Key points are not available for this paper at this time.
Bitter gourd (Momordica charantia L.) is an important vegetable and medicinal crop in tropical/subtropical regions, but suffers severe yield losses (even total failure) from Fusarium wilt caused by Fusarium oxysporum f. sp. momordicae (Fom). There is no specific detection system available to detect this pathogen, and the methods used for other pathogens exhibit cross-reactivity and require specialized equipment. Therefore, this study developed a loop-mediated isothermal amplification (LAMP) assay for early Fom diagnosis. Initially, five sets of LAMP primers targeting the conserved regions of Fom, located within the region amplified by the FOMM-SPF/SPR PCR primers, were tested for specificity and sensitivity. In this experiment, FoM-1-2 showed optimal specificity, identifying 44 Fom strains without cross-reactivity with 10 other non-Fom species after a 60 min incubation at 64 °C. A visual readout based on a fluorescent dye (green for positive, pale orange for negative) eliminated the need for gel electrophoresis and specialized instruments. The LAMP assay was 100-fold more sensitive than conventional PCR (detection limit: 5.6 pg/μL vs. 560 pg/μL). In inoculated seedlings, LAMP detected Fom in basal stems at four days post-inoculation and top leaves at six days, whereas conventional PCR yielded faint bands in the basal stem after eight days. Moreover, LAMP enabled non-destructive detection. Thus, the present study developed a rapid, specific, and sensitive visual LAMP assay, supporting early diagnosis of bitter gourd Fusarium wilt.
Huang et al. (Wed,) studied this question.