Epistatic contributions to quantitative traits in Tribolium castaneum

Triple-testcross experiments were used to analyze epistatic contributions to larva weight, pupa weight, pupa width and adult weight in Tribolium castaneum. Seven diverse inbred lines and the F1. produced by crossing the two tester lines were examined for indications of epistasis. Larva weight was the only trait for which no significant epistasis was detected. There was significant epistasis for pupa weight in three of the inbred lines; for pupa width in four of the inbred lines; for adult weight in five of the inbred lines. Only one inbred line and the F1 line failed to exhibit significant epistasis for any trait. Each inbred line had a unique pattern of epistasis, suggesting that a number of different loci were contributing to the detected epistasis.