The impact of crop rotation and N fertilizer on common root rot of spring wheat in the Brown soil zone of western Canada

2005 ◽  
Vol 85 (3) ◽  
pp. 569-575 ◽  
Author(s):  
M. R. Fernandez ◽  
R. P. Zentner
Keyword(s):  
Fusarium Head Blight ◽  
Crop Rotation ◽  
Spring Wheat ◽  
Root Rot ◽  
Triticum Aestivum L ◽  
Cochliobolus Sativus ◽  
Common Root ◽  
Head Blight ◽  
Common Root Rot ◽  
The Impact

From 2000 to 2003, spring wheat (Triticum aestivum L.) grown in southwest Saskatchewan 1 or 2 yr after summerfallow, and after lentil (Lens culinaris Medik), flax (Linum usitatissimum L.), or continuously with and without fertilizer N was examined for root rot by measuring discoloration of subcrown internodes. Discolored tissue was also plated on nutrient agar for fungal identification. In general, common root rot was present at consistently highest levels in wheat grown after lentil, and at lowest levels in wheat grown continuously with low N fertility. The most common fungal species isolated from affected subcrown internodes were Cochliobolus sativus (Ito and Kurib.) Drechs. ex Dast. and Fusarium spp. Among the latter, F. avenaceum (Fr.) Sacc., F. equiseti (Corda) Sacc. and F. pseudograminearum O’Donnell & T. Aoki were most frequent. Fusarium avenaceum is one of the most common fusarium head blight pathogens in Saskatchewan. Wheat after lentil had one of the highest levels of this fungus. Continuous wheat grown with recommended N rates and wheat grown after summerfallow had in most cases similar root rot levels, but the frequency of fungi differed. Among the crop rotations examined, it appears that the most favourable for development of root rot in wheat was a wheat-lentil rotation. This cereal-pulse system may also contribute to a build-up of F. avenaceum inoculum for the development of fusarium head blight, an important emerging disease of cereals in Saskatchewan. Key words: Crop rotation, common root rot, wheat, Cochliobolus sativus, Fusarium, nitrogen

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.

The effect of soil salinity on common root rot of spring wheat and barley

1993 ◽  
Vol 73 (1) ◽  
pp. 323-330 ◽  
Author(s):  
L. J. Duczek
Keyword(s):  
Spring Wheat ◽  
Soil Salinity ◽  
Root Rot ◽  
Salinity Gradient ◽  
Cochliobolus Sativus ◽  
Liquid Media ◽  
Common Root ◽  
Inoculum Level ◽  
Common Root Rot ◽  
The Relationship

Samples were taken from several sites across a salinity gradient from areas where plants were visibly unaffected to the edge of saline areas where no plants grew, from commercial fields located near Saskatoon in 1984, 1987, 1990 and 1991. There was a significant (P = 0.05) positive correlation for wheat and barley between salinity and common root rot in all years, except 1991 (1984: r = 0.445, n = 26; 1987: r = 0.390, n = 54; 1990: r = 0.244, n = 75; 1991: r = 0.247, n = 40). The correlation between inoculum level and disease was not significant, except for one barley field in 1990. However, when inoculum level was used as a covariate, the significance of the relationship between salinity and common root rot increased. Growth of Cochliobolus sativus was unaffected on solid and liquid media until conductivity levels were higher than 30–50 mmhos cm−1. Since wheat and barley do not grow at levels higher than 10–15 mmhos cm−1, salinity would have a greater affect on plants than on the pathogen. The relationship between salinity and disease is consistent with the theory that stress increases common root rot in plants. However, the variation in salinity only explains about 20% of the variation in common root rot. Key words: Cochliobolus sativus, common root rot, salinity, cereals

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.

scholarly journals Response of wheat root pathogens to crop management in eastern Saskatchewan

2007 ◽  
Vol 87 (4) ◽  
pp. 953-963 ◽  
Author(s):  
M. R. Fernandez ◽  
P. Basnyat ◽  
R. P. Zentner
Keyword(s):  
Spring Wheat ◽  
Root Rot ◽  
Soil Tillage ◽  
Cochliobolus Sativus ◽  
Oilseed Crop ◽  
Relative Role ◽  
Common Root ◽  
Common Root Rot ◽  
Previous Crop ◽  
Tillage System

