Genetic discrimination of the poisonous Urobotrya siamensis from the green-leaf vegetable ‘Pak-wan’

Abstract

© 2019 Elsevier B.V. ‘Pak-wan’; Melientha sauvis PIERRE and Sauropus androgynous, are popular local vegetable in Asia. They are often confused with poisonous species ‘Urobotrya siamensis’ found in the wild, and mistakenly picked. Ingestion of a meal-portion of the poisonous U. siamensis can lead to death within a few hours. This study aimed to identify potential DNA markers to discriminate the 3 “Pak-wan” plant species. DNA sequence analysis of 7 DNA markers showed sequence polymorphisms (SNPs and InDels) in 5 potential DNA markers i.e. ITS, rbcL, trnT-L-F, trnH-psbA, and at103. The 2 DNA markers; i.e., trnH-psbA and at103, revealed sequence length polymorphisms between the 3 species, in which their sizes were different among the 3 plant species. The at103 fragment was unsuccessfully amplified from M. sauvis (no PCR product). For matK and sqd1, the 3 species showed 80–100% and 82–94% sequence similarity, and DNA polymorphisms were insufficient for discrimination. Further DNA-test to identify the poisonous plant, which would benefit to both forensic and food safety issue, is ongoing.