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Summary: Phenotypic plasticity describes a genotype's ability to produce different phenotypes in response to different environments. Breeding crops that exhibit appropriate levels of plasticity for future climates will be crucial to meeting global demand, but knowledge of the critical environmental factors is limited to a handful of well‐studied major crops.Using 727 maize (Zea mays L.) hybrids phenotyped for grain yield in 45 environments, we investigated the ability of a genetic algorithm and two other methods to identify environmental determinants of grain yield from a large set of candidate environmental variables constructed using minimal assumptions.The genetic algorithm identified pre‐ and postanthesis maximum temperature, mid‐season solar radiation, and whole season net evapotranspiration as the four most important variables from a candidate set of 9150. Importantly, these four variables are supported by previous literature. After calculating reaction norms for each environmental variable, candidate genes were identified and gene annotations investigated to demonstrate how this method can generate insights into phenotypic plasticity.The genetic algorithm successfully identified known environmental determinants of hybrid maize grain yield. This demonstrates that the methodology could be applied to other less well‐studied phenotypes and crops to improve understanding of phenotypic plasticity and facilitate breeding crops for future climates. [ABSTRACT FROM AUTHOR]

In a hybrid maize (Zea mays L.) breeding program that utilizes genomic selection, resource allocation used in phenotypic data acquisition must be balanced between population size, number of environments, and the number of testers used for generating hybrids. Plant breeders evaluate newly developed inbred lines using multi‐environment trials to account for genotype‐by‐environment interaction effects. The replication of hybrids across environments in these trials impacts the training data accuracy for developing genomic prediction models. This study examined the impact of resource allocation scenarios on genomic prediction accuracy using a multi‐environment trial dataset generated using inbred lines crossed to multiple testers. A total of 369 Stiff Stalk double haploid lines from a synthetic mapping population were testcrossed to three non‐Stiff Stalk inbred lines as testers, PHZ51, PHK76, and PHP02, and evaluated across 34 environments by the Genomes to Fields Initiative in 2020 and 2021. Resource allocation scenarios significantly impacted site‐specific genomic prediction accuracy for unobserved hybrids in unobserved environments. A training set with three to five environments that had the highest quality data produced similar prediction accuracy as data from 10 random environments for both observed and unobserved hybrids, indicating that strong prediction models can be built with a limited set of environments for both grain yield and plant height. We found that resource‐efficient prediction models that use data from one tester and three to five environments can effectively conduct selection of untested hybrids and in untested environments. Public research programs are often limited in testing capacity, and this study provides support for genomic selection in resource‐limited breeding programs. Core Ideas: Plant breeding programs using genomic selection strive to maximize genetic gain per plot unit of training data.The distribution of resources within a hybrid breeding program significantly impacts genomic prediction accuracy.Accurate genomic prediction models can be produced using data from five or fewer locations.Training data from environments with the greatest heritability led to the highest genomic prediction accuracy.Plant breeding programs with limited budgets can build prediction models using resource‐efficient training sets. [ABSTRACT FROM AUTHOR]

Maize (Zea mays L.) grown in the US Midwest contains only a small fraction of the genetic diversity present in the species. Maize populations from other parts of the world may contain genetic variation that could be used to improve or increase the diversity of US germplasm. This study was conducted to assess the performance and phenotypic stability of hybrids containing diverse exotic introgressions across North American environments. Doubled haploid (DH) lines were created by the Germplasm Enhancement of Maize project from backcross 1 families that used 27 open‐pollinated populations from Latin America as donor parents and PHZ51, a non‐Stiff Stalk inbred developed in Iowa, as the recurrent parent. DH lines were testcrossed with LH195, a Stiff Stalk inbred developed in Iowa, and hybrid field trials were performed at 24 environments in the United States and Canada. Experimental hybrids had variable flowering time, plant and ear height, and test weight, but none had significantly greater yield than the PHZ51 × LH195 hybrid. The slopes of linear reaction norm models were significantly lower for the experimental hybrids than the US‐adapted reference hybrids for three traits: yield, growing degree units (GDU) to anthesis, and GDU to silking. The results suggest that unfavorable alleles and phenotypic stability should be considered when exotic open‐pollinated populations are used in US maize breeding. Core Ideas: Open‐pollinated maize populations are diverse and contain haplotypes that are rare or absent in US germplasm.Hybrids with exotic introgressions had variation in flowering time, plant height, and ear height.None of the hybrids with introgressions had significantly greater yield than the recurrent parent hybrid.Exotic‐derived hybrids and US hybrids had significantly different phenotypic stability for some traits. [ABSTRACT FROM AUTHOR]

