Genetic characteristics of different generations broodstocks of Litopenaeus vannamei (Boone, 1931) in hatchery centers located on the shores of the Persian Gulf in Bushehr province

The aim of this study was to identify different population broodstocks of Litopenaeus vannamei and effect of inbreeding and cross-inbreeding on genetic characteristics and inbreeding coefficient of offspring in the next generation. According to origin of broodstocks kept in hatcheries of Bushehr province in the first generation, different populations were identified through microsatellite method from Hybrid, High health and Molokai stocks then, in the next generations genetic characteristics of offspring from their inbreeding and cross-inbreeding were examined. The results showed that the amount of genetic diversity in Molokai and High Health stocks (0.46±0.09 and 0.50±0.07) was more than hybrid stock (0.38±0.06). The inbreeding coefficients of Molokai, High Health and hybrid stocks were 0.14, 0.31 and 0.41, respectively. Due to the low genetic distance between the hybrid and Molokai stocks, after mixing them together Molokai and High Health populations were introduced as the first generation broodstock. In the second generation, despite the high genetic diversity in the offspring of Molokai×High Health (0.47±0.12) and High Health×Molokai (0.39±0.08) than the offspring of Molokai×Molokai (0.19±0.04) and High Health× High Health (0.11±0.03), these values were reduced compared to the first generation. The lowest and highest inbreeding coefficients were related to the offspring of Molokai×High Health (0.268 ±0.18) and Molokai× Molokai (0.853±0.145), respectively. According to the results, it can be said that the lack of knowledge about the genetic characteristics of broodstocks and mating between individual relationships (full and half sib) can reduce genetic characteristics and genetic depression due to increased inbreeding coefficients in next generations.