A chromosome 16 deletion conferring a high sucrose phenotype in soybean.

KEY MESSAGE: Sucrose in soybean seeds is desirable for many end-uses. Increased sucrose contents were discovered to associate with a chromosome 16 deletion resulting from fast neutron irradiation. Soybean is one of the most economically important crops in the United States. A primary end-use of soybean is for livestock feed. Therefore, genetic improvement of seed composition is one of the most important goals in soybean breeding programs. Sucrose is desired in animal feed due to its role as an easily digestible energy source. An elite soybean line was irradiated with fast neutrons and the seed from plants were screened for altered seed composition with near-infrared spectroscopy (NIR). One mutant line, G15FN-54, was found to have higher sucrose content (8-9%) than the parental line (5-6%). Comparative genomic hybridization (CGH) revealed three large deletions on chromosomes (Chrs) 10, 13, and 16 in the mutant, which were confirmed through whole genome sequencing (WGS). A bi-parental population derived from the mutant G15FN-54 and the cultivar Benning was developed to conduct a bulked segregant analysis (BSA) with SoySNP50K BeadChips, revealing that the deletion on Chr 16 might be responsible for the altered phenotype. The mapping result using the bi-parental population confirmed that the deletion on Chr 16 conferred elevated sucrose content and a total of 21 genes are located within this Chr 16 deletion. NIR and high-pressure liquid chromatography (HPLC) were used to confirm the stability of the phenotype across generations in the bi-parental population. The mutation will be useful to understand the genetic control of soybean seed sucrose content.

Characterization of Fusarium Head Blight Resistance and Deoxynivalenol Accumulation in Hulled and Hulless Winter Barley.

Fusarium head blight (FHB), caused by Fusarium graminearum, is one of the most serious diseases impacting the U.S. barley (Hordeum vulgare) industry. The mycotoxin deoxynivalenol (DON), produced by the pathogen, renders grain unmarketable if concentrations exceed threshold values set for end-use markets. Development of cultivars with improved FHB resistance and reduced DON accumulation is necessary to ensure minimal losses. Elite hulled and hulless genotypes developed by the Virginia Tech winter barley breeding program were screened in inoculated, mist-irrigated FHB nurseries over 2 years at two locations in Virginia to validate resistance levels over years and locations. Results demonstrated that barley genotypes varied significantly for resistance to FHB and DON accumulation. The hulled 'Nomini', hulless 'Eve', and hulless line VA06H-48 were consistently resistant across locations to both FHB and DON accumulation. Screening the genotypes with molecular markers on chromosomes 2H and 6H for FHB and DON revealed quantitative trait loci regions which may confer resistance in the Virginia Tech germplasm. Ongoing and future work with mapping populations seeks to identify novel regions for resistance to FHB and DON accumulation unique to the Virginia Tech breeding program.

Seed physiological traits and environmental factors influence seedling establishment of vegetable soybean (Glycine max L.).

Edamame (Glycine max (L.) Merr.), a specialty soybean prized for its nutritional value and taste, has witnessed a surge in demand within the U.S. However, subpar seedling stands have hindered its production potential, necessitating increased inputs for farmers. This study aims to uncover potential physiological factors contributing to low seedling emergence in edamame. We conducted comprehensive assessments on thirteen prominent edamame genotypes alongside two food-grade and two grain-type soybean genotypes, focusing on germination and emergence speed in both laboratory and field settings. Additionally, we employed single electrical conductivity tests and identified and quantified seed leachate components to distinguish among soybean types. Furthermore, using a LabField™ simulation table, we examined seed emergence across a wide soil temperature range (5°C to 45°C) for edamame and other soybean types. All seeds were produced under the same environmental conditions, harvested in Fall 2020, and stored under uniform conditions to minimize quality variations. Our findings revealed minimal divergence in emergence percentages among the seventeen genotypes, with over 95% germination and emergence in laboratory conditions and over 70% emergence in the field. Nonetheless, edamame genotypes typically exhibited slower germination speeds and higher leachate exudates containing higher soluble sugars and amino acids. Seed size did not significantly impact total emergence but was negatively correlated with germination and emergence speed, although this effect could be mitigated under complex field conditions. Furthermore, this study proposed differences that distinguish edamame from other soybean types regarding ideal and base temperatures, as well as thermal time. The finds offer valuable insights into edamame establishment, potentially paving the way for supporting local edamame production in the U.S.

Determining Genetic Markers and Seed Compositions Related to High Test Weight in Glycine max.

