Identifikasi Molekuler dan Analisis Filogenetik Fusarium Spp. dari Berbagai Tanaman

Abstract

Fusarium is a genus of fungi with diverse ecological characteristics found in various environments, such as soil, water, and plant tissues. Most Fusarium spp. species are important pathogens in cultivated plants, causing wilting, root rot, and even plant death. Morphological diversity and phenotypic similarity among species can potentially lead to errors in species identification. Species misidentification can lead to errors in disease control, including the use of fungicides that are not targeted appropriately, thus requiring a more accurate identification method using a molecular identification approach based on DNA sequencing. This study aims to identify the species status of Fusarium spp. from various host plants molecularly and analyze their phylogenetic relationships through a phylogenetic approach. This study used six isolates consisting of two laboratory collection isolates (red chili and corn) and four isolates from field exploration (bird's eye chili, tomato, tobacco, and red onion). Identification was conducted in stages, starting with field observations of disease symptoms, macroscopic and microscopic morphological characteristics, and molecular identification using PCR techniques with three primer pairs: ITS4/5, EF1/EF2, and Fa/Ra. Sequencing results were analyzed using BLAST for species determination, and a phylogenetic tree was constructed using the maximum likelihood method. The observed disease symptoms indicated Fusarium spp. infection, such as yellowing leaves, curved stems, blackened vascular tissue, and wilting and death of plants. Macroscopic morphological observations showed that Fusarium spp. colonies were generally white to purple in color, spreading with a cotton-like texture. Microscopically, they showed the presence of sickle-shaped macroconidia, oval microconidia, and some produced round chlamydospores. Molecular analysis results indicated that the FCM (red chili) and FBM (red onion) isolates were identified as F. vii acutatum. The FCR (chili pepper), FJG (corn), and FTB (tobacco) isolates were identified as F. incarnatum, F. hainanense, and F. sulawesiense, respectively. he FTM (tomato) isolate was identified as F. solani. Phylogenetic analysis showed that isolates of the same species formed separate clades in the phylogenetic tree. Isolates FCM and FBM formed a single clade within the FGSC group, while FCR, FJG, and FTB were in the FIESC clade, indicating close relatedness among these three species. Isolate FTM formed a separate clade corresponding to the FSSC group. These findings prove that a single plant species is not always infected by the same Fusarium spp. species, and that morphological approaches alone are insufficient for accurate species identification, necessitating molecular and phylogenetic analyses to provide a comprehensive picture. This study demonstrates that an integrative identification approach can reveal the species status and phylogenetic relationships of Fusarium spp. in greater depth