Reactions of Canadian short-season soybean cultivars to three races of Phytophthora sojae

2010 ◽  
Vol 90 (2) ◽  
pp. 207-210 ◽  
Author(s):  
S Z Zhang ◽  
A G Xue ◽  
J X Zhang ◽  
E. Cober ◽  
T R Anderson ◽  
...  
Keyword(s):  
Glycine Max ◽  
Key Words ◽  
Phytophthora Sojae ◽  
Stem Rot ◽  
Soybean Cultivars ◽  
Resistant Sources ◽  
Short Season

Of 87 short-season soybean cultivars evaluated for reactions to three races (1, 3, and 5) of Phytophthora sojae Kaufmann and Gerdemann, 29 showed resistance to at least one of the three races. These resistant sources may be used for pyramiding Rps genes and deployment of P. sojae resistant soybean cultivars in Canada. Key words: Soybean, Glycine max, phytophthora root and stem rot, Phytophthora sojae

Common Phytophthora sojae pathotypes occurring in South Dakota

2021 ◽  
Author(s):  
Rawnaq Chowdhury ◽  
Connie Tande ◽  
Emmanuel Z Byamukama
Keyword(s):  
Glycine Max ◽  
South Dakota ◽  
Resistance Genes ◽  
Phytophthora Sojae ◽  
Stem Rot ◽  
Inoculation Technique ◽  
Glycine Max L ◽  
Rps Gene ◽  
Important Disease

Phytophthora root and stem rot, caused by Phytophthora sojae, is an important disease of soybean (Glycine max L.) in South Dakota. Because P. sojae populations are highly diverse and resistance genes deployed in commercial soybean varieties often fail to manage the disease, this study was initiated to determine P. sojae pathotype distribution in South Dakota. A total of 216 P. sojae isolates were baited from soil collected from 422 soybean fields in South Dakota in 2013-2015 and 2017. The pathotype of each isolate was determined by inoculating 10 seedlings of 13 standard soybean P. sojae differential lines using the hypocotyl inoculation technique. Of the 216 pathotyped isolates, 48 unique pathotypes were identified. The virulence complexity of isolates ranged from virulence on one Rps gene (Rps7) to virulence on 13 Rps genes and mean complexity was 5.2. Harosoy (Rps7), Harlon (Rps1a), Williams 79 (Rps 1c), William 82 (Rps1k), Harosoy 13XX (Rps1b), were susceptible to 98, 80, 78, 73, 72% of the isolates, respectively. These results highlight the highly diverse P. sojae pathotypes in South Dakota and the likely Rps genes to fail in commercial soybean varieties

Evaluation of four Japanese soybean cultivars for Rps alleles conferring resistance to Phytophthora megasperma f. sp. glycinea

1992 ◽  
Vol 72 (1) ◽  
pp. 217-220 ◽  
Author(s):  
B. D. Rennie ◽  
V. D. Beversdorf ◽  
R. I. Buzzell ◽  
T. R. Anderson
Keyword(s):  
Glycine Max ◽  
Key Words ◽  
Phytophthora Megasperma ◽  
Soybean Cultivars ◽  
Glycine Max L ◽  
Phytophthora Resistance

Four Japanese soybean (Glycine max (L) Merr.) cultivars (Fujiotome (PI 360836), Misaodaizu (PI 360839), Nezumisaya (PI 360841) and Honiku 65 (PI 360837)) were evaluated for Rps alleles conferring resistance for Phytophthora megasperma (Drechs.) f. sp. glycinea (Hildeb.) Kuan & Erwin. Fujiotome contains Rps1-a and Rps5; Misaodaizu contains Rsp1-c and Rps3; and Nezumisaya contains Rps1-b and a new allele, designated Rps? (Nezumisaya). Honiku 65 is susceptible but two variants obtained from it each contain a new Rps allele designated Rps? (OX939) and Rps? (OX940).Key words: Soybean, Phytophthora resistance

scholarly journals Virulence Composition of Phytophthora sojae in Michigan

Plant Disease ◽  
2001 ◽  
Vol 85 (10) ◽  
pp. 1103-1106 ◽  
Author(s):  
R. C. Kaitany ◽  
L. P. Hart ◽  
G. R. Safir
Keyword(s):  
Phytophthora Sojae ◽  
Control Measures ◽  
Stem Rot ◽  
Soybean Plant ◽  
Soybean Cultivars ◽  
Plant Samples ◽  
First Time