Seed increase through manual pollination is a critical part of maize breeding and genetics research to advance generations in breeding programs, to create desired research crosses, and produce hybrid seed for trials. Pollination in the field and in controlled environments relies on the availability of high‐quality pollen at the time that recipient silks are receptive. Generally, pollinations are made by capturing pollen from the tassel in a paper pollinating bag placed on the tassels one day prior to pollination and newly released pollen is then transferred to silks on the target plant. In the field, maize pollen is only viable for one to four hours following dehiscence and the rate of desiccation is influenced by environmental conditions. We have developed a method which increases the lifespan of pollen and allows pollen from a single tassel to be used to pollinate many ears by mixing fresh pollen with a dilutant that can be stored for multiple days. We identified characteristics of the size of suitable substrates and selected a PEEK‐based substrate for regular utilization. We evaluated pollen viability and empirically demonstrated the capability to store pollen up to 9 days when pollen is mixed with a PEEK substrate and stored at 6°C. The pollen storage method was used to make successful pollinations across 24 maize inbred lines tested and was generally equivalent to the standard manual pollination process. This method has the potential to increase the efficiency of breeding operations and may be useful in an array of genetic studies. Core Ideas: Manual pollinations in breeding and genetics research requires pollen available when recipient silks are viable.The method collects and stores maize pollen for at least 5 days and facilitates efficient pollination.Pollen is mixed with polyetheretherketone and uses field‐collected pollen and simple storage conditions.The method can increase the number of pollinations per tassel and generates a reasonable number of viable seeds. [ABSTRACT FROM AUTHOR]

Summary: Crop genetic diversity for climate adaptations is globally partitioned. We performed experimental evolution in maize to understand the response to selection and how plant germplasm can be moved across geographical zones.Initialized with a common population of tropical origin, artificial selection on flowering time was performed for two generations at eight field sites spanning 25° latitude, a 2800 km transect. We then jointly tested all selection lineages across the original sites of selection, for the target trait and 23 other traits.Modeling intergenerational shifts in a physiological reaction norm revealed separate components for flowering‐time plasticity. Generalized and local modes of selection altered the plasticity of each lineage, leading to a latitudinal pattern in the responses to selection that were strongly driven by photoperiod. This transformation led to widespread changes in developmental, architectural, and yield traits, expressed collectively in an environment‐dependent manner. Furthermore, selection for flowering time alone alleviated a maladaptive syndrome and improved yields for tropical maize in the temperate zone.Our findings show how phenotypic selection can rapidly shift the flowering phenology and plasticity of maize. They also demonstrate that selecting crops to local conditions can accelerate adaptation to climate change. [ABSTRACT FROM AUTHOR]

Delayed silking relative to pollen shed, measured as the anthesis–silking interval (ASI, the period between pollen shed and silking), is a good indicator of response to abiotic stresses in maize (Zea mays L.). This research was conducted to investigate how ASI is affected by nitrogen (N) and water availability and to assess the utility of ASI to indirectly predict grain yield (GY) under contrasting water and N treatments. Two experiments were conducted in Hancock, WI, in 2018 and 2019. One experiment (Diverse hybrids) included 302 hybrids resulting from the cross of diverse inbred lines by a single tester evaluated at four different treatment levels resulting from combining nonlimited and low N with nonlimited and low water treatments. The second experiment (NSS FAC) included a set of 408 hybrids derived from the cross of biparental doubled‐haploid lines from 13 factorial populations and evaluated under nonlimited and low N treatments. Anthesis and silk time in growing degree days, and GY (Mg ha−1) were measured. Genomic prediction was assessed using a genomic best linear unbiased prediction model, and predictive ability was calculated as the correlation between genomic predictions and adjusted means in the different treatments. Predictive ability ranged from.15 to.49 for NSS FAC and from.06 to.51 for Diverse hybrids across traits and treatments. The ASI was a good indicator of stress and showed higher heritability than GY in the limited treatments for both experiments; however, it did not improve yield predictability. Core Ideas: ASI is more heritable than GY under limited conditions but did not improve prediction in a combined model.The ASI is a good indicator of water and N stress.The top hybrids were tolerant to both water and N limited conditions. [ABSTRACT FROM AUTHOR]

