bioRxiv · 2026-05-23
Scientists found that wheat plants engineered to stay green longer after flowering produce heavier, wider grains and higher yields — but only when flowering time is carefully matched to the right environment. Combining stay-green genetics with early-flowering genes actually backfired, canceling out the yield gains.
Stay-green wheat lines showed 5.8% and 3.7% increases in thousand-grain weight (a measure of grain heaviness) under moderate heat stress, with statistically significant yield gains.
Grain yield improvement was proportional to how long senescence was delayed — the stronger stay-green variant (NAM-A1) outperformed the weaker one (NAM-D1).
Combining stay-green genetics with early-flowering genetics (Ppd-1a) negated yield benefits because early flowering reduces the number of grains the plant can fill, even in environments where early flowering is normally favored.
