FIRST REPORT OF COLLETOTRICHUM SANSEVIERIAE CAUSING ANTHRACNOSE ON SANSEVIERIA TRIFASCIATA IN IRAN

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Sansevieria is a genus of flowering plants which is taxonomically classified in the family Agavaceae. During the summer of 2015, leaf spots were observed on Sansevieria trifasciata in greenhouses of Mazandaran province, Iran. The symptoms initially appeared as small, round, water-soaked lesions resulting in blight of the leaves and as the disease progressed, lesions rapidly enlarged and coalesced. Mature lesions revealed numerous brownish black acervuli that were produced in concentric rings, which is characteristic of anthracnose. Warm, humid and wet conditions are cause of disease development, sporulation and spread of Colletotrichum species. Small pieces were cut from infected tissues and after surface-sterilization, they were transferred to Potato Dextrose Agar (PDA). The isolates were purified and were transferred onto Malt Extract Agar (MEA). Colonies on PDA were grayish white and on MEA were light brown. Conidia were straight, cylindrical and (13)-16.2-22(-31) × (3-)3.9-7(-8.1) µm mean ± SD = 17.86 ± 2.36 × 4.96± 1.04 µm, L/W ratio = 3.6 µm. Based on morphological characteristics, the pathogen was identified as Colletotrichum sansevieriae (Nakamura et al., 2006). In order to confirm Koch's postulates, pathogenicity tests were done three times with conidial suspension (106 spores/ml). One week after inoculation, symptoms were observed on the inoculated plants and C. sansevieriae was consistently reisolated from artificially infected plants. Molecular identification was performed based on the ITS1, 5.8S and ITS2 (ITS) and sequenced using primers ITS1 and ITS4 (White et al., 1990). BLAST search of a 566 bp sequence (accession No. KP835682.1) showed 100% identity with C. sansevieriae (LC179806.1) in accordance with morphological identification. To our knowledge, this is the first report of anthracnose caused by C. sansevieriae on S. trifasciata in Iran.