Speakers

Abstract

Castanea sativa has been severely affected by Phytophthora cinnamomi, a problematic disease in Portugal that was responsible for the disappearance of more than 50% of the chestnut-producing area since the beginning of the 20^th Century. Unfortunately, it continues to be one of the most devastating root rot pathogens of chestnut, being essential to finding alternative strategies that can help the trees to increase their resistance against it.

Silicon (Si) fertilization appears as a possible inducer of tolerance against P. cinnamomi infection, acting as a plant protector against this and other biotic stresses in different crops of the world. This study's main objective was to evaluate
Si effect on plant protection against P. cinnamomi. The chestnut seedlings were fertilized with 10 mM Si, and one month after half of them were inoculated with the oomycete. The mortality rate of chestnut trees treated with Si was 10%. In the in vitro study, realized by Si application in a PDA medium to evaluate its fungi toxic capacity, results showed that 10 mM Si solutions presented a stronger inhibition zone (90%) against P. cinnamomi comparatively to the control treatment (0%) two weeks after incubation. Data obtained in this research demonstrated that Si can act as an elicitor that triggers rapid action by the biochemical defense system. The present research suggests that Si fertilization could be successfully used in the control of
P. cinnamomi by increasing the physical and chemical defense mechanisms of chestnut plants, expands the protection of plants and consequently the quality of the chestnut fruit.