Identification of pathogen causing leaf spot disease of Parthenocissus tricuspidata and establishment of LAMP rapid detection system

Objective To identify the pathogens causing leaf spot disease of Parthenocissus tricuspidata in Yunnan Yulong County, and establish a rapid detection method.

Method The pathogens were isolated by tissue separation method and verified by Koch's postulate. Through morphological characteristics and multi-gene joint construction of phylogenetic tree, the taxonomic status of pathogenic bacteria was clarified. A loop-mediated isothermal amplification (LAMP) assay was established by designing specific primers based on the Alt a1 gene sequence of the pathogen.

Result The pathogen causing P. tricuspidata leaf spot was identified as Alternaria alternata. The established LAMP reaction system could specifically and effectively detect A. alternata. The optimal reaction temperature of the system was 65 ℃, the optimal reaction time was 50 min, and the minimum detection sensitivity was 1 pg/μL. The system was used to detect A.alternata in the leaves of the P.tricuspidata artificially inoculated with pathogens at different time, and the detection time was 12 h or more.

Conclusion This study provides a theoretical basis for early detection, timely and scientific prevention and control of the leaf spot of P. tricuspidata.