scholarly journals Soybean Cultivar and Foliar Fungicide Effects on Phomopsis sp. Seed Infection

Plant Disease ◽  
2004 ◽  
Vol 88 (7) ◽  
pp. 721-723 ◽  
Author(s):  
J. A. Wrather ◽  
J. G. Shannon ◽  
W. E. Stevens ◽  
D. A. Sleper ◽  
A. P. Arelli
Keyword(s):  
Production System ◽  
Foliar Application ◽  
Soybean Seed ◽  
Seed Infection ◽  
Soybean Line ◽  
Breeding Programs ◽  
Phomopsis Seed Decay ◽  
Developing Seed ◽  
Seed Decay ◽  
Foliar Fungicide

Phomopsis seed decay (PSD) caused by Phomopsis spp. can be severe when soybean seed producers in the southern United States use the early soybean production system (ESPS) to avoid late-July through early-September drought damage to soybean. The usefulness of this production system would be greater if developing seed could be protected from PSD by foliar application of fungicides or by planting Phomopsis spp.-resistant soybean lines. The objective of this research was to determine the affects of the fungicides benomyl and azoxystrobin applied to soybean, at various times, on percent Phomopsis spp. infection of seed in Asgrow 3834, a PSD-susceptible cultivar, and SS93-6012, a PSD-resistant soybean line, planted in mid-April. The percent Phomopsis spp. infection of Asgrow 3834 seed averaged over years was significantly less for the benomyl (0.28 kg a.i. ha-1) applied at R3 + R5 treatment (48.6% seed infection) than the control (52.8% seed infection) and significantly greater for the azoxystrobin (0.17 kg a.i. ha-1) applied at R3 + R5 treatment (61.6% seed infection) than the control (52.8% seed infection). This method of managing PSD will not be acceptable to soybean growers. The percent of Phomopsis spp. infection of Asgrow 3834 seed averaged over years (52.8% seed infection) was significantly greater than for line SS93-6012 (2.8% seed infection). There were no differences in percent Phomopsis spp. infection of SS93-6012 seed between the control (2.8% seed infection) and benomyl treatment (4.0% seed infection). The most effective method for PSD management was to plant a resistant soybean line. Line SS93-6012 will be useful in breeding programs focused on developing high yielding PSD-resistant cultivars.

Effects of soybean cultivar, foliar application of azoxystrobin, and year on seed vigor and microflora under delayed harvest conditions.

Plant Disease ◽  
2020 ◽  
Author(s):  
Kimberly Cochran ◽  
Adele Steger ◽  
Robert Holland ◽  
John C. Rupe
Keyword(s):  
Bacillus Subtilis ◽  
Growth Stage ◽  
Foliar Application ◽  
Soybean Seed ◽  
Seed Vigor ◽  
Research Station ◽  
Seed Infection ◽  
Fusarium Spp ◽  
Infection Incidence ◽  
Foliar Fungicide

The effects of cultivar and foliar fungicide application on soybean seed germination, vigor, microflora, and yield after delayed harvest were determined at the University of Arkansas Vegetable Research Station in Kibler, AR, from 2008 to 2010. Seven cultivars with varying levels of resistance to Diaporthe spp. or Cercospora spp. were treated or not treated with a foliar application of azoxystrobin at the R5 growth stage. Plots were harvested three weeks after the plants had reached harvest maturity. Yields were recorded, samples of seed were collected, and standard germination (SG) and accelerated aging (AA) were assessed. Seeds were also assayed for infection by fungi on modified potato dextrose agar and by bacteria on nutrient agar. Seed vigor was significantly reduced by infection with Diaporthe spp., Fusarium spp., and Bacillus subtilis, but not with Cercospora spp. Cultivar had a significant impact on yield, seed vigor, and seed infection levels. The cultivar Osage consistently had high seed vigor and low overall seed infection incidence throughout the study. MO/PSD-0259, AG 4403 and UA 4805 also had relatively high seed vigor and low seed infection incidence. PI 80837 had low incidence of seed infection by Diaporthe spp. and Fusarium spp. in 2008 and 2010, but high levels in 2009 when environmental conditions were especially favorable for these pathogens. AP 350 and Suweon97 generally had relatively high seed infection incidences, particularly of Diaporthe spp. and Fusarium spp., and relatively low seed vigor. Application of the foliar fungicide azoxystrobin at the R5 growth stage significantly increased AA across years and cultivars and increased seed infection by Diaporthe spp. in 2009 across cultivars. There were significant negative correlations between yield and seed infection by Diaporthe spp. and Bacillus subtilis in one year and with Fusarium spp. in all three years. Overall, resistance to seed infection can persist even when harvest is delayed and in addition to Diaporthe spp., other seedborne pathogens may reduce seed vigor and yield.

