scholarly journals First Report of Soybean Cyst Nematode (Heterodera glycines) on Soybean in Puerto Rico

Plant Disease ◽  
1999 ◽  
Vol 83 (6) ◽  
pp. 591-591
Author(s):  
J. R. Smith ◽  
J. A. Chavarria-Carvajal
Keyword(s):  
Puerto Rico ◽  
Common Bean ◽  
Soybean Cyst Nematode ◽  
Heterodera Glycines ◽  
Pigeon Pea ◽  
Cyst Nematode ◽  
Research Field ◽  
Growth Stages ◽  
Infested Soil ◽  
Infested Field

Soybean (Glycine max (L.) Merr.) winter nurseries have been planted in Puerto Rico at the USDA's Isabela farm for 25 consecutive years. The field has had one soybean crop each year, with a summer fallow period between winter nursery seasons. In February 1998, during an inspection of root nodulation, cysts were discovered on roots of an F2 population (Benning × Pureunkong). Microscopic examination of roots confirmed the presence of female nematodes of Heterodera glycines Ichinohe in various stages of development. No cysts were found when soil and roots were randomly sampled at various growth stages (R1 to R7) from other soybean fields in Puerto Rico (Isabela, Salinas, Lajas, and Juana Diaz). Also, no cysts were observed on roots of common bean (Phaseolus vulgaris) at growth stages R7 to R8 in a neighboring research field. However, cysts were observed on 35-day-old roots of soybean cv. Lee, common bean, and pigeon pea (Cajanas cajun) grown in the above infested soil. A race assay, slightly modified from standard protocols (3), determined that the infested soil contained race 2 of H. glycines. The infested field was rotated to sorghum during the summer of 1998 and then soybeans were planted in the 1998-1999 winter nursery. H. glycines occurs in at least 26 states of the U.S., and in Canada, Asia, and South America (1,2). References: (1) M. L. Mendes and D. W. Dickson. Plant Dis. 77:499, 1993. (2) R. D. Riggs and D. P. Schmitt. 1989. Soybean Cyst Nematode. Page 65 in: Compendium of Soybean Diseases. 3rd ed. J. B. Sinclair and P. A. Backman, eds. American Phytopathological Society, St. Paul, MN. (3) D. P. Schmitt and G. Shannon. Crop Sci. 32:275, 1992.

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.

Comparative host suitability of common bean cultivars to the soybean cyst nematode, Heterodera glycines, in Iran

Nematology ◽  
2010 ◽  
Vol 12 (3) ◽  
pp. 335-341
Author(s):  
Naser Safaie ◽  
Zahra Tanha Maafi ◽  
Ebrahim Pourjam ◽  
Ramin Heydari
Keyword(s):  
Common Bean ◽  
Soybean Cyst Nematode ◽  
Field Experiments ◽  
Heterodera Glycines ◽  
Field Trials ◽  
Cyst Nematode ◽  
Host Suitability ◽  
Nematode Reproduction ◽  
Pot Trials ◽  
Moderately Resistant

AbstractThe first occurrence of soybean cyst nematode, Heterodera glycines, on beans in Iran was documented when a cyst-forming nematode was detected in a commercial common bean (Phaseolus vulgaris) field in Iran and subsequently identified as H. glycines. The population was identified as HG Type 0. Host suitability of the 11 P. vulgaris cultivars most commonly grown in the country were evaluated with that population in pot and field trials. Pot assays were conducted in a growth chamber and nematode reproduction on the cultivars was compared. In the field trials, host suitability of the tested entries was evaluated in a field naturally infested with H. glycines. In both the pot and field experiments, most of the common bean cultivars were susceptible or moderately susceptible to the HG Type 0 populations of H. glycines. Common bean cvs Sayad and Dehghan were classified as moderately resistant in pot trials and were moderately resistant and moderately susceptible, respectively, in field trials. The occurrence of H. glycines in commercial bean production fields and lack of high levels of resistance of the commonly grown P. vulgaris cultivars could severely affect common bean and soybean production programmes in Iran.

Developing a Real-time PCR Assay for Direct Identification and Quantification of Soybean Cyst Nematode, Heterodera glycines, in Soil and Its Discrimination from Sugar Beet Cyst Nematode, Heterodera schachtii

Plant Disease ◽  
2021 ◽  
Author(s):  
Richard Baidoo ◽  
Guiping Yan
Keyword(s):  
Sugar Beet ◽  
Real Time Pcr ◽  
Soybean Cyst Nematode ◽  
Heterodera Glycines ◽  
Cyst Nematode ◽  
Qpcr Assay ◽  
Field Soils ◽  
Infested Field ◽  
Sugar Beet Cyst Nematode ◽  
Detection And Quantification

