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.

scholarly journals Distribution and Virulence Phenotypes of Soybean Cyst Nematode (Heterodera glycines) based upon Host Differentials in Jilin Province

2021 ◽  
Vol 25 (03) ◽  
pp. 735-741
Author(s):  
Xiujuan Yan
Keyword(s):  
Soybean Cyst Nematode ◽  
Heterodera Glycines ◽  
Plant Introduction ◽  
Cyst Nematode ◽  
Soil Samples ◽  
Jilin Province ◽  
Limiting Factors ◽  
Population Densities ◽  
Soybean Production ◽  
First Time

Jilin is the dominant soybean production province in China. Soybean cyst nematode [Heterodera glycines] (SCN) is one of the most important yield-limiting factors in soybean production. Information about the distribution and virulence phenotypes of SCN in soybean fields are essential for optimizing varieties choice in the region. The distribution and virulence phenotypes of SCN in 141 soil samples from 38 cites (cities, counties and towns) across Jilin province were investigated. One hundred and four (73.76%) of the samples from all 38 cities (counties, towns) tested positive for SCN and SCN population densities were more than 5 cysts/100 mL soil in 53 samples from 27 cities (counties, towns). In those 53 samples, we identified 7 races and 12 Heterodera glycines (HG) types, with Race 3 and HG Type 7 being the most dominant genotypes. Of all the genotypes identified, Race10 and HG Type 1.7 were found for the first time in China, and HG Type 3.4.5.7 was the first reported worldwide. Thirty-eight SCN populations (34.5%) were virulent on plant introduction (PI) 548316 (#7) and 15 of them had female indices (FI) ≥ 10% on Pickett. PI 548316 and Pickett were not recommended as parents of breeding against cyst nematode in Jilin province. Peking-type resistance sources were preferred to pi88788-type in Jilin province. In addition, it was found neither the race nor HG scheme is sufficient for differentiating SCN populations in Jilin province, nor the combination of the two methods is recommended for studying the genetic diversity of SCN in Jilin province. That is, Pickett which was removed in HG scheme should be included not as an indicator line but just to separate different races from the same HG type. © 2021 Friends Science Publishers

scholarly journals Effect of Soybean Cyst Nematode Resistance Source and Seed Treatment on Population Densities of Heterodera glycines, Sudden Death Syndrome, and Yield of Soybean

Plant Disease ◽  
2017 ◽  
Vol 101 (12) ◽  
pp. 2137-2143 ◽  
Author(s):  
Yuba R. Kandel ◽  
Kiersten A. Wise ◽  
Carl A. Bradley ◽  
Martin I. Chilvers ◽  
Adam M. Byrne ◽  
...  
Keyword(s):  
Sudden Death ◽  
Soybean Cyst Nematode ◽  
Seed Treatment ◽  
Heterodera Glycines ◽  
Plant Introduction ◽  
Cyst Nematode ◽  
Sudden Death Syndrome ◽  
Population Densities ◽  
Scn Resistance ◽  
Pi 88788

A three-year study was conducted in Illinois, Indiana, Iowa, Michigan, and Ontario, Canada, from 2013 through 2015 to determine the effect of soybean (Glycine max) cultivars’ source of soybean cyst nematode (SCN; Heterodera glycines) resistance on SCN population densities, sudden death syndrome (SDS; caused by Fusarium virguliforme), and yield of soybean. Five cultivars were evaluated with and without fluopyram seed treatment at each location. Cultivars with no SCN resistance had greater SDS severity, greater postharvest SCN egg counts (Pf), and lower yield than cultivars with plant introduction (PI) 548402 (Peking) and PI 88788-type of SCN resistance (P < 0.05). Cultivars with Peking-type resistance had lower Pf than those with PI 888788-type and no SCN resistance. In two locations with HG type 1.2-, cultivars with Peking-type resistance had greater foliar disease index (FDX) than cultivars with PI 88788-type. Fluopyram seed treatment reduced SDS and improved yield compared with a base seed treatment but did not affect SCN reproduction and Pf (P > 0.05). FDX and Pf were positively correlated in all three years (P < 0.01). Our results indicate that SDS severity may be influenced by SCN population density and HG type, which are important to consider when selecting cultivars for SCN management.

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.

Distribution, population density, race and type determination of soybean cyst nematode, Heterodera glycines, in Iran

Nematology ◽  
2008 ◽  
Vol 10 (6) ◽  
pp. 919-924 ◽  
Author(s):  
Mansour Salati ◽  
Robert Riggs ◽  
Zahra Tanha Maafi
Keyword(s):  
Soybean Cyst Nematode ◽  
Heterodera Glycines ◽  
Growing Season ◽  
Cyst Nematode ◽  
Soil Samples ◽  
Population Densities ◽  
Northern Iran ◽  
Second Stage ◽  
The World

