Soybean Cultivars Research Articles

Effects of different observed datasets on the calibration of crop model parameters with GLUE: A case study using the CROPGRO-Soybean phenological model.

Suitable combinations of observed datasets for estimating crop model parameters can reduce the computational cost while ensuring accuracy. This study aims to explore the quantitative influence of different combinations of the observed phenological stages on estimation of cultivar-specific parameters (CPSs). We used the CROPGRO-Soybean phenological model (CSPM) as a case study in combination with the Generalized Likelihood Uncertainty Estimation (GLUE) method. Different combinations of four observed phenological stages, including initial flowering, initial pod, initial grain, and initial maturity stages for five soybean cultivars from Exp. 1 and Exp. 3 described in Table 2 are respectively used to calibrate the CSPs. The CSPM, driven by the optimized CSPs, is then evaluated against two independent phenological datasets from Exp. 2 and Exp. 4 described in Table 2. Root means square error (RMSE) (mean absolute error (MAE), coefficient of determination (R2), and Nash Sutcliffe model efficiency (NSE)) are 15.50 (14.63, 0.96, 0.42), 4.76 (3.92, 0.97, 0.95), 4.69 (3.72, 0.98, 0.95), 3.91 (3.40, 0.99, 0.96) and 12.54 (11.67, 0.95, 0.60), 5.07 (4.61, 0.98, 0.93), 4.97 (4.28, 0.97, 0.94), 4.58 (4.02, 0.98, 0.95) for using one, two, three, and four observed phenological stages in the CSPs estimation. The evaluation results suggest that RMSE and MAE decrease, and R2 and NSE increase with the increase in the number of observed phenological stages used for parameter calibration. However, there is no significant reduction in the RMSEs (MAEs, NSEs) using two, three, and four observed stages. Relatively reliable optimized CSPs for CSMP are obtained by using at least two observed phenological stages balancing calibration effect and computational cost. These findings provide new insight into parameter estimation of crop models.

Caracterização da Antixenose e antibiose em cultivares de soja a Anticarsia gemmatalis (Lepidoptera: Erebidae)

ABSTRACT: Anticarsia gemmatalis (Lepidoptera: Erebidae) is distributed in tropical and subtropical regions of America, and is an important pest of Fabaceae, such as: soybean, peanut, common bean, cowpea, pea, chickpea and kudzu. In soybean, the velvet bean caterpillar is important due to the plant defoliation in their larval stage. This study evaluated soybean cultivars as source of resistance to A. gemmatalis by antixenosis (attractiveness and non-preference for feeding) and antibiosis (biological parameters of the insect). The parameters evaluated were: antixenosis: attractiveness and non-preference, dry mass consumed and attractiveness index and antibiosis: duration of larval and pupal stages, adult longevity, total cycle, larval and pupal weights and larval, pupal and total viability. Considering antixenosis and antibiosis the least suitable cultivars for A. gemmatalis were found to be BRS 8383 IPRO, BRS 1074 IPRO, BRS 1061 IPRO, BRS 7180 IPRO, BRS 9383 IPRO, BRS 8980 IPRO and BRS 1003 IPRO due to high mortality in the larval phase. The cultivars BRS 523 and BRS 543 RR “block technology” suggest displays antixenosis and or antibiosis to A. gemmatalis. These cultivars can be used by soybean producers in combination with other control tactics in soybean IPM.

Effect of Soybean Cultivars on the Nutrients and Consumer Acceptance of Soymilk

Effect of Soybean Cultivars on the Nutrients and Consumer Acceptance of Soymilk

Autocorrelação espacial de populações de plantas de soja e atributos físicos de um Latossolo

ABSTRACT Among the necessary phytotechnical adjustments, the correct recommendation of the plant population of each soybean cultivar is of paramount importance for success in crop production. Thus, the objective of this study was to analyze the distribution and spatial autocorrelation of the soybean plant population according to the spatial variability of the physical and chemical attributes of Oxisol in the Brazilian Cerrado region. The attributes studied were plant population, soybean grain yield, apparent soil electrical conductivity, soil organic matter content, cation exchange capacity, hydrogenionic potential, and clay content in the soil. The plant population varied inversely as a function of apparent soil electrical conductivity. The areas with the highest values of apparent soil electrical conductivity, soil organic matter content, cation exchange capacity, and clay content had the lowest plant populations. Soybean yield was not influenced by increase or decrease in the plant population. Thus, it is economically viable to plant with lower plant density to improve the farmer’s profit margin.

