Tracing botanical origins of unifloral Aroeira honey with Geographical Indication: Anacardiaceae pollen characterization from northern Minas Gerais’ Seasonally Dry Tropical Forest and Cerrado.

Abstract

Abstract Many species of Anacardiaceae from the Seasonally Dry Tropical Forest biome and Cerrado, an ecoregion of the Brazilian Tropical Savanna biome, are of great importance as a source of nectar and pollen. They are trees that massively bloom and attract several insects as floral visitors, especially honeybees and stingless bees. We aim to provide a practical tool for use in melissopalynological analyses of honeys, especially those produced in the northern region of Minas Gerais, Brazil. Here, a palynological description of six species of Anacardiaceae occurring in both vegetation types is provided using light and scanning electron microscopy. Statistical analyses were performed with the morphometric data to test the relevance of pollen morphology for defining pollen types and assisting in the certification of the botanical origin of honeys through melissopalynology. The most important metric variables for identifying the analyzed species were a combination of pollen grain size and width of the colpus margo, whereas pollen shape and other variables were less informative due to great intraspecific variation. Spondias tuberosa, with the largest pollen grains, stood out from the other species. The margo of the colpus wide contributed to the distinction of Schinopsis brasiliensis pollen grains. Qualitative traits analysis based on the pollen wall ornamentation contributed greatly to revealing two distinct groups: suprastriato-inframicroreticulate [Astronium fraxinifolium, A. graveolens, A. urundeuva, Schinopsis brasiliensis] and striate-perforate [Schinus terebinthifolia, Spondias tuberosa]. The palynological variation found among the studied species reinforces the importance of pollen morphology for the correct certification of botanical origin of Brazilian Aroeira honey.