Genetic Variations Of Anthurium Blight Pathogen, Xanthomonas Axonopodis Pv. Dieffenbachiae And LAMP-based Diagnosis Technology

Anthurium blight (caused by Xanthomonas axonopodis pv. dieffenbachiae. Xad) is a destructive disease, which represents the main limition factor for anthurium production. Xad is an imported plant pathogen, it spreads quickly in multiple pathway and could infect the numerous species of Araceae, and lacking effective measures for control at present.To explore the population structure and genetic variation of pathogeny for anthurium blight in China,163 candidate strains were isolated from suspected samples collected from different locations, and 93 Xad strains were identificated through morphological, pathological and molecular characteristics.13 RAPD markers with stability and polymorphism were screened and employed to analyze the genetic diversity of the Xad strains, and produced 131 polymorphic bands. The cluster (NTsys-pc2.02 Clustering software, SASsoftware) result showed that the genetic similarity coefficient varied from 0.52 to 0.98, and all of the 93 Xad strains were divided into five groups(Ⅰ～Ⅴ). which contains 1.2.1.53.36 strains, respectively.7 strains belongs to different groups were inoculated with anthurium cultivar ’DAKOTA’ and ’Acropolis’, and showed different virulence. This suggested that anthurium blight had spread over many producing areas in China, and had wide genetic variation, it deduced that the similarity coefficient of population genetics was somewhat related to the variety of geographical origins and hosts this pathogen come from multiple-input occurrence, and would spread and produce variation with the circulation of germchit in future.Germchit quarantine and early diagnosis are economical and effective measures for blight control. However, the routine methods including symptom and morphology observation, physiology and biochemistry detection, ELISA. PCR-based molecular identification, was limited in practical application by their delicencies in testing period, cost, reliability, technical difficulties, and so on. In this study, a new LAMP(Loop-mediated isothermal amplification)-based assay was developed to detect anthurium blight.Firstly, through Multi-locus sequence type (MLST) analysis, we selected the ABC lransportproter gene as candidate target, and designed LAMP primer sets using PrimerExplorer V4. The reaction was optimized and could be completed in 30 min to 50min, at 63℃; Xad-LAMP showed anthurium blight speciality among Xanthomonas species, and the positive rate 100% on 93 Xad strains, its sensibility was up to 10-6 ng Xad genome DNA. exceeded 10 times compared with convention PCR. corresponding to unicellular level. Secondly, we had established the SYBR Geen Ⅰ. calccin-MnCl2 and LFD detection methods to intuitively analysize the result of the amplification. Moreover, the direct LAMP detection method was developed by optimizing the handling method of tissue sample. In this.study, we provided a convenient, reliable, inexpensive.timesaving and practicable method to detect the anthurium blight pathogen, and it would make a positive significance for disease control.