Molecular characterization and genetic diversity studies of Indian soybean (Glycine max (L.) Merr.) cultivars using SSR markers

Depicting Soybean Diversity via Complementary Application of Three Marker Types

Driven by the growing demands for plant-based protein in Europe and attempts of soybean breeding programs to improve the productivity of created varieties, this study aimed to enhance genetic resource utilization efficiency by providing information relevant to well-focused breeding targets. A set of 90 accessions was subjected to a comprehensive assessment of genetic diversity in a soybean working collection using three marker types: morphological descriptors, agronomic traits, and SSRs. Genotype grouping patterns varied among the markers, displaying the best congruence with pedigree data and maturity for SSRs and agronomic traits, respectively. The clear origin-related grouping pattern was not observed for any of the marker types. For the diversity assessed by morphological descriptors, Homogeneity Analysis by Means of Alternating Least Squares (HOMALS) yielded the most efficient classification by identifying the traits with the highest discriminative power and separating the genotypes into homogeneous groups. According to genetic distances (GDs), the highest diversity was found for morphological descriptors (GD = 517), followed by SSRs (GD = 0.317) and agronomic traits (GD = 0.244). The analysis of molecular variance (AMOVA) revealed a weak differentiation between geographic groups (ΦST = 0.061), emphasizing the highest differentiation for Canadian genotypes (ΦST = 0.148 **). A low correlation was found between molecular and morphological, i.e., agronomic trait-based matrices (0.061 *, i.e., -0.027, respectively). The overall assessed diversity highlighted the importance of introducing new sources of variation to promote long-term improvement in soybean breeding.

Development of Roselle (Hibiscus sabdariffa L.) Transcriptome-Based Simple Sequence Repeat Markers and Their Application in Roselle

Roselle (Hibiscus sabdariffa L.) simple sequence repeat (SSR) markers were developed using RNA sequencing technology, providing a foundation for genetic analysis and the identification of roselle varieties. In this study, 10 785 unigenes containing 12 994 SSR loci with an average of one SSR locus per 6.87 Kb were identified, and the occurrence frequency of the SSR loci was 11.36%. Trinucleotide repeat motifs were the most abundant, followed by dinucleotide repeats, with AAG/CTT and AT/AT being the predominant types, respectively. After screening 100 primer pairs with a polymorphic ratio of 32.0%, we obtained 32 primer pairs, resulting in clear and stable polymorphic bands. Twenty-seven primer pairs were highly or moderately polymorphic, and seven primer pairs were highly polymorphic. Genetic relationship analysis based on the selected SSR primers showed that 38 roselle accessions were classified into different clades, with those from the same regions clustered into the same subgroups. In contrast, individuals with unique morphological traits were separated. DNA fingerprints of 38 roselle varieties were constructed using five SSR primers, providing an effective method for identifying roselle varieties at a molecular level. Our data provide novel insights into the genetics of H. sabdariffa and may be used in SSR-assisted roselle breeding.

Identification of New Cultivar and Different Provenances of Dendrocalamus brandisii (Poaceae: Bambusoideae) Using Simple Sequence Repeats Developed from the Whole Genome

Dendrocalamus brandisii is a high-quality bamboo species that can be used for both bamboo shoots and wood. The nutritional components and flavors of D. brandisii vary from different geographical provenances. However, the unique biological characteristics of bamboo make morphological classification methods unsuitable for distinguishing them. Although the new cultivar 'Manxie No.1' has significant differences in the branch characteristics and the color of shoot sheaths compared to the D. brandisii, it still lacks precise genetic information at the molecular level. This study identified 231,789 microsatellite markers based on the whole genome of D. brandisii and analyzed their type composition and distribution on chromosomes in detail. Then, using TP-M13-SSR fluorescence-labeling technology, 34 pairs of polymorphic primers were screened to identify the new cultivar 'Manxie No.1' and 11 different geographical provenances of D. brandisii. We also constructed DNA fingerprinting profiles for them. At the same time, we mapped six polymorphic SSRs to the gene of D. brandisii, among which SSR673 was mapped to DhB10G011540, which is related to plant immunity. The specific markers selected in this study can rapidly identify the provenances and the new cultivar of D. brandisii and help explore candidate genes related to some important traits.

