Abstract
Bombus kashmirensis is a key ecological indicator species on the Qinghai-Tibet Plateau, and clarifying its genetic characteristics in Qinghai Province is essential for supporting bumblebee conservation and management efforts in this region. In this study, we analyzed the genetic diversity, population structure, and environmental factors influencing genetic diversity in 539 B. kashmirensis individuals from 36 geographic populations using 15 SSR markers. A total of 382 alleles were identified across the 15 SSR loci, with an average polymorphic information content (PIC) of 0.85, indicating a high level of genetic polymorphism. The populations also exhibited high genetic diversity, with mean values of the number of alleles (N a) = 10.03, Shannon's information index (I) = 1.98, and unbiased expected heterozygosity (uHe) = 0.84. Genetic differences among populations were generally low but variable, with Nei's genetic distance ranging from 0.130 to 0.710 and Fst values between 0.013 and 0.078. Consistent results from STRUCTURE, UPGMA, and PCoA analyses revealed two major genetic clusters corresponding to eastern and western regions. AMOVA at K = 2 further supported this pattern, showing that genetic variation between groups (2.00%) exceeded that among populations within groups (1.42%). Pearson correlation analysis identified longitude, latitude, solar radiation (July and September), and water vapor pressure (September) as significant environmental factors shaping population genetic diversity. These results provide essential baseline data for understanding the genetic diversity of B. kashmirensis and offer a scientific basis for its regional conservation and management.