Test weight, one of the primary indicators of soybean seed quality, is measured as the amount of soybean seeds in kilograms that can fit into one hectoliter. The price that growers receive for their soybean is dependent on test weight. Over the past 50 years, growers have observed a decreasing trend in test weight. Therefore, it is imperative to understand better the relationship between soybean test weight and other traits to enable breeders to select parental lines with high test weights in breeding programs to ensure the grower's profitability. The objectives of the study were to identify genetic markers associated with high test weight in soybean and to determine the correlation between high test weight and five important seed composition traits (protein, oil, sucrose, raffinose, and stachyose content). Maturity group IV and V germplasms from the USDA soybean germplasm collection were grown in Blacksburg and Warsaw in Virginia from 2019 to 2021 and were measured for all of the above traits. Results show that test weight values ranged from 62-77 kg/hL over the three years. Multiple single-nucleotide polymorphisms (SNPs) significantly associated with high test weight were found on chromosome (Chr.) 15 along with a couple on chromosome 14, and 11 candidate genes were found near these SNPs. Test weight was found to be significantly negatively correlated with oil content, inconsistently correlated with protein content in all environments, and negatively correlated but not significantly with all three sugars except for raffinose in Blacksburg 2019. We concluded that the genes that underlie test weight might be on chromosome 15, and the validated associated SNPs might be used to assist breeding selection of test weight. Breeders should pay special attention to test weight while selecting for high oil content in soybean due to their negative correlation.

Development of new mutant alleles and markers for KTI1 and KTI3 via CRISPR/Cas9-mediated mutagenesis to reduce trypsin inhibitor content and activity in soybean seeds.

The digestibility of soybean meal can be severely impacted by trypsin inhibitor (TI), one of the most abundant anti-nutritional factors present in soybean seeds. TI can restrain the function of trypsin, a critical enzyme that breaks down proteins in the digestive tract. Soybean accessions with low TI content have been identified. However, it is challenging to breed the low TI trait into elite cultivars due to a lack of molecular markers associated with low TI traits. We identified Kunitz trypsin inhibitor 1 (KTI1, Gm01g095000) and KTI3 (Gm08g341500) as two seed-specific TI genes. Mutant kti1 and kti3 alleles carrying small deletions or insertions within the gene open reading frames were created in the soybean cultivar Glycine max cv. Williams 82 (WM82) using the CRISPR/Cas9-mediated genome editing approach. The KTI content and TI activity both remarkably reduced in kti1/3 mutants compared to the WM82 seeds. There was no significant difference in terms of plant growth or maturity days of kti1/3 transgenic and WM82 plants in greenhouse condition. We further identified a T1 line, #5-26, that carried double homozygous kti1/3 mutant alleles, but not the Cas9 transgene. Based on the sequences of kti1/3 mutant alleles in #5-26, we developed markers to co-select for these mutant alleles by using a gel-electrophoresis-free method. The kti1/3 mutant soybean line and associated selection markers will assist in accelerating the introduction of low TI trait into elite soybean cultivars in the future.

La evaluación formativa: aportes para pensar la universidad latinoamericana desde un caso uruguayo / Formative evaluation: contributions to think the latin american university from an uruguayan case / Avaliação formativa: contribuições para pensar a universidade latino-americana desde um caso uruguaio

El presente artículo surgió de una investigación realizada en 2017-2018, que centró su interés en indagar sobre las prácticas de evaluación en las unidades curriculares de la Licenciatura en Educación Física del Instituto Superior de Educación Física. Nos ocupamos de saber: tipos, fondos y formas empleadas, intentando establecer su relación con el contexto universitario y sus funciones (enseñanza, investigación y extensión). Empleó una metodología de corte mixta, aunque con énfasis cualitativo. Entre los procedimientos de rastreo y búsqueda de información, se recurrió a análisis de documentos, cuestionarios on-line y entrevistas. A pesar de las variadas formas en que se pone en marcha la evaluación, concluimos que los fondos de esta, en el ámbito universitario, remiten en cuestiones epistemológicas asociadas a la reproducción o producción del conocimiento.

This article arose from an investigation carried out in 2017-2018 that focused its interest in the evaluation practices in the curricular units of the degree in Physical Education of the Instituto Superior de Educación Física. We focus on types, funds, and forms used, trying to establish their relationship with the university context and its institutional functions (teaching, research, and extension). A mixed methodology was used, although with an emphasis on qualitative methods. Among the procedures for tracking and searching for information, document analysis, online questionnaires, and interviews were used. In spite of the varied ways in which the evaluation is applied, we conclude that its funds in the university field refer to epistemological issues associated with the reproduction or production of knowledge.

Este artigo corresponde a uma pesquisa realizada em 2017-2018, que focalizou seu interesse em investigar as práticas de avaliação nas unidades curriculares do curso de Licenciatura em Educação Física do Instituto Superior de Educación Física. Dedicamo-nos a identificar: tipos, fundos e formas utilizadas, no intuito de estabelecer sua relação com o contexto universitário e suas funções (ensino, pesquisa e extensão). Empregou-se uma metodologia de corte misto, embora com ênfase qualitativa. Entre os procedimentos de levantamento de fontes foram utilizados: a análise de documentos, os questionários on-line e as entrevistas. Apesar das variadas formas em que é desenvolvida a avaliação, concluímos que seus recursos no campo universitário se referem a questões epistemológicas associadas à reprodução ou produção de conhecimento.