scholarly journals Resistance to Soybean Cyst Nematode: Rhg1

2017 ◽  
Vol 1 (2) ◽  
pp. 39-45
Author(s):  
Ahmed J. Afzal ◽  
Ali Srour ◽  
Aparna Natarajan ◽  
Navinder Saini ◽  
M. Javed Iqbal ◽  
...  
Keyword(s):  
Root Development ◽  
Soybean Cyst Nematode ◽  
Cyst Nematode ◽  
Genomic Research ◽  
Sources Of Resistance ◽  
Gene Encoding ◽  
Membrane Biology ◽  
Modifier Locus ◽  
Resistant Seedling ◽  
Seedling Roots

The genes underlying rhg1 lie at a sometimes dominant sometimes co-dominant locus, necessary for resistance to all Hg types of the soybean (Glycine max (L.) Merr.) cyst nematode (Heterodera glycines). Genomic research identified; nucleotide changes within a candidate gene encoding a receptor like kinase (RLK) that were capable of altering root development and thereby part of the resistance to Hg types 0 (race 3); changes in a laccase that are capable of altering cyst development; and genes underlying changes in membrane biology. This set of three genes are subject to co-selection with a modifier locus on another linkage block. Root development is slowed in the resistant seedling and results in end of season yield loss when SCN is not present. However, in the presence of SCN resistant seedling roots grow just as vigorously as the now slower growing parasitized susceptible roots and therefore show little loss to SCN parasitism. In some genotypes but not others the RLK can act alone to confer resistance. Functional paralogs of the three gene cluster have been found on other linkage groups including A1, B1, G, and O and these can be functional in different sources of resistance like G. soja, PI 437654 and PI438489B. At rhg1 the allele differences change the structure, interacting partners and activity of the LRR protein and the laccase. The changes between the alleles result in about 30 other proteins (judged by 2 Dgels), 112 metabolites (by FTICRMS) and 8 metabolites (by GCMS) to increase in abundance in roots during SCN infection in the resistant NILs. Understanding the basis of root stunting by resistance alleles will be used to improve methods for developing new nematode resistant soybean cultivars that do not suffer from the yield suppression and low seed germination rates of existing cultivars.

scholarly journals Influence of Soybean Cropping Sequences on Seed Yield and Female Index of the Soybean Cyst Nematode

Plant Disease ◽  
1998 ◽  
Vol 82 (6) ◽  
pp. 615-619 ◽  
Author(s):  
Lawrence D. Young
Keyword(s):  
Soybean Cyst Nematode ◽  
Cyst Nematode ◽  
Resistant Cultivar ◽  
Breeding Line ◽  
Sources Of Resistance ◽  
Resistant Cultivars ◽  
Cropping Sequence ◽  
Moderately Resistant ◽  
Different Sources ◽  
Female Index

Several soybean (Glycine max) cropping sequences were planted for 12 years in a field that, at the beginning of the test, was infested with race 14 of the soybean cyst nematode, Heterodera glycines. Continuous soybean cropping sequences included H. glycines-susceptible cultivars Forrest, J82-21, Peking × Centennial breeding line, and moderately resistant cultivars Bedford and J81-116. Forrest treated with aldicarb or pentachloronitrobenzene (PCNB) plus metalaxyl and resistant breeding line JS83-236 followed by resistant cultivars Cordell and Hartwig were additional continuous soybean sequences. Rotations included two sequences each of Bedford with J81-116 or J82-21, and three sequences of Bedford with corn (Zea mays) and susceptible Essex soybean. Rotations of Bedford, corn, and Essex had 12-year mean yields significantly greater than continuous Bedford or Forrest. The female index (FI) of H. glycines on five cultivars and lines was used to bioassay changes in parasitic potential in each cropping sequence. The FI on Bedford bioassay plants increased significantly over time for all field treatments involving Bedford. When J82-21 was the bioassay plant, FI decreased significantly in treatments involving Bedford. There were no significant changes in FI for any treatment when Forrest, J81-16, and Peking were used as bioassays. Rotations of soybean cultivars with different sources of resistance and rotations of resistant and susceptible cultivars with a nonhost crop were not successful practices to manage the nematode's ability to parasitize the resistant cultivar Bedford. However, rotation of resistant and susceptible cultivars with a nonhost crop produced greater mean soybean yields and slowed the shift toward greater parasitism of the resistant cultivar sufficiently to warrant adoption of this practice.