scholarly journals Planting Date and Cultivar Effects on Soybean Yield, Seed Quality, and Phomopsis sp. Seed Infection

Plant Disease ◽  
2003 ◽  
Vol 87 (5) ◽  
pp. 529-532 ◽  
Author(s):  
J. A. Wrather ◽  
D. A. Sleper ◽  
W. E. Stevens ◽  
J. G. Shannon ◽  
R. F. Wilson
Keyword(s):  
Seed Quality ◽  
Significant Negative Correlation ◽  
Planting Date ◽  
Seed Infection ◽  
Planting Dates ◽  
Breeding Programs ◽  
Group Iii ◽  
Phomopsis Seed Decay ◽  
Seed Decay

Incidence of Phomopsis seed decay is frequently high and quality low in seed from early-maturing maturity group III and IV soybean cultivars planted in early to mid-April in the southern United States. Cultivars resistant to this disease have not been available until the recent release of germ plasm lines SS 93-6012 and SS 93-6181. Our objective was to determine the effects of planting dates with these lines and one Phomopsis seed decay-susceptible soybean cultivar, Asgrow 3834, on seed infection by Phomopsis spp. and on yield and the correlation between percentage of Asgrow 3834 infected with Phomopsis spp. and seed quality. Generally, yields averaged over years were significantly greater for mid-April than mid-June plantings, and yields of cultivars were similar within a planting date. Soybean lines SS 93-6012 and SS 93-6181 were highly resistant to Phomopsis seed decay compared with the susceptible cultivar, Asgrow 3834. There was a significant, negative correlation between germination of seed from mid-April plantings of Asgrow 3834 and percentage of these seed infected with Phomopsis spp. Moreover, there were significant correlations between fatty acid composition of Asgrow 3834 seed and the percentage of these seed infected with Phomopsis spp. This altered composition of fatty acids may be responsible for reduced quality of oil derived from seed infected with this fungus. Phomopsis seed decay-resistant soybean lines SS 93-6012 and SS 93-6181 should be useful in breeding programs focused on developing high-yielding cultivars resistant to this disease.

Evaluation of Soybean Genotypes for Resistance to Three Seed-borne Diseases

2012 ◽  
Vol 13 (1) ◽  
pp. 21 ◽  
Author(s):  
Alemu Mengistu ◽  
P. A. Arelli ◽  
Nacer Bellaloui ◽  
J. P. Bond ◽  
G. J. Shannon ◽  
...  
Keyword(s):  
Seed Quality ◽  
Soybean Seed ◽  
Seed Infection ◽  
Phomopsis Longicolla ◽  
Phomopsis Seed Decay ◽  
No Till ◽  
Seed Decay ◽  
Soybean Genotypes ◽  
Moderately Resistant ◽  
Purple Seed Stain

Seed-borne diseases of soybeans caused by Phomopsis longicolla (Phomopsis seed decay), Cercospora kukuchii (purple seed stain), and M. phaseolina (charcoal rot) are economically important diseases that affect seed quality. Commercial cultivars marketed as resistant to all three diseases are not available. Reactions of 27 maturity group (MG) III, 30 early MG IV, 33 late MG IV, and 53 MG V genotypes were evaluated for resistance to these pathogens during the 2006 to 2008 growing season in the same field that had been in no-till production, not irrigated, and naturally and artificially infested. There was great variation in seed infection among genotypes and years, indicating the value of screening genotypes over multiple years. Some genotypes were resistant to these pathogens in one, two, or in all three years. Genotypes, DP 3478 (early MG IV), and RO1-769F (MG V) were resistant and DG4460 was moderately resistant to P. longicolla infection across three years. Genotypes AG3705 and FFR3990 (MG III) and DC20300, DC7816, Stoddard, and Ozark (MG V), were resistant to C. kukuchii infection during all three years. Ten genotypes in MG III, eight in early MG IV, seven in late MG IV, and 14 in MG V had no seed infection by M. phaseolina in all three years. These results indicate that seed infection comparison to these pathogens among genotypes should be made over several years, or false conclusions about resistance to any of the three pathogens may be made when disease is assessed for limited period of time. The genotypes identified as having resistance to each or combinations of the seed-borne diseases across the three years could be useful as a source for resistance in improving soybean seed quality. Accepted for publication 20 December 2012. Published 21 March 2012.