Knowing the virulence composition of Phytophthora sojae is important for the management of Phytophthora root and stem rot of soybean. Plant samples were collected in Michigan from diseased plants in soybean fields with Phytophthora root and stem rot symptoms. Eighty-seven isolates of P. sojae were evaluated for virulence using 13 differential soybean cultivars. Rps 3b, 3a, 1b, 1k, and 6 were resistant to 81, 77, 74, 69, and 66% of the isolates, respectively, while Rps 1a and 7 were resistant to only 12 to 13% of the isolates. Races 2, 25, 41, and 44 of P. sojae were identified among the isolates and reported for the first time in Michigan. Virulence formulae of 69 isolates did not match those of currently known races of P. sojae. Nine isolates were considered nonpathogenic. Incorporating Rps genes 1b, 1k, 3a, 3b, and 6 in soybean cultivars with good field tolerance, in conjunction with other control measures, should offer improved protection of soybeans from Phytophthora root and stem rot in Michigan.

Genetic linkage of the Adh1 and W1 loci in soybeans

Genome ◽  
1987 ◽  
Vol 29 (4) ◽  
pp. 582-583 ◽  
Author(s):  
Y. T. Kiang ◽  
Y. C. Chiang
Keyword(s):  
Glycine Max ◽  
Linkage Group ◽  
Alcohol Dehydrogenase ◽  
Key Words ◽  
Genetic Linkage ◽  
Soybean Cultivars ◽  
Recombination Value

Four crosses were made among seven soybean cultivars for determining possible linkage between Adh1 and W1 loci. An examination of F2 seed indicated that these loci are linked with a recombination value of 20.6 ± 1.2%. These loci are located in linkage group 8. Key words: soybean linkage, isozymes, alcohol dehydrogenase (Adh1), color locus (W1), Glycine max.

scholarly journals Soybean Root Suberin and Partial Resistance to Root Rot Caused by Phytophthora sojae

2008 ◽  
Vol 98 (11) ◽  
pp. 1179-1189 ◽  
Author(s):  
Kosala Ranathunge ◽  
Raymond H. Thomas ◽  
Xingxiao Fang ◽  
Carol A. Peterson ◽  
Mark Gijzen ◽  
...  
Keyword(s):  
Glycine Max ◽  
Root Rot ◽  
Partial Resistance ◽  
Infection Process ◽  
Phytophthora Sojae ◽  
Epidermal Cells ◽  
Chemical Defenses ◽  
Stem Rot ◽  
Subsequent Growth ◽  
Initial Infection

Phytophthora sojae is the causal agent of root and stem rot of soybean (Glycine max). Various cultivars with partial resistance to the pathogen have been developed to mitigate this damage. Herein, two contrasting genotypes, the cultivar Conrad (with strong partial resistance) and the line OX760-6 (with weak partial resistance), were compared regarding their amounts of preformed and induced suberin components, and to early events during the P. sojae infection process. To colonize the root, hyphae grew through the suberized middle lamellae between epidermal cells. This took 2 to 3 h longer in Conrad than in OX760-6, giving Conrad plants more time to establish their chemical defenses. Subsequent growth of hyphae through the endodermis was also delayed in Conrad. This cultivar had more preformed aliphatic suberin than the line OX760-6 and was induced to form more aliphatic suberin several days prior to that of OX760-6. However, the induced suberin was formed subsequent to the initial infection process. Eventually, the amount of induced suberin (measured 8 days postinoculation) was the same in both genotypes. Preformed root epidermal suberin provides a target for selection and development of new soybean cultivars with higher levels of expression of partial resistance to P. sojae.

