Morphological and molecular characterization of Fusarium incarnatum as a causal disease agent of pepper (Capsicum annuum) fruit rot

Abstract Chilli pepper ( Capsicum annuum L.) is one of the most important commercially cultivated and consumed vegetables in Turkey. During a disease survey, typical symptoms of fruit rot were observed on mature chilli pepper fruits in several surveyed fields and on dried pepper fruits obtained from local retailers/bazaars in Hatay Province, Turkey. Disease incidence varied from 15 to 45% of the plants in the inspected fields. Following standard isolation procedures, 40 fungal isolates were isolated, purified and single‐spore cultures were obtained from surface‐disinfected, rotted dried pepper tissue. Of these isolates, six fungal isolates with dense, cottony white aerial mycelia that became beige with age, were isolated on a potato sucrose agar. All isolates were found to be pathogenic on artificially inoculated chilli pepper fruit. Based on morphological characteristics, the isolates were initially identified as Fusarium incarnatum (Desm.) Sacc. 1886. Morphological identification of F. incarnatum isolates was further confirmed by MALDI‐TOF and molecular analyses using the sequences of the i nternal t ranscribed s pacer ( ITS ), partial t ranslation e longation f actor‐1α ( TEF‐1α ) and second largest subunit of RNA polymerase II ( RPB2 ) loci. Phylogenetic analysis based on ITS , TEF‐1α , RPB2 and concatenation of TEF‐1α , RPB2 loci sequences performed with several isolates of Fusarium spp. confirmed that representative fungal isolates (MKUZF1 and MKUZF4) belong to F. incarnatum . To our knowledge, this is the first report of F. incarnatum causing fruit rot in chilli peppers grown in Turkey.