ADULT PLANT RESISTANCE OF SOME OAT VARIETIES TO PHYSIOLOGIC RACES OF CROWN RUST

1944 ◽  
Vol 22c (6) ◽  
pp. 287-289 ◽  
Author(s):  
B. Peturson

The reactions of five varieties of oats in the seedling and adult plant stages to seven physiologic races of crown rust, Puccinia coronata Corda var. Avenae Erikss. & Henn. were determined.All five varieties were completely susceptible in the seedling stage to all the races. Two varieties, Erban and Ajax, were resistant in the adult plant stage to some of the races and susceptible or moderately susceptible to others. Two other varieties, R.L. No. 1370 and R.L. No. 1510 were resistant in the adult plant stage to all the races used in this test, and apparently possess a generalized type of adult plant resistance to crown rust.

2021 ◽  
Author(s):  
Sahbi Ferjaoui ◽  
Lamia Aouini ◽  
Rim Ben Slimane ◽  
Karim Ammar ◽  
Suzanne Dreisigacker ◽  
...  

Abstract Background Septoria tritici blotch (STB), caused by Zymoseptoria tritici (Z. tritici), is an important biotic threat to durum wheat in the entire Mediterranean Basin. Although most durum wheat cultivars are susceptible to Z. tritici, research in STB resistance in durum wheat has been limited. Results In our study, we have identified resistance to a wide array of Z. tritici isolates in the Tunisian durum wheat landrace accession ‘Agili39’. Subsequently, a recombinant inbred population was developed and tested under greenhouse conditions at the seedling stage with eight Z. tritici isolates and for five years under field conditions with three Z. tritici isolates. Mapping of quantitative trait loci (QTL) resulted in the identification of two major QTL on chromosome 2B designated as Qstb2B_1 and Qstb2B_2. The Qstb2B_1 QTL was mapped at the seedling and the adult plant stage (highest LOD 33.9, explained variance 61.6 %), conferring an effective resistance against five Z. tritici isolates. The Qstb2B_2 conferred adult plant resistance (highest LOD 32.9, explained variance 42 %) and has been effective at the field trials against two Z. tritici isolates. The Qstb2B_1 QTL was mapped at the seedling and the adult plant stage (highest LOD 33.9, explained variance 61.6 %), conferring an effective resistance against five Z. tritici isolates. The Qstb2B_2 conferred adult plant resistance (highest LOD 32.9, explained variance 42 %) and has been effective at the field trials against two Z. tritici. The physical positions of the flanking markers linked to Qstb2B_1 and Qstb2B_2 indicate that these two QTL are 5Mb apart. In addition, we identified two minor QTL on chromosomes 1A (Qstb1A) and chromosome 7A (Qstb7A) (highest LODs 4.6 and 4.0, and explained variances of 16 % and 9%, respectively) that were specific to three and one Z. tritici isolates, respectively. All identified QTL were derived from the landrace accession Agili39 that represents a valuable source for STB resistance in durum wheat. Conclusion This study demonstrates that Z. tritici resistance in the ‘Agili39’ landrace accession is controlled by two minor and two major QTL acting in an additive mode.


1943 ◽  
Vol 21c (1) ◽  
pp. 10-17 ◽  
Author(s):  
Margaret Newton ◽  
T. Johnson

Nine wheat varieties were studied in two stages of growth, the seedling stage and the heading stage, for their reaction to a number of physiologic races of leaf rust of wheat, Puccinia triticina Erikss. Several varieties susceptible to certain physiologic races in the seedling stage were found to acquire, as they grew to maturity, a resistance to these races. In the adult plant, the resistance was greatest in the uppermost leaves but diminished progressively on lower leaves. The varieties tested fell into three groups on the basis of their rust reaction. (1) Renown and Regent, which developed adult plant resistance to all of the 19 races to which they were tested. In these two varieties, and possibly in other derivatives of H-44 and Hope, adult plant resistance to physiologic races of leaf rust may be a generalized phenomenon comparable to the resistance such varieties show towards stem rust. (2) Thatcher, Apex, Marquis, Reward, and Kenya R.L. 1373, which showed adult plant resistance only to certain physiologic races, a condition not hitherto encountered in other cereal rusts. (3) McMurachy and Warden × Hybrid, each of which reacted somewhat similarly in the seedling and heading stages, the former being susceptible and the latter resistant in both stages.


