Preliminary Identification of New Fungal Pathogen Isolated from Black Pepper Disease

Abstract

Abstract Black pepper (Piper nigrum L.) is one of important spice crop that has been grown and traded globally. In this few years, black pepper industry had recorded unsatisfactory yield production as its has been hampered with disease attacks. Almost all parts of the plant are susceptible to disease infections particularly disease that has been caused by fungal pathogens. This present study aims to isolate and identify fungal pathogen associated with black pepper disease in peninsular Malaysia. In one of sampling location in Jelebu, Negeri Sembilan, two fungus were isolated from symptomatic leaves and berries of black peppers. The leaves produced yellowish to brownish lesions while the berries produce blackish lesions. Morphological identification based on macroscopic and microscopic characteristics showed that the isolates produced similar characteristics with Fusarium and Diaporthe species. The pathogenicity was confirmed by an artificial inoculation test on healthy black pepper plants in which similar simptoms were observed on inoculated plant. Molecular identification based on DNA sequence analysis of the Internal Transcribed Spacers (ITS1 and ITS2) regions was conducted to confirm the identity of both isolates. The sequences were compared with other sequences from the NCBI GenBank database and the blast results indicate 99% percent similarity with Diaporthe phaseolorum and Fusarium polyphialidicum species. Constructed Phylogenetic tree also showed that the isolates were grouped together with the reference strain of Diaporthe phaseolorum and Fusarium polyphialidicum species. This is the first report of the occurrence of both species as pathogen of black pepper plant in peninsular Malaysia.