Evaluation of Lupin Varieties and Assessment of Adaptability to Neutral-pH Soils Via Recording of Morphological, Agronomical, and Seed Quality Characteristics

White lupin (Lupinus albus) is a very important legume crop, having seeds with high protein content but also quantities of antinutritional alkaloids. Regarding cultivation, it is sensitive to neutral or alkaline soil conditions, although it is well adapted to drought conditions. In this study, the adaptability of 17 L. albus (14 commercial varieties and 3 advanced lines) genotypes to neutral-pH soils was investigated in relation to morphological, agronomical, and yield attributes. An extended characterization of seed composition for total alkaloids, trypsin inhibitors, phenolics, tannins, total nitrogen, NDF, ADF, and lignin was also performed. Furthermore, a prebreeding program consisting of 140 targeted crosses was initiated to develop new F1 combinations for genotypes with low alkaloid profiles; at the same time, controlled self-fertilization of elite lines was carried out. The results indicated that the morphological response of L. albus to neutral pH was positive and significantly genotypically dependent. Among the varieties tested, ‘Magnus’ and ‘Figaro’ showed low alkaloid and lignin contents. On the other hand, the advanced lines (LKAP, LKML, LKAU) had high antinutritional components, even though they were high-yielding. This research proposes a model of combined evaluation and selection processes for identification of particular genotypes that can perform well in neutral soils and provides the basis for breeding and producing low-alkaloid genotypes for multi-locational exploitation.