Association between molecular markers and resistance to bacterial blight using binary logistic analysis

The most effective strategy for managing wheat bacterial blight caused by Pseudomonas syringae pv. syringae is believed to be the use of resistant cultivars. Researching the correlation between molecular markers and stress resistance can expedite the plant breeding process. The current study aims to evaluate the response of 27 bread wheat cultivars to bacterial blight disease in order to identify resistant and susceptible cultivars and to pinpoint ISSR molecular markers associated with bacterial blight resistance genes. ISSR markers are recommended for assessing a plant's disease resistance. This experiment is focused on identifying ISSR molecular markers linked to bacterial blight resistance. After applying the bacterial solution to the leaves, we performed sampling to determine the infection percentage in the leaves at different intervals (7, 14, and 18 days after spraying). In most cultivars, the average leaf infection percentage decreased 18 days after spraying on young leaves. However, in some cultivars such as Niknegad, Darab2, and Zarin, leaf infection increased in older leaves and reached up to 100% necrosis. In our study, 12 ISSR primers generated a total of 170 bands, with 156 being polymorphic. The primers F10 and F5 showed the highest polymorphism, while the F7 primer exhibited the lowest polymorphism. Cluster analysis grouped these cultivars into four categories. The resistant group included Qods, Omid, and Atrak cultivars, while the semi-resistant and susceptible groups comprised the rest of the cultivars. Through binary logistic analysis, we identified three Super oxide dismutase-related genes that contribute to plant resistance to bacterial blight. These genes were linked to the F3, F5, and F12 primers in regions I (1500 bp), T (1000 bp), and G (850 bp), respectively. We also identified seven susceptibility-associated genes. Atrak, Omid, and Qods cultivars exhibited resistance against bacterial blight, and three genes associated with this resistance were linked to the F3, F5, and F12 primers. These markers can be used for screening or transferring tolerance to other wheat cultivars in breeding programs.

KASP-IEva: an intelligent typing evaluation model for KASP primers

KASP marker technology has been used in molecular marker-assisted breeding because of its high efficiency and flexibility, and an intelligent evaluation model of KASP marker primer typing results is essential to improve the efficiency of marker development on a large scale. To this end, this paper proposes a gene population delineation method based on NTC identification module and data distribution judgment module to improve the accuracy of K-Means clustering, and introduces a decision tree to construct the KASP-IEva primer typing evaluation model. The model firstly designs the NTC identification module and data distribution judgment module to extract four types of data, grouping and categorizing to achieve the improvement of the distinguishability of amplification product signals; secondly, the K-Means algorithm is used to aggregate and classify the data, to visualize the five aggregated clusters and to obtain the morphology location eigenvalues; lastly, the evaluation criteria for the typing effect level are constructed, and the logical decision tree is used to make conditional discrimination on the eigenvalues in order to realize the score prediction. The performance of the model was tested by the KASP marker typing test results of 2519 groups of cotton varieties, and the following conclusions were obtained: the model is able to visualize the aggregation and classification effects of the amplification products of NTC, pure genotypes, heterozygous genotypes, and untyped genotypes, enabling rapid and accurate KASP marker typing evaluation. Comparing and analyzing the model evaluation results with the expert evaluation results, the average accuracy rate of the four grades evaluated by the model was 87%, and the overall evaluation results showed an uneven distribution of the grades with significant differential characteristics. When evaluating 2519 KASP fractal maps, the expert evaluation consumes 15 hours, and the model evaluation only uses 8min27.45s, which makes the model intelligent evaluation significantly better than the expert evaluation from the perspective of time. The establishment of the model will further enhance the application of KASP markers in molecular marker-assisted breeding and provide technical support for the large-scale screening and identification of excellent genotypes.