Characterization of QoI-Fungicide Resistance in Cercospora Isolates Associated with Cercospora Leaf Blight of Soybean from the Southern United States.

Cercospora leaf blight (CLB) of soybean, caused by Cercospora cf. flagellaris, C. kikuchii, and C. cf. sigesbeckiae, is an economically important disease in the southern United States. Cultivar resistance to CLB is inconsistent; therefore, fungicides in the quinone outside inhibitor (QoI) class have been relied on to manage the disease. Approximately 620 isolates from plants exhibiting CLB were collected between 2018 and 2021 from 19 locations in eight southern states. A novel polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay based on two genes, calmodulin and histone h3, was developed to differentiate between the dominant species of Cercospora, C. cf. flagellaris, and C. cf. sigesbeckiae. A multilocus phylogenetic analysis of actin, calmodulin, histone h3, ITS rDNA, and transcription elongation factor 1-α was used to confirm PCR-RFLP results and identify remaining isolates. Approximately 80% of the isolates collected were identified as C. cf. flagellaris, while 15% classified as C. cf. sigesbeckiae, 2% as C. kikuchii, and 3% as previously unreported Cercospora species associated with CLB in the United States. PCR-RFLP of cytochrome b (cytb) identified QoI-resistance conferred by the G143A substitution. Approximately 64 to 83% of isolates were determined to be QoI-resistant, and all contained the G143A substitution. Results of discriminatory dose assays using azoxystrobin (1 ppm) were 100% consistent with PCR-RFLP results. To our knowledge, this constitutes the first report of QoI resistance in CLB pathogen populations from Alabama, Arkansas, Kentucky, Mississippi, Missouri, Tennessee, and Texas. In areas where high frequencies of resistance have been identified, QoI fungicides should be avoided, and fungicide products with alternative modes-of-action should be utilized in the absence of CLB-resistant soybean cultivars.

Transcriptome and Metabolome Jointly Revealed the Regulation and Pathway of Flower and Pod Abscission Caused by Shading in Soybean (Glycine max L.)

Flowers and pod abscission significantly reduces soybean yield. This study aims to identify the main signaling pathways and key candidate genes in soybean leaves that affect flower and pod abscission under shade conditions. This information will be useful for the localization and cloning of genes related to abscission. Two soybean cultivars with different abscission rates (Liaodou 32 and Shennongdou 28) were used in this experiment. The soybean leaves were subjected to 50% shading treatment and the transcriptome and metabolome was sequenced during the light-sensitive period. The effects of weak light at different growth stages on the metabolic pathways of soybean leaves and organ abscission were investigated by analyzing plant phenotype and physiological changes. The results showed that both two cultivars triggered the same molecular mechanism and similar metabolite accumulation mode by shading, but the regulations of the two cultivars were different. The key candidate genes identified for soybean flower and pod abscission caused by shading were DIV, MYB06, MYB44, MY1R1, MYBS3, WRKY6, WRK53, WRK70, WRK40, DOF14, CDF3, CDF2, GATA5, DREB3 and ERF3; the differentially expressed genes that caused the variation between the cultivars were SRM1, MYB16, WRK24, COL16, MYB61 and TRB1. The main metabolic pathways involved in soybean flower and pod abscission caused by shading were secondary metabolite biosynthesis pathway, metabolic pathway, cofactor biosynthesis pathway, phenylpropanoid biosynthesis pathway, flavonoid biosynthesis pathway, fatty acid biosynthesis pathway and amino acid biosynthesis pathway; the DEMs that caused the differences among the cultivars were carbon metabolism, glutathione metabolism, biotin metabolism, nucleotide metabolism, purine metabolism, plant hormone signaling, flavone and flavonol biosynthesis, lysine degradation, arginine and proline metabolism, amino sugars and nucleotide sugars metabolism, etc. In conclusion, shading treatment in the light-sensitive period of soybean changed the physiological response and gene expression level of leaves, inhibited carbohydrate metabolism and transport and biosynthesis of secondary metabolites, and thereby leading to increased competition and hormonal disruption, which promoted the abscission of soybean flowers/pods and reduced grain yield.