1997 ◽  
Vol 77 (2) ◽  
pp. 279-281 ◽  
Author(s):  
A. G. Xue ◽  
J. C. Sutton ◽  
A. Dale

Nine progeny populations, derived from a half-diallel and self-crosses of strawberry cultivars Vantage, Scotland, Governor Simcoe and Kent were evaluated for resistance to leaf scorch (Diplocarpon earlianum) as seedling runners and at the adult-plant stage. At both stages selfed Vantage and selfed Scotland were resistant; crosses between Vantage and Kent and between Governor Simcoe and Kent were susceptible; and remaining progeny populations were of intermediate resistance. A strong correlation (r = 0.970, P < 0.01) was observed between resistance of seedling runners and adult-plants of the nine S1 and F1 populations. The results suggest that strawberry genotypes can be evaluated effectively at the seedling stage in a breeding program for resistance to leaf scorch. Key words: Leaf scorch, Diplocarpon earlianum, strawberry, Fragaria × ananassa, seedling-runner, adult plant, resistance


Plant Disease ◽  
2013 ◽  
Vol 97 (12) ◽  
pp. 1544-1548 ◽  
Author(s):  
M. Y. A. Tan ◽  
M. L. Carson

Here, we report the screening of 332 new accessions of 11 different wild oat (Avena) species from the United States Department of Agriculture National Small Grains Collection in Aberdeen, ID, for resistance to crown rust disease, caused by Puccinia coronata f. sp. avenae. This collection originated from Morocco and includes Avena agadiriana, A. atlantica, A. barbata, A. damascena, A. eriantha, A. hirtula, A. longiglumis, A. magna, A. murphyi, A. sterilis, and A. wiestii. After screening this collection with a highly diverse population of P. coronata f. sp. avenae, 164 accessions (49%) were rated moderately resistant to resistant in the preliminary screen at the seedling stage and 181 accessions (55%) rated moderately resistant to highly resistant in the adult plant stage. Although none of the accessions showed a highly resistant response consistently in the seedling stage, 20 accessions did display a highly resistant response in the adult plant stage. Both seedling as well as adult plant resistance was found in 150 (45%) of the accessions. Virulence in P. coronata has been reported to all resistance genes currently being used in North American oat cultivars. The new resistance sources presented here are potentially new sources for future breeding. The resistance found in 52 accessions of A. magna and A. murphyi with the AACC genome is especially valuable because these should be relatively easy to transfer into hexaploid A. sativa.


2021 ◽  
Vol 2138 (1) ◽  
pp. 012003
Author(s):  
Yuan Gao ◽  
Changhua Liu ◽  
Xiaoming Wu

Abstract Both the seedling stage and the adult plant stage of rape can be infected with root edema, and the damaged roots swell to form tumors of different sizes and shapes. The incidence of rape root swelling at the seedling stage reached 17%, and the average incidence at the adult plant stage was 15%, resulting in a 10.2% reduction in rape production. The average plant height, number of siliques, number of kernels per horn, 1000-seed weight and yield per plant of healthy plants were significantly higher than those of diseased plants. Grading root lesions can help trace the root causes of root lesions. However, the method of grading is often performed manually by professionals at present, which has the problems of low speed and low efficiency. In order to solve this problem, a method for grading rape root swelling based on deep convolutional neural network is proposed in this paper. Firstly, a rape root swelling model based on convolutional neural network and regional candidate network was established, and then implement it on the deep learning Tensorflow framework Model, and finally compare and analyze the results. The rape root swelling model uses the VGG16 network to extract the characteristics of the rape root swelling image. The regional candidate network generates the preliminary position candidate frame of the rape root swelling, and Fast-RCNN realizes the classification and positioning of the candidate frame. The results show that this method can achieve rapid and accurate detection of healthy, first-level tumors, second-level tumors, and third-level tumors of four-level rape root swelling, with an average accuracy rate of 84.12%. The experimental results show that the accuracy rate can reach more than 90%.


