Parental GCA testing: how many crosses per parent?

Abstract

The impact of increasing the number of crosses per parent (k) on the efficiency of roguing seed orchards (backwards selection, i.e., reselection of parents) was examined by using Monte Carlo simulation. Efficiencies were examined in light of advanced-generation Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) tree improvement programs where information is available from previous generations, seed orchards have reduced genetic variation as a result of selection, and dominance variation is small compared with additive variation. Both the efficiency of reselection and its associated variance leveled off after two or three crosses per parent. The information from previous generations did not significantly increase reselection efficiency.

Citation

Johnson, G.R. 1998. Parental GCA testing: how many crosses per parent?. Canadian Journal of Forest Research. 28(4): 540-545