Tropical strains of maize (Zea mays subsp. mays L.) flower very late in temperate environments. This is a barrier to maize diversification and improvement in regions where a large share of the world's corn production takes place. For investigating early flowering time adaptation, a tightly controlled parallel selection experiment spanning a 28° latitudinal range (∼3,100 km) across the United States was conducted. First, a tropical synthetic population (TropicS‐G0) (Reg. no. GP‐605, PI 698625) of maize was created from seven inbred parents. The molecular genetic diversity in TropicS‐G0 is representative of tropical inbreds that are differentiated from the prevailing germplasm used for hybrid production in the United States. Admixture analysis and genome simulation showed that breeding of TropicS‐G0 captured the parental genomes mostly at random, as intended prior to selection. With TropicS‐G0 as a common base population, a standardized protocol was used to recurrently select for early flowering time at eight locations for two generations, giving rise to location‐specific lineages (TropicS‐G1‐PR, Reg. no. GP‐621, PI 698641; TropicS‐G2‐PR, Reg. no. GP‐622, PI 698642; TropicS‐G2‐FL, Reg. no. GP‐620, PI 698640; TropicS‐G1‐cTX, Reg. no. GP‐618, PI 698638; TropicS‐G2‐cTX, Reg. no. GP‐619, PI 698639; TropicS‐G1‐nTX, Reg. no. GP‐616, PI 698636; TropicS‐G2‐nTX, Reg. no. GP‐617, PI 698637; TropicS‐G1‐NC, Reg. no. GP‐614, PI 698634; TropicS‐G2‐NC, Reg. no. GP‐615, PI 698635; TropicS‐G1‐DE, Reg. no. GP‐610, PI 698630; TropicS‐G1‐IA, Reg. no. GP‐608, PI 698628; TropicS‐G2‐IA, Reg. no. GP‐609, PI 698629; TropicS‐G1‐WI, Reg. no. GP‐606, PI 698626; TropicS‐G2‐WI, Reg. no. GP‐607, PI 698627). Additional generations of selection were performed for the DE lineage (TropicS‐G3‐DE, Reg. no. GP‐611, PI 698631; TropicS‐G4‐DE, Reg. no. GP‐612, PI 698632; TropicS‐G5‐DE, Reg. no. GP‐613, PI 698633). The parallel‐selected maize population is a novel resource for breeders and those seeking to investigate adaptation. Core Ideas: Tropical maize harbors favorable alleles for climate adaptation.Maladaptation restricts infusion of tropical diversity in the temperate zone.Unique tropical germplasm was produced by parallel selection for early flowering time.Location‐specific lineages were preadapted across 28° latitude of the United States.This material would be of interest to breeders and researchers investigating adaptation. [ABSTRACT FROM AUTHOR]

