Soybean cyst nematode: Challenges and opportunities

2006 ◽  
Vol 86 (1) ◽  
pp. 25-32 ◽  
Author(s):  
Shawn M. J Winter ◽  
Istvan Rajcan ◽  
Barry J Shelp
Keyword(s):  
Resistance Genes ◽  
Soybean Cyst Nematode ◽  
Glycine Soja ◽  
Cyst Nematode ◽  
Infested Soil ◽  
Linkage Groups ◽  
Factors Affecting ◽  
Scn Resistance ◽  
Major Resistance Genes ◽  
Time Required

Soybean cyst nematode (SCN) is the primary pest responsible for yield losses of Glycine max. Management of SCN remains difficult in commercial soybean production due to the length of its biological cycle, frequent changes in population virulence, and ease of spread via infested soil. Effective management relies on crop rotation in combination with resistant cultivars, which have been derived from a limited germplasm base. Breeding for SCN resistance in soybean is difficult due to the quantitative nature of the trait, genetic variation within SCN populations, time required for phenotyping experimental soybean lines, and environmental factors affecting SCN reproduction. Quantitative trait loci associated with SCN resistance have been identified on 17 of the 20 soybean linkage groups, explaining 1–91% of the total phenotypic variation. Two major resistance genes, rhg 1 and Rhg 4, have been identified on linkage groups G and A2, respectively. Several minor resistance genes have been identified, but their importance varies with germplasm source and nematode race. Enhancement of SCN resistance in G. max may be achieved by interspecific hybridization with G. soja, the wild ancestor, or by engineering plants with candidate resistance genes such as Hs1pro-1. Key words: Genetic engineering, Glycine soja, soybean cyst nematode, molecular markers, resistance

scholarly journals Novel resistance strategies to soybean cyst nematode (SCN) in wild soybean

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Janice Kofsky ◽  
Hengyou Zhang ◽  
Bao-Hua Song
Keyword(s):  
Gene Pool ◽  
Soybean Cyst Nematode ◽  
Agronomic Traits ◽  
Glycine Soja ◽  
Wild Soybean ◽  
Cyst Nematode ◽  
Resistance Response ◽  
Soybean Cultivars ◽  
Scn Resistance ◽  
Cultivated Soybean

AbstractSoybean cyst nematode (SCN, Heterodera glycine Ichinohe) is the most damaging soybean pest worldwide and management of SCN remains challenging. The current SCN resistant soybean cultivars, mainly developed from the cultivated soybean gene pool, are losing resistance due to SCN race shifts. The domestication process and modern breeding practices of soybean cultivars often involve strong selection for desired agronomic traits, and thus, decreased genetic variation in modern cultivars, which consequently resulted in limited sources of SCN resistance. Wild soybean (Glycine soja) is the wild ancestor of cultivated soybean (Glycine max) and it’s gene pool is indisputably more diverse than G. max. Our aim is to identify novel resistant genetic resources from wild soybean for the development of new SCN resistant cultivars. In this study, resistance response to HG type 2.5.7 (race 5) of SCN was investigated in a newly identified SCN resistant ecotype, NRS100. To understand the resistance mechanism in this ecotype, we compared RNA seq-based transcriptomes of NRS100 with two SCN-susceptible accessions of G. soja and G. max, as well as an extensively studied SCN resistant cultivar, Peking, under both control and nematode J2-treated conditions. The proposed mechanisms of resistance in NRS100 includes the suppression of the jasmonic acid (JA) signaling pathway in order to allow for salicylic acid (SA) signaling-activated resistance response and polyamine synthesis to promote structural integrity of root cell walls. Our study identifies a set of novel candidate genes and associated pathways involved in SCN resistance and the finding provides insight into the mechanism of SCN resistance in wild soybean, advancing the understanding of resistance and the use of wild soybean-sourced resistance for soybean improvement.

