Hybrid Soybean Research Articles

MS2/GmAMS1 encodes a bHLH transcription factor important for tapetum degeneration in soybean.

GmAMS1 is the only functional AMS and works with GmTDF1-1 and GmMS3 to orchestrate the tapetum degeneration in soybean. Heterosis could significantly increase the production of major crops as well as soybean [Glycine max (L.) Merr.]. Stable male-sterile/female-fertile mutants including ms2 are useful resources to apply in soybean hybrid production. Here, we identified the detailed mutated sites of two classic mutants ms2 (Eldorado) and ms2 (Ames) in MS2/GmAMS1 via the high-throughput sequencing method. Subsequently, we verified that GmAMS1, a bHLH transcription factor, is the only functional AMS member in soybean through the complementary experiment in Arabidopsis; and elucidated the dysfunction of its homolog GmAMS2 is caused by the premature stop codon in the gene's coding sequence. Further qRT-PCR analysis and protein-protein interaction assays indicated GmAMS1 is required for expressing downstream members in the putative DYT1-TDF1-AMS-MYB80/MYB103/MS188-MS1 cascade module, and might regulate the upstream members in a feedback mechanism. GmAMS1 could interact with GmTDF1-1 and GmMS3 via different region, which contributes to dissect the mechanism in the tapetum degeneration process. Additionally, as a core member in the conserved cascade module controlling the tapetum development and degeneration, AMS is conservatively present in all land plant lineages, implying that AMS-mediated signaling pathway has been established before land plants diverged, which provides further insight into the tapetal evolution.

Inheritance of quantitative traits and the effect of heterosis in first-generation soybean hybrids

Inheritance of quantitative traits and the effect of heterosis in first-generation soybean hybrids

Analysis of intervarietal soybean hybrids at the initial breeding stages

The results of the study of recombinant soybean hybrids in terms of the degree of heterosis effect, phenotypic dominance and transgressive variability in economically valuable traits with the subsequent selection of the most promising hybrid combinations are presented. The study was conducted from 2018 to 2022 in the laboratory of soybean breeding in the conditions of the steppe zone of the Primorsky Territory. Of the ten hybrid combinations obtained, the maximum effect of heterosis in the first generation was observed in the combinations Primorskaya 1385 × Kofu, Primorskaya 1385 × Dong nong 690, Hei He 38 × Taifun. Phenotypic overdominance of inheritance of indicators (from 1.6 to 76.7) was recorded in all hybrids. Transgressive variability of intervarietal soybean hybrids in the second and third generations varied by combination and generation. High values of the degree of transgression in the third generation were observed in the combinations Primorskaya 1385 × Kofu and Hei He 38 × Talppod-Fisk, in terms of the number of seeds per plant – Primorskaya 1385 × Taifun and Kofu × Taifun, in terms of seed weight per plant – Dong nong 690 × Taifun and Hei He 38 × Taifun. A decrease in the frequency of transgression of hybrids by the third generation was found. The highest values of the degree and frequency of transgression in plant height were observed in the hybrid combinations Hei He 38 × Taifun and Hei He 38 × Talppod-Fisk. Based on the results of the study of the promising soybean genotypes, recombinant hybrids with high productivity and 1000-seed weight in the combinations Kyoto × Dong nong 690 and Monsoon × Taifun were isolated. The hybrids tested had different ripeness groups. Not always the manifestation of high effect of heterosis and transgressive variability in the first – third generations serves as a guarantee of further obtaining samples with high economically valuable indicators.