New maize (Zea mays L.) inbred lines are commonly evaluated based on the performance of their progeny when crossed to a single tester line from a different heterotic group (testcross), making tester choice critical. An alternative progeny test is pairing new lines between heterotic groups such that every parent is observed in one hybrid combination. This approach requires half the number of hybrids to test but the general combining ability (GCA) of each parent cannot be estimated. Genomic information can be used to partition parental GCA, while potentially enabling the prediction of dominance deviations. We evaluated doubled haploid lines extracted from two six‐parent synthetic populations from the Iodent (IO) and Stiff Stalk (SS) heterotic groups using either single crosses from random pairs of inbreds or testcrosses. Hybrids were evaluated for yield and agronomic traits in 2014 and 2015 in south‐central Wisconsin. The experiment was conducted using a randomized complete block design with each population type grown in two replicates within two environments. Coincidence of selection of the 25 top performing lines based on testcross yield and single‐cross hybrid yield was 48% for the SS and 11% for the IO doubled haploid lines, increasing to 56% for the SS and 56% for the IO with genomic prediction based on an additive genomic model. Partitioning dominance deviations with the model increased coincidence to 62% for the SS population. Genomic estimates of grain yield GCA in the single‐cross hybrids were significantly more correlated than phenotypic GCA to testcross values for the IO lines, but not SS. Natural and orthogonal interaction estimates of dominance variation were insignificant for all traits, indicating that the inability to partition dominance based on testcross performance should not be a major limitation to identification of high‐performing hybrids. Genomic information improves the prospects of using single‐cross hybrids made from random pairs of new inbreds as an efficient progeny test by allowing the recovery of parental GCA information. Core Ideas: Testcross analysis may preclude detection of heterotic hybrids of two new inbred lines.We tested random crosses of new inbreds coupled with genomic selection as an approach to hybrid selection.Genomic selection of inbreds from randomly paired single‐crosses was effective.Logistic issues in seed production may preclude the value of hybrid selection using pairs. [ABSTRACT FROM AUTHOR]

Breeders made remarkable progress in improving productivity and stability of cultivars. Breeding progress relies on selecting favorable alleles for performance and stability to produce productive varieties across diverse environments. In this study, we analyzed the Genomes to Fields Initiative 2018–2019 genotype by environment interaction (G × E) dataset, focusing on three populations of double haploid (DH) lines derived from crossing inbrexpired Plant Variety Protection (ex‐PVP) inbred line PHW65 with inbred lines PHN11, Mo44, and MoG. PHW65 is an Iodent/Lancaster‐type inbred; PHN11 is an Iodent type ex‐PVP line; Mo44 is a tropical‐derived inbred; and MoG is an agronomically poor line derived from the variety Mastadon. Hybrids were produced by crossing the resulting DHs with Stiff Stalk testers PHT69 and LH195. The study's objective was to determine the donor inbreds' relative value and understand the impact of selection history on genomic prediction. We conducted a two‐stage analysis to compare hybrid performance and G × E variance of the populations. G × E variance for yield was significantly lower in the PHW65 × PHN11 population relative to the PHW65 × MoG population. The reduced G × E variance of the PHN11 population led to increased indirect prediction accuracy (when training and testing data are drawn from the same population but different environments). In cross‐validation, the PHN11 population had the greatest indirect prediction accuracy 45% of the time, followed by the Mo44 population (30%) and the MoG population (25%). Results demonstrate that prediction accuracy was greater in the population with the longest history of selection for favorable alleles (PHN11), contributing to greater yield stability. [ABSTRACT FROM AUTHOR]

SUMMARY: Single‐parent expression (SPE) is defined as gene expression in only one of the two parents. SPE can arise from differential expression between parental alleles, termed non‐presence/absence (non‐PAV) SPE, or from the physical absence of a gene in one parent, termed PAV SPE. We used transcriptome data of diverse Zea mays (maize) inbreds and hybrids, including 401 samples from five different tissues, to test for differences between these types of SPE genes. Although commonly observed, SPE is highly genotype and tissue specific. A positive correlation was observed between the genetic distance of the two inbred parents and the number of SPE genes identified. Regulatory analysis showed that PAV SPE and non‐PAV SPE genes are mainly regulated by cis effects, with a small fraction under trans regulation. Polymorphic transposable element insertions in promoter sequences contributed to the high level of cis regulation for PAV SPE and non‐PAV SPE genes. PAV SPE genes were more frequently expressed in hybrids than non‐PAV SPE genes. The expression of parentally silent alleles in hybrids of non‐PAV SPE genes was relatively rare but occurred in most hybrids. Non‐PAV SPE genes with expression of the silent allele in hybrids are more likely to exhibit above high parent expression level than hybrids that do not express the silent allele, leading to non‐additive expression. This study provides a comprehensive understanding of the nature of non‐PAV SPE and PAV SPE genes and their roles in gene expression complementation in maize hybrids. Significance Statement: Single‐parent expression (SPE) is defined as gene expression in only one of the two parents. This expression state can arise from differential expression between parental alleles, termed non‐presence/absence (non‐PAV) SPE, or the physical absence of a gene in one parent, termed PAV SPE. This study provides a comprehensive understanding of the nature of non‐PAV SPE and PAV SPE genes and their roles in gene expression complementation in maize hybrids. [ABSTRACT FROM AUTHOR]

