Saudi Journal of Biological Sciences 25(8): 1778-1780 (Dec 2018)
Inoculation with arbuscular mycorrhizal fungi alleviates harmful effects of drought stress on damask rose
Eslam Abdel-Salam, Abdulrahman Alatar, Mohamed, A. El-Sheikh

Abstract
This study was conducted to examine the role of arbuscular mycorrhiza fungi (AMF) in alleviating the adverse effects of drought stress on damask rose (Rosa damascena Mill.) plants. Four levels of drought stress (100, 75, 50, and 25% FC) were examined on mycorrhizal and non-mycorrhizal plants in pots filled with sterilized soil. Our results showed that increasing drought stress level decreased all growth parameters, nutrient contents, gas exchange parameters, and water relations indicators. Under different levels of drought stress, mycorrhizal colonization significantly increased all studied parameters. Pn, gs, and E of the mycorrhizal plants was higher than those of non-mycorrhizal plants under different levels of drought stress. The increase in those rates was proportional the level of the mycorrhizal colonization in the roots of these plants. Majority of growth, nutrition, water status and photosynthetic parameters had a great dependency on the mycorrhizal colonization under all levels of drought stress. The results obtained in this study provide a clear evidence that AMF colonization can enhance growth, flower quality and adaptation of rose plants under different drought stress levels, particularly at high level of drought stress via improving their water relations and photosynthetic status. It could be concluded that colonization with AMF could help plants to tolerate the harmful effects caused by drought stress in arid and semi-arid regions.


2.1. Inoculum preparation

The mycorrhizal inoculum was prepared in an open-culture of sudangrass (Sorghum halepense L.) plants. The wet sieving and decanting technique (Gerdemann and Nicolson, 1963) was followed to isolate the AMF used in this study from different sites cultivated with rose plants subjected to drought stress in Taif region, Saudi Arabia. The spores of AMF were cultured for 6 months on sudangrass plants cultivated in pots containing sandy soil (autoclaved 3 times, 121 C, 30 min, 1.5 air pressure for three separate consequent time) in an environmentally controlled greenhouse (25/16 C day/night, relative humidity of 6065%, 16/8 light/dark photoperiod with light intensity of 700 µmol m-2 s-1). The inoculum used was consisted of 20 g of the sudangrass rhizosphere containing roughly 950 mycorrhizal spores and about 0.5 g of colonized roots.The inoculum average infection level was 78.5%. The mycorrhizal inoculums were placed at 3 cm depth of the rose cutting media upon planting.

Mycorrhizal Fungi