Resistance Gene Pyramiding and Rotation to Combat Widespread Soybean Cyst Nematode Virulence

Plant Disease ◽  
2021 ◽  
Author(s):  
Clinton Meinhardt ◽  
Amanda Howland ◽  
Mark Ellersieck ◽  
Andrew Scaboo ◽  
Brian Diers ◽  
...  
Keyword(s):  
Population Density ◽  
Resistance Gene ◽  
Resistance Genes ◽  
Soybean Cyst Nematode ◽  
Cyst Nematode ◽  
Single Type ◽  
Resistant Cultivars ◽  
Scn Resistance ◽  
Pi 88788 ◽  
Selection Of

Soybean cyst nematode (SCN) is an important pathogen of soybean causing more than $1 billion in yield losses annually in the United States. Planting SCN resistant soybean cultivars is the primary management strategy. Resistance genes derived from the plant introductions (PI) 88788 (rhg1-b) and PI 548402 (Peking; rhg1-a and Rhg4) are the main types of resistance available in commercial cultivars. The PI 88788 rhg1-b resistance allele is found in the majority of SCN resistant cultivars in the north central US. The widespread use of PI 88788 rhg1-b has led to limited options for farmers to rotate resistance sources to manage SCN. Consequently, an over reliance on a single type of resistance has resulted in the selection of SCN populations that have adapted to reproduce on these resistant cultivars. Here we evaluated the effectiveness of rotating soybean lines with different combinations of resistance genes to determine the best strategy for combating the widespread increase in virulent SCN and limit future nematode adaptation to resistant cultivars. Eight SCN populations were developed by either continuous selection of a virulent SCN field population (HG type 1.2.5.7) on a single resistance source or in rotation with soybean pyramiding different resistance gene alleles derived from PI 88788 (rhg1-b), PI 437654 (rhg1-a and Rhg4), PI 468916 (cqSCN-006 and cqSCN-007) and PI 567516C (Chr10). SCN population densities were determined for eight generations. HG type tests were conducted after the eighth generation to evaluate population shifts. The continued use of rhg1-b or 006/007 had limited effectiveness for reducing SCN type 1.2.5.7 population density, whereas rotation to the use of rhg1-a/Rhg4 resistance significantly reduced SCN population density, but selected for broader SCN virulence (HG type 1.2.3.5.6.7). A rotation of rhg1-a/Rhg4 with a pyramid of rhg1-b/006/007/Chr10 was the most effective combination at both reducing population density and minimizing selection pressure. Our results provide guidance for implementation of a strategic SCN resistance rotation plan to manage the widespread virulence on PI 88788 and sustain the future durability of SCN resistance genes.

scholarly journals Soybean cyst nematode resistance QTL cqSCN-006 alters the expression of a ɣ-SNAP protein

2021 ◽  
Author(s):  
Katelyn Butler ◽  
Christina Fliege ◽  
Ryan Zapotocny ◽  
Brian Diers ◽  
Mathew Hudson ◽  
...  
Keyword(s):  
Soybean Cyst Nematode ◽  
Glycine Soja ◽  
Cyst Nematode ◽  
Resistance Locus ◽  
Cyst Nematodes ◽  
Transgenic Roots ◽  
Resistance Qtl ◽  
A Genome ◽  
Scn Resistance ◽  
Splice Forms

Soybean cyst nematode is the most economically damaging pathogen of soybean and host resistance is a core management strategy. The SCN resistance QTL cqSCN-006, introgressed from the wild relative Glycine soja, provides intermediate resistance against nematode populations including those with increased virulence on the heavily used rhg1-b resistance locus. cqSCN-006 was previously fine-mapped to a genome interval on chromosome 15. The present study determined that Glyma.15G191200 at cqSCN-006, encoding a ɣ-SNAP (gamma-SNAP), contributes to SCN resistance. CRISPR/Cas9-mediated disruption of the cqSCN-006 allele reduced SCN resistance in transgenic roots. There are no encoded amino acid polymorphisms between resistant and susceptible alleles. However, other cqSCN-006-specific DNA polymorphisms in the Glyma.15G191200 promoter and gene body were identified, and we observed differing induction of ɣ-SNAP protein abundance at SCN infection sites between resistant and susceptible roots. We identified alternative RNA splice forms transcribed from the Glyma.15G191200 ɣ-SNAP gene and observed differential expression of the splice forms two days after SCN infection. Heterologous overexpression of ɣ-SNAPs in plant leaves caused moderate necrosis, suggesting that careful regulation of this protein is required for cellular homeostasis. Apparently, certain G. soja evolved quantitative SCN resistance through altered regulation of ɣ-SNAP. Previous work has demonstrated SCN resistance impacts of the soybean α-SNAP proteins encoded by Glyma.18G022500 (Rhg1) and Glyma.11G234500. The present study shows that a different type of SNAP protein can also impact SCN resistance. Little is known about ɣ-SNAPs in any system, but the present work suggests a role for ɣ-SNAPs during susceptible responses to cyst nematodes.

