The melissopalynological investigation in the Eastern Dry Zone of Karnataka, India

Melissopalynology, the analysis of pollen grains present in honey, indicates about the pollen and nectar sources in a region utilized by bees, which is used to determine the bee floral resources and botanical origin of the honey. This study investigated the melissopalynological analysis of the honey samples from the Eastern Dry zone of Karnataka. 24 honey samples were examined based on pollen analyses, among them 14 samples were unifloral, rest were multifloral. The unifloral honey had pollens of Callistemon viminalis, Areca catechu, Citrus sp., Mallotus philippensis, Cocos nucifera, Eucalyptus sp., Ocimum sp., Moringa oleifera and Pongamia pinnata. Samples collected in October, November, December, and January were rich in pollens of Eucalyptus sp.. Similarly, samples collected in January, February and March had pollen of tree species viz., Swietenia mahagoni, Canthium parviflorum, Simarouba glauca, Eucalyptus sp., Moringa oleifera, Syzygium cumini, Tabebuia sp., Pongamia pinnata, Acanthaceae, Anacardium occidentale, Cocos nucifera, Areca catechu, Mallotus philippensis, Bauhinia variegata, Psidium guajava, Alangiaceae, Euphorbiaceae, Ulmaceae, Capparis zeylanica, Convolvulaceae. GKVK-11 followed by GKVK-12 sample recorded the highest Shannon diversity and GKVK-9 followed by GKVK-7 sample recorded the least diversity. Based on the similar floral composition samples were classified into four clusters. The PCA revealed that most of the samples grouped into a single cluster, except 7, 19, 20, 21, and 22 which were placed away from the origin. The presence of pollen in the honey of a particular plant species during different months is related to the blooming of that particular plant species from which the bees forage. The flora of honey changes with the season. The diversity of pollen grains in honey varied with location to location. The present study provides scientific knowledge to the beekeepers by indicating important plants for the development of the regional apiculture, through the identification of pollen types.