Effect of fungal endophytes on morphological characteristics,nutrients content and longevity of plane trees (Platanus orientalis L.)

The plane tree is one of the most frequently used street trees in urban landscape in Iran and some Mediterranean countries and some age-old ones are found in these countries. Endophytes are microorganisms which associate with healthy plant tissues, persisting without causing diseases symptoms in the host and normally benefitting them through improving plant ability to withstand environmental stresses. In this contribution, the hypothesis of fungal endophytes existence in the plane trees as well as their relationship with morphological characteristics of trees and nutrient elements of leaves were studied in the central part of Iran. The experiment was performed according to an unbalanced completely randomized design. Approximate age and height of plane trees were recorded and then the greenness and visual appearance were evaluated. Healthy shoots and bark pieces were collected and surface sterilized then placed in petri dishes containing PDA. The results showed that endophytes frequency were significantly greater in age-old trees (60.04%) than young ones (39.96%). Endophytes existence had a positive correlation with iron (Fe) and potassium (K) concentrations of the leaves, and trees height and circumference. Also, there was a positive correlation between the presence of fungal endophytes and improved visual appearance of plane trees. The results suggest that fungal endophytes association enhanced nutrient elements assimilation in trees contributing at least partly to elevated survival of age-old plane trees.