Botanical and geographical origins of some commercial Apis mellifera var. adansonii honeys from Nigeria

In recent times, there has been an increase in adulterated honey in the commercial market owing to the lucrative nature of the honey business in Nigeria. Melissopalynology analyses can be used to obtain information about botanical and geographical origin of honey sources and to verify quality. Thus, this study was conducted to determine pollen composition and diversity in commercial honey samples from three states in Nigeria to ascertain their botanical and geographical origins. Seven commercial Apis mellifera var. adansonii honey samples were collected from three phytogeographical regions in Nigeria between 2017 and 2019. The samples were analysed for pollen content and other remaining structured elements occurring in sediment obtained using a non-acetolysed methodology. A total of 29 pollen types were identified, related to 18 families, 28 genera, and two unidentified pollen types. Fabaceae had the largest number of pollen types, followed by Asteraceae, Malvaceae, Arecaceae, Euphorbiaceae and Rubiaceae. Among the pollen identified, 22 pollen types were from nectariferous plants dominated by Dalbergia, Fagara/Zanthoxylum, Hymenocardia acida, Irvingia gabonensis, Macaranga, Nauclea latifolia and Pterocarpus. Monofloral honey of Nauclea latifolia and Pterocarpus sp. were also identified. The geographical origin demonstrates Apis mellifera var. adansonii using nectariferous sources available from the rainforest, forest-savanna ecotone, and Guinea savanna in the southeast, southwest, and central Nigeria, as well as in the brushwood, secondary forest, and open grassland areas, suggesting their importance as pollinators or pollen disperser agent of native flora and cultivated species.