Spring Wheat's Ability to Utilize Nitrogen More Effectively Is Influenced by Root Phene Variation

Area of Science:

• Agricultural Science
• Plant Breeding
• Genetics

Background:

• Nitrogen use efficiency (NUE) is critical for sustainable agriculture, yet root traits are under-explored in wheat breeding.
• Difficulty in scoring root traits has limited their integration into breeding programs, especially for spring wheat germplasm.

Purpose of the Study:

• To dissect nitrogen use efficiency (NUE) into component traits.
• To assess genetic variability for root and nitrogen-related traits in Indian spring wheat germplasm.
• To identify key traits for improving NUE in wheat breeding.

Main Methods:

• Screened 175 Indian spring wheat genotypes for root traits and nitrogen uptake/utilization under varying nitrogen levels in hydroponics.
• Analyzed genetic variance for NUE components, including nitrogen uptake efficiency (NUpE) and nitrogen utilization efficiency (NUtE).
• Correlated root and shoot traits with overall NUE.

Main Results:

• Substantial genetic variability was observed for NUpE, NUtE, and various root/shoot traits.
• Improved spring wheat lines showed high variability in maximum root length (MRL) and root dry weight (RDW).
• Low nitrogen (LN) environments were more effective than high nitrogen (HN) in differentiating genotypes for NUE traits.
• Shoot dry weight (SDW), RDW, MRL, and NUpE strongly correlated with NUE.
• Root surface area (RSA) and total root length (TRL) are important for RDW and nitrogen uptake.

Conclusions:

• Targeting root traits like MRL, RDW, RSA, and TRL, alongside NUpE, can enhance genetic gain for wheat yield.
• Breeding for improved root architecture and nitrogen acquisition is crucial for both high-input and sustainable low-input agriculture.
• The study identified promising variability in Indian germplasm for developing NUE-enhanced wheat varieties.