DEVELOPMENT OF DETECTION METHOD FOR SEED-BORNE PATHOGENIC FUNGI ON RICE SEED USING FIBER OPTIC FLUORESCENCE SPECTROSCOPY

Abstract

Aspergillus flavus, Bipolaris oryzae and Fusarium semitectum are fungi that infect rice crop both in field and
storage. Seed health testing is conducted in order to prevent or to minimize risks caused by seed-borne pathogens.
One of potential technology which can be developed as detection method is fiber optic fluorescence spectroscopy.
The research aimed to develop an alternative detection method more rapid, accurate, and simple for seed-borne
fungal pathogen based on secondary metabolites by using fiber optic spectroscopy fluorescence. This research
covered: preparation of pure isolates of A. flavus, B. oryzae, and F. semitectum; calibration of fiber optic
fluorescence spectroscopy and fungal secondary metabolite analysis by Py-GC-MS; and detection of A. flavus, B.
oryzae and F. semitectum on rice seed. The data were analyzed by Spectrasuite Ocean Optic software. Fiber optic
fluorescence spectroscopy was able to detect fluorescence emission of fungal metabolites after rice seed were
incubated for 24 hours. Each fungus produced specific secondary metabolite when exposed to violet or ultraviolet
light which has specific fluorescence emission. A. flavus produced aflatoxin B1 at 440 nm, B. oryzae produced
ophiobolin A at 534 nm, and F.semitectum produced beauvericin at 510 nm.