GB/T 36844-2018 in English

1. Standard Overview

Pseudomonas syringae pv. maculicola is an important pathogen that harms cruciferous plants. GB/T 36844-2018 specifies the quarantine and identification methods for this pathogen, and is applicable to the detection of Pseudomonas syringae pv. maculicola in cruciferous vegetables and their seeds and other plant materials. This standard was proposed and coordinated by the National Technical Committee for Plant Quarantine and Standardization, and the main drafting units were the Hunan Entry-Exit Inspection and Quarantine Bureau of the People's Republic of China and the Shanghai Entry-Exit Inspection and Quarantine Bureau.

2. Laboratory Isolation and Identification

Isolation and identification are carried out by biological microscope and PCR amplification instrument, combined with the characteristics of the culture medium (such as KB culture medium).

3. Biochemical and molecular biological detection technology

This standard adopts a variety of detection methods:

• LOPAT test: including sucrose formation of fructan, oxidase reaction, potato soft rot test, etc.
• GATTa test: involving gelatin liquefaction, aesculin hydrolysis and tyrosinase activity detection.
• Biolog biochemical identification system: used to further confirm the characteristics of the strain.
• PCR detection technology: amplify the target gene fragment through specific primers, and combine agarose electrophoresis or real-time fluorescence quantitative PCR for identification.

In the laboratory, use constant temperature incubator and centrifuge and other equipment to complete the sample processing and detection process.

4. PCR detection method and result judgment

The result judgment needs to be based on the colony characteristics, biochemical reactions and PCR test results. If the sample contains the black spot pathogen of the cruciferous plant, it needs to be properly preserved and registered.

5. Recommendations for the implementation of the standard

• Strengthen quarantine efforts to ensure that imported and exported plant materials meet national standards.
• The laboratory should be equipped with key equipment such as clean bench and real-time fluorescence quantitative PCR instrument.
• Carry out regular technical training to familiarize technical personnel with standard operating procedures and detection methods.

The implementation of this standard can effectively prevent the spread of crucifer bacterial black spot pathogens and ensure agricultural production safety.