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 ◽  
...  

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.

Plant Disease ◽  
2017 ◽  
Vol 101 (12) ◽  
pp. 1990-1997 ◽  
Author(s):  
Shuxian Li ◽  
Gabe Sciumbato ◽  
John Rupe ◽  
Grover Shannon ◽  
Pengyin Chen ◽  
...  

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.


2021 ◽  
pp. PHYTOFR-10-20-0
Author(s):  
Shuxian Li ◽  
Youjin Deng

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 .


Plant Disease ◽  
2015 ◽  
Vol 99 (11) ◽  
pp. 1517-1525 ◽  
Author(s):  
Shuxian Li ◽  
John Rupe ◽  
Pengyin Chen ◽  
Grover Shannon ◽  
Allen Wrather ◽  
...  

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.


ISRN Agronomy ◽  
2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Shuxian Li ◽  
Pengyin Chen

Phomopsis seed decay (PSD) of soybean is caused primarily by the fungal pathogen Phomopsis longicolla Hobbs along with other Phomopsis and Diaporthe spp. This disease causes poor seed quality and suppresses yield in most soybean-growing countries. Infected soybean seeds can be symptomless, but are typically shriveled, elongated, cracked, and have a chalky white appearance. Development of PSD is sensitive to environmental conditions. Hot and humid environments favor pathogen growth and disease development. Several control strategies have been used to manage PSD and reduce its impact; however, the use of resistant cultivars is the most effective method for controlling PSD. Efforts have been made to identify sources of PSD resistance in the past decades. At least 28 soybean lines were reported to have certain levels of PSD resistance in certain locations. Inheritance of resistance to PSD has been studied in several soybean lines. In this paper, general information about the disease, the causal agent, an overview of research on evaluation and identification of sources of resistance to PSD, and inheritance of resistance to PSD are presented and discussed.


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

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.


Plant Disease ◽  
2010 ◽  
Vol 94 (8) ◽  
pp. 1035-1040 ◽  
Author(s):  
Shuxian Li ◽  
Glen L. Hartman ◽  
Deborah L. Boykin

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.


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

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.


Plant Disease ◽  
2012 ◽  
Vol 96 (11) ◽  
pp. 1693-1693 ◽  
Author(s):  
Z. Shan ◽  
S. Li ◽  
Y. Liu ◽  
Z. Yang ◽  
C. Yang ◽  
...  

Phomopsis seed decay of soybean (Glycine max (L.) Merr.) causes poor seed quality and suppresses yield in most soybean-growing areas in the world. The disease is caused primarily by Phomopsis longicolla Hobbs. During the spring of 2010, soybean seeds without symptoms were planted in the fields but emergence was poor and the emergence rates ranged from 30 to 70% in south China. Approximately 3,000 symptomless seeds were randomly collected from seven fields at three locations in Guangzhou, Nanchang, and Wuhan. Seeds were surface disinfected with 1% sodium hypochlorite for 12 min, rinsed in sterile distilled water three to four times, and placed on 2% agar. Plates were then incubated at 26°C under 16/8-h photoperiod for 3 to 4 days. About 10 to 20% of the seeds produced white hyphae that spread rapidly and covered the whole seed. The hyphae from fungal isolates were transferred to potato dextrose agar (PDA) and incubated at 26°C in the dark. After 3 to 4 weeks, conidia were elliptical with two oil drops at both ends and hyaline (6.2 to 7.2 × 2.6 to 3.2 μm). The cultural and morphological characteristics of the isolates corresponded with the description of P. longicolla (2). Colonies on PDA were floccose, dense, and white. Stromata were large, black, and spreading. To confirm the morphological identification, the ribosomal internal transcribed spacers (ITS1-5.8S-ITS2) from three isolates were sequenced (GenBank Accession Nos. JQ899030, JQ899031, and JQ899032). BLAST analysis indicated that the isolates had 99% nucleotide sequence identity with P. longicolla (GenBank Accession Nos. AY857868.1, EF026104, and HQ130441.1). Pathogenicity tests were conducted on 2-week-old soybean seedlings (3). A mycelial plug (3 mm in diameter) from the margin of 1-week-old PDA culture of the Wuhan isolate was individually placed mycelial side down directly on the top of cut stem 1 to 2 cm above cotyledon node of the soybean seedling. PDA plugs without the fungus was used as the negative control. All seedlings were kept in a growth chamber at 26°C with 92 to 94% relative humidity. After 2 weeks, all inoculated seedlings showed browning, stem wilt, and the lesions were 0.3 to 2.0 cm long. No symptoms were observed in the control plants. P. longicolla was reisolated from the infected seedlings. The pathogenicity test was repeated three times. Soybean stem blight caused by P. longicolla has been reported in northeast China (1). To our knowledge, this is the first report of P. longicolla causing Phomopsis seed decay of soybean in south China. This report will establish a foundation for developing a program for screening germplasm for resistance to this disease in south China. References: (1) Y. L. Cui et al. Plant Pathol. 58:799, 2009. (2) T. W. Hobbs et al. Mycologia 77:535,1985. (3) S. Li et al. Plant Dis. 85:1031, 2001.


Plant Disease ◽  
1998 ◽  
Vol 82 (5) ◽  
pp. 584-589 ◽  
Author(s):  
R. R. Walcott ◽  
D. C. McGee ◽  
M. K. Misra

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.


1995 ◽  
Vol 75 (2) ◽  
pp. 543-545 ◽  
Author(s):  
T. R. Anderson ◽  
R. I. Buzzell ◽  
B. R. Buttery ◽  
V. A. Dirks

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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