Adaptation of soybean to Swiss climatic conditions cannot be achieved without a significant reduction of leaf area. This aim can be reached by breeding lines with small leaflets, and also by hybridization using genotypes with lanceolate foliage. In general, the ln allele coding for narrow leaves has no effect on yield while reducing the leaf surface. In this study, nine pairs of near isogenic lines lanceolate/ovate (ln/ov) were tested in the field. Two of these pairs were analyzed at their juvenile development. At this stage, the oval type plantlets are more vigorous than lanceolate ones. The type ln shows a reduction in leaf area, a better light penetration into the canopy, a more efficient photosynthesis of lower leaves and improved yield stability. The ln allele contributes positively to the adaptation of soybean to the climate of Switzerland.
Agronomic interest of lanceolate leaf in soybean