Effects of Different Harvest Stages on Forage Yield and Quality of Soybean Cultivars Grown as Second Crops

In this study, the effect of three different harvesting stages [full bloom stage (R2), full pod stage (R4), and full seed stage (R6)] on forage yield and quality of three soybean (Glycine max (L.) Merr.) cultivars (Adasoy, Derry and Yeşilsoy) were evaluated under Mediterranean climate conditions in Adana, Türkiye in second crop seasons. Plant height, green herbage yield, dry matter yield, crude protein (CP), crude protein yield (CPY), leaf and stem ratio, dry matter intake (DMI), acid detergent fiber (ADF), neutral detergent fiber (NDF), digestible dry matter (DDM) and relative feed value (RFV) were determined. The results showed that the average plant height of three soybean cultivars was 106.5-203.5 cm and green herbage yield was 190 42-603 50 kg ha-1. The highest values were obtained from cv. Derry at R4 and R6 harvest stages. In both years, the highest CPY values were determined from the R6 harvest stages. Obtained ADF, NDF, DMI, DDM, and RFV values were found to be between 32.8-47.1%, 41.1-59.3%, 2.0-3.6%, 52.1-63.3%, 83.0-180.2%, respectively, and the best results were obtained from the R6 harvest stage of cv. Yeşilsoy. According to these results, in second crop conditions, while cv. Derry came to the fore of soybean yield, cv. Yeşilsoy stands out in terms of quality. As a result, it is thought that it is appropriate to harvest soybean in the R6 harvest period, the use of soybean as a green herbage should be expanded and its addition to feed rations can provide positive contributions.

Evaluation of foliar fungicides for frogeye leaf spot control and yield protection in soybean in Arkansas

The efficacy of fifteen foliar fungicides to control frogeye leaf spot (caused by Cercospora sojina K. Hara) and protect soybean grain yield was investigated over three years (2014–2016) in two field experiments. Experiments were divided into two fungicide groups: premix fungicides, which included combinations of quinone outside inhibitors (QoI), demethylation inhibitors (DMI), succinate dehydrogenase inhibitors (SDHI), or methyl benzimidazole carbamates (MBC), and solo fungicides, all DMI fungicides. Fungicides were applied once at the full pod (R4) in 2014 and 2015 and at the beginning seed (R5) growth stage in 2016. A very susceptible frogeye leaf spot cultivar, Armor 48R40, was used. Frogeye leaf spot severity at fungicide application timing average 1.0, 0.5, and 8.0% in 2014, 2015, and 2016, respectively. Final disease severity averaged 21.7, 14.5, and 15.1% in 2014, 2015, and 2016, respectively on the non-treated control. Azoxystrobin provided no disease control, suggesting the presence of QoI-resistant C. sojina. Three fungicides: azoxystrobin + difenoconazole, flutriafol, and thiophanate-methyl + tebuconazole applied at R4 provided effective disease control compared to the non-treated control. Fungicides applied at R5 provided no disease control. No fungicide provided significant grain yield protection in either experiment. Overall, the average yield protection trend by fungicides applied at R4 and R5 was 6.8 and 3.0%, respectively compared to the non-treated control. These data suggest that although foliar fungicides can provide effective frogeye leaf spot control, yield protection may be limited when applied at the R4 growth stage, particularly when disease severity exceeds 0.5% on a very susceptible soybean cultivar.

PHYSIOLOGICAL AND BIOCHEMICAL PROPERTIES OF SOYBEAN CULTIVARS INFECTED WITH PHYTOPATHOGENIC FUNGI

An investigation on soybean (Glycine max L.) commenced at the experimental field of the Institute of Genetics and Plant Experimental Biology, Academy of Sciences, Republic of Uzbekistan. The purposive study aimed to determine the effects of Fusarium solani phytopathogenic micromycetes on the physiological and biochemical composition of five soybean cultivars, viz., Sochilmas, Genetic-1, Nafis, Tomaris, and Baraka. The results revealed in the budding and flowering stages, the soybean cultivar leaves infected with F. solani showed decreased amounts of chlorophyll a and b compared with the healthy plants (control). In the control comparison against the soybean variants with phytopathogenic micromycetes, some soybean cultivars showed enhanced contents of carotenoids in the leaves, and others revealed a decline in carotenoids to varying degrees. The peroxidase enzyme activity was higher in soybean cultivars Tomaris and Nafis artificially infected with F. solani than the other cultivars. It was evident that the peroxidase enzyme activity under the influence of F. solani in the leaves of studied soybean cultivars increased by 20.76%, 43.6%, and 35.4%, respectively, in Baraka, Tomaris and Nafis cultivars. Results further indicated that under the influence and stressful conditions of F. solani, the activity of the polyphenol oxidase enzyme enhanced by 84.1% and 117.1%, respectively, in soybean cultivars Tomaris and Nafis. The phenylalanine-ammonia-lyase enzyme activity was also higher in the said cultivars with F. solani infection compared with the control. The earlier situation confirmed that the soybean plant leaves’ physiological and biochemical parameters are closely associated with the phytopathogenic micromycetes

