Scientists Crack Alfalfa’s Chromosome Mystery After Decades of Debate

Researchers used chromosome painting and rDNA mapping to trace alfalfa-related genomes in Medicago.

They found seven-chromosome Medicago species likely evolved from an eight-chromosome ancestor through repeated breakage and reassembly, not a single fusion.

The M. sativa complex, by contrast, showed strong karyotype stability.

The findings settle a long-running debate in plant genetics and clarify how chromosome restructuring shapes forage crop evolution.