Limited‐Transpiration Trait May Increase Maize Drought Tolerance in the US Corn Belt

Abstract

Yield loss due to water deficit is ubiquitous in maize (Zea mays L.) production environments in the United States. The impact of water deficits on yield depends on the cropping system management and physiological characteristics of the hybrid. Genotypic diversity among maize hybrids in the transpiration response to vapor pressure deficit (VPD) indicates that a limited‐transpiration trait may contribute to improved drought tolerance and yield in maize. By limiting transpiration at VPD above a VPD threshold, this trait can increase both daily transpiration efficiency and water availability for late‐season use. Reduced water use, however, may compromise yield potential. The complexity associated with genotype × environment × management interactions can be explored in a quantitative assessment using a simulation model. A simulation study was conducted to assess the likely effect of genotypic variation in limited‐transpiration rate on yield performance of maize at a regional scale in the United States. We demonstrated that the limited‐transpiration trait can result in improved maize performance in drought‐prone environments and that the impact of the trait on maize productivity varies with geography, environment type, expression of the trait, and plant density. The largest average yield increase was simulated for drought‐prone environments (135 g m−2), while a small yield penalty was simulated for environments where water was not limiting (–33 g m−2). Outcomes from this simulation study help interpret the ubiquitous nature of variation for the limited‐transpiration trait in maize germplasm and provide insights into the plausible role of the trait in past and future maize genetic improvement.

Use of Crop Growth Models with Whole‐Genome Prediction: Application to a Maize Multienvironment Trial

“…The grain yield data were obtained using a two-plot combine harvest system that measured the and solar radiation are environmental variables that are input to the model. The vapor pressure deficit is calculated from temperature data following Messina et al (2015).…”

“…In a few cases, the genetic and environmental contributions to specific GEIs have been described and in some cases these descriptions lend themselves to prediction of GEIs (Chapman et al, , 2003Chenu et al, 2009;Messina et al, 2011Messina et al, , 2015. Nevertheless, to date, there has been limited use of such information to improve prediction in plant breeding.…”

“…The motivation for such applications of CGMs is to extend the results of the empirical studies to the broader range of conditions that can be expected by farmers in the TPE. Recently, extensions of these CGMs have been proposed to incorporate functional relationships between the environmental variables and traits that are influential on the genetic variation for yield and agronomic performance in elite reference populations of interest to plant breeders (Chapman et al, , 2003Cooper et al, 2002;Hammer et al, 2006;Chenu et al, 2009;Messina et al, 2011Messina et al, , 2015. These developments of CGMs provide tools for extending the study of GEIs to the level of the prediction problems of the plant breeder seeking to create novel improved genotypes from within the breeding program.…”

Root Water Uptake and Ideotypes of the Root System: Whole‐Plant Controls Matter

“…Simulations show that this trait is favorable in the driest areas of the United States, and can be unfavorable under milder conditions (Messina et al, 2015). It is not known whether this can be attributed to root system characteristics or to stomatal control, but it shows that maximum water uptake, favored by VZJ | Advancing Critical Zone Science p. 7 of 10 an efficient root system, is not necessarily a favorable trait in the driest scenarios.…”

“…Lines improved for drought tolerance had a lower root biomass and length than those considered in the first selection cycle. This is discussed below.Maize hybrids have been developed that restrict transpiration during the vegetative phase, so flowering time and grain filling occur with more favorable soil water status than with hybrids displaying high transpiration during the vegetative phase (Messina et al, 2015). Simulations show that this trait is favorable in the driest areas of the United States, and can be unfavorable under milder conditions (Messina et al, 2015).…”