Identification of novel haplotype of a cyst nematode resistance gene, GmSNAP18 in soybean [Glycine max (L.) Merr.]

2020 ◽  
Vol 80 (03) ◽  
Author(s):  
Ik-Young Choi ◽  
Prakash Basnet ◽  
Hana Yoo ◽  
Neha Samir Roy ◽  
Rahul Vasudeo Ramekar ◽  
...  
Keyword(s):  
Soybean Cyst Nematode ◽  
Gene Families ◽  
Nematode Resistance ◽  
Cyst Nematode ◽  
Soybean Breeding ◽  
Resistant Varieties ◽  
Soybean Genotypes ◽  
Glycine Max L ◽  
Scn Resistance

Soybean cyst nematode (SCN) is one of the most damaging pest of soybean. Discovery and characterization of the genes involved in SCN resistance are important in soybean breeding. Soluble NSF attachment protein (SNAP) genes are related to SCN resistance in soybean. SNAP genes include five gene families, and 2 haplotypes of exons 6 and 9 of SNAP18 are considered resistant to the SCN. In present study the haplotypes of GmSNAP18 were surveyed and chacterized in a total of 60 diverse soybean genotypes including Korean cultivars, landraces, and wild-types. The target region of exons 6 and 9 in GmSNAP18 region was amplified and sequenced to examine nucleotide variation. Characterization of 5 haplotypes identified in present study for the GmSNAP18 gene revealed two haplotypes as resistant, 1 as susceptible and two as novel. A total of twelve genotypes showed resistant haplotypes, and 45 cultivars were found susceptible. Interestingly, the two novel haplotypes were present in 3 soybean lines. The information provided here about the haplotypic variation of GmSNAP18 gene can be further explored for soybean breeding to develop resistant varieties.

Classification methods and identification of reniform nematode resistance in known soybean cyst nematode resistant soybean genotypes

Plant Disease ◽  
2021 ◽  
Author(s):  
Mariola Usovsky ◽  
Robert Robbins ◽  
Juliet Fultz Wilkes ◽  
Devany Crippen ◽  
Vijay Shankar ◽  
...  
Keyword(s):  
Soybean Cyst Nematode ◽  
Germplasm Collection ◽  
Nematode Species ◽  
The United States ◽  
Cyst Nematode ◽  
Classification Methods ◽  
Reniform Nematode ◽  
Plant Introductions ◽  
Scn Resistance ◽  
Moderately Resistant

Plant parasitic nematodes are a major yield-limiting factor of soybean in the United States and Canada. It has been indicated that soybean cyst nematode (SCN, Heterodera glycines Ichinohe) and reniform nematode (RN, Rotylenchulus reniformis Linford and Oliveira) resistance could be genetically related. For many years fragmentary data has shown this relationship. This report evaluates RN reproduction on 418 plant introductions (PIs) selected from the USDA Soybean Germplasm Collection with reported SCN resistance. The germplasm was divided into two tests of 214 PIs reported as resistant, and 204 PIs moderately resistant to SCN. The defining and reporting of RN resistance changed several times in the last 30 years, causing inconsistencies in RN resistance classification among multiple experiments. Comparison of four RN resistance classification methods was performed: (1) ≤10% as compared to the susceptible check, (2) using normalized reproduction index (RI) values, and transformed data (3) log10 (x) and (4) log10 (x+1), in an optimal univariate k-means clustering analysis. The method of transformed data log10 (x) was selected as the most accurate for classification of RN resistance. Among 418 PIs with reported SCN resistance, the log10 (x) method grouped 59 PIs (15%) as resistant, and 130 PIs (31%) as moderately resistant to RN. Genotyping of a subset of the most resistant PIs to both nematode species revealed their strong correlation with rhg1-a allele. This research identified genotypes with resistance to two nematode species and potential new sources of RN resistance that could be valuable to breeders in developing resistant cultivars.

