A Quantitative PCR Method for Detecting Phytophthora parasitica var. nicotianae in Tobacco Planting Soil Based on LNA Sensitization

In order to efficiently detect the colonization of Phytophthora parasitica var. nicotianae in tobacco planting soil, a quantitative PCR method was researched based on locked nucleic acid (LNA) primer. The results showed that: 1) Comparing with conventional DNA primers, the LNA primer raised PCR reaction annealing temperature, reduced the formation of primer dimers and non-specific products, and improved the sensitivity and specificity of detection. 2)LNA quantitative PCR analysis revealed that the concentration of Phytophthora parasitica var. nicotianae in 14 soil samples of tobacco / garlic rotation fields ranged from 2.76×10³ to 5.20×10⁴ per gram. This method is sensitive and efficient, the detection can be completed within 4-5 hours.