A Muscodor strain isolated from Citrus sinensis and its production of volatile organic compounds inhibiting Phyllosticta citricarpa growth

Abstract

The citrus industry is among the most important worldwide, but citrus plants are affected by a large number of diseases, such as Citrus Black Spot (CBS), caused by the fungus Phyllosticta citricarpa. To identify alternative methods for CBS control, endophytic fungi were isolated by our group from healthy citrus plants in Brazil. Over 400 fungal isolates were obtained, and isolate LGMF1254 was selected based on its inhibitory effect on the growth of P. citricarpa because of the production of volatile organic compounds (VOCs). This isolate was identified as Muscodor sp. by morphological examination and phylogenetic analysis using the internal transcribed spacer (ITS) region: High similarity with M. sutura, M. vitigenus, and M. equiseti was observed. We also sequenced the RPB2 gene, and isolate LGMF1254 showed 99% similarity with M. sutura. To identify this isolate at the species level, the main VOCs were determined, and according to this analysis, LGMF1254 may be classified as an M. sutura strain; however, sequences from regions other than ITS and RPB2 are necessary for conclusive genotyping. The VOCs produced by strain LGMF1254 can be considered an alternative way to control P. citricarpa during the transport of fruits and to prevent the development of CBS signs.