Abstract
Comprehensive decisions on the management of commercially produced
livestock, including solitary bees, depend largely on associated
knowledge of genetic diversity. In this study, we present novel
microsatellite markers to support the breeding, management, and
conservation of the blue orchard bee, Osmia lignaria. Native to
North America, O. lignaria has been trapped from wildlands and
propagated on-crop and used to pollinate certain fruit, nut, and berry
crops. Harnessing the O. lignaria genome assembly, we identified
59,632 candidate microsatellite loci in silico, of which 22 were tested
using molecular techniques. Of the 22 loci, 14 loci were in
Hardy-Weinberg equilibrium (HWE) and demonstrated no linkage
disequilibrium (LD) in two Intermountain North American wild populations
in Idaho and Utah. We found no difference in population genetic
diversity between the two populations, but there was evidence for low
but significant population differentiation. Also, to determine if these
markers amplify in other Osmia, we assessed 23 species across the
clades apicata, bicornis, emarginata, and
ribifloris. Nine loci amplified in three species/subspecies of
apicata, 22 loci amplified in 11 species/subspecies of
bicornis, 11 loci amplified in seven species/subspecies of
emarginata, and 22 loci amplified in two species/subspecies of
ribifloris. Further testing is necessary to determine the
capacity of these microsatellite loci to characterize genetic diversity
and structure under the assumption of HWE and LD for species beyond
O. lignaria. These markers will help to inform the conservation
and commercial use of trapped and managed O. lignaria and other
Osmia species for both agricultural and non-agricultural systems.