Diversity of Ultraviolet Reflection Pattern in Arachis Flowers

Over a third of global agriculture is dependent on insect pollination, especially by bees. Yields of insect-pollinated crops are often managed by the addition of honeybees (Apis mellifera) to increase pollination, yet wild bee species (Bombus spp.) also increase pollination and fruit set for many globally important crops. Plant biodiversity within and surrounding crop fields can attract wild bee species and increase pollination in those fields. Peanut is an important global food crop known to attract honeybee and wild bee pollinators despite being self-pollinating and not reliant on bee pollination for seed set. Some wild Arachis species derived breeding materials have been documented to have early flowering, high flowering throughout the growing season, and large flowers as compared to cultivated peanut, which can increase attractiveness to bees. However, the presence and diversity of UV floral guides, color and UV absorbance and reflectance flower patterns that aid in flower detection and orientation towards nectar and/or pollen, have not been studied in Arachis. This study documents the presence and diversity of UV floral guides in two A. hypogaea genotypes, two peanut breeding lines, eight wild Arachis species, 19 unique allotetraploids, and four BC1F3 lines. All Arachis genotypes studied had UV floral guides and genotype was a significant indicator of flower size and UV floral guide size. Further studies evaluating the nutritional quality and abundance of pollen in Arachis species are needed to better understand the impact of ornamental Arachis species and peanut cultivars on wild bee abundance and diversity in urban landscapes and in agricultural fields, respectively.