Molecular analysis of Karawang local soybean genotypes with national superior varieties based on SSR analysis

The aim of this study was to analyze the similarities between the Karawang local superior varieties and several national superior varieties based on chromosome analysis or allele size. Analysis were carried out in the laboratory of the Biogen Research Institute in 2021. There were 9 genotypes analyzed, consisting of 8 national superior varieties, namely NS Karawang, Argomulyo, Grobogan, Anjasmoro, Devon-1, Detap-1, Dena-1 and Dena-2 and 1 Karawang local soybean genotypes. The results of the analysis show that Karawang local soybean has a difference with the national superior variety. The similarity of local soybeans from Karawang to NS Karawang with varieties Agromulyo and Grobogan is 68%, with soybean varieties Anjasmoro and Devon-1 is 71%, while with soybeans Detap-1, Dena-1 and Dena-2 is 76%.

Identification of loci associated with water use efficiency and symbiotic nitrogen fixation in soybean

Soybean (Glycine max) production is greatly affected by persistent and/or intermittent droughts in rainfed soybean-growing regions worldwide. Symbiotic N2 fixation (SNF) in soybean can also be significantly hampered even under moderate drought stress. The objective of this study was to identify genomic regions associated with shoot carbon isotope ratio (δ13C) as a surrogate measure for water use efficiency (WUE), nitrogen isotope ratio (δ15N) to assess relative SNF, N concentration ([N]), and carbon/nitrogen ratio (C/N). Genome-wide association mapping was performed with 105 genotypes and approximately 4 million single-nucleotide polymorphism markers derived from whole-genome resequencing information. A total of 11, 21, 22, and 22 genomic loci associated with δ13C, δ15N, [N], and C/N, respectively, were identified in two environments. Nine of these 76 loci were stable across environments, as they were detected in both environments. In addition to the 62 novel loci identified, 14 loci aligned with previously reported quantitative trait loci for different C and N traits related to drought, WUE, and N2 fixation in soybean. A total of 58 Glyma gene models encoding for different genes related to the four traits were identified in the vicinity of the genomic loci.

Genome-Wide Identification of the WD40 Gene Family in Tomato (Solanum lycopersicum L.)

WD40 proteins are a superfamily of regulatory proteins widely found in eukaryotes that play an important role in regulating plant growth and development. However, the systematic identification and characterization of WD40 proteins in tomato (Solanum lycopersicum L.) have not been reported. In the present study, we identified 207 WD40 genes in the tomatoes genome and analyzed their chromosomal location, gene structure and evolutionary relationships. A total of 207 tomato WD40 genes were classified by structural domain and phylogenetic tree analyses into five clusters and 12 subfamilies and were found to be unevenly distributed across the 12 tomato chromosomes. We identified six tandem duplication gene pairs and 24 segmental duplication pairs in the WD40 gene family, with segmental duplication being the major mode of expansion in tomatoes. Ka/Ks analysis revealed that paralogs and orthologs of WD40 family genes underwent mainly purifying selection during the evolutionary process. RNA-seq data from different tissues and developmental periods of tomato fruit development showed tissue-specific expression of WD40 genes. In addition, we constructed four coexpression networks according to the transcriptome and metabolome data for WD40 proteins involved in fruit development that may be related to total soluble solid formation. The results provide a comprehensive overview of the tomato WD40 gene family and will provide valuable information for the validation of the function of tomato WD40 genes in fruit development.

Biochemical and SSR based molecular characterization of elite rice varieties for straw lignocellulose

BACKGROUND

Lignocellulosic biomass from rice straw possesses enormous potential in generating bioenergy thereby reducing the dependence of human on non-renewable fuel sources. Developing rice varieties of such calibre necessitates biochemical characterization as well as assessing the presence of genetic diversity among the rice genotypes with respect to cellulose content.

METHODS AND RESULTS

Forty-three elite rice genotypes were selected for biochemical characterization and SSR marker-based genetic fingerprinting. For genotyping, 13 cellulose synthase specific polymorphic markers were used. The diversity analysis was performed using TASSEL 5.0 and GenAlE × 6.51b2, software program. Of the 43 rice varieties, CR-Dhan-601, CR-Dhan-1014, Mahanadi, Jagabandhu, Gouri, Samanta and Chandrama were found to possess desirable lignocellulosic composition with respect to harnessing green fuels. The marker OsCESA-1.3 expressed the highest PIC (0.640), while the marker OsCESA-6.3 of lowest PIC (0.128). A moderate average estimate (0.367) of PIC was observed under current set of genotypes and marker system. The dendrogram analysis grouped the rice genotypes into two principal clusters i.e., cluster I and II. Cluster-II is monogenetic, while cluster-I is having 42 genotypes.