Nematicidal activity of ethanol solutions on soybean cyst nematode Heterodera glycines

Nematology ◽  
2019 ◽  
Vol 22 (1) ◽  
pp. 111-121
Author(s):  
Luma A. Pedroso ◽  
Vicente P. Campos ◽  
Aline F. Barros ◽  
Julio C.P. Silva ◽  
Gustavo M. Assis ◽  
...  
Keyword(s):  
Lipid Content ◽  
Sustainable Management ◽  
Soybean Cyst Nematode ◽  
Management Practices ◽  
Heterodera Glycines ◽  
Cyst Nematode ◽  
Infested Soil ◽  
Tropical Regions ◽  
Second Stage ◽  
Low Concentrations

Summary The cyst nematode, Heterodera glycines, is a major pathogen of soybean in tropical regions, which demands novel sustainable management practices. In this work, the use of ethanol against H. glycines was evaluated as both a solution and a fumigant. On second-stage juveniles (J2) of H. glycines, ethanol at low concentration was more effective by direct dipping than by only fumigating the J2. Hatching was significantly reduced by direct dipping in ethanol solutions. Fumigation of H. glycines-infested soil with ethanol reduced infectivity by almost 100% and the number of eggs by about 67% at ethanol concentrations of 48% and 72%, respectively. Only the ethanol at 48% concentration significantly reduced the J2 lipid content, while J2 infectivity and the number of eggs were reduced by dipping at 6% ethanol. The J2 were internally altered by the ethanol solutions. Therefore, ethanol is toxic to H. glycines at low concentrations and affects its pathogenic behaviour rather than simply reducing the lipids.

Localization of Two Loci that Confer Resistance to Soybean Cyst Nematode from Glycine soja PI 468916

Crop Science ◽  
2005 ◽  
Vol 45 (6) ◽  
pp. 2473-2481 ◽  
Author(s):  
E. A. Kabelka ◽  
S. R. Carlson ◽  
B. W. Diers
Keyword(s):  
Soybean Cyst Nematode ◽  
Glycine Soja ◽  
Cyst Nematode

scholarly journals Accessions of Perennial Glycine Species With Resistance to Multiple Types of Soybean Cyst Nematode (Heterodera glycines)

Plant Disease ◽  
2017 ◽  
Vol 101 (7) ◽  
pp. 1201-1206 ◽  
Author(s):  
L. Wen ◽  
C. Yuan ◽  
T. K. Herman ◽  
G. L. Hartman
Keyword(s):  
Resistance Genes ◽  
Soybean Cyst Nematode ◽  
Heterodera Glycines ◽  
Cost Effective ◽  
Cyst Nematode ◽  
Disease Genes ◽  
Sources Of Resistance ◽  
Plant Introductions ◽  
Glycine Species ◽  
Cost Effective Method

Soybean cyst nematode (SCN; Heterodera glycines; HG) is a widely occurring and damaging pathogen that limits soybean production. Developing resistant cultivars is the most cost-effective method for managing this disease. Genes conferring SCN resistance in soybean have been identified; however, there are SCN populations that overcome known resistance genes. In order to identify additional sources of resistance and potentially new resistance genes, 223 plant introductions (PIs) of G. tomentella and 59 PIs of 12 other perennial Glycine species were inoculated with HG Types 0, HG 2, and HG 1.2.3, and then 36 PIs out of this set were further evaluated with HG Type 1.2.3.4.5.6.7, a population that overcomes all the resistance genes in soybean. Of 223 G. tomentella PIs evaluated, 86 were classified as resistant to three HG types, 69 as resistant to two HG types, and 22 as resistant to one HG type. Of the other 12 perennial Glycine species, all PIs of G. argyrea and G. pescadrensis were resistant to all three HG types. Of the 36 PIs challenged with HG Type 1.2.3.4.5.6.7, 35 were resistant with 16 showing no cyst reproduction. Our study confirms that there are high levels of resistance to SCN among the perennial Glycine species. This represents an untapped resource for use in genetic studies and for improving resistance to SCN in soybean.

