Germplasm resources characteristics of farmed Perca fluviatilis populations in Xinjiang

【Objective】 To characterize the germplasm resources of farmed Perca fluviatilis populations, which could provide reference for genetic improvement programs and sustainable utilization. 【Method】 Three farmed Perca fluviatilis populations were collected from Altay, Xinjiang, including HA population from Ehe Unique Cold Water Fish Breeding and Development Co., Ltd. in Burjin County, HB population from Haifute Breeding Company in Fuhai County and HC population from Kelanyuan Fishery Co., Ltd. in Xinjiang. The germplasm resource characteristics were evaluated from 4 aspects: measurable traits, quality traits, antioxidant capacity and genetic diversity. 【Result】 Obvious differences in body size were observed among the 3 farmed Perca fluviatilis populations. Specifically, the HA population exhibited an average body length of 161.49±25.18 mm and an average body weight of 83.00±59.16 g; the HB population showed an average body length of 160.78±19.07 mm and an average body weight of 111.26±43.66 g; while the HC population exhibited an average body length of 218.25±14.20 mm and an average body weight of 219.58±48.21 g. No significant differences were observed in the routine nutritional components（crude protein, crude fat and total sugar） of muscle tissues among the 3 farmed Perca fluviatilis populations（P＞0.05, the same below）; a total of 17 amino acids were identified, with glutamic acid（Glu）, aspartic acid（Asp）, leucine（Leu）, and lysine（Lys） exhibiting relatively high concentrations, accounting for 44.9% to 45.1% of the total amino acids; a total of 20 fatty acids were detected, characterized by a remarkably high content of unsaturated fatty acids, among which the total polyunsaturated fatty acid（PUFA） content ranged from 220.92 to 241.70 mg/100 g. The total antioxidant capacity（T-AOC） of the 3 farmed Perca fluviatilis populations ranged from 0.49 to 0.94 μmol/g. While no significant difference was observed in T-AOC between the HB and HC populations, both exhibited significantly higher values than the HA population（P＜0.05）. The 3 farmed Perca fluviatilis populations exhibited polymorphism information content（PIC） ranged from 0.2128 to 0.2244, with inbreeding coefficients(F_HOM) distributed between-0.0660 and-0.0460. Pairwise genetic differentiation indices(F_st) among populations varied from 0.0095 to 0.0152, while gene flow（N_m） values ranged between 16.1974 and 26.0658. At the whole-genome level, the 3 farmed Perca fluviatilis populations were distinctly classified into 2 major clusters: cluster I was predominantly comprised of individuals from HA and HC populations with minor admixture from HB population, while cluster II was principally composed of HB population specimens. 【Conclusion】 The farmed Perca fluviatilis in Altay, Xinjiang exhibits nutritionally favorable characteristics with low fat and high protein content, meeting premium aquatic protein source standards; the degree of differentiation among different farmed Perca fluviatilis populations is low, and there is an excess of hybridization. Thus, it is imperative to strengthen monitoring systems throughout the entire breeding and farming cycle, be cautious about new genetic stocks, prevent inbreeding-induced genetic diversity depletion.