Общее содержание и фракционный состав белка в семенах сортов сои селекции ФГБНУ ФНЦ ВНИИМК

The use of high-protein soybean cultivars is one of the most important reserves for solving the problem of protein deficiency in the production of feed and food products. In recent years, soybean cultivars with high productivity potential and improved biochemical composition of seeds have been developed in the V.S. Pustovoit All-Russian Research Institute of Oil Crops. The cultivars approved for usage in various regions of the Russian Federation were assessed by the total protein content in seeds and its fractional composition as the main biochemical characteristics of raw materials. The cultivars with a high content of water-soluble (albumin) and stable indicators of salt- and alkali-soluble (globulins and glutelins) fractions, respectively, were noted. It was established that the studied indicators depended not only on the genetic properties of the cultivars, but also on the characteristics of the conditions of the reproduction year. Thus, in soybean seeds of the 2021 harvest, the cultivars Iney (39.0%), Triada (39.9%) and Graya (42.0%) stood out with the highest protein content; in terms of albumin content in protein – Graya and Bars (91.8 and 92.0%, respectively). And in the seeds of the 2022 harvest, the maximum protein content was observed in the cultivars Puma (38.9%), Graya (39.4%) and Gnom (40.2%), albumin content – Barguzin (92.7%), Bars (94.5%) and Puma (95.1%). A weakly positive correlation was noted between the total protein content and the proportion of the water-soluble fraction in it (r = +0.33).

Биохимический состав семян сортов сои, возделываемых в различных регионах России, и аспекты его биологической ценности (обзор)

This work presents a review of the main biochemical traits of soybean seeds. The dependence of the protein content, oil and amino acid composition on a growing season and weather and climatic conditions has been noted. The influence of a negative correlation between protein and oil content as well as chang-ing of trypsin-inhibiting activity (TIA) in most soybean cultivars of both modern and earlier breeding produced in different regions of the Russian Federation is emphasized. Data on the main protein fractions in soybean seeds, their ratio depending on varietal and genotypic features are presented. The polymorphism of the fractional profile of soybeans and the possibility of breeding for specific fractions are noted. The prospects of breeding of new highly productive cultivars with specified properties and further breeding for the oil/protein trait are considered.

Новыe перспективныe образцы сои

During the period of the 60-year breeding in the “Omsk Agrarian Scientific Center” (earlier SibNIISh), a unique Siberian soybean gene pool was created, more than 15 varieties were included into the State Register of the Russian Federation. However, breeding science does not stand still; it develops in accordance with the needs of the present day. The purpose of the research was to characterize the new promising samples of soybeans. There are presented data of the research of 2019–2021. The weather conditions of the growing season from May to September were contrasting. So, 2019 was characterized as medium-dry (hydrothermal coefficient = 0.99) and severe drought was noted in 2020 and 2021 (hydrothermal coefficient = 0.58 and 0.55, respectively). The adaptability of cultivars in productivity and quality indicators (mass fraction of protein and raw fat) is calculated. The weather conditions of the year and the genotype of the cultivar had an equal influence on the formation of the mass fraction of the protein (49.43 and 47.44%, respectively), on raw fat – the conditions of the year (86.85%) only. The increased protein and oil contents (39.85 and 20.01%, respectively) was noted in 2019, the greatest productivity (2.96 t/ha) – in 2020. The soybean cultivar Sibiryachka was the standard, it has been included into the State Register of the Russian Federation since 2013. For further breeding work, lines L 53/14 and L 217/18 are recommended, they are characterized by a high contents of protein grain (+1.04 and +0.98% to st.) and raw fat (+0.88 and +1.92% to st), as well as yield increase (0.29 and 0.42 t/ha to st.). In addition, these lines are plastic and stable (Regression coefficient > 1 and the degree of stability of responses to cultivation conditions < 1): L 53/14 in oil content and yield, L 217/18 – in protein and yield.