scholarly journals Races of Phytophthora sojae in Arkansas Soybean Fields and Their Effects on Commonly Grown Soybean Cultivars

Plant Disease ◽  
2004 ◽  
Vol 88 (4) ◽  
pp. 345-351 ◽  
Author(s):  
T. A. Jackson ◽  
T. L. Kirkpatrick ◽  
J. C. Rupe
Keyword(s):  
Phytophthora Sojae ◽  
Soil Samples ◽  
Effective Resistance ◽  
Stem Rot ◽  
University Of Arkansas ◽  
Soybean Field ◽  
Inoculation Methods ◽  
Soybean Cultivars ◽  
Pathogenic Variability ◽  
The University

Isolates of Phytophthora sojae were collected during 1995 to 1998 from soil samples collected in 23 Arkansas soybean fields in 14 counties, and characterized by race. A total of seven races (races 2, 10, 14, 15, 24, 26, and 38) were found. Races 10, 24, and 15 were the most common and comprised 47, 22, and 9% of the 32 isolates, respectively. A single isolate each of races 2, 14, 26, and 38 also was found. Three of the isolates collected could not be characterized to race due to inconsistent results. In 1997 and 1998, a portion of a single soybean field at the University of Arkansas Southeast Research and Experiment Center near Rohwer, AR was surveyed intensively for P. sojae. The area was planted each year to the P. sojae-susceptible cv. Williams and both plants and soil were collected to assay for P. sojae from 16 and 28 plots (4.9 by 7.6 m) in 1997 and 1998, respectively. A total of 83 isolates were collected (11 from plants and 72 from soil), and found to represent 13 pathotypes, including 6 with virulence formulae that have not been described previously. Nine commercial soybean cultivars representing a range of reported resistance and tolerance to Phytophthora root and stem rot were screened for resistance to races 10, 15, and 26 of P. sojae using both hypocotyl injection and inoculum layer techniques. Cvs. Manokin, Hartz Variety 5545, and Riverside 499 were consistently resistant to all of the races using both inoculation methods. These results indicate that, although considerable pathogenic variability in P. sojae exists in soybean fields in Arkansas, cultivars with effective resistance are available to help growers manage Phytophthora root and stem rot.

Effects of wounding and inoculation with Sclerotinia sclerotiorum on isoflavone concentrations in soybean

2005 ◽  
Vol 85 (4) ◽  
pp. 749-760 ◽  
Author(s):  
Stephen N. Wegulo ◽  
Xiao-Bing Yang ◽  
Charlie A. Martinson ◽  
Patricia A. Murphy
Keyword(s):  
Heart Disease ◽  
Key Words ◽  
Sclerotinia Sclerotiorum ◽  
Defense Response ◽  
Dry Weight ◽  
Stem Rot ◽  
Sclerotinia Stem Rot ◽  
Soybean Cultivars ◽  
Causal Fungus ◽  
Soybean Leaves

