Genetic Diversity of Urban Apis cerna Bee Populations: Insights from Phylogeography and Microsatellite Analysis

Abstract

Abstract Obligate floral specialists such as bees are threatened by the loss or degradation of valuable feeding and nesting resources due to human intervention in their natural habitat. Despite land use change and anthropogenic influence, flower rich urban green spaces have become an indispensable ecological habitat as they provide a valuable refuge for bees. Though species diversity and pattern of bee distribution has proven the usefulness of urban green habitats, the conservational priorities of such habitats can be confirmed through phylogeography and genetic diversity of regional populations. Therefore, the present study was conducted to determine the phylogeography of native keystone species Apis cerana indica from urban green space in Bangalore, a metropolitan city in India. The genetic structure and pattern of gene flow of urban population was compared with rural and wild populations to establish the genetic diversity and phylogeography of urban population. The genetic analysis of 12 microsatellite loci confirmed a high level of genetic polymorphism and heterozygosity of alleles within populations as well as between regions. The low degree of genetic variance (2%) has ruled out any introgression and genetic differentiation between the geographical populations. The pairwise population FST (<0.1) values ensured a high degree of gene flow between the geographical populations. The study of allelic frequency (20.909), heterozygosity (He=0.938) assured a stable gene flow and genetic mixing of populations ruling out possible threat of inbreeding or the genetic isolation of urban bee populations. The STRUCTURE analysis and PCoA has further indicated the genetic closeness and the pattern of gene flow between urban and rural populations and rural and wild populations, indicating the genetic connectivity between three geographical locations. The microsatellite allelic diversity and phylogeography has confirmed the merit of urban green area for long term conservation of threatened pollinator species. Therefore, scientific management of bee friendly floral and nesting resources along with stable geographical connectivity can safe guard threatened pollinator community in modified green spaces within human dominated cities.