Selection in Lupinus albus L. for lower seed manganese concentration

Abstract

Seeds of 49 Mediterranean white lupin accessions and of 36 F5 families derived from 13 of them were analysed for manganese concentration. High concentrations in the range 1770–4640 µg g-1 dry matter were found in material grown near Canberra and lower ones (1060-2750 µg g-l) at Wagga Wagga, N.S.W. A small number of L. angustifolius L. lines grown under comparable conditions at both sites had 7- to 70-fold lower concentrations of manganese in their seeds than L. albus. The means for accessions and families of L. albus varied widely and continuously about the site means. High alkaloid lines had approximately two-thirds the manganese concentration of low alkaloid lines. Seeds from primary inflorescences had 6% lower manganese concentrations than those from higher order inflorescences. About one-quarter of the variation within the low alkaloid class was associated with seed yield variation, there being a negative correlation between these traits. There was no line x site interaction. Broad sense heritabilities at Canberra and Wagga Wagga were moderately high, so that selection for lower concentrations should be effective. The results suggest that selection for higher yield could be almost as effective as direct selection in reducing seed manganese concentration. The reduction should be sufficient to enable white lupin seeds, grown on soils no higher in available manganese than those used in this study at Canberra, to be safely used as a high protein supplement in pig and poultry rations. Selection for lower seed manganese should not affect seed calcium, phosphorus or protein concentrations, but would tend to increase seed yield and plant height at maturity.