A survey of common root rot in spring wheat (Triticum aestivum L.) and durum wheat (T. turgidum L. var. durum) crops was conducted in eastern Saskatchewan from 1999 to 2001 to investigate the association of agronomic practices with disease and fungal populations, in particular Fusarium species associated with Fusarium head blight (FHB), which is a disease of increasing importance in this region. Spring wheat preceded by summerfallow, or grown after a sequence that included summerfallow and a cereal crop, had increased levels of Cochliobolus sativus and lower levels of most Fusarium spp. in discoloured subcrown internodes. Cropping sequences that included at least one noncereal crop in the previous 2 yr resulted in higher percentage isolations of F. avenaceum and F. graminearum than sequences which did not include noncereal crops. Highest levels of F. avenaceum, the most common FHB pathogen in the province, were observed when the previous crop was a pulse. Tillage system effects depended on the previous crop. When wheat was preceded by an oilseed crop, C. sativus decreased as the number of tillage operations decreased, whereas F. avenaceum and M icrodochium bolleyi increased with a reduction in tillage. Associations of fungal isolations with previous glyphosate use were negative for C. sativus and positive for F. avenaceum and M. bolleyi, although these effects varied depending on tillage system. Increased levels of important Fusarium pathogens were thus associated with current trends in production practices, namely continuously cropped diversified rotations and less reliance on mechanical soil tillage. Further investigation into the relative role of tillage intensity and glyphosate use versus cropping sequence on Fusarium populations in underground wheat tissue is needed. Key words: Common root rot, wheat, Cochliobolus sativus, Fusarium, tillage, glyphosate, crop rotation, nitrogen

The effect of common root rot on the yield of resistant and susceptible wheat

1996 ◽  
Vol 76 (4) ◽  
pp. 869-877 ◽  
Author(s):  
R. L. Conner ◽  
G. C. Kozub ◽  
K. L. Bailey
Keyword(s):  
Disease Severity ◽  
Root Rot ◽  
Field Tests ◽  
Cochliobolus Sativus ◽  
Common Root ◽  
Back Cross ◽  
Common Root Rot ◽  
The Impact ◽  
Disease Free

The impact of common root rot, caused by Cochliobolus sativus, on the yield of mixtures of resistant and susceptible backcross-6 derivative lines of Neepawa and Chester wheat was examined in field tests at three locations between 1991 and 1994. Different blends consisting of all 25% incremental combinations of resistant and susceptible back-cross lines within each cultivar were evaluated for disease severity and yield at root rot nurseries and disease-free sites. Significant (P < 0.05) differences in yield were often detected among cultivars. However, within cultivars, no consistent yield differences were observed among blends of resistant and susceptible lines of the same cultivar regardless of root rot severity. Key words:Cochliobolus sativus, common root rot, yield, wheat

INHERITANCE OF THATCHER-TYPE RESISTANCE TO COMMON ROOT ROT IN SPRING WHEAT

1968 ◽  
Vol 48 (5) ◽  
pp. 479-486 ◽  
Author(s):  
Hugh McKenzie ◽  
T. G. Atkinson
Keyword(s):  
Triticum Aestivum ◽  
Spring Wheat ◽  
Root Rot ◽  
Recessive Gene ◽  
Cochliobolus Sativus ◽  
Common Root ◽  
Wheat Stem Sawfly ◽  
Common Root Rot ◽  
Resistant Varieties ◽  
Stem Solidness

Inheritance of reaction to common root rot, caused chiefly by Cochliobolus sativus, was studied in F3 populations of wheat, Triticum aestivum, from crosses between the root-rot-resistant, hollow-stemmed varieties, Thatcher and Pembina, and the moderately root-rot-susceptible, solid-stemmed variety, CT 733. The results indicated that the resistance of Thatcher and Pembina, which appear to have the same gene complement, is controlled by a major recessive gene and one or two minor genes.No association was found between inheritance of root-rot reaction and the inheritance of stem solidness which determines resistance to the wheat stem sawfly (Cephus cinctus). Therefore, there should be no difficulty in incorporating root-rot resistance into sawfly-resistant varieties.

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