Isoflavones play an important role in the defense response of soybean to pathogen attack. They are involved in nodulation of legumes and are associated with human health benefits including the prevention of heart disease and cancers. Concentrations of the isoflavones daidzein, genistein, and glycitein, the glucoside conjugates daidzin, genistin and glycitin, the acetylglucoside conjugates acetyldaidzin, acetylgenistin, and acetylglycitin, and the malonylglucoside conjugates malonyldaidzin, malonylgenistin, and malonylglycitin were determined in ovendried leaves of 12 soybean cultivars whose stems were (i) non-wounded, non-inoculated (NWNI), (ii) wounded, non-inoculated (WNI), and (iii) wounded and inoculated (WI) with mycelia of Sclerotinia sclerotiorum, the causal fungus of Sclerotinia stem rot of soybean. There were significant differences (P ≤ 0.05) among cultivars in concentrations of isoflavones and their conjugates in all wounding treatments. Concentrations of the aglycones daidzein and genistein were higher (P ≤ 0.05) in WI than in WNI and NWNI plants in all cultivars. Glycitein and its conjugates were detected only in some cultivars in much lower concentrations than daidzein and genistein and their conjugates. Concentrations of total daidzein in the 12 cultivars ranged from 68 to 491, 174 to 781, and 282 to 553 µg g-1 dry weight in NWNI, WNI, and WI plants, respectively. Concentrations of total genistein ranged from 128 to 427, 290 to 840, and 296 to 759 µg g-1 dry weight in NWNI, WNI, and WI plants, respectively. Concentrations of total glycitein ranged from 0 to 44, 0 to 13, and 0 to 24 µg g-1 dry weight in NWNI, WNI, and WI plants, respectively. In NWNI plants, the cultivar Corsoy 79 ranked in the top two (rank 1 = highest concentration, rank 12 = lowest concentration) in concentrations of daidzein and genistein and their conjugates except genistin (ninth rank). In WNI plants, Parker ranked first in concentrations of all conjugates of daidzein and genistein whereas Corsoy 79 consistently ranked in the top four in concentrations of the two isoflavones and their conjugates. In WI plants, Parker ranked first in concentrations of all conjugates of daidzein and genistein except acetyldaidzin (second rank), S19-90 ranked in the top five in concentrations of all conjugates of daidzein and genistein, whereas Corsoy 79 ranked in the top five in concentrations of daidzein and genistein and all of their conjugates. The results from this study suggest that soybean cultivars differ in concentrations of constitutive or induced isoflavones and in their ability to accumulate isoflavones following wounding and/or infection by S. sclerotiorum. Key words: Isoflavones, soybean, leaves, Sclerotinia sclerotiorum, wounding, HPLC

scholarly journals Soybean Genotypes Resistant to Phytophthora sojae and Compensation for Yield Losses of Susceptible Isolines

Plant Disease ◽  
1998 ◽  
Vol 82 (3) ◽  
pp. 303-306 ◽  
Author(s):  
J. R. Wilcox ◽  
S. K. St. Martin
Keyword(s):  
Seed Yield ◽  
Phytophthora Sojae ◽  
Stem Rot ◽  
Yield Losses ◽  
Yellow Seed ◽  
Soybean Cultivars ◽  
Black Seed ◽  
Soybean Genotypes ◽  
Seed Yields ◽  
Seed Coats

Two isolines, with different alleles for resistance to Phytophthora sojae, of the soybean cultivars, Beeson, Century, and Williams were grown in replicated tests to assess yield losses attributable to this pathogen. Isolines susceptible to prevalent races of the pathogen had black seed coats as a marker trait; isolines resistant to prevalent races of the pathogen had yellow seed coats. Included in the tests were blends composed of equal numbers of seed of the two isolines for each cultivar. Tests were conducted at three locations in Indiana and one location in Ohio for three years. In six environments, where Phytophthora root and stem rot damaged soybean, isolines susceptible to prevalent races of the pathogen produced seed yields from 65 to 93% of the yields of isolines resistant to these races. In four of these environments, isoline blends produced yields equal to those of the resistant isoline. In two environments, where susceptible isolines averaged 65 and 69% of the yield of the resistant isoline; the blends averaged 89 and 83% of the yield of the resistant isoline. Where the pathogen reduced yields of susceptible isolines, yellow seeds of the isoline resistant to prevalent races of the pathogen contributed from 10 to 33% more seed than would be expected if resistant and susceptible isolines contributed equally to seed yield. The data demonstrate that plants of the resistant isoline were compensating for reduced productivity of the susceptible plants in the blend.

scholarly journals Identification of Resistance Genes to Phytophthora sojae in Domestic Soybean Cultivars from China Using Particle Bombardment

