cardinale

1989

S. 183-192

17 Abb., 24 Lit. Ang.

Unselbständiges Werk

200040233

IAWA Bulletin 1989 ; 10(2), S. 183-192

Between 1980 and 1986 two serious diseases of Cupressus sempervirens were found in Israel: Seiridium cardinale and Diplodia pinea. Visual symptoms of both pathogens are similar and are characterised by canker formation accompanied by strong resing secretion from lesions. Histological examinations in the centre of the canker reveal similar reactions of C. sempervirens to Seiridium and Diplodia inoculation. Numerous resin ducts are formed in the bark, necrophyllactic periderm formation occurs several months after inoculation, disorganisation of the xylem is conspicuous, production of abnormal lignified parenchyma cells instead of tracheids occur at the injured site, and curved tracheids and transverse walls are formed. Tannin accumulation occurs in the bark and xylem. Similar reactions of C. sempervirens to wounding and similar effects of Matsucoccus josephi on Pinus halepensis are discussed.