GENOTYPE X ENVIRONMENT INTERACTION EFFECTS ON CULTIVAR DEVELOPMENT(1)

The peanut (Arachis hypogaea L.) breeding programs in Virginia and Nor th Carolina develop germplasm for a common production duction area. Cu rrently, both programs select lines for advanced testing based on thei r performance at a single location within each state. If the genotype X environment interaction does not affect early generation performance between these two environments, then similar crosses and lines within crosses would be selected in each state. The purpose of this study wa s to examine the G x E interaction effect on genotypes grown in these two environments. Yield and market grade characteristics were determin ed each of 2 years at the two selection sites for nine crosses represe nted by eight lines per cross in the F4 and F5 generations. Significan t differences for all traits occurred among cross populations and amon g lines within populations. Crosses interacted with the environment fo r all traits, while lines within crosses interacted with the environme nt for all traits except yield. The crosses interacted with the enviro nment because their rankings of performance changed in the different e nvironments. In spite of a significant cross x environment interaction , the three best performing cross populations were identified as being high yielding at both locations. An examination of genetic components of variance for crosses and lines within crosses for the different en vironments indicates that superior crosses can be identified at a sing le location. However, individual lines within crosses should be select ed on mean performance across environments (years and locations).