[A Rapid and Simple Method for Detection of Colchicum autumnale Using PCR].

Colchicum autumnale is a perennial, toxic plant that originated in Europe and North Africa. Although inedible, it is occasionally consumed accidentally because it resembles the edible Allium victorialis and other related species. This misidentification has led to episodes of food poisoning in Japan. However, determining the causative agent of a food poisoning outbreak by observing the sample visually or analyzing the chemical composition is challenging when dealing with small samples. Therefore, we developed a novel set of PCR primers that anneal to the internal transcribed spacer (ITS) region of C. autumnale ribosomal DNA, designed to detect the presence of C. autumnale in small samples. These primers successfully detected C. autumnale in all samples in which it was present, and did not give a positive PCR band in the 48 other distinct crop species tested, in which it was not present. Further, our method could amplify DNA from samples of C. autumnale that had been heat-treated and digested using artificial gastric fluids. Thus, this PCR strategy is highly specific and can be used to distinguish C. autumnale simply and rapidly from various other crops.

Identification of Alocasia odora (Kuwazuimo in Japanese) Using PCR Method.

Kuwazuimo (Alocasia odora) and shimakuwazuimo (Alocasia cucullata) are evergreen perennial plants that originated in East Asia. Although inedible, they are occasionally eaten by mistake because they resemble satoimo (Colocasia esculenta), and this has caused food poisoning in Japan. It is not easy to determine the cause of a food poisoning outbreak from the shape or chemical composition when the available sample is small. Therefore, we developed a new primer pair for PCR to identify kuwazuimo and shimakuwazuimo in small samples, based on the internal transcribed spacer (ITS) region of ribosomal DNA. Using PCR with the developed primer pair, we detected all samples of kuwazuimo obtained from the market, while excluding 17 other kinds of crops. The samples were identified as shimakuwazuimo by DNA sequencing of the PCR products. The present PCR method showed high specificity and was confirmed to be applicable to the identification of kuwazuimo and shimakuwazuimo from various crops.