Genetius

A comprehensive multi‑environment trial of 437 maize testcross hybrids derived from 38 MLN‑tolerant lines and 29 testers identified additive genetic effects as the primary driver of grain yield, disease resistance, and drought tolerance. Strong general combining ability and specific combining ability patterns were uncovered, with top hybrids delivering up to 5.75 t ha⁻¹ under MLN pressure while maintaining high performance under optimum and drought conditions. The study provides a framework for selecting elite parents and exploiting both additive and non‑additive effects to develop resilient maize hybrids for sub‑Saharan Africa.

Double mutant hybrids in the miR394‑regulated genes ZmLCR1 and ZmLCR2, created in a W22/B73 maize background, display enhanced drought tolerance through increased epicuticular wax and reduced ROS production, while maintaining normal flowering and nutrition. Under field rainfed conditions the mutants achieve significantly higher yields (greater ear weight and kernel number) compared to wild‑type hybrids.

The study mapped the macroscopic and cellular development of maize leaves and internodes, revealing a shared growth design with organ‑specific timing. Using high‑resolution spatiotemporal transcriptome profiling of 272 tissue samples under well‑watered and drought conditions, the authors generated a searchable expression atlas and identified conserved and organ‑specific gene regulatory patterns, including genes linked to leaf angle and vascular development. This resource advances understanding of shoot organ development and drought response for targeted trait engineering in maize.