A cytogenetic analysis of reaction to common root rot in some hard red spring wheats

1970 ◽  
Vol 48 (11) ◽  
pp. 2059-2067 ◽  
Author(s):  
Ruby I. Larson ◽  
T. G. Atkinson

Chromosome 5B is the most important chromosome differentiating the root rot resistance of the hollow-stemmed cultivars, Apex and Cadet, from the root rot susceptibility of the solid-stemmed cultivars, S-615 and Rescue. A pair of chromosomes 5B of Apex substituted for their homologues in S-615 usually made the latter as resistant to root rot as Apex. Conversely, the substitution of 5B from Rescue into Cadet made Cadet as susceptible as Rescue. The root rot reactions of the 5B monosomics of the cultivars and substitution lines, and of the F1 between S-615 and the S-615-Apex 5B substitution, showed that the genes for resistance and susceptibility are antimorphic alleles, with susceptibility dominant.The substitution of chromosome 2B or 2D from Apex for their homologues in S-615 increased the root rot resistance of S-615, but not to the same extent as did the substitution of chromosome 5B. Their effect, although usually hypostatic to that of 5B, was evident under some test conditions. Dosage studies showed that genes on chromosomes 2B and 2D promote the disease, those from Apex less than those from S-615. Substitutions of these chromosomes from Rescue into Cadet did not affect root rot reaction.


1970 ◽  
Vol 16 (3) ◽  
pp. 153-158 ◽  
Author(s):  
J. L. Neal Jr. ◽  
T. G. Atkinson ◽  
Ruby I. Larson

Substitution of a chromosome pair (5B) from Apex (A), a variety of spring wheat (Triticum aestivum) relatively resistant to common root rot (primarily Cochliobolus sativus), for the corresponding chromosome of S-615 (S), a highly susceptible variety, changed the rhizosphere microflora qualitatively and quantitatively. Microbial analyses of the parental varieties, the substitution line (S-A5B), and non-rhizosphere soil included estimates of total microbial populations and physiological and nutritional groupings. In all characteristics a typical rhizosphere effect was evident, and significant differences were found between the different rhizospheres. In most characteristics the rhizosphere microflora of the substitution line was significantly different from either parent. The incidence of rhizosphere bacteria antagonistic to C. sativus was the most notable exception. Twenty percent of the rhizosphere isolates from both Apex and the resistant substitution line S-A5B were antagonistic to C. sativus. None of the isolates from the susceptible variety was antagonistic. The differences between the rhizospheres of the substitution line (S-A5B) and the recipient variety (S-615) are attributable to changes induced by disomic substitution of chromosome 5B.



Genome ◽  
1993 ◽  
Vol 36 (1) ◽  
pp. 173-180 ◽  
Author(s):  
R. L. Conner ◽  
E. D. P. Whelan ◽  
A. Laroche ◽  
J. B. Thomas

Resistance to common root rot and black point, caused by Cochliobolus sativus, was evaluated in alien chromosome substitution and addition lines of the cultivars 'Cadet' and 'Rescue'. Substitution of chromosome 5B in 'Rescue' with 5Ag from Agropyron elongatum decreased root rot susceptibility to a level intermediate between that in the susceptible 'Rescue' and the resistant 'Cadet'. The substitution of 'Rescue' chromosome 5A or 5D with 5Ag, or the addition of 5Ag to 'Rescue' complement had no consistent effect on root rot susceptibility. The root rot resistance of 'Cadet' was unaffected by substitution of chromosomes 5A, 5B, or 5D with 5Ag, or the addition of 5Ag. This indicates that the susceptible allele of the gene Crr is the primary determinant in the reaction of wheat to common root rot. Black point resistance in the susceptible cultivar 'Rescue' was significantly increased by substitution of chromosome 5B with 5Ag, or the addition of 5Ag. No corresponding effect was demonstrated for black point incidence in the moderately resistant cultivar 'Cadet' with substitution of chromosome 5Ag for 5B, or the addition of 5Ag. Chromosome 5Ag apparently carries one or more genes conferring resistance to black point. The identity of these lines was confirmed by restriction fragment length polymorphism analysis using group 5 chromosome arm specific probes. This extends the use of these molecular probes to the Agropyron genome.Key words: Cochliobolus sativus, common root rot, black point, wheat, Triticum aestivum, Agropyron elongatum, restriction fragment length polymorphism, chromosome arm specific probes.