Soil compaction development facilitated the decadal improvement of the root system architecture and rhizosheath soil traits of soybean in the North China Plain

Machinery agriculture has increased crop yield but induced soil compaction worldwide in the last decades. The crop yield increase is partly attributed to high-yielding crop breeding, but the effects of emerging soil compaction on the selection of root system traits and its impact on yield increase remain unclear. The objectives of this study were 1) to identify the effects of soil compaction on grain yield and root system architecture and rhizosheath soil traits of soybean (Glycine max (L.) Merr.) at the full-bloom stage, 2) to understand whether and how the development of soil compaction affected the selection of merit root and rhizosheath soil traits through crop breeding and contributed to soybean grain yield increase. Thirty-four most popular soybean cultivars released before and after the wide use of agricultural machinery in the North China Plain were grown in the fields without (NOM) and with (COM) applied soil compaction in 2017 and 2018. The phenotypes of root system, including rhizosheath soil, of soybean, were separated by soil compaction and cultivar release period, confirming the development of soil compaction and its impacts on the co-development of rhizosheaths with the root system of soybean. The correlation with the year of release of the cultivar demonstrated that 21 out of the 24 measured traits were selected by crop breeding. Multivariate analysis of the variance demonstrated that the selection of thinner hypocotyl, more root tips, and denser rhizosheath soil were relevant to the soil compaction development. The selection of shorter plant height, larger root biomass and area, thinner root tip, thicker taproot, and rhizosheath soil mass were likely relevant to the experimental year factor caused by drought or its associated change in nutrient availability. Most of the selected traits increased the resistance or the resilience to soil compaction and nine of them correlated with the grain yield of cultivars released at different periods. These results for the first time suggested that crop breeding increased grain yield partly by increasing the resistance and resilience to soil compaction. Soil compaction could be considered in a future breeding program design to increase crop breeding efficiency by selecting resistant and resilient root traits.

Устойчивый к полеганию, крупносемянный сорт сои Рысь

Resistant to lodging, large-seeded mid-early maturing soybean cultivar Rys’ was obtained as a result of individual selection in F4 from the hybrid combination Slavia × Shama SRP on differentiating back-grounds based on the characteristics of semi-determinant stem growth, large seeds, reduced response to day length, cold and frost resistance. Based on the results of variety testing 2019–2022, the soybean cultivar Rys’ exceeded the standard cultivar Vilana by 0.54 t/ha by yield. The height of plants at the latitude of Krasnodar (45°) is 90–109 cm. In optimal moisture conditions, the weight of 1000 seeds of this cultivar is 165–207 g. The new high-yielding soybean cultivar Rys’ is highly resistant to low air and soil temperatures, and also reacts poorly to nonoptimal day lengths. This allows it to be cultivated in soybean-producing farms in the North Caucasus and Lower Volga regions of the Russian Federation, as well as in the republics of Central Asia and Transcaucasia at latitudes from 40 to 50°.

Очень высокорослый среднеспелый сорт сои Мамонт

A very tall, middle maturing soybean cultivar Mamont, with traits of gigantism, was obtained as a result of individual selection in F4 from the hybrid combination Vilana × Pin GD for the characteristics of tall growth (> 160 cm) of the stem, large seeds, mid-ripening and non-lodging ability. Based on the results of variety testing 2020–2022, the soybean cultivar Mamont exceeded the standard cultivar Vilana by 0.18 t/ha by yield. The height of plants at the latitude of Krasnodar (45°) is 152–174 cm. In optimal cultivation conditions for moisture supply, the weight of 1000 seeds of this cultivar is 165–195 g. The phenomenon of the gigantism in plants of the Mamont cultivar in optimal growing conditions is confirmed to be 48 % more intense daily increase in plant height, and a 71% more intense daily increase in aboveground biomass compared to these indicators for the standard cultivar Vilana. The new very tall middle maturing soybean cultivar Mamont, with traits of gigantism, is distinguished by increased responsiveness to additional moisture by increasing the traits of plant height to ultra-high, increasing the number of nodes, beans and seeds, seed size and weight, and yield. It has increased resistance of tall plants to tilting and lodging due to excessive moisture due to the increased mechanical strength of the stem. Due to its tall growth and high positive response to additional moisture supply, it is suitable for cultivation in the southern foothill and central zones of the Krasnodar region and on irrigated plot throughout the North Caucasus and Lower Volga regions of the Russian Federation.