scholarly journals Detection of Asymptomatic Fungal Infections of Soybean Seeds by Ultrasound Analysis

Plant Disease ◽  
1998 ◽  
Vol 82 (5) ◽  
pp. 584-589 ◽  
Author(s):  
R. R. Walcott ◽  
D. C. McGee ◽  
M. K. Misra
Keyword(s):  
Moisture Content ◽  
Fungal Infections ◽  
Soybean Seed ◽  
Soybean Seeds ◽  
Seed Infection ◽  
Seed Moisture Content ◽  
Phomopsis Seed Decay ◽  
Storage Fungi ◽  
Seed Decay ◽  
Ultrasound Signals

Different levels of asymptomatic, seed-borne infection by storage fungi (Aspergillus and Penicillium spp.) or Phomopsis seed decay (PSD) (Phomopsis longicolla, Diaporthe phaseolorum var. sojae, and D. phaseolorum var. caulivora) were induced in sub-lots of separate soybean seed lots by incubation of seeds or pods, respectively, for different times at 25°C and at a relative humidity >95%. Seeds were then air-dried to a constant moisture content in the laboratory atmosphere, and each sub-lot was tested for incidence of infection, germination, and moisture content. Individual seeds in each sub-lot also were dropped 10 cm onto a transducer in an ultrasound analyzer. The average peak value of the ultrasound signals for each sub-lot, which indicates the weight of seeds, decreased linearly as the incidence of seed infection by storage fungi (r2 = 0.85) or PSD (r2 =0.82) increased. The slope and width of the signal, which indicates seed softness, increased as seed infection increased for both groups of fungi, although coefficients of determination were lower (r2 ranged from 0.42 to 0.59). Germination values, which decreased as seed infection for both pathogens increased, showed similar but inverse relationships to ultrasound parameters. Peak values of ultrasound signals decreased, and slope and width increased, as seed moisture content increased for sub-lots of soybeans at three levels of infection by Phomopsis seed decay. The potential for ultrasound technology to identify soybean seeds with asymptomatic infections of seed-borne pathogens was thus established.

scholarly journals Aggressiveness of Phomopsis longicolla and Other Phomopsis spp. on Soybean

Plant Disease ◽  
2010 ◽  
Vol 94 (8) ◽  
pp. 1035-1040 ◽  
Author(s):  
Shuxian Li ◽  
Glen L. Hartman ◽  
Deborah L. Boykin
Keyword(s):  
Soybean Seed ◽  
Poor Quality ◽  
Stem Length ◽  
Lesion Length ◽  
Phomopsis Longicolla ◽  
Phomopsis Seed Decay ◽  
Stem Lesion ◽  
Seed Decay ◽  
Geographic Origins ◽  
Soybean Plants

Phomopsis seed decay of soybean is a major cause of poor-quality soybean seed. The disease is caused primarily by the fungal pathogen Phomopsis longicolla. Aggressiveness of isolates of P. longicolla from soybean and other Phomopsis spp. from other hosts were compared by inoculating 2-week-old soybean plants of cv. Williams 82. There were significant (P ≤ 0.0001) differences among isolates based on stem length and stem lesion length. The P. longicolla soybean isolate PL16, from Mississippi, caused the shortest stem length while the non-soybean isolate P9, from Illinois, caused the greatest stem lesion length. The type isolate of P. longicolla, PL31 (Fau 600), was one of the 3 most aggressive isolates among all 48 isolates tested. The velvetleaf isolate P9 was the most aggressive among 13 isolates from non-soybean hosts. This study provided the first evaluation of aggressiveness of P. longicolla isolates from different geographic origins and the first demonstration that Phomopsis spp. isolated from cantaloupe, eggplant, and watermelon infected soybean. Knowledge about the variability of the pathogen is important for selecting isolates for breeding soybean lines with broad-based resistance to Phomopsis seed decay.

