Genetic diversity of invasive Oreochromis spp. (tilapia) populations in Guangdong province of China using microsatellite markers

Ten microsatellites were used to assess the genetic diversity and genetic differences of six wild Oreochromis spp. populations in the primary rivers of Guangdong Province of China, where natural populations have been established. Significant genetic differentiation was observed in Oreochromis spp. populations using “FST” and exact tests. The six populations can be divided into two groups based on the genetic similarity indices. The phylogenetic tree indicated that the HUI (Huizhou) and the SG (Shaoguan) populations formed one cluster, whereas the H (Huazhou), M (Meihua), MU (Muzhou), and ZQ (Zhaoqing) populations formed another cluster. The average mean levels of the observed heterozygosity in the six populations were 0.3972, 0.4264, 0.6977, 0.6335, 0.6680, and 0.6829, respectively. The high genetic diversity observed in most wild tilapia populations suggests that most wild populations are large in size, which is a finding that is supported by field investigations. •Genetic diversity of the wild Oreochromis spp. populations in China was described.•Significant genetic differentiation was found in wild Oreochromis spp. populations.•Genetic diversity of wild populations is high compared with the breeding strains.