Wheat growth genes act 100-200 growing degree days before height changes appear.

To understand crop growth, scientists need to track plant height over time without measuring every plant by hand. Researchers flew camera-equipped drones over fields of bread wheat across three seasons in southern Italy. They turned the photos into 3D point cloudspoint cloudsA set of 3D coordinates collected from a sensor that digitally represents a surface. to accurately measure canopy height as the wheat grew. Then, they matched these height trajectories and growth rates to the plants' DNA. They found that growth-rate signals revealed genetic effects 100-200 growing degree daysgrowing degree daysA measure of accumulated heat used to predict plant development timing. earlier than total height measurements. A tillering plateau split growth into two genetic phases. An early phase connected to cold and daylight response genes (Vrn and Ppd). A later phase connected to dwarfing genes (Rht). Key genetic signals clustered in five chromosome regions and pointed to regulators like DELLA and TB1-like genes. Tracking growth rates with drones exposes exactly when specific genes turn on to shape plant height.

Why it matters

For wheat breeders, knowing exactly when each growth gene kicks in means they can select for early vigor or final height separately. This study shows that measuring growth rate over time, not just final height, reveals those timings. That could speed up breeding of wheat suited to different climates and soil conditions.

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