Investigating the Signs of decline and its impact on the total phenolic compounds, flavonoids and protein of the leaves Quercus, brantii (Case Study: Lorestan province)

The phenomenon of Oak decline is one of worrying phenomena that has been occurred in Zagros forests, and the extent of the infected forest areas is spread increasingly. The present study aims to investigate the symptoms of Oak decline on the individuals and its effect on the secondary compounds of Quercus brantii leaves. For this purposes, three forest regions including Abolivafa, Miankouh and Mellasaban in Lorestan province, which are of the most important centers of Oak decline, were selected. To better introduction of oak decline, trees with different levels of crown decline and healthy trees were randomly determined. The symptoms of Oak decline include the debarking of the trunk, emission of the extraction from xylem, fraction in the bulk of the trees, leaf browning and premature leaves fall. Regarding the findings of secondary compounds, the results showed that flavonoid compounds in the leaves affected by Oak decline were significantly higher than that of the healthy trees in Miankooh, Male Shaban and Abolvafa (p≤0.5). However, the content of total phenol were significantly higher in the healthy trees only in Miankooh and Male Shaban (p≤0.5). The amount of measured protein was not significantly different in healthy and infected trees. In addition, due to the further development of the disease in Miankouh region, the increase of these compounds was higher than other regions. In conclusion, the results show that oak decline increases the secondary compounds such as flavonoids and phenol compounds, which have an effective role in the resistance of Quercus brantii against pathogens and prolonging the trees’ survival.