Seed coat colour and structure are related to the seed dormancy and overwintering ability of crop-to-wild hybrid soybean

Abstract The possible persistence of genetically modified (GM) crop-to-wild hybrid seeds in the soil seed bank is a major concern in risk assessment and is closely related to seed characteristics such as dormancy. In the present study, we generated F3 hybrids via crosses between GM soybean accessions and wild soybean and evaluated the dormancy, overwintering ability and inheritance of foreign genes in different-coloured hybrid seeds (yellow, green, brown and black). The results revealed that the 5-enolpyruvylshikimate-3-phosphate synthase transgene may have no influence on crop wild hybrid seed dormancy and overwintering ability, and the dormancy of the hybrid seeds was closely related to seed coat colour. F3 hybrid seeds with light colours (yellow and green) were relatively nondormant, while seeds that were dark (brown and black) in colour were relatively dormant. Moreover, the hybrid seeds that were dark in colour had a much stronger overwintering ability than the lighter-coloured seeds, with 21.33 % of the black seeds and 33.33 % of the brown seeds remaining viable after 240 days of soil burial. In contrast, almost all the F3 yellow and green seeds were no longer viable during winter. Scanning electron microscopy revealed that the lighter-coloured seeds had a thin palisade layer and very few surface deposits, while the darker-coloured seeds had a thicker palisade layer and a large area of honeycomb-like surface deposits similar to those of wild soybean seeds. Thus, the physical dormancy and overwintering ability of the darker-coloured seeds may be related to the seed coat. Our results suggest that transgenes of GM soybean might disperse into wild populations and persist in seed banks.

Evaluation of the Nutritional Quality of Different Soybean and Pea Varieties: Their Use in Balanced Diets for Different Pathologies

Among the cultivated plants of great interest at the planetary level, soy and pea can be highlighted. Soy represents a major source of protein and oil, with exceptional and widely accepted qualities in most cultures and religions. It is also a very good substitute for animal protein, having significant amounts of essential amino acids. Peas, although less cultivated than soybeans, contain large amounts of protein and carbohydrates, and they are also a source of food used in many diets due to their high nutritional content. The present study focuses on the nutrient composition analysis of five soybean varieties and four pea varieties grown in Romania for their use in food in the most efficient way. Protein dosage was carried out using Bradford and Kjeldahl methods, and the amino acids were dosed using gas chromatography. It was demonstrated that the analyzed varieties are rich in nutrients with different content depending on their type. Among the soybean hybrid varieties analyzed, the beans from the early Ovidiu F type and the semi-early Anduța F stood out for their increased content of lipids (23.28%) and proteins with increased biological value, and in the case of the pea beans, those from the Evelina F (22.21%) varieties of the Afila and Spectral F autumn types presented the highest content of proteins (21.06%) and essential amino acids (16.87%). All the obtained results offer a theoretical foundation for the advanced and balanced application of different varieties of soybean and pea bean in a balanced diet.

Natural variation of MS2 confers male fertility and drives hybrid breeding in soybean.

A complete and genetically stable male sterile line with high outcrossing rate is a prerequisite for the development of commercial hybrid soybean. It was reported in the last century that the soybean male sterile ms2 mutant has the highest record with seed set. Here we report the cloning and characterization of the MS2 gene in soybean, which encodes a protein that is specifically expressed in the anther. MS2 functions in the tapetum and microspore by directly regulating genes involved in the biosynthesis of secondary metabolites and the lipid metabolism, which is essential for the formation of microspore cell wall. Through comparison of the field performance with the widely used male sterile mutants in the same genetic background, we demonstrated that the ms2 mutant conducts the best in outcrossing rate and makes it an ideal tool in building a cost-effective hybrid system for soybean.

Marker-Assisted Selection for Early Maturing E Loci in Soybean Yielded Prospective Breeding Lines for High Latitudes of Northern Kazakhstan.

The photoperiodic sensitivity of soybean (Glycine max L.) is one of the limiting factors affecting plant growth and yield. At higher latitudes, early flowering and maturity with neutral reaction to photoperiods are required for adaptation of soybean plants to long-day conditions. Currently, the production and distribution of new varieties of soybeans adapted to widespread agricultural regions in northern Kazakhstan is in strong demand. Eleven soybean hybrid populations were obtained from crosses between 17 parents with four maturity groups, MG 000, 00, 0, and I. Marker-assisted selection (MAS) was assessed for suitable SSR markers and successfully applied for genes E1, E3, E4, and E7, targeting homozygous genotypes with recessive alleles. The identified and selected genotypes were propagated and tested in the conditions of 53° N latitude in the Kostanay region of northern Kazakhstan. Finally, 20 early maturing F4 breeding lines were identified and developed with genotypes e1 e3 E4 e7, e1 E3 E4 e7, and e1 E3 e4 e7, all completing their growth period within 92-102 days. These breeding lines were developed by MAS and should provide very prospective superior varieties of soybean for northern Kazakhstan through a strategy that may be very helpful to other countries with high latitudes.