Characterization of Virulence Phenotypes of Soybean Cyst Nematode (Heterodera glycines) Populations in North Dakota

2021 ◽  
Author(s):  
Intiaz Amin Chowdhury ◽  
Guiping Yan ◽  
Addison Plaisance ◽  
sam markell
Keyword(s):  
North Dakota ◽  
Soybean Cyst Nematode ◽  
Heterodera Glycines ◽  
The United States ◽  
Cyst Nematode ◽  
Sources Of Resistance ◽  
Resistance Sources ◽  
First Time ◽  
Primary Strategy

Soybean cyst nematode (SCN; Heterodera glycines) continues to be the greatest threat to soybean production in the United States. Since host resistance is the primary strategy used to control SCN, knowledge of SCN virulence phenotypes (HG types) is necessary for choosing sources of resistance for SCN management. To characterize SCN virulence phenotypes in North Dakota (ND), a total of 419 soybean fields across 22 counties were sampled during 2015, 2016, and 2017. SCN was detected in 42% of the fields sampled and population densities in these samples ranged from 30 to 92,800 eggs and juveniles per 100 cm3 of soil. The SCN populations from some of the infested fields were virulence phenotyped with seven soybean indicator lines and a susceptible check (Barnes) using the HG type tests. Overall, 73 SCN field populations were successfully virulence phenotyped. The HG types detected in ND were HG type 0 (frequency rate: 36%), 7 (27%), 2.5.7 (19%), 5.7 (11%), 1.2.5.7 (4%), and 2.7 (2%). However, prior to this study only HG type 0 was detected in ND. The designation of each of the HG types detected was then validated in this study by repeating the HG type tests for thirty-three arbitrarily selected samples. This research for the first time reports several new HG types detected in ND and confirms that the virulence of SCN populations is shifting and overcoming resistance, highlighting the necessity of utilization of different resistance sources, rotation of resistance sources, and identification of novel resistance sources for SCN management in ND.

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 Distribution and Virulence Phenotypes of Heterodera glycines in Missouri

Plant Disease ◽  
2003 ◽  
Vol 87 (8) ◽  
pp. 929-932 ◽  
Author(s):  
T. L. Niblack ◽  
J. A. Wrather ◽  
R. D. Heinz ◽  
P. A. Donald
Keyword(s):  
Soybean Cyst Nematode ◽  
Heterodera Glycines ◽  
Phenotypic Diversity ◽  
Research Priorities ◽  
Plant Introduction ◽  
Cyst Nematode ◽  
Population Densities ◽  
Sources Of Resistance ◽  
Resistant Varieties ◽  
Two Samples

The soybean cyst nematode, Heterodera glycines, is the most economically important pathogen of soybean in Missouri. Knowledge of the nematode's distribution and ability to adapt to resistant varieties is important for determining crop losses and establishing research priorities. No previous surveys of Missouri have provided reliable population density and phenotypic diversity data; therefore, we conducted a random survey to obtain both. Two samples from each of 200 fields were collected; 392 samples were processed for extractions of cysts and eggs. Two hundred and forty seven (63%) of the samples had detectable cyst nematode populations, which ranged from 15 to 149,700 eggs per 250 cm3 of soil. The lowest average population densities were observed in the east-central region of Missouri (2,260 eggs per 250 cm3 of soil), and the highest were observed in the northeast (9,238 eggs per 250 cm3 of soil), but among the eight regions sampled, mean population densities did not differ significantly. These population densities were potentially responsible for losses worth over $58 million in 1999 in Missouri. Race tests were conducted on populations from 183 samples. In order of frequency, races 3, 1, and 2 accounted for 86% of H. glycines populations. Nearly 60% of the populations were virulent (able to produce females) on plant introduction (PI) 88788, which is the source of resistance for most H. glycines-resistant cultivars. More than a third of the populations were virulent on cv. Peking, another common resistance source. Very few populations were virulent on PI 90763 or PI 437654, suggesting that these sources of resistance should be exploited more frequently.

