Identification of RAPD markers for common root rot and spot blotch (Cochliobolus sativus) resistance in barley

Genome ◽  
1996 ◽  
Vol 39 (1) ◽  
pp. 206-215 ◽  
Author(s):  
H. R. Kutcher ◽  
K. L. Bailey ◽  
B. G. Rossnagel ◽  
W. G. Legge
Keyword(s):  
Root Rot ◽  
Rapd Markers ◽  
Bulked Segregant Analysis ◽  
Rapd Marker ◽  
Spot Blotch ◽  
Cochliobolus Sativus ◽  
Common Root ◽  
Gene Manipulation ◽  
Common Root Rot ◽  
The Cross

The identification of RAPD markers associated with genes for resistance to Cochliobolus sativus in barley would increase the efficiency of gene manipulation by reducing the number of lines that must be evaluated from a resistant by susceptible cross and by allowing selection during the off season. Two barley crosses consisting of resistant and susceptible parent genotypes ('Virden' × 'Ellice' and Fr926-77 × 'Deuce', both 2 row × 6 row crosses) and more than 140 homozygous progeny lines were rated for their reactions in field nurseries to common root rot and in a controlled environment for spot blotch. Putative RAPD markers were identified using bulked segregant analysis followed by individual progeny line analyses. Polymorphisms associated with disease reaction were detected between bulked segregant samples as differences in the band intensity of DNA fragments. The bulked segregant samples were screened against 186 RAPD primers (decamers) using the polymerase chain reaction. For the cross Fr926-77 × 'Deuce', one RAPD marker was obtained that did not segregate as expected but was associated with both diseases. For the cross 'Virden' × 'Ellice', a single RAPD marker was obtained that did not have the expected segregation ratio but was associated with spot blotch reaction. One RAPD marker linked to 2-rowed and 6-rowed spike locus was obtained in each cross, and both the marker and row type were associated with common root rot and spot blotch reactions. For the cross 'Virden' × 'Ellice', a linkage group consisting of three RAPD markers was associated with common root rot and spot blotch reaction. The genes associated with these markers condition significant levels of resistance to C. sativus and may be used to increase the speed and precision of resistance gene manipulation in barley germplasm. Key words : common root rot, spot blotch, Cochliobolus sativus, molecular markers, barley.

Linked morphological and molecular markers associated with common root rot reaction in barley

1996 ◽  
Vol 76 (4) ◽  
pp. 879-883 ◽  
Author(s):  
H. R. Kutcher ◽  
K. L. Bailey ◽  
B. G. Rossnagel ◽  
J. D. Franckowiak
Keyword(s):  
Molecular Markers ◽  
Root Rot ◽  
Rapd Marker ◽  
Cochliobolus Sativus ◽  
Common Root ◽  
Morphological Marker ◽  
Common Root Rot ◽  
Barley Germplasm ◽  
Efficiency Of Selection ◽  
Selection Of

Selection of common root rot [Cochliobolus sativus (Ito & Kurib.) Drechsl. ex Dastur] resistant barley germplasm is difficult due to the influence of environment on disease expression and the quantitative nature of resistance. Morphological and molecular markers associated with common root rot resistance could be used to increase the efficiency of selection of resistant germplasm and facilitate transfer to desirable barley genotypes Forty-five morphological marker sets consisting of four to six backcross-derived lines for each marker in a common background (cultivar Bowman) were planted in disease nurseries at two locations in each of 3 yr. Disease reactions of the back-cross-derived lines were tested for a difference from the disease reaction of Bowman, which indicated a putative association between the marker and common root rot reaction. An association was obtained between common root rot reaction and one set of backcross-derived lines that contained two linked markers: glossy-sheath (gs4) and orange lemma (o). A RAPD marker closely linked to gs4 and o was also associated with common root rot reaction. The RAPD marker was associated with the allele for resistance, while gs4 and o were associated with the allele for susceptibility. The RAPD marker would be most useful in the selection of common root rot resistant germplasm and the transfer of this resistance to other genotypes. Key words: Common root rot, Cochliobolus sativus, barley, morphological markers, molecular markers

scholarly journals First Report of Spot Blotch and Common Root Rot Caused by Bipolaris sorokiniana on Switchgrass in Tennessee

Plant Disease ◽  
2011 ◽  
Vol 95 (9) ◽  
pp. 1195-1195 ◽  
Author(s):  
A. L. Vu ◽  
M. M. Dee ◽  
K. D. Gwinn ◽  
B. H. Ownley
Keyword(s):  
Root Rot ◽  
Panicum Virgatum ◽  
Bipolaris Sorokiniana ◽  
The United States ◽  
Small Subunit ◽  
Spot Blotch ◽  
Cochliobolus Sativus ◽  
Common Root ◽  
First Report ◽  
Common Root Rot

