APS Homepage

Poster: Diseases of Plants: Disease Detection & Diagnosis


Inmunochemical detection of the Silvelrleaf disease of fruit trees caused by Chondrostereum pupureum
D. GRINBERGS (1), J. Chilian (1), A. France (1) (1) Instituto de Investigaciones Agropecuarias, Chile

The Silverleaf disease affects numerous species, including important fruit crops such as apple, blueberry, cherry, kiwi, peach, pear and plum. The leaves silvering is caused by the acumulation of an enzyme (endoPG) produced by Chondrostereum purpureum, however, foliar symptoms are not visible untill the third year after the orchard plantation. Curative control is not effective, thus, an early detection is essential to avoid the fungus dissemination. Therefore, the objective of this work was to develop an early and non destructive method to detect the disease. Using the endoPG’s aminoacidic sequence, monoclonal antibodies were synthesized and DAS-ELISA protocol developed. Mature leaves showing different silvering intensity were assessed, using healthy plants as negative control and purified endoPG as positive control. The presence of C.purpureum in the plants was confirmed through its isolation on 25% potato dextrose agar (PDA) and by the amplification of the large intergenic spacer (IGS) región, located between 5S and 18S rDNA. Results indicated that there was a positive correlation between foliar symptoms intensity and endoPG concentration, and that the method was able to discriminate among leaves from healthy and diseased but asymptomatic plants. This detection method was validated in apple, blueberry, peach and plum, as far, becoming a useful tool to prevent the disemination of the Silverleaf disease.