CONCLUSIONS

The moderate level of both PIC and H average estimates indicate the narrow genetic bases of the germplasms. The varieties falling under different clusters possessing desirable lignocellulosic composition can be used in a hybridization programme to develop bioenergy efficient varieties. The promising varietal combinations that can be used as parents for developing bioenergy efficient genotypes are Kanchan / Gobinda, Mahanadi / Ramachandi, Mahanadi / Rambha, Mahanadi / Manika, Rambha / Manika, Rambha / Indravati and CR-Dhan-601 / Manika as they offer an advantage of higher cellulose accumulation. This study helped in identification of suitable dual purpose rice varieties for biofuel production without compromising food security.

Morphological and microsatellite marker-based characterization and diversity analysis of novel vegetable soybean [Glycine max (L.) Merrill]

BACKGROUND

Vegetable soybean seeds are among the most popular and nutrient-dense beans in the world due to their delicious flavor, high yield, superior nutritional value, and low trypsin content. There is significant potential for this crop that Indian farmers do not fully appreciate because of the limited germplasm range. Therefore, the current study aims to identify the diverse lines of vegetable soybean and explore the diversity produced by hybridizing grain and vegetable-type soybean varieties. Indian researchers have not yet published work describing and analysing novel vegetable soybean for microsatellite markers and morphological traits.

METHODS AND RESULTS

Sixty polymorphic SSR markers and 19 morphological traits were used to evaluate the genetic diversity of 21 newly developed vegetable soybean genotypes. A total of 238 alleles, ranging from 2 to 8, were found, with a mean of 3.97 alleles per locus. The polymorphism information content varied from 0.05 to 0.85, with an average of 0.60. A variation of 0.25-0.58 with a mean of 0.43 was observed for Jaccard's dissimilarity coefficient.

CONCLUSION

The diverse genotypes identified can be helpful to understand the genetics of vegetable soybean traits and can be used in improvement programs; study also explains the utility of SSR markers for diversity analysis of vegetable soybean. Here, we identified the highly informative SSRs with PIC > 0.80 (satt199, satt165, satt167, satt191, satt183, satt202, and satt126), which apply to genetic structure analysis, mapping strategies, polymorphic marker surveys, and background selection in genomics-assisted breeding.

Development of EST-SSR markers based on transcriptome sequencing for germplasm evaluation of 65 lilies (Lilium)

BACKGROUND

Lilium genus consists of approximately 100 species and numerous varieties, many of which are interspecific hybrids, which result in a complicated genetic background. The germplasm identification, genetic relationship analysis, and breeding of Lilium rely on exploiting genetic information among different accessions. Hence, an attempt was made to develop new EST-SSR markers and study the molecular divergence among 65 genotypes of Lilium.

METHODS AND RESULTS

A total of 5509 EST-SSRs were identified from the high-throughput sequencing database of L. 'Elodie'. After primer screening, six primer pairs with the most abundant polymorphic bands were selected from 100 primer pairs. Combined with the other 10 reported SSR primers, a total of 16 pairs detected genetic information with an average PIC value of 0.7583. The number of alleles per locus varied from four to 33, the expected heterozygosity varied from 0.3289 to 0.9231, and the observed heterozygosity varied from 0.2857 to 0.5122. Based on the phylogenic results, 22 Asiatic hybrids (A), seven Longiflorum × Asiatic hybrids (LA), as well as two native species were grouped. Eighteen Oriental hybrids (O) and nine Oriental × Trumpet (OT) hybrids, four native species, one LO, and one LL (L. pardalinum × L. longiflorum) variety were grouped.

