Sampling and DNA extraction
We sampled a total of 408 B. terrestris workers from fourteenpopulations in the Mediterranean region in Turkey (Table 1). To
assess the genetic structure of native and commercial populations and
the potential impacts of introducing non-native subspecies (or
populations), we divided the sampled populations into three groups;1)
greenhouses (commercial) populations 2) nearby greenhouses and 3) far
from the greenhouses populations. A total of 212 worker samples (one
worker bee per commercial hive) from seven different commercial
companies (belonging to all local and global companies, CP1-CP7) were
collected from greenhouses populations. A total of 100 worker samples
from four populations (AK, KU, DE and GB-at least 30 km away from each
other) were collected within the 5 km areas surrounding the greenhouses
where commercial B. terrestris colonies are intensively used for
crop pollination. A total of 96 worker samples from three native
populations (TM, FS, BB) were collected in the best preserved areas more
than 30 km away from greenhouses and each other. In a previous study,
Ozbek (1997) observed native B. terrestris populations all areas
in which we collected field worker samples (seven locations) before the
use of commercial B. terrestris colonies in Turkey. All sampled
workers were stored in 95% ethanol solution at -18 ° C until DNA
extraction. Total genomic DNA was extracted from thorax muscles of each
worker bee using a 10% Chelex solution (Walsh, Metzger, & Higuchi,
1991).