scholarly journals Spatial Distribution of Soybean Cyst Nematode in Research Plots

Plant Disease ◽  
2019 ◽  
Vol 103 (8) ◽  
pp. 1876-1883
Author(s):  
Susilo H. Poromarto ◽  
Luis E. del Río Mendoza ◽  
Berlin D. Nelson

Soybean cyst nematode (SCN; Heterodera glycines Ichinohe) is a major pathogen of soybean [Glycine max (L.) Merr.] in the United States. The spatial distribution of SCN in 10 naturally infested research sites in North Dakota was examined between 2006 and 2009. Egg densities were measured in plots and expressed as arithmetic means or grouped into classes using two categorical scales based on the effect of SCN on yield. Data were used to determine spatial distribution, egg cluster sizes, minimum plot sizes, and replications in field experiments. SCN populations varied among plots from undetected to 25,800 eggs/100 cm3 of soil, and differences between adjacent plots were as high as sixfold. Mean to median ratios and Lloyd’s index of patchiness suggested an aggregated distribution in nine of the 10 sites. SCN cluster sizes varied in five of the 10 sites and optimum plot size over all sites varied depending on calculation methods. The minimum number of replications needed to detect specific differences among plots varied between field sites. Grouping data into either of the two categories generally increased the ability to detect differences between plots. The spatial distribution of SCN can be a critical factor affecting design and outcomes of field experiments.

2020 ◽  
Vol 80 (03) ◽  
Author(s):  
Ik-Young Choi ◽  
Prakash Basnet ◽  
Hana Yoo ◽  
Neha Samir Roy ◽  
Rahul Vasudeo Ramekar ◽  
...  

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.


Author(s):  
Kangfu Yu ◽  
Lorna Woodrow ◽  
M. Chun Shi

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).


2018 ◽  
Vol 98 (6) ◽  
pp. 1389-1391
Author(s):  
S. Torabi ◽  
B.T. Stirling ◽  
J. Kobler ◽  
M. Eskandari

OAC Bruton is an indeterminate large-seeded food-grade soybean [Glycine max (L.) Merr.] cultivar with high yield potential, high seed protein concentration, and resistance to soybean cyst nematode (SCN). OAC Bruton is developed and recommended for soybean growing areas in southwestern Ontario with 2950 or greater crop heat units. OAC Bruton is classified as a maturity group 1 (MG1) cultivar with a relative maturity of 1.8.


2003 ◽  
Vol 95 (4) ◽  
pp. 936-948 ◽  
Author(s):  
Felicitas Avendaño ◽  
Oliver Schabenberger ◽  
Francis J. Pierce ◽  
Haddish Melakeberhan

Plant Disease ◽  
2021 ◽  
Author(s):  
Mariola Usovsky ◽  
Robert Robbins ◽  
Juliet Fultz Wilkes ◽  
Devany Crippen ◽  
Vijay Shankar ◽  
...  

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.


2021 ◽  
Author(s):  
Intiaz Amin Chowdhury ◽  
Guiping Yan ◽  
Addison Plaisance ◽  
sam markell

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.


2020 ◽  
Vol 34 (5) ◽  
pp. 699-703
Author(s):  
Jason K. Norsworthy ◽  
Jacob Richburg ◽  
Tom Barber ◽  
Trenton L. Roberts ◽  
Edward Gbur

AbstractAtrazine offers growers a reliable option to control a broad spectrum of weeds in grain sorghum production systems when applied PRE or POST. However, because of the extensive use of atrazine in grain sorghum and corn, it has been found in groundwater in the United States. Given this issue, field experiments were conducted in 2017 and 2018 in Fayetteville and Marianna, Arkansas, to explore the tolerance of grain sorghum to applications of assorted photosystem II (PSII)-inhibiting herbicides in combination with S-metolachlor (PRE and POST) or mesotrione (POST only) as atrazine replacements. All experiments were designed as a factorial, randomized complete block; the two factors were (1) PSII herbicide and (2) the herbicide added to create the mixture. The PSII herbicides were prometryn, ametryn, simazine, fluometuron, metribuzin, linuron, diuron, atrazine, and propazine. The second factor consisted of either no additional herbicide, S-metolachlor, or mesotrione; however, mesotrione was excluded in the PRE experiments. Crop injury estimates, height, and yield data were collected or calculated in both studies. In the PRE study, injury was less than 10% for all treatments except those containing simazine, which caused 11% injury 28 d after application (DAA). Averaged over PSII herbicide, S-metolachlor–containing treatments caused 7% injury at 14 and 28 DAA. Grain sorghum in atrazine-containing treatments yielded 97% of the nontreated. Grain sorghum receiving other herbicide treatments had significant yield loss due to crop injury, compared with atrazine-containing treatments. In the POST study, ametryn- and prometryn-containing treatments were more injurious than all other treatments 14 DAA. Grain sorghum yield in all POST treatments was comparable to atrazine, except prometryn plus mesotrione, which was 65% of the nontreated. More herbicides should be evaluated to find a comparable fit to atrazine when applied PRE in grain sorghum. However, when applied POST, diuron, fluometuron, linuron, metribuzin, propazine, and simazine have some potential to replace atrazine in terms of crop tolerance and should be further tested as part of a weed control program across a greater range of environments.


2018 ◽  
Vol 98 (6) ◽  
pp. 1392-1394
Author(s):  
S. Torabi ◽  
B.T. Stirling ◽  
J. Kobler ◽  
M. Eskandari

OAC Ramsay is an indeterminate large-seeded food-grade soybean [Glycine max (L.) Merr.] cultivar with high yield potential, high seed protein and oil concentrations, and resistance to soybean cyst nematode. OAC Ramsay is developed and recommended for soybean growing areas in southwestern Ontario with 3050 or greater crop heat units and has a relative maturity of 2.2 (MG 2.2).


2009 ◽  
Vol 10 (1) ◽  
pp. 24 ◽  
Author(s):  
Allen Wrather ◽  
Steve Koenning

Research must focus on management of diseases that cause extensive losses, especially when funds for research are limited. Knowledge of yield suppression caused by various soybean diseases is essential when prioritizing research. The objective of this project was to compile estimates of soybean yield suppression due to diseases in the USA from 1996 to 2007. The goal was to provide information to help funding agencies and scientists prioritize research objectives and budgets. Yield suppression due to individual diseases varied among years. Soybean cyst nematode suppressed USA soybean yield more from 1996 to 2007 than any other disease. Phytophthora root and stem rot ranked second among diseases that most suppressed yield seven of 12 years. Seedling diseases and charcoal rot also suppressed soybean yield during these years. Research and extension efforts must be expanded to provide more preventive and therapeutic disease management strategies for producers to reduce disease suppression of soybean yield. Accepted for publication 25 February 2009. Published 1 April 2009.


2019 ◽  
Vol 99 (6) ◽  
pp. 969-971
Author(s):  
K. Yu ◽  
L. Woodrow ◽  
C. Shi

AAC Big Ben is a high yielding, soybean cyst nematode resistant food-grade soybean [Glycine max (L.) Merr.] cultivar with yellow hilum and acceptable processing quality for foreign and domestic tofu, soymilk, and miso markets. AAC Big Ben was developed at the Agriculture and Agri-Food Canada (AAFC) Harrow Research and Development Centre (Harrow-RDC), Harrow, ON. AAC Big Ben is adapted to areas of southwestern Ontario with 3300 or more crop heat units and has a relative maturity group of 2.3 (MG 2.3).


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