Abstract:

To establish a rapid and specific technique for quantitative detection of lotus rhizome rot pathogen Fusarium commune, evaluate the feasibility of this technique for quantitative detection of F. commune, the dynamic monitoring on the number of F. commune in soil and lotus root samples from lotus lake in Dongguan was carried out, so as to provide a basis for the control of the disease. Real-time fluorescence quantitative PCR (qPCR) technology with SYBR Green I as the fluorescent dye was used to detect the contents of F. commune in lotus plants and underground soil with different disease levels, and the correlation between the content of F. commune and disease level was analyzed. The results showed that the minimal detection limit of qPCR technique was 1 fg/µL, and the minimal detection limit of qPCR technique was 10 pg/µL after the addition of genomic DNA from healthy lotus tissues. The dissolution curve of the qPCR reaction was analyzed, and there was only one peak value of the amplified product, indicating that the DNA product amplified by the qPCR technique was highly specific. There was a positive correlation between the content of F. commune DNA and the degree of disease in infected plants, whereas the content of F. commune in lotus lake soil had a low correlation with the disease levels, however, the number of F. commune in soil increased with the increase of disease level. This qPCR detection system could dynamically mornitor the content of F. commune in the lotus lake soil and infected lotus roots, and thus provides a basis for the effective control of this disease.

Key words: lotus rhizome rot disease, Fusarium commune, quantitative detection, real-time fluorescence quantitative PCR (qPCR), dynamic monitoring