Genotypic variation of seed yield and architectural traits in dwarf autumn-sown white lupin

Dwarfism is a way of preventing excessive vegetative development in the indeterminate autumn-sown white lupin. Thirty-five dwarf genotypes of autumn-sown white lupin were evaluated in France in five different environments. The genotypes were XA100, the dwarf progenitor, and thirty-four other genotypes selected in the progenies of crosses between XA100 and tall genotypes. Seed yield, mean seed weight and number of seeds per square metre showed large genetic variations and high heritability. The dwarf population yielded an average of 37.8 q/ha and the dwarf progenitor yielded an average of 34.9 q/ha. The genotype*environment interaction was not significant in seed yield when tested throughout the five environments. The first-order branches contributed to the major part of the total seed yield. Traits of plant architecture were recorded in four environments. The flowering date, and number of leaves showed large genetic variations. Internode length varied among genotypes. The genetic variation of the number of branches was low. Few relationships between seed yield and architectural traits were observed. The genetic correlations between the mainstem or branch length and seed yield were positive. The flowering date and seed yield were not related.