CONCLUSIONS

Two major clusters were reported and a large number of genotypes were grouped based on UPGMA and STRUCTURE analysis methods. The PIC value as well as other parameters revealed that the EST-SSR markers selected were informative. In addition, the clustering pattern displayed better agreement with the cultivar's pedigree. The newly identified SSRs in this study provides molecular markers for germplasm characterization and genetic diversity for Lilium.

Comprehensive Analyses of Simple Sequence Repeat (SSR) in Bamboo Genomes and Development of SSR Markers with Peroxidase Genes

Simple sequence repeats (SSRs) are one of the most important molecular markers, which are widespread in plants. Bamboos are important forest resources worldwide. Here, the comprehensive identification and comparative analysis of SSRs were performed in three woody and two herbaceous bamboo species. Altogether 567,175 perfect SSRs and 71,141 compound SSRs were identified from 5737.8 Mb genome sequences of five bamboo species. Di-nucleotide SSRs were the most predominant type, with an average of ~50,152.2 per species. Most SSRs were located in intergenic regions, while those located in genic regions were relatively less. Moreover, the results of annotation distribution indicated that terms with P450, peroxidase and ATP-binding cassette transporter related to lignin biosynthesis might play important roles in woody and herbaceous bamboos under the mediation of SSRs. Furthermore, the peroxidase gene family consisted of a large number of genes containing SSRs was selected for the evolutionary relationship analysis and SSR markers development. Fifteen SSR markers derived from peroxidase family genes of Phyllostachys edulis were identified as polymorphic in 34 accessions belonging to seven genera in Bambusoideae. These results provided a comprehensive insight of SSR markers into bamboo genomes, which would facilitate bamboo research related to comparative genomics, evolution and marker-assisted selection.

Molecular markers-based DNA fingerprinting coupled with morphological diversity analysis for prediction of heterotic grouping in sunflower (Helianthus annuus L.)

Cultivated sunflower holds a very narrow genetic base and the efficient utilization of available genetic diversity is very important for a successful breeding program. In the present study, 109 sunflower genotypes were assessed for diversity paneling through a combined approach of morphological and molecular markers analysis. Morphological parameters including days to flower initiation, days to flower completion, plant height, stem curvature, number of leaves per plant, leaf area, head diameter, hundred seed weight, and seed yield per plant were studied. Simple sequence repeats (40 DNA markers) were deployed for diversity profiling. Data were analyzed by both univariate and multivariate statistics. SD and coefficient of variation confirm the presence of significant amounts of genetic variation for all the morphological parameters. Cluster Analysis and Principal Component Analysis further confirm the presence of distinct grouping patterns in the studied material. Cluster analysis of both morphological and molecular analysis revealed that restorer lines tend to group separately from A, B, and open-pollinated lines. Further grouping, at the sub-cluster level, revealed six distinct sub-clusters in each of the two major clusters. In total, 12 genotypes, 6 CMS lines (CMS-HAP-12, CMS-HAP-54, CMS-HAP-56, CMS-HAP-99, CMS-HAP-111, and CMS-HAP-112) and 6 restorer lines (RHP-38, RHP-41, RHP-53, RHP-68, RHP-69, and RHP-71) could be used as potential parents for hybrid development. As genotypes of similar genetic backgrounds tend to group closer, it is deduced that one genotype with the highest seed yield per plant could be used for further hybrid breeding programs in sunflowers.

Identification and characterization of chickpea genotypes for early flowering and higher seed germination through molecular markers

BACKGROUND

Chickpea is the fourth most important legume crop contributing 15.42% to the total legume production and a rich source of proteins, minerals, and vitamins. Determination of genetic diversity of wild and elite cultivars coupled with early flowering and higher seed germination lines are quintessential for variety improvement.

METHODS AND RESULTS

In the present study, we have analyzed the genetic diversity, population structure, cross-species transferability, and allelic richness in 50 chickpea collections using 23 Inter simple sequence repeats (ISSR) markers. The observed parameters such as allele number varied from 3 to 16, range of allele size varied from 150 to 1600 bp and polymorphic information content (PIC) range lies in between 0.15 and 0.49. Dendrogram was constructed with ISSR marker genotypic data and classified 50 chickpea germplasms into groups I and II, where the accession P 74 - 1 is in group I and the rest are in group II. Dendrogram, Principal component analysis (PCA), dissimilarity matrix, and Bayesian model-based genetic clustering of 50 chickpea germplasms revealed that P 74 - 1 and P 1883 are very diverse chickpea accessions.