Oyster-inspired carbon dots-functionalized silica and dialdehyde chitosan to fabricate a soy protein adhesive with high strength, mildew resistance, and long-term water resistance

Developing multifunctional adhesives with exceptional cold-pressing strength, water resistance, toughness, and mildew resistance remains challenging. Herein, inspired by oysters, a multifunctional organic-inorganic hybrid soybean meal (SM)-based adhesive was fabricated by incorporating amino-modified carbon dots functionalized silica nanoparticles (CDs@SiO2) and dialdehyde chitosan (DCS) into SM matrix. DCS effectively enhanced the interface interactions of organic-inorganic phases and the rigid nanofillers CDs@SiO2 uniformly dispersed in the SM matrix, which provided energy dissipation to improve the adhesive's toughness. Owing to the stiff skeleton structure and enhanced crosslinking density, the crosslinker-modified SM (MSM)/DCS/CDs@SiO2–2 wood adhesive exhibited outstanding cold-pressing strength (0.74 MPa), wet shear strength (1.36 MPa), and long-term water resistance (49 d). Additionally, the resultant adhesive showed superior antimildew and antibacterial properties benefiting from the introduction of DCS. Intriguingly, the fluorescent properties endowed by carbon dots further broadened the application of adhesives for realizing security testing. This study opens a new pathway for the synthesis of multifunctional biomass adhesives in industrial and household applications.

GmUFO1 Regulates Floral Organ Number and Shape in Soybean.

The UNUSUAL FLORAL ORGANS (UFO) gene is an essential regulatory factor of class B genes and plays a vital role in the process of inflorescence primordial and flower primordial development. The role of UFO genes in soybean was investigated to better understand the development of floral organs through gene cloning, expression analysis, and gene knockout. There are two copies of UFO genes in soybean and in situ hybridization, which have demonstrated similar expression patterns of the GmUFO1 and GmUFO2 genes in the flower primordium. The phenotypic observation of GmUFO1 knockout mutant lines (Gmufo1) showed an obvious alteration in the floral organ number and shape and mosaic organ formation. By contrast, GmUFO2 knockout mutant lines (Gmufo2) showed no obvious difference in the floral organs. However, the GmUFO1 and GmUFO2 double knockout lines (Gmufo1ufo2) showed more mosaic organs than the Gmufo1 lines, in addition to the alteration in the organ number and shape. Gene expression analysis also showed differences in the expression of major ABC function genes in the knockout lines. Based on the phenotypic and expression analysis, our results suggest the major role of GmUFO1 in the regulation of flower organ formation in soybeans and that GmUFO2 does not have any direct effect but might have an interaction role with GmUFO1 in the regulation of flower development. In conclusion, the present study identified UFO genes in soybean and improved our understanding of floral development, which could be useful for flower designs in hybrid soybean breeding.

Male sterility and hybrid breeding in soybean

Hybrid breeding can help us to meet the challenge of feeding a growing world population with limited agricultural land. The demand for soybean is expected to grow; however, the hybrid soybean is still in the process of commercialization even though considerable progress has been made in soybean genome and genetic studies in recent years. Here, we summarize recent advances in male sterility-based breeding programs and the current status of hybrid soybean breeding. A number of male-sterile lines with cytoplasmic male sterility (CMS), genic-controlled photoperiod/thermo-sensitive male sterility, and stable nuclear male sterility (GMS) have been identified in soybean. More than 40 hybrid soybean varieties have been bred using the CMS three-line hybrid system and the cultivation of hybrid soybean is still under way. The key to accelerating hybrid soybean breeding is to increase the out-crossing rate in an economical way. This review outlines current problems with the hybrid soybean breeding systems and explores the current efforts to make the hybrid soybean a commercial success.

