Etiology of four foliar and root diseases of wild plants in Oman

The Oman Botanic Garden (OBG) was established in 2006 to conserve, display and research the plants and ethnobotany of Oman. However, thousands of seedlings and plants were killed over the past few years by diseases of unknown aetiology. This study was conducted to characterize the main fungal pathogens associated with foliar and root diseases of four wild plants at OBG. A survey showed that root rot, soft rot of stems, wilt symptoms, die back, leaf spots, canker and galls are the main disease symptoms associated with plants at OBG. Leaf spot was found to affect 100% of Aloe while mortality in African rattlebox, Echidnopsis and Caralluma due to root rot and/or wilt diseases reached 75%, 60% and 45%, respectively. Isolations followed by molecular-based identification of fungal pathogens showed that Alternaria alternata was associated with leaf spot of Aloe. Fusarium solani, Pythium aphanidermatum and Rhizoctonia solani were the most common pathogens associated with root diseases of African rattlebox, Echidnopsis and Caralluma, respectively. This is the first report of these diseases on the four wild plant species.