scholarly journals Effects of Crotalaria juncea and C. spectabilis on hatching and population density of the soybean cyst nematode, Heterodera glycines (Tylenchida: Heteroderidae)

2003 ◽  
Vol 38 (3) ◽  
pp. 393-399 ◽  
Author(s):  
Atsuhiko Kushida ◽  
Nobuko Suwa ◽  
Yasuo Ueda ◽  
Youji Momota
Keyword(s):  
Population Density ◽  
Soybean Cyst Nematode ◽  
Heterodera Glycines ◽  
Cyst Nematode ◽  
Crotalaria Juncea

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.

Effects of agronomic practices on the timeline of Heterodera glycines establishment in a new location

Nematology ◽  
2015 ◽  
Vol 17 (6) ◽  
pp. 705-713 ◽  
Author(s):  
Haddish Melakeberhan ◽  
Wei Wang ◽  
Alexandra Kravchenko ◽  
Kurt Thelen
Keyword(s):  
Zea Mays ◽  
Glycine Max ◽  
Population Density ◽  
Soybean Cyst Nematode ◽  
Heterodera Glycines ◽  
Sandy Loam ◽  
Cyst Nematode ◽  
Agronomic Practices ◽  
No Till ◽  
New Location

How soybean cyst nematode (SCN,Heterodera glycines) adapts when introduced into a new location under tillage, rotation and crop treatments is unknown. SCN race 3 (Hg Type 0) was introduced into a sandy loam field at more than 4000 eggs (100 cm3soil)−1and observed over 6 years under till and no-till, and either maize (Zea mays; C), SCN race 3 resistant soybean (Glycine max; R) or susceptible soybean (S) monocrop, or RCRC and SCSC rotations. While SCN population density was lower in no-till than in tilled treatments, and highest in S and lowest in C or RC rotations, it was detected at less than 1 cyst (100 cm3soil)−1. This suggests a prolonged phase of decline from the introduced levels. The interaction effects of tillage, rotation and/or time on SCN suggest that outcomes vary by agronomic practice and time, providing agro-biologically-based understanding of SCN establishment in a new location.

Temporal-spatial population density of Heterodera glycines in soybean roots during the early growth stage

Nematology ◽  
2011 ◽  
Vol 13 (1) ◽  
pp. 79-86 ◽  
Author(s):  
Zhenhua Wang ◽  
Haiyan Wu ◽  
Jing Liu ◽  
Xiuxia Li
Keyword(s):  
Population Density ◽  
Soybean Cyst Nematode ◽  
Growth Stage ◽  
Heterodera Glycines ◽  
Soil Depth ◽  
Lateral Roots ◽  
Cyst Nematode ◽  
Soybean Plant ◽  
Nematode Density ◽  
Soybean Roots

AbstractPrevious research found that the population density of Heterodera glycines in soybean fields fluctuated during the growth of soybeans. However, the population density in soybean root was unclear. In this study, the dynamics of soybean cyst nematode (SCN; Heterodera glycines, race 4) in soybean roots were investigated over a period of 2 years. Soybean plant roots were sampled during a period of 7-37 days after seedling emergence, and SCN in taproots and lateral root were counted. The results indicated that the total population density of nematodes increased with the growth of soybean roots, showing a sigmoid curve. A comparison of nematode density between taproots and lateral roots showed a decrease in the numbers of nematodes in taproots and an increase in the numbers in lateral roots with increasing age of the plants. There was an overall decrease in nematode numbers with increasing soil depth. Our results show that most of the nematodes were found in roots from 5-15 cm soil depths (2006, 81.3-91.4%; 2007, 86.6-97.6%) during the soybean seedling growth stage, which may provide some useful information for integrated management of soybean cyst nematode.

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.

Efficacy of the fungi Hirsutella minnesotensis and H. rhossiliensis from liquid culture for control of the soybean cyst nematode Heterodera glycines

Nematology ◽  
2005 ◽  
Vol 7 (1) ◽  
pp. 149-157 ◽  
Author(s):  
Shufen Liu ◽  
Senyu Chen
Keyword(s):  
Heat Treatment ◽  
Population Density ◽  
Soybean Cyst Nematode ◽  
Liquid Culture ◽  
Heterodera Glycines ◽  
Nematode Population ◽  
Solid Culture ◽  
Nematode Population Density ◽  
Biological Control Potential ◽  
Shoot Weight

AbstractHirsutella minnesotensis and H. rhossiliensis are endoparasites of nematodes, and their biological control potential against Heterodera glycines when cultured and applied on corn grits has been reported. In this study, the potential of liquid cultures of the two fungi was evaluated in two glasshouse experiments. Both liquid culture at 0.2, 0.4 and 0.8 g of fresh mycelium/300 cm3 soil (per pot) and solid culture at 1% (corn grits: soil, w/w) reduced nematode egg population densities in both autoclaved and unheated soils as compared with soil-only control or corn-grits control. However, the liquid culture at 0.2–0.8 g of mycelium/pot appeared to be more effective in reducing the nematode population than the solid culture of 1%. Hirsutella rhossiliensis resulted in lower nematode population density than H. minnesotensis only in unheated soil in one experiment. The soil heat treatment generally increased the nematode population density but did not affect percentage reduction of the nematode population density as compared with respective controls, except that reduction by H. rhossiliensis was greater in unheated soil than heat-treated soil in one experiment. Percentage of second-stage juveniles (J2) parasitised by fungi at the end of the experiment (60 days after planting) was generally higher with H. minnesotensis than with H. rhossiliensis. The percentage parasitism was positively correlated with initial fungal inoculation level. The soil heat treatment increased fungal parasitism in one experiment but not in the other. Plant growth was unaffected by treatments except that the soil heat treatment increased plant shoot weight as compared with unheated soil in one experiment.

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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