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

Abstract

Wheat genotypes that efficiently capture and convert available soil nitrogen into harvested grain protein are key to sustainably meeting the rising global demand for grain protein. The purposes of this study were: to characterize the genetic variation for nitrogen use efficiency (NUE) traits within hard winter wheat adapted to the Great Plains of the United States and evaluate trends in the germplasm with year of release; to explore relationships among traits that may be used for selection within breeding programs; and to identify quantitative trait loci associated with NUE traits in this germplasm. NUE traits were measured in a panel of 299 hard winter wheat genotypes, representing historically important and contemporary germplasm, from across the growing region. Trials were grown in two years at two levels of nitrogen fertility. Genotype and genotype 9 year interaction effects were highly significant for NUE traits, while genotype 9 nitrogen rate interactions were non-significant. Strong genetic correlations of plant height and flowering date with NUE traits were observed. Wheat breeders have improved NUE: the subset of 183 genotypes that were released as cultivars after 1960 demonstrated significant trends with year of release for improved grain N yield, grain yield, nitrogen harvest index, nitrogen uptake efficiency, nitrogen utilization efficiency, and post-anthesis nitrogen uptake. In genome-wide association analyses, plant height and flowering date were important covariates in the mixed models, and plant height and flowering date substantially explained the variation in NUE traits in this germplasm. Marker-trait associations were identified that may prove useful in breeding.

Effect of Deprivation and Excessive Application of Nitrogen on Nitrogen Use Efficiency‐Related Traits Using Wheat Cultivars, Lines, and Landraces

“…This result is in agreement with those of Guttieri et al (2017). This result is in agreement with those of Guttieri et al (2017).…”

“…The significant effect of the environment, observed in the current study, could be attributed to the difference in the soil conditions (i.e., texture, salinity, and pH) and the climate factors (i.e., temperature and relative humidity) that might affect the productivity of wheat genotypes (Shimelis and Laing, 2012). For instance, Guttieri et al (2017) evaluated a panel of 299 hard winter wheat genotypes for GY and NUE under two N levels (low and moderate). The low GY observed in this study at low N supply across environments was expected and was reported previously in several other studies (Gaju et al, 2011;Cormier et al, 2013).…”

“…However, increasing N application rate, without considering the inefficient N uptake has unintended adverse environmental and economical impacts, including contaminating surface and groundwater by N leaching (Huang et al, 2017), and gaseous emissions such as N 2 O by volatilization (Hawkesford, 2017), which contribute to climate change. Moreover, N is not only the most expensive input element in wheat grain production, but also its price has increased by 10% annually since 2000 (Guttieri et al, 2017). Thus, losing 40 to 60% of the amount of applied N means the costs of growing wheat is higher than it should be.…”

Cell Membrane Stability and Association Mapping for Drought and Heat Tolerance in a Worldwide Wheat Collection

“…Currently, phenotyping became a major bottleneck and resource constraint on genome-wide association mapping [19]. Thus we focused our efforts and resources on conducting a time-consuming phenotyping for CMS using 2111 spring wheat accessions with publicly available 9K SNP marker data [85].…”

Allelic Variants of Glutamine Synthetase and Glutamate Synthase Genes in a Collection of Durum Wheat and Association with Grain Protein Content

“…Recently, a genome-wide association analysis with high-density SNP markers was conducted in order to identify genomic regions that may be associated with NUE traits in Great Plains hard winter wheat germplasm [35]. Interestingly, it was found that SNP markers on the long arm of a 2D chromosome were associated with NUE traits, in the same distal position where GS2 genes map.…”