The hydroxycinnamic acids p‐coumaric acid (pCA) and ferulic acid (FA) add diversity to the portfolio of products produced by using grass‐fed lignocellulosic biorefineries. The level of lignin‐bound pCA in Zea mays was modified by the alteration of p‐coumaroyl‐CoA monolignol transferase expression. The biomass was processed in a lab‐scale alkaline‐pretreatment biorefinery process and the data were used for a baseline technoeconomic analysis to determine where to direct future research efforts to couple plant design to biomass utilization processes. It is concluded that future plant engineering efforts should focus on strategies that ramp up accumulation of one type of hydroxycinnamate (pCA or FA) predominantly and suppress that of the other. Technoeconomic analysis indicates that target extraction titers of one hydroxycinnamic acid need to be >50 g kg−1 biomass, at least five times higher than observed titers for the impure pCA/FA product mixture from wild‐type maize. The technical challenge for process engineers is to develop a viable process that requires more than 80 % reduction of the isolation costs. [ABSTRACT FROM AUTHOR]

Publicly available maize (Zea mays L.) inbred lines with expired Plant Variety Protection certificates (ex‐PVP) constitute the elite germplasm used in hybrids grown by North American farmers during the past half century. A set of 329 ex‐PVP inbreds and eight public reference inbreds was evaluated for genetic diversity using molecular marker and pedigree‐based relationships. The majority of inbreds originated from Dekalb Genetics Corporation, Holden's Foundation Seed, Pioneer Hi‐Bred International, and Syngenta via Novartis and Northrup King. Flowering ranged from 968–1806 growing degree days to anthesis, supporting that these inbreds represent adaptation across the range of North American production environments. Admixture analysis supported eight subgroups (B14, B37, B73, Oh43, Iodent, Iodent‐Lancaster, Lancaster, and Flint), reflecting heterotic patterns and company of origin. Five diallel‐cross experiments identified primary yield heterotic patterns within early‐, intermediate‐, and late‐maturity groups. Parental pedigree information was compiled for 2392 Plant Variety Protection and/or utility patented inbreds through 2017, allowing for multigenerational analysis of progenitors and the eight heterotic subgroups across current proprietary breeding programs. Key progenitors were identified for recently merged companies, Bayer Crop Science and Corteva Agriscience. The results of this study strengthen the value of the ex‐PVP inbreds as a source of elite and relevant germplasm for breeders and researchers to exploit. This study provides information that will be logistically useful to researchers who use ex‐PVP inbreds and adds to our understanding of heterotic grouping within North American proprietary germplasm. [ABSTRACT FROM AUTHOR]

Sugarcane mosaic virus (SCMV) and Maize dwarf mosaic virus can cause yield loss in maize (Zea mays L.). Previous studies identified two key genomic regions controlling host resistance: Scmv1 on chromosome 6 and Scmv2 on chromosome 3. In this study a diverse set of 578 inbreds adapted to a northern US Corn Belt environment, was inoculated at the three-leaf stage with SCMV and rated for presence of virus symptoms at 7, 10, 14, 21, 28, and 35 d after inoculation. Scmv1 was present in all resistant inbreds. A single-nucleotide polymorphism associated with SCMV resistance was found 5 Mb downstream of the putative location of Scmv1, and resistance at this downstream locus was correlated with a group of inbreds containing the presence allele of a 2.7-Mb presence-absence variation (PAV) in the region encompassing Scmv1. The Scmv2 region was associated with resistance 35 d after inoculation only among the inbreds containing the presence allele, including Scmv1. Several other loci unlinked to Scmv1 and Scmv2 were associated with resistance in this panel, providing evidence for multigenic modification of the efficacy of Scmv1 and Scmv2. Sixty-nine inbreds representing haplotype variation in the region surrounding Scmv1 on chromosome 6 were inoculated with SCMV at the three- and six-leaf stage. Symptom development was reduced when inoculation was delayed to the six-leaf stage, but 24 inbreds became fully symptomatic after 35 d regardless of the growth stage at inoculation. Inbreds with the presence allele of the PAV encompassing Scmv1 were more resistant to SCMV when inoculation was delayed to the six-leaf stage than those that had the absence allele. Inbreds with the absence allele were susceptible regardless of growth stage at inoculation. [ABSTRACT FROM AUTHOR]

