PS 48-253 - Plant species composition analysis of longan honey from Taiwan and Thailand using DNA metabarcoding

Abstract: Honey bees play a vital role in pollination and maintaining ecosystem balance, producing different types of honey. Longan honey is a significant product in Taiwan and Thailand, labeled as monofloral. In this study, we collected longan honey samples and used DNA metabarcoding to analyze the plant species composition between the two countries.

Although considered monofloral, our analysis identified a total of 39 plant species, with 9-21 species per sample. The invasive species Bidens alba accounted for 22.6% of the total reads, followed by Dimocarpus longan at 14.1%. Ageratum conyzoides (12.1%) and Zelkova serrata (9.6%) were also abundant. Six out of eight samples were dominated by Bidens alba, while the other two had Dimocarpus longan or Ageratum conyzoides as the major species. We also found Camellia japonica in Taiwan honey products and Balakata baccata in Thailand. The rbcL sequences of Leucaena leucocephala varied slightly between the two countries. However, some species, including Pinus thunbergii, P. taiwanensis, P. yunnanensis, and P. densiflora, could not be identified using the rbcL sequence. This study shows that DNA metabarcoding is an efficient method for species identification in honey. We conclude that rbcL sequencing can be used to identify plant species and determine the origin of honey.