Integrated identification of the Botanical origins of Uzbekistan Bee Pollen by Morphological and Molecular Methods

Bee pollen is an important nutritional source for the growth and development of bee colonies. The botanical origins of bee pollen can vary significantly based on geographic and temporal factors. This study employed both palynological and molecular identification methods to determine the botanical origins of bee pollen samples collected from Tashkent, Uzbekistan. The palynological analysis identified 11 botanical origins, with major sources including Capparis spinosa, Apiaceae, Hypericum scabrum, Onobrychis sp., Papaveraceae, and Capparaceae. In contrast, the molecular method, employing DNA metabarcoding, identified 26 plant taxa, demonstrating higher resolution and efficiency. Major taxa identified included Capparis spinosa, Cucurbitaceae, Papaveraceae, Onobrychis sp., Eremurus robustus, and Rosa sp. A linear mixed-effects model (LMEM) revealed a positive correlation between the proportion of rbcL reads and the actual proportion of taxa, underscoring the reliability of molecular methods. The use of both methods highlighted the strengths and limitations of each approach: palynology offers cost-effective and stable morphological identification, while molecular identification offers greater accuracy with wider range of taxa. The findings of this study provide valuable insights into the available floral resources and foraging preference of honey bees in Uzbekistan and can be utilized by policy makers and local beekeepers to enhance the sustainability and productivity of honey bees.