INTRAPLANT VARIABILITY IN SEED SIZE AND SEED QUALITY IN LUPINUS-ALBUS L

The origin of variation in seed size and seed quality was studied in 3 genotypes with different architectures (indeterminate, dwarf, determinate) of autumn-sown white lupin under a range of cropping conditions. The environmental conditions (year and density) and the origin of the seed (genotype and pod level) influenced the mean seed weight. The different pod levels corresponded to the pods produced on the mainstem, the primary branches and the secondary branches. The year significantly influenced the mean seed weight of all the genotypes, whatever the density and the pod level. The reduction of the density from 20 to 12 plants/m2 had no effect on the yield and slightly reduced the mean seed weight. For a given genotype, the pod level that produced the greatest number of seeds also produced the largest seeds. The major origin of the variation of the individual seed mass was the within-pod-level variation, as also reported in other species with a determinate or indeterminate growth habit. The autumn-sown white lupin genotype with a determinate architecture showed a reduced within-pod-level variation in individual seed size. The consequences of the genotype and the husbandry techniques on the quality of the seed were analysed. The protein content was mainly influenced by the genotype and was not affected by the density or the pod level. The oil content was highest in seeds from the highest pod level. The possible origin of this feature is discussed. The oil content was also influenced by the genotype but the stand density had no effect.