The soybean cyst nematode (SCN) Heterodera glycines continues to be a major threat to soybean production worldwide. Morphological discrimination between SCN and other nematodes of the H. schachtii sensu stricto group is not only difficult and time-consuming, but also requires high expertise in nematode taxonomy. Molecular assays were developed to differentiate SCN from sugar beet cyst nematode (SBCN) and other nematodes; and to quantify SCN directly from DNA extracts of field soils. SCN and SBCN-specific quantitative real-time PCR (qPCR) primers were designed from a nematode-secreted CLAVATA gene and used for these assays. The primers were evaluated based on specificity, efficiency, and target specificity to SCN or SBCN using DNA from 20 isolates of SCN and 32 isolates of other plant-parasitic nematodes. A standard curve relating threshold cycle and log values of nematode numbers was generated from artificially infested soils and was used to quantify SCN in naturally infested field soils. There was a high correlation between the SCN numbers estimated from naturally infested field soils by conventional methods, and the numbers quantified using the SYBR Green I-based qPCR assay. The qPCR assay is highly specific and sensitive and provides improved SCN detection sensitivity down to 1 SCN egg in 20 g of soil (10 eggs/200 g soil). This assay is useful for efficient detection and quantification of SCN directly from field soil. Species-specific conventional PCR assays were also developed each for SCN and SBCN, alongside a qPCR assay that simultaneously discriminates SCN from SBCN. These assays require no expertise in nematode taxonomy and morphology, and may serve as useful diagnostic tools in research, diagnostic labs, and extension services for SCN management. Sensitive and accurate detection and quantification of SCN are essential for recommending effective management measures against SCN. We also investigated the impact of soil texture and nematode life stage on molecular quantification of SCN.

Assessing direct and residual effects of cover crops on the soybean cyst nematode, Heterodera glycines

Plant Disease ◽  
2021 ◽  
Author(s):  
Chelsea J. Harbach ◽  
Gregory L. Tylka
Keyword(s):  
Cover Crops ◽  
Cover Crop ◽  
Soybean Cyst Nematode ◽  
Heterodera Glycines ◽  
Cyst Nematode ◽  
Residual Effects ◽  
Infested Soil ◽  
Annual Ryegrass ◽  
Population Densities ◽  
Crimson Clover

Greenhouse experiments were conducted to determine if cover crops directly decrease population densities of the soybean cyst nematode (SCN), Heterodera glycines, and/or have residual effects on reproduction of the nematode on soybean (Glycine max). Population densities of SCN were not significantly decreased by nine cover crop plants or three cover crop mixes compared to a non-planted soil control in a repeated 60-day-long greenhouse experiment. When susceptible soybeans were grown in the soils after cover crop growth, fewer SCN females formed following three annual ryegrass (Lolium multiflorum) cultivars (Bounty, King, and RootMax), the Daikon radish (Raphanus sativus var. longipinnatus) cultivar CCS779, Kodiak mustard (Brassica juncea), and a mix containing cereal rye, crimson clover (Trifolium incarnatum), plus Daikon radish (cultivars not stated) compared to following the non-planted control. In another repeated experiment, cover crops were grown for 56 days in SCN-infested soil in the greenhouse then exposed to Iowa winter conditions for 28 days to simulate winter termination of the plants. One treatment, a cover crop mix containing Bounty annual ryegrass plus Enricher Daikon radish, had a decrease in SCN population density greater than the non-planted control at the end of the experiment. Significantly fewer SCN females formed on soybeans grown following several cover crops, including the three annual ryegrass cultivars that had the suppressive residual effects in the first experiment. In summary, there were no cover crop treatments that consistently decreased SCN population densities across experiments, and only one cover crop treatment in one experiment significantly reduced SCN population densities more than a non-planted soil control. However, there was a somewhat consistent, adverse, residual effect of cover crops on reproduction of SCN on susceptible soybeans following growth of multiple cover crops.

scholarly journals Weeds Hosting the Soybean Cyst Nematode (Heterodera glycines Ichinohe): Management Implications in Agroecological Systems

Agronomy ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 146
Author(s):  
Leonardo F. Rocha ◽  
Karla L. Gage ◽  
Mirian F. Pimentel ◽  
Jason P. Bond ◽  
Ahmad M. Fakhoury
Keyword(s):  
Weed Management ◽  
Soybean Cyst Nematode ◽  
Heterodera Glycines ◽  
Integrated Management ◽  
Cropping System ◽  
Cyst Nematode ◽  
Weed Species ◽  
Initial Inoculum ◽  
Herbicide Resistant ◽  
Sites Of Action