A BREEDING STUDY TO DEVELOP EARLY MATURING SOYBEAN CROSSES SUITABLE FOR DOUBLE CROPPING

The present research was undertaken to evaluate of soybean hybrids environmental interaction and adaptability on Mediterranean region conditions. Seven advanced (F7) soybean lines selected from the Kunitz x SS-201 and Kunitz x Bert cross populations based on earliness and yield characteristics in the preliminary trials and three soybean varieties (Bravo, Nova and Arisoy) were tested in the trial in four replications in 2017 and 2018 in accordance with the RCBD. The analysis of variance revealed significant variations for all characters. According to results, the yield of lines and varieties 2017 and 2018 varied from 2.87-4,47 t ha-1 and 2.61-3.90 t ha-1 respectively and KS-39 advanced soybean line had the highest grain yield in terms of two years average. The number of flowering days varied between 32.50 days and 36.75 days according to the two-year averages, and the KS-12 genotype was the earliest flowering genotype. The lines KS-10 (103.38) and KS-12 (103.50) came to the fore as the genotypes with the earliest maturation days. With this study, it has been concluded that promising genotypes can be obtained in regions dominated by the Mediterranean climate zone (especially the Aegean coastline), and soybean cultivation can be done in double crop agriculture within the cropping system.

Identification of a Candidate restorer-of-fertility Gene Rf3 Encoding a Pentatricopeptide Repeat Protein for the Cytoplasmic Male Sterility in Soybean.

The cytoplasmic male sterility/restorer-of-fertility (CMS/Rf) system plays a vital role in high-efficiency hybrid seed production in crops, including soybean (Glycine max (L.) Merr.). The markers linked to fertility restoration and the restorer-of-fertility (Rf) genes are essential because they can facilitate the breeding of new CMS lines and production of commercial hybrid soybean seeds. To date, several soybean Rf genes have been mapped to various genetic loci in diverse genetic populations. However, the mapping range of restorer genes remains narrow, with relatively limited practical applicability. Therefore, in the present study, F2 and F3 segregating populations derived from the CMS line JLCMS5A crossed with the restorer line JLR2 were developed and used for Rf3 gene fine mapping. Genetic investigation indicated that the restorer line JLR2 was controlled by a single dominant gene, Rf3. By integrating bulk-segregant analysis and next-generation sequencing, a 4 Mb region on chromosome 9 was identified, which was most likely the target region harboring the candidate gene responsible for fertility restoration. This region was further narrowed down to 86.44 Kb via fine mapping in F2 and F3 populations using SSR, InDel, and dCAPS markers. This region contained 10 putative genes (Glyma.09G171100–Glyma.09G172000). Finally, Glyma.09G171200, which encodes a mitochondria-targeted pentatricopeptide repeat protein, was proposed as the potential candidate for Rf3 using sequence alignment and expression analysis in restorer and CMS lines. Based on single-nucleotide polymorphisms in Glyma.09G171200, a CAPS marker co-segregated with Rf3 named CAPS1712 was developed. Our results will be fundamental in the assisted selection and creation of potent lines for the production and rapid selection of novel restorer lines.

Heterosis and Differential DNA Methylation in Soybean Hybrids and Their Parental Lines.

Heterosis is an important biological phenomenon and is widely applied to increase agricultural productivity. However, the underlying molecular mechanisms of heterosis are still unclear. Here we constructed three combinations of reciprocal hybrids of soybean, and subsequently used MethylRAD-seq to detect CCGG and CCWGG (W = A or T) methylation in the whole genome of these hybrids and their parents at the middle development period of contemporary seed. We were able to prove that changes in DNA methylation patterns occurred in immature hybrid seeds and the parental variation was to some degree responsible for differential expression between the reciprocal hybrids. Non-additive differential methylation sites (DMSs) were also identified in large numbers in hybrids. Interestingly, most of these DMSs were hyper-methylated and were more concentrated in gene regions than the natural distribution of the methylated sites. Further analysis of the non-additive DMSs located in gene regions exhibited their participation in various biological processes, especially those related to transcriptional regulation and hormonal function. These results revealed DNA methylation reprogramming pattern in the hybrid soybean, which is associated with phenotypic variation and heterosis initiation.

