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

Abstract

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.