scholarly journals Increase in Soybean Cyst Nematode Virulence and Reproduction on Resistant Soybean Varieties in Iowa From 2001 to 2015 and the Effects on Soybean Yields

2017 ◽  
Vol 18 (3) ◽  
pp. 146-155 ◽  
Author(s):  
Michael T. McCarville ◽  
Christopher C. Marett ◽  
Mark P. Mullaney ◽  
Gregory D. Gebhart ◽  
Gregory L. Tylka
Keyword(s):  
Soybean Cyst Nematode ◽  
Field Experiments ◽  
Yield Loss ◽  
Plant Introduction ◽  
Cyst Nematode ◽  
Population Densities ◽  
Sources Of Resistance ◽  
Nematode Reproduction ◽  
Soybean Yield ◽  
Pi 88788

Management of the soybean cyst nematode (SCN) relies heavily on use of SCN-resistant soybean varieties to limit nematode reproduction and minimize yield loss. For Iowa, almost all SCN-resistant soybean varieties contain SCN resistance genes from a breeding line named Plant Introduction (PI) 88788. Iowa State University conducts experiments to evaluate numerous SCN-resistant and three to four SCN-susceptible soybean varieties in up to nine field experiments across Iowa each year. Data on SCN population density, virulence (SCN race and HG type), soybean yield, precipitation, and growing degree days from more than 25,000 four-row plots in field experiments conducted from 2001 to 2015 were analyzed to determine how these factors affected SCN reproduction and yield. SCN population densities were positively correlated with temperatures and negatively associated with precipitation during the growing seasons, indicating that SCN reproduction was greatest in hot, dry years. Over the years, virulence of SCN populations on PI 88788 increased in the fields in which the experiments were conducted, resulting in increased end-of-season SCN population densities and reduced yields of SCN-resistant soybean varieties with the PI 88788 source of resistance. These results indicate that soybean yield loss caused by SCN on resistant varieties with the common PI 88788 source of resistance likely will increase as virulence of SCN populations increases unless new sources of resistance become widely available and used in the future.

scholarly journals Variability in Distribution and Virulence Phenotypes of Heterodera glycines in Missouri During 2005

Plant Disease ◽  
2007 ◽  
Vol 91 (11) ◽  
pp. 1473-1476 ◽  
Author(s):  
Melissa G. Mitchum ◽  
J. Allen Wrather ◽  
Robert D. Heinz ◽  
J. Grover Shannon ◽  
Gene Danekas
Keyword(s):  
Soybean Cyst Nematode ◽  
Heterodera Glycines ◽  
Cyst Nematode ◽  
Common Source ◽  
Sources Of Resistance ◽  
Resistant Cultivars ◽  
Soybean Cultivars ◽  
Geographical Regions ◽  
Two Samples ◽  
Pi 88788

