Evaluation of alkaloids in yellow lupin (Lupinus luteus L.): New insight to genetic resources diversity and future breeding perspectives

The agronomic potential of many species, including lupins, is underutilized due to poor characterization of the genetic resources conserved by genebanks. Thus, this study aimed to evaluate the seed alkaloid content and alkaloid profiles of 292 yellow lupin (YL, Lupinus luteus L.) accessions from the Polish Lupinus Collection using gas chromatography, coupled to a flame ionization detector. The YL collection showed wide diversity, as indicated by a broad range of total alkaloid content (0.0004-1.8042%) and various qualitative alkaloids compositions in specific genotypes. A statistical approach allowed comparing classes at different domestication level and identifying divergent germplasm. Wild accessions had higher total alkaloid content, dominated by lupinine, whereas domesticated accessions had lower alkaloid content and alkaloid profiles mainly composed of sparteine and ammodendrine. The study identified accessions with promising breeding potential or for detailed research, such as wild, low-alkaloid germplasm or those with only one specific alkaloid detected. Furthermore, the study assessed the "breeding progress" toward reducing the total alkaloid content of YL cultivars in comparison with two other lupin crops (narrow-leafed and white lupin). This comparative study showed the significant progress in YL, which could be caused by lupinine synthesis inhibition. Overall, the study provides advanced knowledge on YL genetic resources and highlights the importance of their comprehensive characterization.