Multiplicative Mixed Models for Genetic Gain Assessment in Lupin Breeding

Genetic gain is used as a long-term measure of the efficiency of a breeding program. A spatial linear mixed model that includes a multiplicative mixed model (MMM) for the variety by environment (VxE) effect has been used for the analysis of 39 trials of 25 historical lupin varieties for the period of 1997 to 2006. The 25 varieties were produced by the Australian breeding effort from 1967 to 2007 and are a result from five cycles of breeding. Genetic gain was assessed on the basis of the overall performance of the varieties across all environments based on the MMM results. The genetic gain from the first early flowering variety, Unicrop, to the highest yielding variety, Mandelup, represents a yield gain of 81% over 31 yr. The varieties' yield stability across the environments and their broad or specific adaptations are discussed.