Genome edited zm-D8 reduced stature maize hybrids have improved climate resilience and competitive yields

As the frequency of intensive storm events increases in the U.S. Corn Belt, reduced stature maize hybrids could provide a new approach to improved climate resilience in maize production. We designed gene-edited D8 (dwarf8, zm-D8) maize germplasm with reduced stature to evaluate morphometric traits and grain yield. Four elite edited zm-D8 maize hybrids and their isogenic standard height hybrid comparators were evaluated over a total of 17 field locations in 2021 and 2022. Across three plant densities (80 K, 100 K and 120 K plants ha⁻¹), plant height of the edited zm-D8 reduced stature hybrids was reduced 34 % and ear height was decreased 32 %. In each of the three plant densities, grain yield of the edited zm-D8 reduced stature hybrids was comparable to the isogenic standard height hybrids. Also, edited zm-D8 hybrids had significantly less lodging than the standard hybrids. In a separate study, DP202216 (ZmGos2:zmm28) a transgenic event with increased and extended expression of the zmm28 transcription factor, was crossed with reduced stature edited zm-D8 hybrids. Combining edited zm-D8 with event DP202216 significantly increased hybrid yields over those of edited zm-D8 hybrids under high density (120 K plants ha⁻¹). These results support a maize production system where edited zm-D8 reduced stature hybrids, alone or in combination with DP202216, provide improved climate resilience with grain yields competitive to standard height hybrids.