Grain yield of the maize plant depends on the sizes, shapes, and numbers of ears and the kernels they bear. An automated pipeline that can measure these components of yield from easily-obtained digital images is needed to advance our understanding of this globally important crop. Here we present three custom algorithms designed to compute such yield components automatically from digital images acquired by a low-cost platform. One algorithm determines the average space each kernel occupies along the cob axis using a sliding-window Fourier transform analysis of image intensity features. A second counts individual kernels removed from ears, including those in clusters. A third measures each kernel's major and minor axis after a Bayesian analysis of contour points identifies the kernel tip. Dimensionless ear and kernel shape traits that may interrelate yield components are measured by principal components analysis of contour point sets. Increased objectivity and speed compared to typical manual methods are achieved without loss of accuracy as evidenced by high correlations with ground truth measurements and simulated data. Millimeter-scale differences among ear, cob, and kernel traits that ranged more than 2.5-fold across a diverse group of inbred maize lines were resolved. This system for measuring maize ear, cob, and kernel attributes is being used by multiple research groups as an automated Web service running on community high-throughput computing and distributed data storage infrastructure. Users may create their own workflow using the source code that is staged for download on a public repository. [ABSTRACT FROM AUTHOR]

Expression of a phenotype is a function of the genotype, the environment, and the differential sensitivity of certain genotypes to different environments, also known as genotype by environment (G x E) interaction. This special issue of Crop Science includes a collection of manuscripts that reviews the long history of G xE research, describes new and innovative ideas, and outlines future challenges. Improving our understanding of these complex interactions is expected to accelerate plant breeding progress, minimize risk through improved cultivar deployment, and improve the efficiency of crop production through informed agriculture. Achieving these goals requires the integration of broad and diverse science and technology disciplines. [ABSTRACT FROM AUTHOR]

Maize is an important model species and a major constituent of human and animal diets. It has also emerged as a potential feedstock and model system for bioenergy research due to recent worldwide interest in developing plant biomass-based, carbon-neutral liquid fuels. To understand how the underlying genome sequence results in specific plant phenotypes, information on the temporal and spatial transcription patterns of genes is crucial. Here we present a comprehensive atlas of global transcription profiles across developmental stages and plant organs. We used a NimbleGen microarray containing 80 301 probe sets to profile transcription patterns in 60 distinct tissues representing 11 major organ systems of inbred line B73. Of the 30 892 probe sets representing the filtered B73 gene models, 91.4% were expressed in at least one tissue. Interestingly, 44.5% of the probe sets were expressed in all tissues, indicating a substantial overlap of gene expression among plant organs. Clustering of maize tissues based on global gene expression profiles resulted in formation of groups of biologically related tissues. We utilized this dataset to examine the expression of genes that encode enzymes in the lignin biosynthetic pathway, and found that expansion of distinct gene families was accompanied by divergent, tissue-specific transcription patterns of the paralogs. This comprehensive expression atlas represents a valuable resource for gene discovery and functional characterization in maize. [ABSTRACT FROM AUTHOR]