Light-to-dark brown, irregular-shaped leaf spots, chlorosis, necrotic roots, and severe stunting were observed on ‘Alamo’ switchgrass (Panicum virgatum L.) grown on the campus of the University of Tennessee in December 2007. Symptomatic leaf and root samples were surface sterilized, air dried on sterile filter paper, and plated on 2% water agar amended with 10 mg/liter of rifampicin (Sigma-Aldrich, St. Louis, MO) and 10 μl/liter of 2,4 EC Danitol miticide (Valent Chemical, Walnut Creek, CA). Plates were incubated at 25°C in darkness for 4 days. A sporulating, dematiaceous mitosporic fungus was noted and transferred to potato dextrose agar (PDA). Conidia were ovate, oblong, mostly straight, and olive to brown with three to nine septa. Conidial dimensions were 12.5 × 27.5 (17.5) to 20 × 77.5 (57) μm. Conidia were produced on single, light brown, multiseptate conidiophores that were polytretic, geniculate, and sympodial. Morphological features were as described for Bipolaris sorokiniana (Sacc.) Shoemaker (teleomorph = Cochliobolus sativus) (2,3). Disease assays were conducted with 5-week-old ‘Alamo’ switchgrass grown from surface-sterilized seed. Ten 9 × 9-cm2 with ~20 switchgrass seedlings were sprayed with 2.4 × 105 spores/ml of sterile water. Plants were subjected to high humidity created by enclosure in a plastic bag for 45 h. The bag was removed and plants were incubated at 25/20°C with 50 to 60% relative humidity. During the incubation, plants were maintained in growth chamber with a 12-h photoperiod of fluorescent and incandescent lighting. Foliar leaf spot symptoms appeared 6 to 10 days postinoculation for plants in all 10 replicates and necrotic lesions were observed on roots. Foliar lesions and diseased roots were surface sterilized, plated on water agar, and resultant fungal colonies were identified as B. sorokiniana. The internal transcribed spacer (ITS) and mitochondrial small subunit (SSU) regions of ribosomal DNA from the original isolate, and the isolate recovered from plants in the pathogenicity assay, were amplified with PCR, with primer pairs ITS4 and ITS5 and NMS1 and NMS2. PCR amplicons of ~551 and 571 bp were obtained with the two primer pairs, respectively. Both amplicons were obtained from both isolates and sequenced. Amplicon sequences from the original isolate and re-isolate were identical and the sequences were submitted to GenBank (Accession Nos. HQ611957 and HQ611958). The ITS sequences had 98% homology to 23 B. sorokiniana isolates, including B. sorokiniana strain DSM 62608 (GenBank Accession No. EF187908); SSU sequences had 99% homology to Cochliobolus sativus isolate AFTOL-ID 271 (GenBank Accession No. FJ190589). Spot blotch caused by B. sorokiniana has been reported on switchgrass in Iowa, Nebraska, Pennsylvania, and Virginia (1). To our knowledge, this is the first report of B. sorokiniana causing spot blotch or common root rot of switchgrass in Tennessee, which extends the current known distribution of these diseases. More recently, we isolated B. sorokiniana from switchgrass seed received from commercial sources in the United States, indicating a seedborne transmission. References: (1) D. F. Farr and A. Y. Rossman. Fungal Databases. Systematic Mycology and Microbiology Laboratory, ARS, USDA. Retrieved from http://nt.ars-grin.gov/fungaldatabases/ , 15 November 2010. (2) R. F. Nyvall and J. A. Percich. Plant Dis. 83:936, 1999. (3) A. Sivanesan and P. Holliday. CMI Descr. Pathog. Fungi bact. 71:701, 1981.

The epidemiology of common root rot in Manitou wheat: disease progression during the growing season

1974 ◽  
Vol 52 (7) ◽  
pp. 1757-1764 ◽  
Author(s):  
P. R. Verma ◽  
R. A. A. Morrall ◽  
R. D. Tinline
Keyword(s):  
Triticum Aestivum ◽  
Disease Severity ◽  
Plant Development ◽  
Root Rot ◽  
Growing Season ◽  
Cochliobolus Sativus ◽  
Infection Rates ◽  
Common Root ◽  
Common Root Rot ◽  
Disease Rating