The soybean cyst nematode (SCN; Heterodera glycines Ichinohe) is a major soybean-yield-limiting soil-borne pathogen, especially in the Midwestern US. Weed management is recommended for SCN integrated management, since some weed species have been reported to be hosts for SCN. The increase in the occurrence of resistance to herbicides complicates weed management and may further direct ecological–evolutionary (eco–evo) feedbacks in plant–pathogen complexes, including interactions between host plants and SCN. In this review, we summarize weed species reported to be hosts of SCN in the US and outline potential weed–SCN management interactions. Plants from 23 families have been reported to host SCN, with Fabaceae including most host species. Out of 116 weeds hosts, 14 species have known herbicide-resistant biotypes to 8 herbicide sites of action. Factors influencing the ability of weeds to host SCN are environmental and edaphic conditions, SCN initial inoculum, weed population levels, and variations in susceptibility of weed biotypes to SCN within a population. The association of SCN on weeds with relatively little fitness cost incurred by the latter may decrease the competitive ability of the crop and increase weed reproduction when SCN is present, feeding back into the probability of selecting for herbicide-resistant weed biotypes. Therefore, proper management of weed hosts of SCN should be a focus of integrated pest management (IPM) strategies to prevent further eco–evo feedbacks in the cropping system.

AAC Richard Soybean

2022 ◽  
Author(s):  
Kangfu Yu ◽  
Lorna Woodrow ◽  
M. Chun Shi
Keyword(s):  
Glycine Max ◽  
Research And Development ◽  
Soybean Cyst Nematode ◽  
Protein Concentration ◽  
Heterodera Glycines ◽  
Cyst Nematode ◽  
Processing Quality ◽  
Food Grade ◽  
High Protein Concentration ◽  
Glycine Max L

AAC Richard is a food grade soybean [Glycine max (L.) Merr] cultivar with yellow hilum, high protein concentration, and good processing quality for foreign and domestic soymilk, tofu, and miso markets. It has resistance to SCN (soybean cyst nematode) (Heterodera Glycines Ichinohe). AAC Richard was developed at the Agriculture and Agri-Food Canada (AAFC) Harrow Research and Development Centre (Harrow-RDC), Harrow, Ontario and is adapted to areas of southwest Ontario with 3100 or more crop heat units and has a relative maturity of 2.3 (MG 2.3).

scholarly journals Taxonomic Resolution of the Nematophagous Fungal Isolate ARF18 via Genome Sequencing

2017 ◽  
Vol 5 (34) ◽  
Author(s):  
Sandeep Sharma ◽  
Alex Z. Zaccaron ◽  
John B. Ridenour ◽  
Amy Bradshaw ◽  
Terry L. Kirkpatrick ◽  
...  
Keyword(s):  
Soybean Cyst Nematode ◽  
Heterodera Glycines ◽  
Novel Species ◽  
Biological Control Agent ◽  
Draft Genome ◽  
Control Agent ◽  
Nematophagous Fungus ◽  
Cyst Nematode ◽  
Fungal Isolate ◽  
Taxonomic Resolution

ABSTRACT The taxonomically uncharacterized nematophagous fungus ARF18, which parasitizes cysts, juveniles, and adults of the soybean cyst nematode (Heterodera glycines), was proposed as a nematode biological control agent in 1991. A 46.3-Mb draft genome sequence of this fungus is presented, and a tentative taxonomic identification as a novel species of Brachyphoris is proposed.

scholarly journals The genome of the soybean cyst nematode (Heterodera glycines) reveals complex patterns of duplications involved in the evolution of parasitism genes

2018 ◽  
Author(s):  
Rick Masonbrink ◽  
Tom R. Maier ◽  
Usha Muppiral ◽  
Arun S. Seetharam ◽  
Etienne Lord ◽  
...  
Keyword(s):  
Soybean Cyst Nematode ◽  
Heterodera Glycines ◽  
Control Strategies ◽  
Cyst Nematode ◽  
Effective Control ◽  
Evolutionary Mechanisms ◽  
Long Read ◽  
Soybean Plants ◽  
Parasitism Genes ◽  
Nematode Genomes

AbstractHeterodera glycines, commonly referred to as the soybean cyst nematode (SCN), is an obligatory and sedentary plant parasite that causes over a billion-dollar yield loss to soybean production annually. Although there are genetic determinants that render soybean plants resistant to certain nematode genotypes, resistant soybean cultivars are increasingly ineffective because their multi-year usage has selected for virulentH. glycinespopulations. The parasitic success ofH. glycinesrelies on the comprehensive re-engineering of an infection site into a syncytium, as well as the long-term suppression of host defense to ensure syncytial viability. At the forefront of these complex molecular interactions are effectors, the proteins secreted byH. glycinesinto host root tissues. The mechanisms of effector acquisition, diversification, and selection need to be understood before effective control strategies can be developed, but the lack of an annotated genome has been a major roadblock. Here, we use PacBio long-read technology to assemble aH. glycinesgenome of 738 contigs into 123Mb with annotations for 29,769 genes. The genome contains significant numbers of repeats (34%), tandem duplicates (18.7Mb), and horizontal gene transfer events (151 genes). Using previously published effector sequences, the newly generatedH. glycinesgenome, and comparisons to other nematode genomes, we investigate the evolutionary mechanisms responsible for the emergence and diversification of effector genes.

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