DETERMINING OIL AND FATTY ACID PROFILES OF SELECTED SOYBEAN (Glycine max L.) CULTIVARS UNDER SECOND CROP CONDITION IN EAST MEDITERRANEAN AGROECOLOGY

The objective of this study was to analyse the oil contents and composition of fatty acids (linolenic, stearic, oleic,
 palmitic and linoleic acids) of 20 distinct soybean (Glycine max L. Merrill) cultivars cultivated as the second crop
 in Cukurova Delta in the Mediterranean region of Turkey. Soybean cultivars Ilksoy, Traksoy maturity group
 II (MG: II), Atakisi, Arisoy, Cinsoy, Atem-7, Sa 88, Altinay, Asya, Bravo, Gapsoy, Kocaturk, Mitchell, Samsoy,
 Kristal, Umut-2002 (MG: III), Adasoy, ANP 2018, Nazlican, Lider (MG:3.8) were used. Field tests of this study
 were carried out in a randomized complete block design with three replications at the Eastern Mediterranean
 Agricultural Research Institute's Dogankent-Adana location in 2020-2021. Years, genotypes, and year x
 genotype interactions were all determined as significant in the variance analysis of the experiment's data. The
 fatty acid content of soybean cultivars varied between 10.00 and 12.64% for palmitic acid, 4.15 and 5.17% for
 stearic acid, 25.75 and 33.90% for oleic acid, 43.22 and 51.59% for linoleic acid, and 4.85 and 5.98% for linolenic
 acid, according to a 2-years average. Soybean cultivars' oil content ranged from 23.12 to 24.78 percent.

Boron Fertilization Improves the Agronomic Performance of Soybean Genotypes in the Brazilian Cerrado

Currently, Brazil is the largest producer and exporter of soybeans in the world. Most of this cultivation is concentrated in the Cerrado region, which has soils with low boron levels. Boron performs functions that are directly linked to plant performance. The objective of this study was to evaluate the agronomic performance of soybean cultivars with and without boron fertilization. Two field experiments were carried out in the agricultural years 2018/2019 and 2019/2020. Each experiment was carried out in a randomized block design with four replications and 10 soybean cultivars (Desafio, Foco, Bonus, Maracaí, 7067, 7110, 7739, 8372, 7100, and Population). Boron fertilization was carried out at the V3 stage of the crop using ulexite (10% of boron) at a rate of 3194 kg ha−1 and 0.0 kg ha−1 of B. The application of boron to the soil increased plant height, pod insertion height, number of branches, main stem diameter, and number of pods per plant, in addition to increasing the cycle of these cultivars. The cultivars 7110, 7739 and Desafio did not statistically differ in terms of grain yield in response to boron fertilization. The cultivars Foco, Bonus, Maracaí, 7067, 8372, 7100, and Population responded favorably to this fertilization. Furthermore, genetic breeding programs incorporate advanced strategies, such as the use of boron fertilization, in order to improve the performance of the selected genotypes. Implementing boron fertilization as an integral part of breeding programs helps not only to achieve high-yielding cultivars but also to optimize key agronomic traits. This integrated approach not only boosts breeding research but also provides a solid basis for sustainable and efficient agricultural practices.

Introgression of a Danbaekkong high-protein allele across different genetic backgrounds in soybean.