Comprehensive assessment of promising soybean lines of the Northern ecotype for cultivation in a mixture with corn

The article presents the results of studies of promising soybean hybrids of the northern ecotype for cultivation in a mixture with corn and soy for green fodder and silage. Crops were evaluated according to the dynamics of plant growth, yield and productivity. As a result of the conducted research, it was found that the hybrid 3143-15-28 in the conditions of the Chuvash Republic has a sufficiently high productivity. The yield of green mass in singlespecies crops reaches more than 40 t/ha, which exceeds the standard variety twice.

Productivity inheritance of one plant in interspecific soybean hybrids

Productivity inheritance of one plant in interspecific soybean hybrids

Metabolomic Variability of Different Soybean Genotypes: β-Carotene-Enhanced (Glycine max), Wild (Glycine soja), and Hybrid (Glycine max × Glycine soja) Soybeans.

We obtained a new hybrid soybean (Hybrid) by hybridizing β-carotene-enhanced soybean (BCE; Glycine max L.) containing the phytoene synthase-2A-carotene desaturase gene and wild-type soybean (Wild; Glycine soja). To investigate metabolic changes between variants, we performed metabolic profiling of leaves (three growth stages) and seeds. Multivariate analyses revealed significant metabolic differences between genotypes in seeds and leaves, with seeds showing accumulation of phytosterols, tocopherols, and carotenoids (BCE only), indicating co-induction of the methylerythritol 4-phosphate and mevalonic acid pathways. Additionally, Hybrid produced intermediate levels of carotenoids and high levels of amino acids. Principal component analysis revealed metabolic discrimination between growth stages of soybean leaves and identified differences in leaf groups according to different genotypes at 8, 12, and 16 weeks, with Wild showing higher levels of environmental stress-related compounds relative to BCE and Hybrid leaves. The metabolic profiling approach could be a useful tool to identify metabolic links in various soybean cultivars.

MS1 is essential for male fertility by regulating the microsporocyte cell plate expansion in soybean.

Male sterility is an essential trait in hybrid seed production, especially for monoclinous and autogamous food crops. Soybean male-sterile ms1 mutant has been known for more than 50 years and could be instrumental in making hybrid seeds. However, the gene responsible for the male-sterile phenotype has remained unknown. Here, we report the map-based cloning and characterization of the MS1 gene in soybean. MS1 encodes a kinesin protein and localizes to the nucleus, where it is required for the male meiotic cytokinesis after telophase II. We further substantiated that MS1 colocalizes with microtubules and is essential for cell plate formation in soybean male gametogenesis through immunostaining. Both ms1 and CRISPR/Cas9 knockout mutants show complete male sterility but are otherwise phenotypically normal, making them perfect tools for producing hybrid seeds. The identification of MS1 has the practical potential for assembling the sterility system and speeding up hybrid soybean breeding.

Generation of male-sterile soybean lines with the CRISPR/Cas9 system

Soybean [Glycine max (L.) Merr.] provides a rich source of plant protein and oil worldwide. The commercial use of transgenic technology in soybean has become a classical example of the application of biotechnology to crop improvement. Although genetically modified soybeans have achieved commercial success, hybrid soybean breeding is also a potential way to increase soybean yield. Soybean cytoplasmic male-sterile (CMS) lines have been used in three-line hybrid breeding systems, but their application to exploiting soybean heterosis has been limited by rare germplasm resource of sterile lines. The generation of various genetic diversity male-sterile soybean lines will help to overcome the shortcoming. In this study, we used targeted editing of AMS homologs in soybean by CRISPR/Cas9 technology for the first time to generate stable male-sterile lines. Targeted editing of GmAMS1 resulted in a male-sterile phenotype, while editing of GmAMS2 failed to produce male-sterile lines. GmAMS1 functions not only in the formation of the pollen wall but also in the controlling the degradation of the soybean tapetum. CRISPR/Cas9 technology could be used to rapidly produce stable male-sterile lines, providing new sterile-line materials for soybean hybrid breeding systems.

