Drought and heat stress tolerance screening in wheat using computed tomography

Area of Science:

• Plant science
• Agricultural science
• Biotechnology

Background:

• Abiotic stress tolerance in wheat is crucial for food security.
• Traditional phenotyping of wheat yield components is laborious and time-consuming.
• Computed tomography (CT) offers a faster, more accurate alternative for assessing yield components.

Purpose of the Study:

• To develop and validate a high-throughput computed tomography pipeline for wheat seed phenotyping.
• To assess the impact of drought and combined drought-heat stress on wheat seed traits.
• To accelerate wheat breeding programs for enhanced abiotic stress tolerance.

Main Methods:

• X-ray computed tomographic analysis of 203 diverse wheat accessions.
• Exposure of wheat to drought and combined drought-heat stress conditions.
• Development of a CT pipeline for evaluating grain set and seed morphology.

Main Results:

• The CT pipeline achieved 95-99% accuracy in evaluating grain set.
• Combined drought and heat stress resulted in smaller, shrivelled seeds with increased surface area.
• Seed weight, seed number, and single seed size were significantly reduced under combined stress compared to drought alone.

Conclusions:

• A high-throughput CT pipeline with 7-minute scanning time per ear was established.
• The pipeline accurately predicts agronomical seed traits and visualizes complex traits like seed deformations.
• This method can be scaled for high-throughput phenotyping, significantly advancing breeding efforts for abiotic stress tolerance.