On Apr. 23, 2025, a team of researchers led by the John Innes Centre (JIC) in Norwich, UK, announced they have identified the genes responsible for the final three pea traits studied by the Gregor Mendel.

The Augustinian friar Gregor Mendel completed his groundbreaking work on genetic inheritance more than 160 years ago, after carefully studying seven traits in peas, including the shape and colour of their seeds and pods. Yet until now, scientists still hadn’t worked out which genes drive three of those traits in the garden pea (Pisum sativum). In a paper published on in Nature, researchers add a fresh chapter to Mendel’s pivotal story, perhaps in the process launching a new era in the genomic study of peas, which are a popular source of plant-based protein.

Using the JIC’s Germplasm Resource Unit — which houses more than 3,500 pea variants, alongside publicly available genomic data sets — the group amassed and deep sequenced nearly 700 pea genomes. These contained roughly 155 million single-nucleotide polymorphisms (SNPs) — single base-pair differences in the DNA sequences compared with the standard, or ‘reference’, P. sativum genome.

Using several methods, including selective breeding of pea plants and genome-wide association studies, which probe each genome for differences in the number and location of SNPs, the group identified the genes linked to the three remaining traits.

Specifically, the researchers found that pea-pod colour is controlled by a gene that disrupts chlorophyll biosynthesis, leading to either green or yellow pods. They also identified two genes that probably help to control pod shape by inducing disruption of cell-wall thickening in the plant. And they determined that a deletion in the genetic code at a particular point in another gene can cause changes in the branching or clustering of flowers on the plants — a process known as fasciation.