Multi-trait multi-environment Bayesian model reveals G x E interaction for nitrogen use efficiency components in...

Area of Science:

• Agricultural Science
• Plant Breeding
• Genetics

Background:

• Excessive nitrogen fertilization in maize cultivation leads to significant environmental and economic consequences.
• Nitrogen use efficiency (NUE) is a key trait for sustainable agriculture, comprising nitrogen uptake efficiency (NUpE) and nitrogen utilization efficiency (NUtE).
• Traditional single-trait analyses may not fully capture the complexity of multi-trait breeding data in maize.

Purpose of the Study:

• To estimate genetic parameters for NUpE and NUtE under varying nitrogen (N) levels.
• To identify superior maize inbred lines with enhanced nitrogen use efficiency.
• To propose and validate a Bayesian multi-trait multi-environment (MTME) model for analyzing NUE components.

Main Methods:

• Evaluation of 64 tropical maize inbred lines across high (HN) and low (LN) nitrogen environments.
• Comparison of a Bayesian MTME model with single-trait multi-environment (STME) models using deviance information criteria (DIC).
• Estimation of heritability for NUpE and NUtE under different N conditions.

Main Results:

• Both MTME and STME models indicated significant genotypes x environments (G x E) interactions.
• Nitrogen uptake efficiency (NUpE) exhibited low heritability (0.016 HN, 0.023 LN).
• Nitrogen utilization efficiency (NUtE) showed high heritability under HN (0.490) and moderate heritability under LN (0.215).

Conclusions:

• The MTME model provides more accurate breeding values compared to single-trait models for NUE components.
• Superior inbred lines for NUpE and NUtE were identified, offering valuable genetic resources.
• This research facilitates strategic crosses to develop maize hybrids with enhanced nitrogen use efficiency, promoting sustainable agriculture.