scholarly journals Modulations in Gene Expression and Mapping of Genes Associated with Cyst Nematode Infection of Soybean

2001 ◽  
Vol 14 (1) ◽  
pp. 42-54 ◽  
Author(s):  
Zarir Vaghchhipawala ◽  
Ronald Bassüner ◽  
Kathryn Clayton ◽  
Kimberley Lewers ◽  
Randy Shoemaker ◽  
...  
Keyword(s):  
Gene Expression ◽  
Soybean Cyst Nematode ◽  
Genetic System ◽  
Cyst Nematode ◽  
Infection Process ◽  
Resistance Locus ◽  
Root Cells ◽  
Feeding Site ◽  
Susceptible Line ◽  
Scn Resistance

Infection of the soybean root by the soybean cyst nematode (SCN) (Heterodera glycines Ichinohe) induces a well-documented, yet poorly understood, response by the host plant. The plant response, involving the differentiation of a feeding structure, or “syncytium,” facilitates the feeding and reproduction of the nematode to the detriment of the host. We used a genetic system involving a single dominant soybean gene conferring susceptibility to an inbred nematode strain, VL1, to characterize the nematode-host interaction in susceptible line PI 89008. The restriction fragment length polymorphism marker pB053, shown to map to a major SCN resistance locus, cosegregates with resistance among F2 progeny from the PI 89008 × PI 88287 cross. Cytological examination of the infection process confirmed that syncytium development in this genetic system is similar to that reported by others who used noninbred nematode lines. Our study of infected root tissue in the susceptible line PI 89008 revealed a number of genes enhanced in expression. Among these are catalase, cyclin, elongation factor 1α, β-1,3-endoglucanase, hydroxymethylglutaryl coenzyme A reductase, heat shock protein 70, late embryonic abundant protein 14, and formylglycinamidine ribonucleotide synthase, all of which we have genetically positioned on the public linkage map of soybean. Formylglycinamidine ribonucleotide synthase was found to be tightly linked with a major quantitative trait locus for SCN resistance. Our observations are consistent with the hypothesis proposed by others that feeding site development involves the dramatic modulation of gene expression relative to surrounding root cells.

scholarly journals Marker-assisted selection strategies for developing resistant soybean plants to cyst nematode

2014 ◽  
Vol 14 (3) ◽  
pp. 180-186 ◽  
Author(s):  
Fernanda Abreu Santana ◽  
Martha Freire da Silva ◽  
Julierme Kellen Freitas Guimarães ◽  
Marcia Flores da Silva Ferreira ◽  
Waldir Dias Pereira ◽  
...  
Keyword(s):  
Marker Assisted Selection ◽  
Soybean Cyst Nematode ◽  
Cyst Nematode ◽  
Selection Strategies ◽  
Resistant Lines ◽  
Resistance Trait ◽  
Scn Resistance ◽  
Soybean Plants ◽  
Moderate Resistance ◽  
Selection Of

Resistant lines can be identified by marker-assisted selection(MAS), based on alleles of genetic markers linked to the resistance trait. This reduces the number of phenotypically evaluated lines, one of the limitations in the development of cultivars with resistance to soybean cyst nematode (SCN).This study evaluated the efficiency of microsatellites near quantitative traitloci (QTL) for SCN resistance, in the linkage groups (LG) G and A2 of soybean, for the selection of resistant genotypes in populations originated from crosses between the cultivars Vmax and CD201. The QTL of LG A2 was not detected in 'Vmax' (derived from PI 88788). In MAS, the microsatellites of LG G were efficient in selecting F6:7 families with resistance and moderate resistance to SCN race 3. The selection efficiency of the microsatellites Sat_168, Satt309 and Sat_141 was greater than 93%.

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