1981 ◽  
Vol 23 (2) ◽  
pp. 173-182 ◽  
Author(s):  
Ruby I. Larson ◽  
T. G. Atkinson

Triticum aestivum L. cv. S-615 has a dominant gene for susceptibility to common root rot and cv. Apex a recessive gene for resistance on chromosome 5B. One hundred and twenty-two lines, each homozygous for a different random crossover between loci on Apex and S-615 chromosomes 5B, but near-isogenic with S-615 for the other 20 chromosomes, were tested for root rot reaction in soil naturally infested with the causal organism, Cochliobolus sativus (Ito and Kurib.) Dachs. ex Dastur, to determine whether the two genes are alleles. The ratio of resistant to susceptible lines was 1:1, and there were no intermediate or transgressive types. It was concluded, therefore, that the genes for resistance and susceptibility are alleles. The recessive gene for resistance has been given the symbol Crr for Cochliobolus root rot. Minor genes appear to exist on chromosome 5B of Apex which, when combined in some of the crossover lines with the dominant gene for susceptibility, crr, increase the percentage of seedlings killed by the disease but not the mean root rot rating of these lines



2013 ◽  
Vol 39 (9) ◽  
pp. 1576 ◽  
Author(s):  
Li-Hua YANG ◽  
Jin-Feng WANG ◽  
Li-Pu DU ◽  
Hui-Jun XU ◽  
Xue-Ning WEI ◽  
...  


2013 ◽  
Vol 39 (2) ◽  
pp. 368
Author(s):  
Liang DANG ◽  
Zhen-Qi SU ◽  
Xing-Guo YE ◽  
Hui-Jun XU ◽  
Zhao LI ◽  
...  


1974 ◽  
Vol 52 (7) ◽  
pp. 1757-1764 ◽  
Author(s):  
P. R. Verma ◽  
R. A. A. Morrall ◽  
R. D. Tinline

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.



1981 ◽  
Vol 3 (4) ◽  
pp. 239-243 ◽  
Author(s):  
P.R. Verma ◽  
S.H.F. Chinn ◽  
W.L. Crowle ◽  
D.T. Spurr ◽  
R.D. Tinline


Pathogens ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1526
Author(s):  
Yanjie Yi ◽  
Youtian Shan ◽  
Shifei Liu ◽  
Yanhui Yang ◽  
Yang Liu ◽  
...  

Common root rot, caused by Bipolaris sorokiniana, is one of the most prevalent diseases of wheat and has led to major declines in wheat yield and quality worldwide. Here, strain XZ34-1 was isolated from soil and identified as Bacillus amyloliquefaciens based on the morphological, physiological, biochemical characteristics and 16S rDNA sequence. Culture filtrate (CF) of strain XZ34-1 showed a high inhibition rate against B.sorokiniana and had a broad antifungal spectrum. It also remarkably inhibited the mycelial growth and spore germination of B. sorokiniana. In pot control experiments, the incidence and disease index of common root rot in wheat seedlings were decreased after treatment with CF, and the biological control efficacy was significant, up to 78.24%. Further studies showed XZ34-1 could produce antifungal bioactive substances and had the potential of promoting plant growth. Lipopeptide genes detection with PCR indicated that strain XZ34-1 may produce lipopeptides. Furthermore, activities of defense-related enzymes were enhanced in wheat seedlings after inoculation with B.sorokiniana and treatment with CF, which showed induced resistance could be produced in wheat to resist pathogens. These results reveal that strain XZ34-1 is a promising candidate for application as a biological control agent against B.sorokiniana.



2020 ◽  
Author(s):  
Jun Su ◽  
Jiaojie Zhao ◽  
Shuqing Zhao ◽  
Mengyu Li ◽  
Xiaofeng Shang ◽  
...  

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.



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