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This study was done aimed to compare the genetic characteristics and inbreeding coefficient (Fis) of imported Litopenaeus vannamei broodstocks of zero generation 95 (F0:95) and 96 (F0:96), broodstocks first-generation 96 (F1: 96) and four different stocks of broodstocks of selected breeding from hatchery centers of Bushehr province (Pop 1-4: 99) which were maintained in the specific pathogenic free (SPF) shrimp production center of Iranian Shrimp Research Center (ISRC). For each stock, 30 pieces of male and female shrimp were sampled equally, and then their swimming leg muscles were separated and stored in 70% ethanol. After DNA extraction by the commertial kit Parseh of pishgam biological, genetic parameters, including genetic diversity, frequency of alleles, inbreeding coefficient, genetic distance, genetic similarity and genetic differentiation of each stock, were determined by ten pairs of microsatellite markers. The results showed that the mean of heterozygosity observed (Ho) and expected (He) in broodstoocks of F0: 95, F1: 96, F0: 96, Pop1: 99, Pop2: 99, Pop3: 99 and Pop4: 99, 0.38, 0.42, 0.51, 0.33, 0.36, 0.35 and 0.55, 0.64, 0.59, 0.58, 0.49, 0.42, 0.57, respectively. However, this index was higher in the broodstock of Pop 1:99 than other broodstock F0:95, F1:96, and F0:96. The highest number of alleles was also observed in the three stocks of F0: 95, F1: 96 and F0: 96, with four alleles related to the stock of F1: 96, and for the four stocks in 2020 with four alleles related to the stocks of Pop1: 99 and Pop4: 99. The study results showed that the rate of inbreeding confidence (Fis) in imported broodstocks of F0: 95 and Pop 1: 99 is lower than in other stocks. The study results showed that the rate of inbreeding confidence in imported broodstocks of F0: 95 and Pop 1: 99 is lower than in other stocks. In contrast, due to the increased genetic distance between Pop4: 99 and other broodstocks, these broodstocks were placed on a separate branch. The genetic differentiation between F0: 95 and F1: 96 stocks was 0.079, and the highest rate was between Pop2: 99 and Pop3: 99 broodstocks with 0.317. Therefore, it can be concluded that appropriate broodstock selective breeding and use of different stocks in hatchery centers in addition to increasing the fundamental population will cause the rate of genetic parameters to not decrease after several generations. Hence, due to the short life and annual reproduction of L.vannamei, in addition to identifying different populations, it is necessary to determine their genetic characteristics, including inbreeding coefficient and genetic diversity.
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