The effects of Loranthus europeaus on Carbohydrate, proline and chlorophyll in different tree species of Zagros forest

Loranthus europeaus Jacq. is a threatening factor in Zagros forests. It is seen on various tree species. This study was conducted to investigate the effect of continental mistletoe (Loranthus europeaus Jacq.) on carbohydrate, proline and chlorophyll content in Persian Oak (Quercus brantii Lindl.), Montpellier maple (Acer monspessulanum L.) and Almond (Amygdalus elaeagnifolia Spach.) as its common hosts in Ilam forests.
Nine habitats with the mistletoe infested were selected in different forest areas of the Ilam province. From each habitat six infected trees of Quercus brantii, Acer monspessulanum and Amygdalus elaeagnifolia were sampled. These trees were in the same conditions of diameter, height, severity of infectious and aspect conditions. After that, the leaves were collected from healthy and infected branches. From each tree, four mature leaves were individually sampled from below and above the mistletoe clump in the host tree, the leaf of the mistletoe, and the leaf of the healthy branch of the host tree. For measuring the carbohydrate, proline and chlorophyll content, the leaves then transferred to the laboratory.
The results showed that the content of chlorophyll a, b and carbohydrate in almond and Persian oak had significant different in the various position including below and above of mistletoe clump in the host tree, mistletoe leaves and uninfected branch. In addition, the highest levels of chlorophyll a and b were observed in the two mentioned-above tree species. A. monspessulanum species did not show significant difference in terms of proline, chlorophyll and carbohydrate in different sampling parts, but the highest amount of chlorophyll (2.282 mg/g) and proline (0.552μm/g) was determined in L. europeaus. A significant difference was seen between chlorophyll b values of L. europeaus and below the clump, and the highest amount of this feature was in almond. The highest amount of carbohydrate (3.017 mg/g) in the almond was in the mistletoe clump and tree leaves below it (2.99 mg/g). In Persian oak, the lowest (2.159 mg/g) and highest (3.094 mg/g) amount of carbohydrates was observed in the L. europeaus and oak leaves below the clump, respectively. Also, among the host trees, the leaves in the position above the mistletoe clump showed some differences and Q. brantii and A. monspessulanum had the most and lowest amount of carbo. The proline values were significantly different between mistletoe leaves and leaves of host trees. Highest amount of proline can attributed to the leaves of almond tree.
The amount of features like proline, carbohydrate and chlorophyll were significantly different in diverse sites as well as in different sample leaves. In other words, it can be said that the hemiparasite mistletoe as a biological stress affects the physiological activity of forest trees, which differs from one species to another.