The soybean cyst nematode, Heterodera glycines, is a serious economic threat to soybean producers in Missouri. Periodic monitoring for the presence, population densities, and virulence phenotypes of H. glycines is essential for determining crop losses and devising management strategies implementing the use of resistant cultivars. A survey using area-frame sampling was conducted to determine the distribution and virulence phenotypes of H. glycines in Missouri during 2005. Two samples from each of 125 fields representing eight geographical regions of Missouri were collected; 243 samples were processed for extraction of cysts and eggs. In all, 49% of samples had detectable cyst nematode populations, which ranged from 138 to 85,250 eggs per 250 cm3 of soil. Race and H. glycines type tests were conducted on populations from 45 samples. Nearly 80% of the populations that were tested, irrespective of the region, were virulent on the indicator line plant introduction (PI) 88788, which is the source of resistance for most H. glycines-resistant cultivars. More than 70% of populations could reproduce on the indicator lines PI 88788, PI 209332, and PI 548316 (Cloud), indicating that soybean cultivars with resistance derived from these sources need to be carefully monitored and used only in rotation with nonhost crops and soybean cultivars with resistance from other sources. Approximately one-third of the populations, primarily in the southern regions of Missouri, could reproduce on PI 548402 (Peking), another common source of resistance. Fewer than 10% of the populations could reproduce on PI 90763, PI 437654, PI 89772, or PI 438489B, suggesting that these sources of resistance should be used in soybean breeding programs to develop H. glycines-resistant soybean cultivars.

Shift in Virulence of Soybean Cyst Nematode is Associated with Use of Resistance from PI 88788

2008 ◽  
Vol 9 (1) ◽  
pp. 29 ◽  
Author(s):  
T. L. Niblack ◽  
A. L. Colgrove ◽  
K. Colgrove ◽  
J. P. Bond
Keyword(s):  
Soybean Cyst Nematode ◽  
Plant Introduction ◽  
The United States ◽  
Cyst Nematode ◽  
Management Tool ◽  
Sources Of Resistance ◽  
Resistant Cultivars ◽  
Significant Yield ◽  
Pi 88788 ◽  
Alternative Sources

The soybean cyst nematode (SCN) is the most economically important pathogen of soybean in the United States. Most of the SCN-resistant cultivars being grown in this region have resistance derived from a single source, Plant Introduction (PI) 88788. A survey conducted in 2005 showed that 83% of the soybean hectarage in Illinois is infested with SCN, with average population densities high enough to cause significant yield suppression (2,700 eggs/100 cm3 soil). Further characterization of these populations showed that 70% have adapted to PI 88788 at some level, reducing the effectiveness of using SCN-resistant cultivars as a crop management tool. Rotation with alternative sources of resistance is recommended as a means to slow the adaptation to PI 88788. Accepted for publication 11 October 2007. Published 18 January 2008.

scholarly journals Esophageal Gland RNA-seq Resource of a Virulent and Avirulent Population of the Soybean Cyst Nematode, Heterodera glycines.

2021 ◽  
Author(s):  
Tom Maier ◽  
Rick E. Masonbrink ◽  
Paramasivan Vijayapalani ◽  
Michael Gardner ◽  
Amanda D. Howland ◽  
...  
Keyword(s):  
Soybean Cyst Nematode ◽  
Gland Cell ◽  
Heterodera Glycines ◽  
The United States ◽  
Cyst Nematode ◽  
Effector Proteins ◽  
Genomic Research ◽  
Natural Resistance ◽  
Rna Seq ◽  
Management Options

The soybean cyst nematode, Heterodera glycines, is the most economically devastating pathogen of soybean in the United States and threatens to become even more damaging through the selection of virulent nematode populations in the field that can overcome natural resistance mechanisms in soybean cultivars. This pathogen, therefore, demands intense transcriptomic/genomic research inquiries into the biology of its parasitic mechanisms. H. glycines delivers effector proteins that are produced in specialized gland cells into the soybean root to enable infection. The study of effector proteins, thus, is particularly promising when exploring novel management options against this pathogen. Here we announce the availability of a gland cell-specific RNA-seq resource. These data represent an expression snapshot of gland cell activity during early soybean infection of a virulent and an avirulent H. glycines population, which provides a unique and highly valuable resource for scientists examining effector biology and nematode virulence.

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