SN/T 4734-2016 in English

Technical Background of the Standard

SN/T 4734-2016 is a specialized testing standard for Phytophthora lateralis, the primary cause of cedar root rot. The standard was first published in December 2016 and officially implemented in July 2017. Its technical framework references GB/T 1.1-2009 Guidelines for Standardization.

Comparison of Core Detection Methods

Key Technical Points

1. Culture Medium Preparation

The standard recommends using V8 medium. The specific formula is as follows:
- Centrifuge V8 juice at 1500 rpm for 10 minutes and collect 177 mL of supernatant
- Add 2.5 g of calcium carbonate and 15 g of agar powder
- Sterilize at 121°C for 20 minutes, then add 50 mg of penicillin and 100 mg of streptomycin

2. PCR Detection Procedure

1. DNA extraction: Use the CTAB method, add 10% SDS to lyse cells
2. Primer design: Specific primers T3/T4 (5'-GTTCGAATCCCTTTTTTGC-3')
3. Amplification procedure: Pre-denaturation at 94°C for 5 minutes, 35 cycles (94°C for 30 seconds → 60°C for 30 seconds → 72°C for 30 seconds)

Implementation Recommendations

Quality Control Points

• A negative control (sterile water) should be set for each batch of testing.
• A standard strain DNA (ATCC MYA-4891) should be used as a positive control.
• A characteristic band of 192bp should appear on electrophoresis.