Common root rot in Triticum aestivum cultivar Manitou caused primarily by Cochliobolus sativus was followed during plant development in 1969, 1970, and 1971 at Matador, Saskatchewan. Plants were sampled at intervals, and three variables based mainly on the occurrence of lesions on subcrown internodes were studied: number of diseased plants per square meter; percentage of diseased plants; and disease rating which integrated percentage of diseased plants and disease severity on each plant. All variables increased with time, and the progression curves in all 3 years were hyperbolic, indicating that the increases were like those of a simple interest disease as described by Van der Plank. In two of the years, almost 100% of the plants were diseased considerably before the end of the season. The transformation proposed by Van der Plank for simple interest diseases, log10[1/(1 − x)], was applied to the percentages of diseased plants, and regressions were calculated. The slopes of these lines (infection rates) were as follows: 1969, 0.99% plants per day; 1970, 1.32%; and 1971, 1.96%. In 1969 the onset of disease was later than in 1970 and 1971, and there was correspondingly less disease at the end of the growing season.

scholarly journals Genetic Determinants of Wheat Resistance to Common Root Rot (Spot Blotch), Fusarium Crown Rot, and Sharp Eyespot

2020 ◽  
Author(s):  
Jun Su ◽  
Jiaojie Zhao ◽  
Shuqing Zhao ◽  
Mengyu Li ◽  
Xiaofeng Shang ◽  
...  
Keyword(s):  
Root Rot ◽  
Spot Blotch ◽  
Crown Rot ◽  
Genetic Determinants ◽  
Common Root ◽  
Fusarium Crown Rot ◽  
Common Root Rot ◽  
Sharp Eyespot ◽  
Root And Crown Rot ◽  
Moderate Resistance

Due to the field soil changes, high density planting, and straw-returning methods, wheat common root rot (spot blotch), Fusarium crown rot (FCR), and sharp eyespot have become severe threatens to global wheat productions. Only a few wheat genotypes show moderate resistance to these root and crown rot fungal diseases, and the genetic determinants of wheat resistance to these devastating diseases have been poorly understood. This review summarizes the recent progress of genetic studies on wheat resistance to common root rot, Fusarium crown rot, and sharp eyespot. Wheat germplasms with relative higher resistance are highlighted and genetic loci controlling the resistance to each of the disease are summarized.

The effect of common root rot on components of grain yield in Manitou wheat

1976 ◽  
Vol 54 (24) ◽  
pp. 2888-2892 ◽  
Author(s):  
P. R. Verma ◽  
R. A. A. Morrall ◽  
R. D. Tinline
Keyword(s):  
Triticum Aestivum ◽  
Grain Yield ◽  
Disease Severity ◽  
Root Rot ◽  
Major Effect ◽  
Kernel Weight ◽  
The Other ◽  
Cochliobolus Sativus ◽  
Common Root ◽  
Common Root Rot

The effects of common root rot (Cochliobolus sativus) on components of grain yield in naturally infected Triticum aestivum cultivar Manitou were studied at Matador, Saskatchewan, by sampling plants at maturity in 1969, 1970, and 1971. Plants were sorted into severe (SE), moderate (MO), slight (SL), and clean (CL) categories based mainly on the extent of lesions on the subcrown internodes. The number of tillers per plant, the number and weight of grains per head, the weight per head, and the 1000-kernel weight in each category were determined. Increasing values of all five components were consistently associated with decreasing disease severity. SE was mostly significantly different from the other three categories in all components except 1000-kernel weight; differences between SL and MO were usually non-significant. CL and SL were mostly significantly different for the number of tillers per plant and weight per head but non-significant for the weight and number of grains per head and 1000-kernel weight. Apparently, the major effect of common root rot was to reduce the number of tillers per plant and number of grains per head.

Further sources of resistance to common root rot (Cochliobolus sativus) of wheat

1974 ◽  
Vol 14 (70) ◽  
pp. 666 ◽  
Author(s):  
GB Wildermuth
Keyword(s):  
Bread Wheat ◽  
Root Rot ◽  
First Record ◽  
Cochliobolus Sativus ◽  
Wheat Cultivars ◽  
Common Root ◽  
Sources Of Resistance ◽  
Common Root Rot ◽  
High Level

One cultivar of einkhorn, one cultivar of emmer, three cultivars of durum and 43 cultivars of bread wheat were screened for resistance to common root rot (Cochliobolus sativus). The emmer cultivar, Yaroslav and the white-grained bread wheat cultivars, Festival and Mexico 120, showed a high level of resistance. This is the first record of resistance in white-grained cultivars and the advantage of using whitegrained rather than red-grained cultivars as sources of resistance in Australia is indicated. It is considered that the major source of resistance in Festival, Gamut and Spica has been derived from Pusa cultivars.

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