AbstractThe soybean cyst nematode (SCN), Heterodera glycines, found in most soybean growing regions in the world, is considered the most economically damaging pathogen of soybean worldwide. A survey conducted in the northern provinces of Mazandaran and Golestan, the main soybean-producing areas in Iran, revealed SCN was widespread in different localities of these regions. Of the 55 and 88 soil samples collected from soybean fields in Mazandaran and Golestan provinces, respectively, ten (18.8%) and 23 (26%) samples were infested with H. glycines; the population densities of second-stage juveniles (J2) and eggs ranged from 500 to 60 000 and 500 to ≥100 000 per 250 cm3 soil, respectively. These population densities of H. glycines are indicative of reductions in soybean yield. HG Type tests were conducted on 16 field populations. HG Type 0 (race 3) was the most common with 94% frequency, whereas HG Type 7 (race 6) was found in 6% of tested populations. Most populations of H. glycines parasitised PI88788 and PI548316. Eight of the most commonly used soybean cultivars were tested against H. glycines HG Type 0; seven of them, Sepideh, Sahar (Pershing), Gorgan 3, Williams 82, JK (Sari), BP (Telar) and Hill, had high female indices and were considered susceptible to HG Type 0. Only the cultivar DPX showed low female indices and was resistant to race 3. The initial observations showed that the first life cycle of SCN required 30-34 days in early-planted fields (late May and early June), whereas in late-planted fields (early July), white females were visible 20 days after planting. Several generations could be expected in a single growing season under field conditions in northern Iran.

scholarly journals Soybean Stem Colonization by Genotypes A and B of Cadophora gregata Increases with Increasing Population Densities of Heterodera glycines

Plant Disease ◽  
2006 ◽  
Vol 90 (10) ◽  
pp. 1297-1301 ◽  
Author(s):  
G. M. Tabor ◽  
G. L. Tylka ◽  
C. R. Bronson
Keyword(s):  
Population Density ◽  
Soybean Cyst Nematode ◽  
Heterodera Glycines ◽  
Cyst Nematode ◽  
Stem Rot ◽  
Population Densities ◽  
Brown Stem Rot ◽  
Phialophora Gregata ◽  
Soybean Genotypes ◽  
Genotype A

Growth chamber experiments were conducted to investigate whether parasitism by increasing population densities of Heterodera glycines, the soybean cyst nematode, increases the incidence and severity of stem colonization by the aggressive genotype A and the mild genotype B of Cadophora gregata (Phialophora gregata), causal agents of brown stem rot of soybeans. Soybean genotypes with three combinations of resistance and susceptibility to H. glycines and genotype A of C. gregata were inoculated with each genotype of C. gregata alone or each genotype with two population densities of H. glycines eggs, 1,500 or 10,000 per 100 cm3 of soil. Stems of two H. glycines-susceptible soybeans were more colonized by both aggressive and mild genotypes of C. gregata in the presence of high than in the presence of low H. glycines population density.

scholarly journals First Report of Soybean Cyst Nematode (Heterodera glycines) on Soybean in North Dakota

Plant Disease ◽  
2004 ◽  
Vol 88 (11) ◽  
pp. 1287-1287 ◽  
Author(s):  
C. A. Bradley ◽  
C. R. Biller ◽  
B. D. Nelson
Keyword(s):  
North Dakota ◽  
Soybean Cyst Nematode ◽  
Heterodera Glycines ◽  
Plant Introduction ◽  
Cyst Nematode ◽  
Diagnostic Laboratory ◽  
First Report ◽  
Second Stage ◽  
The North ◽  
Pi 88788

During August 2003, soybean (Glycine max) plants from Richland County, North Dakota with white-to-yellow, lemon-shaped structures on the roots were brought to the North Dakota State University Plant Diagnostic Laboratory. To confirm that the structures were females of a cyst nematode, they were crushed and observed microscopically to determine if nematode eggs and second-stage juveniles were present. Morphology of the second-stage juveniles was consistent with Heterodera glycines, the soybean cyst nematode (SCN). A survey was conducted in soybean fields in 34 km2 around the field in which the samples originated. Ten of twenty fields surveyed had visible females on the roots of plants. Symptoms observed in those fields included patches of stunted, chlorotic, and dead plants. Soil samples were collected from selected areas within eight fields, eggs were extracted using standard soil sieving techniques, and egg numbers were determined. Egg numbers ranged from 550 to 20,000 eggs per 100 cm3 of soil. SCN collected from two different fields, designated as Dwight and LaMars, were used to determine their HG Type. Standardized procedures (1) were used in a growth chamber set at 27°C with 16-h days. Pots in the test were organized in a completely randomized design with three replicates; the test was repeated over time. After 30 days, females were extracted from roots and counted, and a female index (FI) was calculated for each indicator line (1). The mean number of females on susceptible standard cv. Lee 74, was 110. The Dwight SCN population had an FI of 5.3 on plant introduction (PI) 88788, 1.5 on PI 209332, 5.8 on PI 548316 (Cloud), and 0 on all other indicator lines. The LaMars population had an FI of 1.0 on PI 88788, 3.1 on PI 548316 (Cloud), and 0 on all other indicator lines. These results indicate that both SCN populations tested are HG Type 0. To our knowledge, this is the first report of SCN on soybean in North Dakota. Because other hosts of SCN, as well as soybean, are economically important in North Dakota, such as dry edible bean (Phaseolus vulgaris) and dry pea (Pisum sativum), this disease could adversely impact several commodities throughout the state. Reference: (1) T. L. Niblack et al. J. Nematol. 34:279, 2002.

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.

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