David Anthony Van Sanford

There is strong demand for new Fusarium head blight (FHB)‐resistant small grain crop varieties that accumulate less of the mycotoxin deoxynivalenol (DON). It is difficult to breed for FHB resistance because it is a quantitative trait, and phenotyping is tedious and subjective. Implementation of high‐throughput, objective phenotyping methods would advance breeding success in developing FHB resistant varieties. Optical sorting uses a camera to rapidly and efficiently separate healthy grains from Fusarium ‐infected grains. The sorter does not rely on potentially biased human observations but rather utilizes a calibrated camera to autonomously and reproducibly classify and separate the grains based on their appearance. We evaluated the ability of the optical sorter to reduce DON in closely related wheat ( Triticum aestivum L.) breeding lines with various combinations of scab resistance genes. The sorter did an excellent job of reducing DON content (10%–22%). However, this did not translate into consistently reduced DON with each cycle of selection. Combinations of resistance genes in a small subset of genotyped lines did not affect the ability of the sorter to reduce DON. Previous research has shown that Fhb1 frequency increases with cycles of selection, which was confirmed in this study. Furthermore, the frequencies of resistance quantitative trait loci (QTL) 1A and 4A Neuse also increased with just one cycle of selection. However, the frequency of 3B Massey decreased. Results suggest the optical sorter can be an effective tool for selecting grain with reduced DON content and more FHB resistance QTL for breeding purposes.

Fusarium Head Blight (FHB) is an economically devastating disease of wheat (Triticum aestivum L.) causing low yields and poor quality. FHB, caused by Fusarium graminearum, disrupts the grain filling phase and results in bleached spikes and shriveled seeds. Deoxynivalenol (DON) is a mycotoxin produced by the fungal pathogen when it infects the plant; DON

Cereal rye ( Secale cereale ) is a grain, forage, and cover crop, with specific regional production practices. Maintaining regional varieties is challenged by rye reproductive biology, as wind pollination may dilute varietal distinction. Similarly, breeding new population varieties for regional needs lacks efficiency gains seen in other grains. We sought to address the challenges in maintaining and breeding rye population varieties in the Southeastern United States, where rye is a forage and cover crop, with emerging grain markets. Genetic and phenotypic variation within and between populations was characterized to determine varietal differentiation and test the efficacy of genomic selection for population improvement. Using 15 Southeastern rye accessions and eight breeding populations, we genotyped and phenotyped more than 500 individuals and found that most phenotypic and genetic variation is within rather than among accessions. Latitude of variety source, but not end use, contributed to intervarietal variation for heading date, but not traits associated with seed yield. Genomic prediction accuracy was moderately high ( r  > 0.3) for most traits, but within‐population prediction accuracy was more variable, with only some populations having nonzero within‐population prediction accuracy. This work establishes the inter‐ and intravarietal differentiation in Southeastern rye accessions, and demonstrates viability of genomics‐enabled population improvement for regional varieties.

Rye (Secale cereale L.) grain production in Kentucky is insufficient to meet the needs of distillers and bakers, in part because there is a knowledge gap about rye management that discourages farmers from choosing this crop. We conducted an economic study to develop recommendations for profitable rye grain production. The aim of this study was to determine the influence of two different nitrogen (N) rates (35 lb N acre⁻¹ and 70 lb N acre⁻¹) on yield and profitability of winter rye grain production. Experiments were conducted in 2020–2021 season at three Kentucky locations: Lexington, Princeton, and Adairville. Twenty‐four rye entries were planted in a split plot design experiment and the two N rates (35 lb N acre⁻¹ and 70 lb N acre⁻¹) were assigned to main plots. There was no significant difference in mean yield between 35 and 70 lb N acre⁻¹. This indicates that less investment in N fertilizer will not adversely affect grain yield level, will enhance profitability of production, and will benefit distillers due to the higher alcohol yield associated with higher starch and lower protein levels.

Focus on local food production and supply chains has heightened in recent years, as evidenced and amplified by the COVID-19 pandemic. This study aimed to assess the suitability of soft red winter (SRW) wheat breeding lines for local artisan bakers interested in locally sourced, strong gluten wheat for bread. Seventy-six genotyped SRW wheat breeding lines were milled into whole wheat flour and baked into small loaves. Bread aroma, flavor, and texture were evaluated by a sensory panel, and bread quality traits, including sedimentation volume, dough extensibility, and loaf volume, were measured to estimate heritability. SE-HPLC was performed on white flour, and breeding lines were characterized for different protein fraction ratios. Heritability of loaf volume was moderately high (h² = 0.68), while heritability of sedimentation volume, a much easier trait to measure, was slightly lower (h² = 0.55). Certain protein fraction ratios strongly related to loaf volume had high heritability (h² = 0.7). Even though only a moderate heritability estimate of dough extensibility was found in our study, high positive correlations were found between this parameter and sedimentation volume (r = 0.6) and loaf volume (r = 0.53). This low-input and highly repeatable parameter could be useful to estimate dough functionality characteristics. Flavor and texture heritability estimates ranged from 0.16 to 0.37, and the heritability estimate of aroma was not significantly different from zero. However, the sensorial characteristics were significantly correlated with each other, suggesting that we might be able to select indirectly for aroma by selecting for flavor or texture characteristics. From a genome-wide association study (GWAS), we identified six SNPs (single nucleotide polymorphisms) associated with loaf volume that could be useful in breeding for this trait. Producing high-quality strong gluten flour in our high rainfall environment is a challenge, but it provides local growers and end users with a value-added opportunity.

