Morphological characterization and molecular identification of three fungal pathogens isolated from Solanum melongena L. in Sri Lanka.

Abstract

Purpose: Solanum melongena L. (brinjal/ eggplant) is a popular vegetable in Sri Lanka. Like many solanaceous crops, brinjal fruits and plants are susceptible to various diseases. The objective of this study was to isolate, confirm pathogenicity and characterize fungal pathogens causing leaf blight, yellowing and necrosis in S. melongena plants in selected localities in Gampaha district, Sri Lanka. Research Method: Fungi associated with symptomatic S. melongena plants collected from three localities in Gampaha district, Sri Lanka, were isolated onto potato dextrose agar and their pathogenicity was tested on healthy S. melongena plants. Fungal isolates that were confirmed to be pathogenic were subjected to morphological and molecular characterization. Findings: Fifteen fungal isolates were obtained from infected leaves of S. melongena plants, and four fungal isolates were confirmed to be pathogenic on S. melongena. Isolates H32a and H32b causing similar disease symptoms were identified as Lasiodiplodia theobromae with 99.81% sequence similarity by the analysis of the internal transcribed spacer region (ITS1-5.8S-ITS2). The remaining two pathogenic isolates were identified as Pseudopestalotiopsis theae and Diaporthe eugeniae, with 100% and 99.82% sequence similarities, respectively. Originality/ Value: To our knowledge, this is the first report of leaf necrosis by L. theobromae, leaf yellowing by P. theae and leaf blight by D. eugeniae associated with S. melongena plants in Sri Lanka