scholarly journals Evaluation of Commercial Soybean Cultivars for Reaction to Phomopsis Seed Decay

Plant Disease ◽  
2017 ◽  
Vol 101 (12) ◽  
pp. 1990-1997 ◽  
Author(s):  
Shuxian Li ◽  
Gabe Sciumbato ◽  
John Rupe ◽  
Grover Shannon ◽  
Pengyin Chen ◽  
...  
Keyword(s):  
Seed Quality ◽  
Effective Means ◽  
Seed Infection ◽  
Phomopsis Longicolla ◽  
Genetic Studies ◽  
Phomopsis Seed Decay ◽  
Soybean Cultivars ◽  
Seed Decay ◽  
Poor Seed ◽  
Selection Of

Phomopsis seed decay (PSD), caused by Phomopsis longicolla (syn. Diaporthe longicolla), is an economically important soybean disease causing poor seed quality. Planting resistant cultivars is one of the most effective means to control PSD. In this study, 16 commercially available maturity groups IV and V soybean cultivars, including two previously identified PSD-resistant and two PSD-susceptible checks, were evaluated for seed infection by P. longicolla in inoculated and noninoculated plots, and harvested promptly or with a 2-week delay in harvest. The test was conducted at Stoneville, Mississippi, in 2012 and 2013. Seed infection by P. longicolla ranged from 0.5 to 76%, and seed germination ranged from 18 to 97%. One MG IV cultivar (Morsoy R2 491) and five MG V cultivars (Progeny 5650, Progeny 5706, Asgrow 5606, Asgrow 5831, and Dyna-Gro33C59) had significantly (P ≤ 0.05) lower percent seed infected by P. longicolla than their respective susceptible checks and other cultivars in the same tests. Information obtained from this study will be useful for soybean growers and breeders for selection of cultivars for planting or breeding and future genetic studies in the development of cultivars with improved resistance to PSD.

scholarly journals Mitochondrial Genome Resource of Phomopsis longicolla, a Fungus Causing Phomopsis Seed Decay in Soybean

2021 ◽  
pp. PHYTOFR-10-20-0
Author(s):  
Shuxian Li ◽  
Youjin Deng
Keyword(s):  
Mitochondrial Genome ◽  
Seed Quality ◽  
Gc Content ◽  
Soybean Seed ◽  
Rrna Genes ◽  
Phomopsis Longicolla ◽  
Sequencing Project ◽  
Phomopsis Seed Decay ◽  
Seed Decay ◽  
A Genome

Phomopsis seed decay is one of the most devastating seed diseases reducing soybean seed quality worldwide. This disease is caused primarily by a seed-borne fungus, Phomopsis longicolla (syn. Diaporthe longicolla). As part of a genome sequencing project for P. longicolla, we present the mitochondrial genome resource of the isolate MSPL 10-6, one of the most aggressive field isolates. The circular mitochondrial genome is 53,646 bp long with GC content of 34.27%, and it encodes 14 common protein genes, 23 tRNA and two rRNA genes, and 10 introns. Forty-five SNPs and InDels also were identified during comparative analyses with another isolate. The mitochondrial genome sequence provides a useful resource for developing molecular markers for pathogen detection and for improvement of control strategies for the disease. [Formula: see text] Copyright © 2020 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .

scholarly journals Evaluation of Diverse Soybean Germplasm for Resistance to Phomopsis Seed Decay

Plant Disease ◽  
2015 ◽  
Vol 99 (11) ◽  
pp. 1517-1525 ◽  
Author(s):  
Shuxian Li ◽  
John Rupe ◽  
Pengyin Chen ◽  
Grover Shannon ◽  
Allen Wrather ◽  
...  
Keyword(s):  
Fungal Pathogen ◽  
Seed Quality ◽  
Seed Infection ◽  
Sources Of Resistance ◽  
Phomopsis Longicolla ◽  
Breeding Lines ◽  
Soybean Germplasm ◽  
Phomopsis Seed Decay ◽  
Seed Decay ◽  
Germplasm Accessions

