Selecting Tolerant Maize Hybrids Using Factor Analytic Models and Environmental Covariates as Drought Stress...

Area of Science:

• Agricultural Science
• Plant Breeding
• Climate Change Adaptation

Background:

• Maize growth is vulnerable to unpredictable drought stress exacerbated by climate change.
• Developing drought-tolerant maize cultivars is essential for food security.
• Screening germplasm under varied environmental conditions is a key strategy for identifying resilient varieties.

Purpose of the Study:

• To evaluate drought tolerance in maize hybrids under field conditions.
• To identify environmental variables influencing maize yield during drought.
• To correlate latent environmental factors with drought indices and genotypic tolerance.

Main Methods:

• Tested 32 maize hybrids across 6 locations over 2 years.
• Collected meteorological data to compute Self-calibrating Palmer Drought Severity Index (scPDSI) and Vapor Pressure Deficit (VPD).
• Employed a factor analytic model to link latent environmental variables with yield data and drought indices.

Main Results:

• Two latent variables explained significant yield variability (47.97% and 9.57%).
• The first variable correlated with VPD (r = -0.58), the second with scPDSI (r = -0.74).
• Genotypic sensitivities to these variables correlated with drought tolerance, indicating distinct drought impact mechanisms.

Conclusions:

• Drought affects maize yield through at least two different mechanisms.
• Understanding these mechanisms can improve breeding strategies for drought-tolerant maize.
• The study provides insights into selecting maize hybrids for enhanced resilience to water deficit.