Characterization of Fusarium oxysporum f. sp. cubense Caused Fusarium Wilt in Donomulyo, Malang Regency, Indonesia

Abstract

Fusarium oxysporum f. sp. cubense (Foc) is a soil-borne fungal pathogen responsible for fusarium wilt, which constitutes one of the major constraints in banana cultivation. Information on the occurrence and molecular characteristics of Foc in Malang Regency, one of the banana-producing areas in East Java, Indonesia, remains limited, hindering effective disease surveillance and management. This study was conducted to isolate and characterize fungal isolates associated with fusarium wilt disease in banana plants using an integrated approach combining morphological characterization, pathogenicity testing, PCR amplification, ITS sequence analysis, and phylogenetic analysis. Three fungal isolates were recovered from symptomatic banana plants collected in Donomulyo, Malang Regency, and one representative isolate (DNM) was selected for molecular characterization based on its morphological similarity to the other isolates. Morphological observations revealed characteristics typical of Fusarium oxysporum. ITS sequence analysis showed 100% query coverage and 100% sequence identity with reference Foc sequences available in GenBank, while phylogenetic analysis clustered the DNM isolate with reference Foc isolates with 94% bootstrap support. Pathogenicity assays demonstrated that the isolate induced typical fusarium wilt symptoms, resulting in an LDI of 16.39% at 14 DAI and an RDI of 41.67% at 45 DAI. These findings provide baseline information on putative Foc isolates in Malang Regency, particularly in the Donomulyo area, and establish an integrated characterization framework to support disease surveillance, early detection, and the development of integrated management strategies for fusarium wilt in banana production systems.