CONCLUSION

Based on genetic diversity analysis, 15 chickpea germplasm having been screened for early flowering and higher seed germination and found that the P 1857-1 and P 3971 have early flowering and higher seed germination percentage in comparison to P 1883 and other germplasm. These agronomic traits are essential for crop improvement and imply the potential of ISSR markers in crop improvement.

Analysis of genetic diversity among Onobrychis accessions with high agronomic performance by simple sequence repeat (SSR) markers

BACKGROUND

Onobrychis viciifolia Scop. is a short-lived perennial cool-season legume used for forage production. It is a common native species in Asia Minor, especially in Turkey, the districts of the Caucasus, and the Caspian fringes. It can grow well in a broad range of climatic and soil types found in Asia, Europe, and North America. It is a non-bloating crop, making it suitable for use in both hay and pasture.

METHODS AND RESULTS

The aim was to assess the diversity of the 83 sainfoin genotypes selected based on their high agronomic performance from a germplasm collection evaluated in the experimental field of Tekirdag Namik Kemal University, Turkey. Ten nuclear simple sequence repeat (nSSR) primers (OVK036, OVK046, OVK094, OVK101, OVK125, OVK161, OVK174, OVM033, OVM061, and OVM125) were used in the study. All nSSR loci were found to be polymorphic and totally 92 alleles were detected. The mean observed number of alleles per locus was calculated as 9.2. Among the genetic diversity parameters, Shannon Index (I = 0.375), unbiased genetic diversity value (uh = 0.243), and mean polymorphic information content (PIC = 0.240) were calculated. The genetic distance value varied between 0.43 and 0.95. Based on the dendrogram built by the UPGMA clustering method using genetic distance values, it was observed that the studied sainfoin genotypes were divided into two main clusters, whereas the STRUCTURE analysis results had high support for three clusters.

CONCLUSIONS

The results obtained from this study provide important information on the genetic structures of the studied sainfoin genotypes and their genetic relationship. Therefore acquired genetic data will be useful in designing more efficient polycross nurseries, allowing open pollination of best performing and genetically diverse genotypes in the isolated conditions, which will increase genetic gain in sainfoin breeding programs.

Genetic variability, combining ability and molecular diversity-based parental line selection for heterosis breeding in field corn (Zea mays L.)

Background

The demand of maize crop is increasing day by day, hence to reduce the production and demand gap, there is a need to extract the high yielding parental lines to improve per se yield of the hybrids, which could help to enhance the productivity in maize crops.

Methods and results

The present investigation was carried out to select the best medium maturing inbred lines, among a set of 118 inbred lines. Based on the Duncan multiple range test, out of 118 lines, 16 inbred lines were selected on the basis of its high yield per se and flowering time. The molecular diversity was carried out using SSR markers linked to heterotic QTL and up on diversity analysis it classified selected genotypes in to three distinct groups. Among the selected inbred lines, a wider genetic variability and molecular diversity were observed. A total of 39 test crosses were generated after classifying 16 inbred lines in to three testers and thirteen lines (based on per se grain yield and molecular diversity) and crossing them in line × tester manner.

Conclusion

Combining ability analysis of these parental lines showed that female parents, PML 109, PML 110, PML 111, PML 114 and PML 116 showed additive effect for KRN and grain yield, whereas male parents, PML 46, and PML 93 showed epistatic effect for KRN and PML 102 showed epistatic effect for grain yield. The generated information in the present investigation may be exploited for heterosis breeding in filed corn.

Key messages

To tackle the balanced dietary requirement of Indian population; we focused to enhance the productivity of maize hybrids using genetically broad based, elite, diverse inbred lines. Combination of selection criterion, not only augment the productivity but also improves the quality of hybrid/s.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11033-022-07295-3.