The demand for biofeedstocks is increasing with the growth of the biofuel industry. Mutations such as grassy tillers1 (gt1), which increase the number of primary lateral branches (tillers) from below ground nodes, as well as Corngrass1 (Cg1), which alters cell wall composition, are hypothesized to increase theoretical ethanol yield on a per hectare basis. To test this, gt1 isogenic hybrids and Cgl hybrids were evaluated at two densities (20,000 and 70,000 plants ha-1). Stover samples were collected at grain physiological maturity and evaluated for cell wall composition. The effect of density treatment was significant for grain, stover, whole plant yield, and acid detergent lignin (ADL) on the whole data set (p = 0.05). Negative correlations were observed between stover yield and cell wall composition traits, while positive correlations were observed among compositional traits. The Cgl hybrids were the lowest yielding hybrids and had higher ADL than the commercial checks. Tiller number was positively correlated with grain, stover, and whole plant yield at the low density. Homozygous gt1/gt1 hybrids planted at low density were not different than their wild-type counterparts planted at high density for stover yield. The ability of tillering plants to equate biomass production of their wild-type counterparts at nearly four times higher density demonstrates the utility in exploring alternative plant morphologies in an effort to meet the needs of the biofuel industry. [ABSTRACT FROM AUTHOR]

Association analysis to identify genes and alleles underlying quantitative genetic variation is growing in value as the density of, genotypic data increases. Association panels are often chosen to maximize molecular and phenotypic diversity, but traits measured at harvest require restricted phenology to obtain data on plants that mature within a comparable interval. The objective of this study was to characterize a set of inbred lines that will mature reliably in the upper midwestern United States for the purpose of assessing traits relevant to grain and stover yield as well as stover quality. A total of 1411 lines from the North Central Regional Plant Introduction Station, our program, and contributed by collaborators were grown in observation plots. A set of 627 lines were chosen based on flowering within the desired interval, production of viable seed, agronomic suitability, uniformity, and pedigree information. Flowering time ranged from 944 to 1645 growing degree days (GDD). Genotypic data for the 627 lines was obtained using a 1536 Iflumina GoldenGate assay. The panel offers deep replication of most Midwest dent alleles. There is a lesser representation of tropical alleles relative to other association panels but includes some Germplasm Enhancement of Maize (GEM)-derived lines and early flowering lines of tropical origin. The information described in this manuscript is anticipated to facilitate the use of this material for association genetic studies. [ABSTRACT FROM AUTHOR]

Genotype x environment interaction influences the market value of soybean [Glycine max (L.) Merrj protein, oil, and fatty acid traits. The objectives of this research were (i) to evaluate agronomic trait performance and stability of soybean genotypes in individual environments and across environments; and (ii) to evaluate the relationship of test environments for selecting superior genotypes within the mega-environment for soybean production in the southern region of Wisconsin. A total of 68 soybean genotypes were selected from University of Wisconsin soybean evaluation trials and grown at four locations in 2003 and 2004. Soybean genotypes, grown in trials with conventional and Roundup Ready herbicide treatments were analyzed for yield, protein, oil, and the fatty acid components palmitic acid, stearic acid, oleic acid, linoleic acid, and linolenic acid. Repeatability estimates among genotypes ranged from 0.27 to 0.98 with yield and the fatty acid component linofenic acid being the most sensitive to environment effects. Superior genotypes could be consistently selected for yield, protein, oil, and fatty acid components using biplot analyis and stability estimates. Among locations in the southern region in Wisconsin, Arlington provides unique information for soybean fatty acid evauations, but similar information about soybean yield, protein, and oil with Janesville or Lancaster. So, if soybean fatty acid is not important then Arlington could be dropped as a test site. [ABSTRACT FROM AUTHOR]

Examines the language and literacy practices in first- and fourth-grade classrooms in two schools in a small town in central Mexico. Importance of Mexican literacies to U.S. schools; Discussion on globalization and access to knowledge about Mexican schools; Differences in the uses of oral and written language.

Keywords: acids; biomass; industrial chemistry; protein engineering; synthesis design EN acids biomass industrial chemistry protein engineering synthesis design 1918 1918 1 04/22/20 20200421 NES 200421 B The Front Cover b shows how a diverse team with expertise in many different fields works together in an integrated fashion to address complex problems. Acids, biomass, industrial chemistry, protein engineering, synthesis design. [Extracted from the article]