Phomopsis seed decay (PSD), caused primarily by the fungal pathogen Phomopsis longicolla, is one of the most important diseases reducing seed quality and yield of soybean. Few cultivars have been identified as resistant. To identify new sources of resistance to PSD, 135 soybean germplasm accessions, originating from 28 countries, were field screened in Arkansas, Mississippi, and Missouri in 2009. Based on seed assays of natural field infection by P. longicolla in 2009, 42 lines, including the most resistant and susceptible lines, were reevaluated in the field in 2010, 2011, and 2012 with P. longicolla-inoculated and noninoculated treatments. Six maturity group (MG) III (PI 189891, PI 398697, PI 417361, PI 504481, PI 504488, and PI 88490), four MG IV (PI 158765, PI 235335, PI 346308, and PI 416779), and five MG V (PI 381659, PI 381668, PI 407749, PI 417567, and PI 476920) lines had significantly lower percent seed infection by P. longicolla than the susceptible checks and other lines in the same test (P ≤ 0.05). They appeared to have some levels of resistance to PSD. These new sources of PSD resistance can be used in developing soybean breeding lines or cultivars with resistance to PSD, and for genetic mapping of PSD resistance genes.

scholarly journals Ergosterol as a Quantifiable Biomass Marker for Diaporthe haseolorum and Cercospora kikuchi

Plant Disease ◽  
2006 ◽  
Vol 90 (11) ◽  
pp. 1395-1398 ◽  
Author(s):  
H. Q. Xue ◽  
R. G. Upchurch ◽  
P. Kwanyuen
Keyword(s):  
Fungal Pathogens ◽  
Soybean Seed ◽  
Dry Mass ◽  
Causal Agent ◽  
Fungal Colonization ◽  
Phomopsis Seed Decay ◽  
Ergosterol Content ◽  
Diaporthe Phaseolorum ◽  
Seed Decay

The relationship between ergosterol content and biomass was determined for the soybean fungal pathogens Diaporthe phaseolorum (Cooke & Ellis) Sacc. var. sojae, causal agent of Phomopsis seed decay, and Cercospora kikuchii (Matsumoto & Tomoy.), causal agent of leaf blight and purple seed stain. Biomass was manipulated by varying incubation period, and ergosterol was quantified by high-pressure liquid chromatography. Fungal dry mass was linearly correlated with ergosterol content (r2 = 0.90, P < 0.05 for D. phaseolorum, and r2 = 0.95, P < 0.01 for C. kikuchii). In vitro ergosterol content of fungi was 3.16 μg/mg for D. phaseolorum and 2.85 μg/mg for C. kikuchii. Ergosterol content of inoculated seed was qualitatively correlated with observed seed colonization by both pathogens. Soybean variety had a significant effect on fungal colonization by D. phaseolorum and ergosterol content. Results show that ergosterol content can be used to quantify colonization of soybean seed by both pathogens.

Incidence of pod and seed infection in two soybean lines differing in resistance to Phomopsis seed decay

1995 ◽  
Vol 75 (2) ◽  
pp. 543-545 ◽  
Author(s):  
T. R. Anderson ◽  
R. I. Buzzell ◽  
B. R. Buttery ◽  
V. A. Dirks
Keyword(s):  
Glycine Max ◽  
Field Trials ◽  
Seed Infection ◽  
Phomopsis Longicolla ◽  
Phomopsis Seed Decay ◽  
Date Seed ◽  
Diaporthe Phaseolorum ◽  
Seed Decay ◽  
Seed Moisture ◽  
Soybean Resistance

Two soybean (Glycine max) lines differing in resistance to Phomopsis seed decay were evaluated in field trials, over 3 yr, for time and incidence of pod and seed infection caused by Phomopsis longicolla, Diaporthe phaseolorum var. caulivora and D. p. var. sojae. Pod infection increased linearly with time but OX615 averaged 15% less than Coles at each sample date. Seed infection increased curvilinearly in conjunction with decreasing seed moisture with marked increases between the fifth and seventh weeks after flowering. At maturity, average seed infection was 69% in Coles and 28% in OX615. Key words:Glycine max, soybean, resistance to Phomopsis seed decay

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