Assessment of the heterosis of F1 hybrids of Misgurnus anguillicaudatus and Paramisgurnus dabryanus using microsatellite-based parentage assignment

Misgurnus anguillicaudatus and Paramisgurnus dabryanus hybrids were generated via full diallel crosses between the Meishan (M_M) and Fuyang (M_F) populations of M. anguillicaudatus and Meishan (P_M) and Ziyang (P_Z) populations of P. dabryanus. The purebred and hybrid offspring were co-cultured in a pool for 4 months, and 96.5% of the offspring could be assigned to a single parental pair based on nine potentially cross-species polymorphic microsatellites. The average body weight (BW) of the P_M x P_Z (female x male, in this order hereafter) hybrids was the highest (4.88 g), followed by that of the P_Z x P_M and P_M x P_M hybrids. The general combining abilities (GCA) of BW from both the sires and dams of P_M and P_Z were high, and that from M_M and M_F were low. The specific combining ability (SCA) of P_M x P_Z was the largest (16.61), followed by that of P_Z x P_M, M_F x M_M, and M_M x M_F (-15.89). The combination of M_F x P_M, M_F x P_Z, and P_M x M_F showed > 10% heterosis. This is the first study to use microsatellite-based parentage assignment in hybrid fish and lays foundation for loach crossbreeding.

Automated summary

The hybrid offspring generated from full diallel crosses between different populations of Misgurnus anguillicaudatus and Paramisgurnus dabryanus showed that the P_M x P_Z hybrid had the highest body weight, with high general combining abilities and specific combining ability, demonstrating over 10% heterosis in specific combinations. This study is the first to use microsatellite-based parentage assignment in hybrid fish, providing a foundation for loach crossbreeding.