Open AccessEffects of Intraspecific Hybridization in Tilapia nilotica on Survival Under Ambient Winter Temperature in Alabama
Author(s) -
Tave Douglas,
Jayaprakas V.,
Smitherman R. Oneal
Publication year - 1990
Publication title -
journal of the world aquaculture society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.655
H-Index - 60
eISSN - 1749-7345
pISSN - 0893-8849
DOI - 10.1111/j.1749-7345.1990.tb01023.x
Subject(s) - backcrossing , hybrid , biology , heterosis , intraspecific competition , crossbreed , tilapia , interspecific hybridization , zoology , fish <actinopterygii> , botany , fishery , genetics , gene
Viability under ambient winter temperatures in Alabama was assessed for Auburn University‐Egypt and Auburn University‐Ivory Coast strains of Tilapia nilotica and their F 1 , F 2 , and four backcross hybrids. Egypt strain was more viable ( P = 0.05) than Ivory Coast strain. Observed mean viabilities of the F 1 hybrids were intermediate between those of the parental strains. Viabilities of the reciprocal F 1 hybrids were not significantly different. Viabilities of the reciprocal F 2 hybrids were not significantly different. Backcross hybrids that were produced by crossing F 1 hybrid females to Egypt strain had a greater observed mean viability than those that were produced by crossing F 1 hybrid females to Ivory Coast strain. Average viabilities of the parental strains, F 1 , F 2 , and backcross hybrids were not significantly different. Heterosis in F 1 , F 2 , and backcross hybrids was −1.39%,−0.82%, and −2.08%, respectively. Viability under ambient winter temperatures in Alabama in T. nilotica appears to be controlled by additive rather than by dominance effects, which means that selection rather than crossbreeding is the breeding technique that should be evaluated to improve this trait in T. nilotica .