GENETIC AND ENVIRONMENTAL VARIATION IN ARCHITECTURE AND YIELD COMPONENTS IN DETERMINATE WHITE LUPIN (LUPINUS-ALBUS L)

Determinate architecture is of great interest for lupin production in Europe but the extent of genetic and environmental variation in the structure and yield of determinate lupins must be evaluated. Forty-three genotypes of determinate autumn-sown white lupin were studied in four environments in France in 1991/92 and 1992/93. Wide variation was observed for phenological (dates of mainstem and branch flowering, date of end of flowering and date of maturity), morphological (numbers of branch orders, branches and leaves) and seed characters (seed yield, mean seed weight, number of seeds/m(2)). Both genetic and environmental effects contributed to the observed variation. Heritabilities were high for all characters, acid the interaction between genotype and location effects was low. There were significant positive correlations of flowering dates with vegetative plant development including the number of branches, number of leaves and number of branch orders. Seed yield and phenological and architectural characters were significantly correlated. Distribution of yield on the vegetative orders showed important variations according the genotype, and the variations were related to variation for the architecture. There are possibilities for yield improvement using morphological characters in determinate autumn-sown lupin.