Deviation from the grain protein concentration–grain yield negative relationship is highly correlated to post-anthesis N uptake in winter wheat

Abstract

In plants, carbon and nitrogen (N) economies are intimately linked at the physiological and biochemical level. The strong genetic negative correlation between grain yield and grain protein concentration observed in various cereals is an illustration of this inter-relationship. Studies have shown that deviation from this negative relationship (grain protein deviation or GPD) has a genetic basis, but its physiological basis is still poorly understood. This study analysed data on 27 genotypes grown in multienvironment field trials, representing a wide range of agricultural practices and climatic conditions. The objective was to identify physiological processes related to the genetic variability in GPD. Under most environments, GPD was significantly related to post-anthesis N uptake independently of anthesis date and total N at anthesis. The underlying physiological trait might be related to genotypic differences in either access to soil N, regulation of N uptake by plant N status, or ability to maintain root activity during the grain-filling period. GPD is an interesting potential target in breeding as it appears to be relatively robust across different environments and would be valuable in increasing total N uptake by maturity.

Overexpression of a NAC transcription factor delays leaf senescence and increases grain nitrogen concentration in wheat

“…This is consistent with the study of Bogard et al . (2010), who found that deviations from the grain protein concentration–grain yield relationship in wheat were consistently explained by differences in post‐anthesis N uptake.…”

Variation for nitrogen use efficiency traits in current and historical great plains hard winter wheat

“…Both parameters respond to N fertilization, yet it has been difficult to improve both yield and protein simultaneously. The negative relationship between grain yield and GPC is well established and has a genetic basis (Oury and Godin 2007;Bogard et al 2010;Gaju et al 2011;Oury et al 2003;Barraclough et al 2010;Simmonds 1995). Among 27 wheat genotypes grown in 27 environments ranging in available N (Bogard et al 2010), mean grain yield variability accounted for 78% of mean GPC variability across all environments with a slope of -0.015% g -1 m 2 .…”

“…The negative relationship between grain yield and GPC is well established and has a genetic basis (Oury and Godin 2007;Bogard et al 2010;Gaju et al 2011;Oury et al 2003;Barraclough et al 2010;Simmonds 1995). Among 27 wheat genotypes grown in 27 environments ranging in available N (Bogard et al 2010), mean grain yield variability accounted for 78% of mean GPC variability across all environments with a slope of -0.015% g -1 m 2 . The two principle hypotheses to explain the negative correlation of grain yield and GPC are competition for energy resources by C and N assimilation processes (Munier-Jolain and Salon 2005) and a N dilution effect by carbohydrates (Acreche and Slafer 2009).…”

“…In winter wheat 15 N tracer studies, 71.2% of grain N originated from remobilization of pre-anthesis N (Kichey et al 2007). Similarly, using subtraction analysis, Bogard (2010) determined that 76-80% of winter wheat grain N originated from remobilization, and genetic variability for NREM was low. Postanthesis N uptake and NREM are distinct processes.…”

“…Postanthesis N uptake and NREM are distinct processes. Although both PANU and NREM contribute to NUE, the traits were strongly negatively correlated (r = -0.51 to -0.87) (Bogard et al 2010). Grain protein deviation (GPD) is the deviation of observed GPC from the concentration predicted by the grain yield-GPC relationship.…”