Mendel's work led to the discovery of genetic inheritance and the laws of segregation and independent assortment. While most of the genes behind his seven trait pairs — such as round vs wrinkled seeds and tall vs short plants — had been found in recent decades, three remained unidentified until now.

A key part of the project involved building a broad and genetically diverse panel of pea accessions. Chayut, head of the germplasm resources group at the John Innes Centre, worked with Ellis, a long-time pea genetics expert, to select more than 700 samples from the institute's Pisum collection.

"To find rare variants, a broad and representative sampling was essential," said Chayut.