First report of charcoal disease caused by Biscogniauxia mediterranea (De Not.) Kuntze on Juniperus excelsa M. Bieb. in Iran

Juniperus excelsa M. Bieb. (Cupressaceae) is the most common species among the six juniper species in Iran. Unfortunately, in recent years, due to anthropogenic disturbances, low natural reproduction, and excessive drought, the population of this valuable endangered species has decreased significantly. In a case study conducted in Parvar Protected Area in Semnan province, the decline was associated with strip-cankers on the trunk, detached bark, discolorations and browning of the plant, resulting in its complete dryness. After isolating the fungus associated with declined trees, macro- and micro-morphological characteristics showed that the obtained isolate belonged to Biscogniauxia mediterranea (De Not.) Kuntze. Then, evaluation of rDNA ITS region sequence information confirmed it. The pathogenicity test was performed in the greenhouse conditions and its pathogenicity was confirmed on juniper plants. This is the first report of B. mediterranea causing disease on J. excelsa as a new host, from Iran and worldwide. This study confirms the current spread of B. mediterranea to different regions and hosts in Iran, as reported in other parts of the world, most likely due to ongoing climate change that create optimal conditions for the survival of the fungus in other areas, that were previously unsuitable for it.