MicroRNAs Involved in Regulatory Cytoplasmic Male Sterility by Analysis RNA-seq and Small RNA-seq in Soybean.

Cytoplasmic male sterility (CMS) is an important plant characteristic for exploiting heterosis to enhance crop traits during breeding. However, the CMS regulatory network remains unclear in plants, even though researchers have attempted to isolate genes associated with CMS. In this study, we performed high-throughput sequencing and degradome analyses to identify microRNAs (miRNAs) and their targets in a soybean CMS line (JLCMS9A) and its maintainer line (JLCMS9B). Additionally, the differentially expressed genes during reproductive development were identified using RNA-seq data. A total of 280 miRNAs matched soybean miRNA sequences in miRBase, including mature miRNAs and pre-miRNAs. Of the 280 miRNAs, 30, 23, and 21 belonged to the miR166, miR156, and miR171 families, respectively. Moreover, 410 novel low-abundant miRNAs were identified in the JLCMS9A and JLCMS9B flower buds. Furthermore, 303 and 462 target genes unique to JLCMS9A and JLCMS9B, respectively, as well as 782 common targets were predicted based on the degradome analysis. Target genes differentially expressed between the CMS line and the maintainer line were revealed by an RNA-seq analysis. Moreover, all target genes were annotated with diverse functions related to biological processes, cellular components, and molecular functions, including transcriptional regulation, the nucleus, meristem maintenance, meristem initiation, cell differentiation, auxin-activated signaling, plant ovule development, and anther development. Finally, a network was built based on the interactions. Analyses of the miRNA, degradome, and transcriptome datasets generated in this study provided a comprehensive overview of the reproductive development of a CMS soybean line. The data presented herein represent useful information for soybean hybrid breeding. Furthermore, the study results indicate that miRNAs might contribute to the soybean CMS regulatory network by modulating the expression of CMS-related genes. These findings lay the foundation for future studies on the molecular mechanisms underlying soybean CMS.

Comparative assessment of the work of photosystem II in the leaves of soybean varieties and hybrids

The efficiency of PS II of soybean leaves was shown depending on the genotype of the variety, the phase of plant growth and development, and the intensity of their illumination in the field. Purpose of the work: to study the intensity of photosynthetic processes in soybean leaves using a MINI-PAM fluorometer to isolate highly active ones. The object of research was early maturing and mid-maturing varieties, white-flowered soybean hybrids. The efficiency of PS II (Y) with a sequential increase in the illumination intensity was determined in the early ripening variety Sonata and the mid-ripening Oktyabr 70. The most stable efficiency of PS II was in the leaves of the varieties Sonata and Oktyabr 70 at an illumination degree of ≈ 800 to 1500 μmol quanta m-2 s-1. The Sonata cultivar had a higher potential in the restoration of the photochemical activity of PS II. The dependence of PS II activity on the phase of plant growth and development was revealed. A high level of effective quantum yield of PS II (0.84 … 0.86 rel. units) during the growing season was noted in the leaves of new soybean varieties Kruzhevnitsa, Evgeniya, Persona and Kitrossa. Plants of the white-flowered collection had the maximum parameters of the quantum yield of PS II during the period of formation of reproductive organs. The data obtained allowed us to recommend the varieties Sonata, Kruzhevnitsa, Evgeniya, Persona, and Kitrossa, as well as hybrids KB (5) and KB (26) for inclusion in the breeding process, as they have a high level of PS II work, when creating varieties with increased photosynthetic activity.