Identification of the Pol Gene as a Species-Specific Diagnostic Marker for Qualitative and Quantitative PCR Detection of Tricholoma matsutake

Identification of s9ap used as an endogenous reference gene in qualitative and real-time quantitative PCR detection of Pleurotus eryngii

BACKGROUND

Pleurotus eryngii is a kind of edible fungi with good quality, and it is popular among consumers. At present, some adulterated edible fungi are available in the market. The rights and interests of consumers can be ensured by establishing a practical edible fungi detection system. Among the existing methods for detecting food adulteration, endogenous reference gene amplification is convenient and reliable. However, no ideal endogenous reference gene is available for P. eryngii.

METHODS AND RESULTS

In this study, s9ap was screened as an endogenous reference gene through sequence alignment. Qualitative and quantitative PCR analysis of this gene was carried out in one P. eryngii variety and 18 other species. The detection limit of quantitative PCR was 400 pg, and no s9ap amplification products were detected in the 18 other species.

CONCLUSIONS

This study confirmed that s9ap was an ideal endogenous reference gene for the detection of P. eryngii. This method was also suitable for processed food products.

Identification of matB used as an endogenous reference gene for the qualitative and real-time quantitative polymerase chain reaction detection of Lentinus edodes

Lentinus edodes is a fungus with rich nutritional value and good medicinal value and has accordingly become a substitute for other expensive wild edible mushrooms. In this study, for the first time, the matB gene was selected as an endogenous reference gene of L. edodes and identified as the species-specific gene. The matB genes of L. edodes and 18 non-L. edodes species were determined by qualitative polymerase chain reaction (PCR), but no amplification was found in non-L. edodes species. In SYBR Green quantitative PCR analysis, the detection limit was as low as 16 pg/µl of DNA template. All of these experiments indicated that the matB gene is an ideal reference gene and can detect L. edodes material through qualitative and quantitative PCR assays. It also provides a convenient and accurate approach for the detection of L. edodes products and the adulteration in wild edible mushroom products.

Identification techniques and detection methods of edible fungi species

Edible fungi have high nutritional value and great potential. Confusion among edible fungi species, and foodborne diseases due to toadstool poisoning or death induced by inadvertent consumption exist across the world. Therefore, edible fungi must be accurately identified. Based on different substances in edible fungi, there are different detection methods, and the same method can use different identification technology. Sensory identification methods include morphological and odor methods. Instrumental analysis methods based on chemical composition include chromatographic, mass spectrometry and spectral technology. Molecular biology identification methods based on nucleic acids include molecular marker technology, sequencing technology, isothermal amplification technology and endogenous reference gene method. Method is channel, and technology is the means. The principles, advantages, disadvantages and applications of various identification techniques and detection methods were discussed in this work to provide reference for the identification research of edible fungi and technical support for preventing food safety incidents caused by toadstools.