Plant Disease ◽  
2020 ◽  
Vol 104 (7) ◽  
pp. 1888-1893
Author(s):  
Jin Yang ◽  
Sujiao Zheng ◽  
Xiaomen Wang ◽  
Wenwu Ye ◽  
Xiaobo Zheng ◽  
...  
Keyword(s):  
Resistance Genes ◽  
Particle Bombardment ◽  
Phytophthora Sojae ◽  
Stem Rot ◽  
Avirulence Genes ◽  
Breeding Programs ◽  
Soybean Cultivars ◽  
Primary Means ◽  
Soybean Plants ◽  
Source Materials

Phytophthora root and stem rot caused by Phytophthora sojae is a destructive disease that afflicts soybean plants throughout the world. The use of resistant soybean cultivars is the primary means of managing this disease, as well as the most effective and economical approach. There are abundant soybean germplasm resources in China that could be deployed for breeding programs; however, the resistance genes (Rps genes) in most cultivars are unknown, leading to uncertainty concerning which are resistant cultivars for use. The resistance genes Rps1a, Rps1c, and Rps1k prevent root and stem rot caused by most P. sojae isolates within a Chinese field population. This study identified three Rps genes in Chinese domestic soybean cultivars using three related avirulence genes by particle bombardment. The complex genetic diversity of soybean cultivars and P. sojae strains has made it difficult to define single Rps genes without molecular involvement. Gene cobombardment is a method for identifying Rps genes quickly and specifically. We showed that cultivars Dongnong 60 and Henong 72 contained Rps1a, while Hedou 19, Henong 76, 75-3, Wandou 21020, Zheng 196, Wandou 28, Heinong 71, and Wandou 29 all contained Rps1c. The cultivars Jidou 12, Henong 72, Heinong 71, and Wandou 29 contained Rps1k. The cultivar Henong 72 contained both Rps1a and Rps1k, while Wandou 29 and Heinong 71 contained both Rps1c and Rps1k. We then evaluated the phenotype of 11 domestic soybean cultivars reacting to P. sojae using the isolates P6497 and Ps1. The 11 domestic cultivars were all resistant to P6497 and Ps1. This research provides source materials and parent plant strains containing Rps1a, Rps1c, and Rps1k for soybean breeding programs.

scholarly journals New Races of Phytophthora sojae with Rps1-d Virulence

Plant Disease ◽  
1997 ◽  
Vol 81 (6) ◽  
pp. 653-655 ◽  
Author(s):  
T. S. Abney ◽  
J. C. Melgar ◽  
T. L. Richards ◽  
D. H. Scott ◽  
J. Grogan ◽  
...  
Keyword(s):  
Glycine Max ◽  
Phytophthora Sojae ◽  
Stem Rot ◽  
Physiologic Races ◽  
New Races

Hypocotyl inoculations of differential soybean (Glycine max) cultivars were used to identify seven new physiologic races of Phytophthora sojae (syn. P. megasperma f. sp. glycinea). Five of the new races were virulent on soybeans with the Rps1-d allele, while four of the new races were virulent on soybeans with the Rps1-k allele. The Rps1-k and Rps1-d alleles provide resistance to a majority of the previously described races that cause Phytophthora root and stem rot. The seven new races were assigned race numbers 33, 34, 41, 42, 43, 44, and 45 since race numbers 35 through 40 were assigned to other new races recently identified in Ohio, California, Arkansas, and Iowa. The new races identified in this study constituted 14% of the 1993 isolates evaluated from 27 counties in central and northern Indiana. Races 1 and 3 were the most prevalent, representing 31 and 26% of the P. sojae isolates identified in 1993. Races 4, 6, 7, 8, 9, 13, 28, and 29 each constituted 2 to 6% of the 1993 isolates. Other races identified among the 1993 isolates included races 19, 21, 25, and 30.

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