Cereal rye (Secale cereale) is a multi‐purpose crop, harvested for grain (for food, feed, and other products) as well as used as a forage or cover crop. The functionality of rye across these spheres is due to its abiotic and biotic stress tolerance and unique phytochemical composition. In this review, we focus on the current state and prospects of breeding rye for quality traits, where we define quality traits as grain, feed, or forage quality. Rye grain for human consumption has numerous healthful compounds, notably high dietary fiber content in grain and unique flavors that contribute to the signature properties of rye baked products and distilled spirits. As a forage, rye is useful in marginal environments and has high quality, including high crude protein, and is thus valuable for livestock production. While yield remains a major focus of breeding efforts, due to recent improvements in rye genomic and phenotypic resources, there are now opportunities for increased attention on breeding high‐quality ryes for multiple end uses. Through genetic improvement of quality traits, cereal rye has the potential to expand and serve multiple markets as a climate‐resilient crop.

Reducing generation time is critical to achieving the goals of genetic gain in important crops like wheat (Triticum aestivum). Speed breeding (SB) has been shown to considerably reduce generation times in crop plants. Unlike spring wheat cultivars, winter wheat varieties require typically 6–9 weeks of cold treatment, called vernalization, for flowering which extends the generation time for the development of improved winter wheat cultivars. Here, we optimized the SB method using a set of 48 diverse soft red winter wheat (SRWW) cultivars by testing vernalization duration, light and temperature requirements, and the viability of seeds harvested after different durations post‐anthesis under extended daylight conditions. We have found that using a 22‐h setting (22 h day/2 h night, 25°C/22°C) in high‐density 50‐cell trays results in rapid generation advancement. We used genotypic data for a panel of soft red winter wheat varieties from the regional programs to determine the impact of photoperiod and vernalization alleles on the efficiency of the SB approach. Using a set of 48 SRWW cultivars and germplasm from Maryland and four other public breeding programs, we establish that this protocol can allow for the advancement of four generations per year in controlled conditions for winter wheat varieties, experimental lines, or emerging cultivars. Our work shows the potential to reduce generation time by ∼30 days per generation faster than what had been reported in the SB strategies for winter wheat, thus allowing for a quicker turnaround time from original cross to genetically stable experimental genotypes that can be tested in field settings.

Breeding wheat (Triticum aestivum L.) has resulted in small gains in improved nutrient acquisition and use as numerous traits are involved. In this study, we evaluated the impact of breeding on P-acquisition and identified both plant and soil variables that could be used to inform the selection of germplasm with increased P acquisition efficiency. We previously screened a historic panel of winter wheat cultivars for root system architecture and root tip organic acid content when grown in P-deficient solution/agar and used these characteristics together with breeding history to develop a predicted P extraction potential (PEP). We tested the validity of the PEP classification by growing cultivars under sufficient and insufficient soil P conditions. Old, wild-type cultivars had the greatest P utilization efficiency (PUtE) when grown under insufficient P, likely a result of the chemical potential of wild-type (with respect to Rht-B1) cultivars (greater organic acid production) rather than root system size. Wild-type plants had differences in rhizosphere microbial community structure, rhizosphere bicarbonate-extractable P, and bulk soil Fe and Al, indicating the utilization of typically less available P pools. The PEP classification based on the presence of dwarfing allele and era of release offers a path forward for breeding for improved P acquisition.

Kentucky's wheat (Triticum aestivum L.) crop is planted into a rotation in which corn (Zea mays L.) is followed by wheat, which is followed by double‐crop soybean [Glycine max (L.) Merr.]. The causal agent of Fusarium head blight (FHB), Fusarium graminearum Schwabe, overwinters in corn stubble; thus, the Kentucky wheat crop is always at risk for FHB. The preeminent goal of the University of Kentucky wheat breeding program is releasing FHB‐resistant winter wheat cultivars. ‘Pembroke 2021’ (Reg. no. CV‐1198, PI 701381) is an early‐maturing, semi‐dwarf, soft red winter wheat cultivar developed and released in 2020 by the Kentucky Agricultural Experiment Station for FHB resistance, high yield and test weight potential, and lodging resistance. Pembroke 2021, tested as KY 07C‐1145‐94‐12‐5, was developed from the cross ‘IL99‐15867’/B990081//KY97C‐0554‐04‐05. The pedigree of the KY parent is VA94‐54‐549/Roane//Kristy. Pembroke 2021 was named for the Pembroke silt loam soil series prevalent in the main wheat‐producing area of Kentucky. Pembroke 2021 was selected from F_4:5 head rows using a modified bulk breeding method; selected rows carried the resistance allele at the following FHB resistance quantitative trait loci: 1B Jamestown, 1A Neuse, 4A Neuse, and 3B Massey. Pembroke 2021 was tested in Kentucky in multi‐location replicated yield trials, the Uniform Eastern Soft Red Winter Wheat Nursery, the Mason‐Dixon nursery, the Uniform Northern Winter Wheat Scab Nursery, and the Kentucky Wheat Variety Trial.