Temporal progression of common root rot [Cochliobolus sativus] lesions on subcrown internodes of wheat and barley cultivars

1982 ◽  
Vol 4 (4) ◽  
pp. 349-352 ◽  
Author(s):  
P.R. Verma
Keyword(s):  
Root Rot ◽  
Cochliobolus Sativus ◽  
Common Root ◽  
Barley Cultivars ◽  
Common Root Rot

Effect of common root rot (Cochliobolus sativus) on yields of barley under experimental conditions in northern Syria

1997 ◽  
Vol 48 (3) ◽  
pp. 351 ◽  
Author(s):  
J. A. G. van Leur ◽  
M. Z. Alamdar ◽  
S. Khawatmi
Keyword(s):  
Root Rot ◽  
Crop Improvement ◽  
Cochliobolus Sativus ◽  
Common Root ◽  
Experimental Conditions ◽  
Yield Increase ◽  
Barley Cultivars ◽  
Common Root Rot ◽  
Improvement Programs ◽  
The Impact

The impact of Cochliobolus sativus on grain yield of different barley cultivars was studied for 3 seasons in northern Syria by comparing plots with and without artificial inoculation. Distributing oat kernels infested with C. sativus next to barley seed and inoculating seed with C. sativus conidia in a peat carrier resulted in an increase in common root rot symptoms on the subcrown internode. Subcrown internodes were shorter in inoculated than uninoculated plots. The effect of inoculation differed greatly among cultivars and years. Highest losses from the common root rot occurred under dry growing conditions, whereas a significant yield increase was noted on 2 susceptible lines grown under adequate moisture. As common root rot can reduce barley yield in unfavourable environments, the disease should be considered by crop improvement programs aimed at low-rainfall zones in Mediterranean environments.

Histology of Cochliobolus sativus infection in subcrown internodes of wheat and barley

1976 ◽  
Vol 54 (12) ◽  
pp. 1344-1354 ◽  
Author(s):  
H. C. Huang ◽  
R. D. Tinline
Keyword(s):  
Hair Cells ◽  
Root Rot ◽  
Histological Study ◽  
Infection Process ◽  
Cochliobolus Sativus ◽  
Common Root ◽  
Barley Cultivars ◽  
Common Root Rot ◽  
Stomatal Guard Cells ◽  
Infection Cushions

Histological study of the infection process of Cochliobolus sativus in subcrown internodes of postseedling plants failed to disclose differences in wheat and barley cultivars that differed markedly in resistance to common root rot in the field. Appressoria and infection cushions were formed on the host surface before penetration. The dome-shaped infection cushions consisted of short-celled hyphae surrounded by long-celled running hyphae. Penetration occurred by fine infection pegs produced from appressoria or the short-celled hyphae in the infection cushions. A lignituber occurred beneath each penetration site. The fungus penetrated wheat or barley subcrown internodes via various epidermal cells, including hair cells, stomatal guard cells, and the rectangular cells. Infection proceeded from the epidermis to the cortex and endodermis, resulting in breakdown of these tissues. Sometimes the stele also was invaded and vascular tissues were occluded. Three morphologically different hyphae, namely fine aseptate infection hyphae, long-celled running hyphae, and coarse, short-celled hyphae, were observed. Dark-stained objects, directly or indirectly associated with the fungus, frequently were found in infected tissues.

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.

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.

EFFECTS OF SEED SPACING ON COMMON ROOT ROT OF SOME BARLEY CULTIVARS

1983 ◽  
Vol 63 (3) ◽  
pp. 611-616 ◽  
Author(s):  
L. J. PIENING
Keyword(s):  
Root Rot ◽  
Plant Competition ◽  
Yield Reduction ◽  
Common Root ◽  
Barley Cultivars ◽  
Common Root Rot ◽  
Economic Method ◽  
Seed Spacing ◽  
Interplant Competition ◽  
Moderately Resistant

The effect of varying interplant competition on common root rot and yield was examined in barley over a 4-yr period. One experiment studied the effects of thinning. Other tests with a constant level of interplant competition examined the effects of interplanted root-rot-resistant barley or oat cultivars on the root rot reaction and yield of susceptible barley cultivars. Increasing interplant spacing by thinning reduced root rot significantly in Gateway and Bonanza barley in 1 out of 4 years, but yield was increased significantly only in Gateway in 2 out of 4 years. Yield reduction due to root rot was significantly less in 1 out of 2 years when the distance between Gateway plants was increased due to the interplanting of oats. The lack of a consistent reduction in root rot or yield loss by reducing plant competition or interplanting with moderately resistant barley or oats precludes use of lower seeding rates or mixed crops as an economic method of reducing root rot.Key words: Interplant competition, common root rot, barley

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.

The transfer and characterization of resistance to common root rot from Thinopyrum ponticum to wheat

Genome ◽  
2004 ◽  
Vol 47 (1) ◽  
pp. 215-223 ◽  
Author(s):  
Hongjie Li ◽  
Robert L Conner ◽  
Qin Chen ◽  
Haiyan Li ◽  
André Laroche ◽  
...  
Keyword(s):  
In Situ Hybridization ◽  
Root Rot ◽  
Triticum Aestivum L ◽  
Genomic In Situ Hybridization ◽  
Cochliobolus Sativus ◽  
Common Root ◽  
Thinopyrum Ponticum ◽  
Common Root Rot ◽  
Kernel Color

Common root rot, caused by Cochliobolus sativus (Ito and Kurib) Drechs. ex Dastur, is a major soil-borne disease of spring and winter wheat (Triticum aestivum L. em Thell.) on the Canadian prairies. Resistance to common root rot from Thinopyrum ponticum (Podp.) Liu and Wang was transferred into wheat via crossing with Agrotana, a resistant wheat – Th. ponticum partial amphiploid line. Evaluation of common root rot reactions showed that selected advanced lines with blue kernel color derived from a wheat × Agrotana cross expressed more resistance than the susceptible T. aestivum 'Chinese Spring' parent and other susceptible wheat check cultivars. Cytological examination revealed 41 to 44 chromosomes in the advanced lines. Genomic in situ hybridization, using total genomic DNA from Pseudoroegneria strigosa (M. Bieb) A. Löve (St genome) as a probe, demonstrated that the blue kernel plants had two pairs of spontaneously translocated J–Js and Js–J chromosomes derived from the J and Js genome of Th. ponticum. The presence of these translocated chromosomes was associated with increased resistance of wheat to common root rot. The lines with blue aleurone color always had a subcentromeric Js–J translocated chromosome. The subtelocentric J–Js translocated chromosome was not responsible for the blue kernel color. The genomic in situ hybridization analysis on meiosis revealed that the two spontaneous translocations were not reciprocal translocations.Key words: Cochliobolus sativus, genomic in situ hybridization, blue kernel color.

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