Polyphasic identification and MAT1-2 isolates of Phyllosticta citricarpa in Cuba

Citrus black spot (CBS), caused by Phyllosticta citricarpa (McAlpine) van der Aa, is a disease that affects Citrus spp. causing production losses, high costs associated with management, and constraints on the fresh market trade. The present investigation aimed to confirm the identity of the CBS pathogen as P. citricarpa and determine its mating-type distribution in Cuba. Phyllosticta isolates were collected from major Cuban citrus-producing provinces (Matanzas, Cienfuegos, Camagüey, and Santiago de Cuba). P. citricarpa and the endophyte P. capitalensis (Henn.) were identified by polyphasic taxonomy, integrating morpho-physiological characteristics with the phylogenetic analysis of ITS, actA, LSU and tef1 loci. Mating-type (MAT) analysis revealed that only the MAT1-2 idiomorph of P. citricarpa is present in Cuba, providing evidence of an atypical CBS disease cycle. These results contribute to a better understanding of the epidemiology of CBS in Cuba and the improvement of CBS management.