Modulation of early maize seedling performance via priming under sub-optimal temperatures

Area of Science:

• Agricultural Science
• Plant Physiology
• Crop Science

Background:

• Early spring planting of maize (Zea mays) often exposes seeds to suboptimal low soil temperatures, hindering germination and early growth.
• Seed priming is a technique that can mitigate abiotic stress effects in various crops, but its efficacy in maize under cold conditions requires further investigation.

Purpose of the Study:

• To evaluate the effectiveness of seed priming in enhancing the cold tolerance of diverse maize inbred lines.
• To assess the impact of priming on key seedling emergence metrics under simulated cold soil conditions (10°C).

Main Methods:

• Twenty-four maize inbred lines were subjected to seed priming using a synthetic solid matrix (Micro-Cel E).
• Primed and unprimed seeds were exposed to controlled 10°C soil temperatures.
• Seedling emergence was monitored using time-lapse photography, and emergence metrics (total emergence, mean emergence time, emergence uniformity) were manually scored.

Main Results:

• Cold stress significantly reduced total emergence in two out of 24 maize genotypes.
• Seed priming effectively protected these cold-sensitive genotypes, enabling near-complete emergence.
• Priming also significantly decreased mean emergence time and improved emergence uniformity in chilling-sensitive maize lines.

Conclusions:

• Seed priming demonstrates a significant protective effect against low-temperature stress in susceptible maize genotypes.
• Priming is a promising strategy to improve maize seedling establishment and performance in cold spring soils.
• Standard kernel traits (density, weight, oil, protein, starch) were not predictive of seedling emergence performance under cold stress.