Plant Breeding: How Domestication Changes Many Traits

Scientists used the process of turning wild plants into crops as a living laboratory.
They studied 13 different species, measuring between 11 and 57 traits that can be seen or counted.

Key Findings

• Loss of Diversity:
  By comparing each species with its wild relatives, researchers found a clear pattern: most plants lose diversity in their traits once humans start breeding them.

• Leaf‑Colour Test:
  A quick test of leaf colour with near‑infrared light reveals changes in plant traits that are not caused by breeding. This test helps scientists ignore background differences when comparing species.

• Multivariate Phenotypic Divergence Index (mPDI):
  The team created a new tool called the multivariate phenotypic divergence index (mPDI) to quantify how much each species changed.
  Using this score, they ranked the species from most to least altered by human selection.

• Uniform Change Across Species:
  Every plant showed a big split between its wild and cultivated versions, but the amount of change did not depend on how long ago domestication began or whether the plant mates with itself or others.

• Weakening Trait Correlations:
  An interesting side finding was that the links between different traits weaken over time as a plant is domesticated.
  This loss of correlation means that the way one trait influences another changes as humans pick and choose features.

Takeaway

The study offers a fresh way to compare many species at once and highlights common rules that govern how plants adapt when they become crops.