The many outbreeding techniques, including line breeding, crossbreeding and graded upbreeding, are crucial for enhancing genetic diversity, growth performance and disease resistance in aquaculture species. The importance of hybrid vigor or heterosis, in the success of outbreeding could be aptly illustrated by the superior growth of hybrids, such as crossbreds of common carp (Cyprinus carpio), in early life history. Crossbreeding techniques like two-way, three-way and rotational crossings increase fish stocks' productivity and flexibility. Multiple studies on Atlantic salmon show that outbreeding frequently increases the likelihood of outbreeding depression when it impedes local adaptation. In Asia, genetic enhancement activities have surged for species such as the giant freshwater prawn, tilapia and carp. However, the adoption has been constrained by economic and technological factors. Future aquaculture breeding programs must successfully include genomics and multi-omics techniques.
Subash, M., 2025. Outbreeding, crossbreeding, utilization of heterotic effect. Biotica Research Today 7(7), 206-209.
Crossbreeding, Genetic improvement, Heterosis, Outbreeding depression
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