Wheat (Triticum aestivum L.) grain mineral concentrations tend to decrease as yields increase, therefore, breeding for yield improvement may reduce wheat nutritional quality. The objectives of this study were to survey grain mineral concentration in Great Plains hard winter wheat to assess (i) the heritable variation for grain mineral concentrations in the germplasm pool, (ii) the effects of more than 50 yr of wheat breeding on mineral concentrations, and (iii) opportunities to exploit the underlying physiological relationship between grain protein concentration (GPC) and grain mineral concentration to improve nutritional quality. Grain mineral concentrations were measured in a panel of 299 winter wheat genotypes grown in 2012 and 2013 in Oklahoma and Nebraska. Cadmium and Li concentrations were most heritable across environments, and the low heritabilities of Fe and Zn concentrations will challenge direct breeding efforts, particularly within low‐yield environments that minimize genetic variance. Within the subset of cultivars released from 1960 to 2014, grain yield increased 0.58 to 1.25% yr−1, and Zn concentration decreased 0.15 to 0.26% yr−1, relative to the reference cultivar Scout 66. Grain concentrations of Fe, P, and S also trended lower over this time period. Significant genetic variation persists within contemporary germplasm. Among 93 cultivars released since 2000, Zn concentration max/min ratios ranged from 1.5 to 2.3, depending on environment. The positive interrelationship between GPC and grain Fe and Zn concentrations could be exploited in a yield‐neutral breeding strategy that selects genotypes based on positive grain protein deviation (GPD) in multiple environments.

The oilseed species Thlaspi arvense (pennycress)-a weed that was only recently removed from the wild-has the potential to provide new sources of food and bioproducts when grown as a winter cover crop. Domestication of wild species has historically taken hundreds to thousands of years, but by making use of large-scale high-throughput comparative gene and phenotype analyses, along with recently developed technological tools, it has been possible to greatly accelerate this process. By taking advantage of extensive gene and phenotype knowledge in the related plant Arabidopsis, mutations for early maturity, reduced pod shatter, reduced seed glucosinolates and improved fatty acid composition were identified. Progress has been made to rapidly stack these traits in order to domesticate the plant, allowing it to fit within current crop cycles and to have improved seed harvestability and nutritional content. Pennycress, domesticated as a winter cover crop, may provide new sources of food, animal feed and bioproducts-and solutions to food security.

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.

Agriculture in the Upper Midwest of the USA is characterized by a short growing season and unsustainable farming practices including low-diversity cropping systems and high fertilizer inputs. One method to reduce the magnitude of these problems is by integrating a winter annual into the summer-annual-dominant cropping system. For this reason, pennycress (Thlaspi arvense) has garnered interest in the agricultural community due to its winter annual growth habit and potential for industrial oil production, making it an ecologically and economically desirable crop. Despite decades of research focusing on pennycress as an agricultural weed, little is known about its best management practices as an intentionally cultivated crop. The majority of agronomic research has occurred within the past 10 years, and there are major gaps in knowledge that need to be addressed prior to the widespread integration of pennycress on the landscape. Here we review relevant agronomic research on pennycress as a winter annual crop in the areas of sowing requirements, harvest, seed oil content, seed oil quality, cropping strategies, ecosystem services, and germplasm development. The major points are as follows: (1) there is little consensus regarding basic agronomic practices (i.e., seeding rate, row spacing, nutrient requirements, and harvest strategy); (2) pennycress can be integrated into a corn (Zea mays)soybean (Glycine max) rotation, but further research on system management is required to maximize crop productivity and oilseed yields; (3) pennycress provides essential ecosystem services to the landscape in early spring when vegetation is scarce; (4) breeding efforts are required to remove detrimental weedy characteristics, such as silicle shatter and high sinigrin content, from the germplasm. We conclude that pennycress shows great promise as an emergent crop; however, current adoption is limited by a lack of conclusive knowledge regarding management practices and future research is required over a multitude of topics.

Wheat (Triticum aestivum L.) is a primary staple cereal and significant source of mineral nutrients in human diets. Therefore, increasing concentration of the essential mineral, Zn, and decreasing concentration of the toxic mineral, Cd, could significantly improve human health. Because plant mechanisms for uptake and translocation of Cd and Zn are related, we assessed both Cd and Zn concentration to evaluate their independence in hard winter wheat germplasm. Grain Cd concentrations of some genotypes grown in Nebraska trials were above the Codex guidance level (0.2 mg kg–1), and highly repeatable differences in grain Cd were found between pairs of low and moderate‐Cd commercial cultivars. Grain Cd concentration was predicted by Cd concentration in aboveground plant tissues at anthesis. However, grain Zn concentration was not predicted by Zn concentration in aboveground plant tissues. Genome‐wide association scans using high‐density single nucleotide polymorphism (SNP) markers identified Cd‐associated SNPs on 5AL in a region homoeologous to the Cdu1 locus on 5BL in durum wheat (Triticum turgidum L. var. durum Desf.). Genetic regulation of grain cadmium concentration in bread wheat may be more complex than in durum wheat because epistatic interactions between SNP markers were identified, and SNP marker haplotypes were imperfect predictors of grain Cd phenotype. The SNP marker associations with Zn concentration were weak and inconsistent across trials, and Zn concentration was independent of 5AL markers. The independent genetic regulation of grain Cd and Zn concentrations indicates that breeding low Cd hard winter wheat genotypes without reducing Zn concentration has high potential for success.