Seed manganese affects the early growth of lupins in manganese-deficient conditions

Poor crop establishment and split seed associated with manganese (Mn) deficiency are major problems in the production of narrow-leafed lupins (Lupinus angustifolius L.) in Western Australia. A survey of Western Australian seed producers indicated that Mn concentrations in lupin seeds ranged from 8 to 62 mg kg-1, with the majority of the seed containing less than 20 mg kg-1. We studied seedling growth of lupins (cultivars Gungurru and Danja) in nutrient solution, from seed with Mn concentrations ranging from 8 (Seed8) to 223 (Seed 223) mg kg-1. Without added Mn, the final weight of plants grown from Seed8 was 39% for shoots and 30% for roots, compared to maximum growth (Seed62). With adequate external Mn supply, there was no effect of seed Mn on growth of plants grown from undamaged seedlings. Shoot weight of Gungurru lupins 42 days after imbibing increased with increasing seed Mn concentration up to about 55 mg kg-1 when grown without added Mn. Growth of Danja plants increased similarly with increasing seed Mn concentration.

The importance of seed manganese content for the growth of narrow-leafed lupins in manganese-deficient conditions

No abstract available.

Growth, yield components and seed composition of two soybean cultivars as affected by manganese supply

The influence of manganese nutrition on growth and yield of two soybean cultivars (Lee and Bragg) was studied in sand culture. Increasing the manganese concentration from 1.0�M to 275�M reduced vegetative growth and grain yield in both cultivars, the reduction being greater for Bragg than for Lee. The reduction in grain yield at high manganese levels resulted mainly from a reduced individual seed weight and a lower number of pods, with a slight reduction in the number of fertile nodes. There was no effect of high manganese supply on oil and protein levels or on the germination percentage of harvested seed. Manganese deficiency reduced vegetative growth, advanced flower initiation and pod formation, and decreased the grain yields of both cultivars. The reduced seed yield was mainly due to a reduction in the number of pods per plant and the individual seed weight. Manganese deficiency also reduced the concentration of oil in the seeds, but there was no effect on seed protein level or on the germination percentage cf harvested seed. Seed manganese concentration increased with the supply of the nutrient, but no difference in concentration was found between the two cultivars.

Selection in Lupinus albus L. for lower seed manganese concentration

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.