Soybean meal is a major component of livestock feed due to its high content and quality of protein. Understanding the genetic control of protein is essential to develop new cultivars with improved meal protein. Previously, a genomic region on chromosome 20 significantly associated with elevated protein content was identified in the cultivar Danbaekkong. The present research aimed to introgress the Danbaekkong high-protein allele into elite lines with different genetic backgrounds by developing and deploying robust DNA markers. A multiparent population consisting of 10 F5-derived populations with a total of 1,115 recombinant inbred lines (RILs) was developed using "Benning HP" as the donor parent of the Danbaekkong high-protein allele. A new functional marker targeting the 321-bp insertion in the gene Glyma.20g085100 was developed and used to track the Danbaekkong high-protein allele across the different populations and enable assessment of its effect and stability. Across all populations, the high-protein allele consistently increased the content, with an increase of 3.3% in seed protein. A total of 103 RILs were selected from the multiparent population for yield testing in five environments to assess the impact of the high-protein allele on yield and to enable the selection of new breeding lines with high protein and high yield. The results indicated that the high-protein allele impacts yield negatively in general; however, it is possible to select high-yielding lines with high protein content. An analysis of inheritance of the Chr 20 high-protein allele in Danbaekkong indicated that it originated from a Glycine soja line (PI 163453) and is the same as other G. soja lines studied. A survey of the distribution of the allele across 79 G. soja accessions and 35 Glycine max ancestors of North American soybean cultivars showed that the high-protein allele is present in all G. soja lines evaluated but not in any of the 35 North American soybean ancestors. These results demonstrate that G. soja accessions are a valuable source of favorable alleles for improvement of protein composition.

CROPGRO-soybean model – Validation and application for the southern Amazon, Brazil

Agricultural models are useful tools for predicting phenology, biomass, and crop yield under different environmental conditions during the growth period. Notwithstanding their use in the Southern Cone of Rondônia (southern Amazon, Brazil) is still limited. Thus, the objective in this work was to calibrate and validate the CROPGRO-Soybean model with soybean data collected in harvests of 2017 to 2019, being the data from the first growing period devoted to model calibration, and crop data from 2018/2019 to model validation. Six soybean cultivars were planted at the municipality of Vilhena, State of Rondônia, Brazil. The model was parameterized using climatic, hydric and physical soil properties, and growth data of the evaluated soybean cultivars. To evaluate the accuracy of model prediction we used the coefficient of determination (r2), percentage difference (Pd), root mean square error (RMSE), and Willmott’s index of agreement (d-value). The model accurately simulates the vegetative and reproductive stages, and the yields of the soybean cultivars under the climatic conditions of the Southern Cone of Rondônia. However, the CROPGRO-Soybean model tended to overestimate soil moisture content especially in upper soil layer (0.0–0.1 m depth). Taking the observed data, as the baseline, the model predicted the time to flowering, first pod, seeding, and physiological maturity, with a discrepancy of just one to seven days. In most of the soybean cultivars (five of the six cultivar evaluated), the differences between observed and simulated yields (growing cycle of 2018/2019 – validation harvest) ranged from –6 % to (underestimation) to 27 % (overestimation).

The GmCYP2-GmHAL3 module regulates salt tolerance in soybean seedlings

Soybean (Glycine max L. Merr) production is severely affected by soil salinization as an important crop. The discovery of salt stress-responsive genes is essential for soybean breeding. To our knowledge, cyclophilins (CYPs) play important roles in salt stresses in crops such as rice and cotton, except in soybean. This study cloned GmCYP2 from soybean salt-tolerant cultivar Suxie No. 1 and obtained ten stable transgenic soybean lines overexpressing GmCYP2 by Agrobacterium rhizogenes-mediated transformation. Two of the higher-expressing transgenic lines (OE1 and OE2) were used to compare salt tolerance with the wild type (WT). Under the salt stress, the chlorophyll content, the maximum efficiency of PSII photochemistry (Fv/Fm) and actual photochemical quantum yield [Y(II)] of OE1 and OE2 lines were significantly higher than those of the WT. Meanwhile, the accumulation of malondialdehyde (MDA) in the OE1 and OE2 lines was significantly lower than that in the WT. In addition, the Na+/K+ ratio was also significantly lower than that of the WT in leaves and roots. The results also confirmed that the salt tolerance of GmCYP2-silencing soybean seedlings obtained by virus-induced gene silencing (VIGS) was reduced compared to the control. Subcellular localization showed that GmCYP2 was expressed in the plasma membrane and nucleus of Nicotiana benthamiana. RNA-seq results demonstrated that GmCYP2 is involved in key regulators of the ABA and Ca2+ signaling pathway. Yeast two-hybrid, bimolecular fluorescence complementation (BiFC) and split-luciferase complementation assay demonstrated that GmCYP2 protein interacts with salt-associated halotolerance 3 (HAL3) protein. These results suggest that the GmCYP2-GmHAL3 module enhances salt tolerance of soybean seedlings by maintaining the Na+/K+ ratio and good photosynthetic state and it may be involved in the ABA and Ca2+ signaling pathway.