2018 ◽  
Author(s):  
Matthew Haas ◽  
Martin Mascher ◽  
Claudia Castell-Miller ◽  
Brian J. Steffenson

AbstractSpot blotch, caused byBipolaris sorokiniana(Sacc.) Shoem., is an economically important disease affecting barley (Hordeum vulgareL.). The disease has largely been controlled in the Upper Midwest region of the USA through a suite of quantitative trait loci (QTL) termed the Midwest Six-rowed Durable Resistance Haplotype (MSDRH). These QTL have been bred into all six-rowed Midwest barley cultivars, including the widely used cultivar Morex. We identified a gamma ray- induced Morex mutant (MUT) that exhibits spot blotch susceptibility at the seedling stage. This mutant also spontaneously develops extremely large necrotic lesions in the absence of the pathogen at the adult plant stage. Spot blotch susceptibility at the seedling stage and necrotic lesion formation at the adult plant stage are highly correlated. To start dissecting the molecular responses underlying the observed symptoms at the seedling stage, we conducted a time course RNA-seq experiment comparing the wild type (WT) and the mutant (MUT) Morex at 12, 24 and 36 h afterB. sorokinianainoculation. Mock-inoculated controls were also included. A total of 10,772 and 11,530 genes were differentially expressed between treatments for WT and MUT genotypes, respectively, while 277 and 195 genes were differentially expressed between fungal and mock-inoculated genotypes, respectively. The transcript expression profiles of WT and MUT Morex samples were similar for most treatments. Two genes whose expression was putatively knocked out in the MUT were identified: HORVU3Hr1G019920 (glycine-rich protein) and HORVU5Hr1G120850 (Long- chain-fatty-acid—CoA ligase 1). The latter appears to be genetically intact, but not expressed. Collectively, these data suggest that MUT susceptibility toB. sorokinianais a result of minor, rather than major, differences in the defense responses.


1964 ◽  
Vol 44 (5) ◽  
pp. 418-426 ◽  
Author(s):  
G. J. Green ◽  
R. I. H. McKenzie

New races of oat stem rust that can attack varieties carrying all identified resistance genes were found in Canada between 1957 and 1963. Varieties moderately resistant to some of these races have been found, but they are susceptible to other less-prevalent races. Some of the sources of resistance are: Ukraine, C.I. 3259; Ark. 674(2)-39-F, C.I. 4529; C.I. 4673; C.I. 5109; Santa Fe Selection, C.I. 5844; C.I. 6792; Silva No. 1729-49-1, C.I. 6849; and Rosen’s Mutant. White Russian (gene D) and Sevnothree (gene E) were resistant in the adult plant stage to one culture of race 6AF, although susceptible in the seedling stage.


Genome ◽  
1990 ◽  
Vol 33 (2) ◽  
pp. 198-202 ◽  
Author(s):  
D. E. Harder ◽  
J. Chong ◽  
P. D. Brown ◽  
J. W. Martens

Accessions of wild Avena spp. obtained from the Iberian Peninsula were screened for resistance to oat crown and oat stem rust. Of a number of accessions which showed resistance, A. sterilis accession IB3056 was selected for further genetic analysis because it had combined resistance to both crown and stem rusts and as a hexaploid was readily hybridizable with A. sativa. IB3056 was crossed and backcrossed with the susceptible cultivar 'Makuru' and progeny were analyzed for segregation to a range of rust races. A single dominant gene conferred resistance to crown rust. The resistance was highly effective against all isolates of Puccinia coronata avenae tested. The crown rust resistance of IB3056 was due either to gene Pc68 or was very closely linked or allelic to Pc68. Seedling plants of the IB3056 parent were susceptible to all isolates of P. graminis avenae tested, but in the adult plant stage they were resistant. All IB3056/2* Makuru progeny also were susceptible to stem rust as seedlings, but BC1F2 adult plants segregated for resistance in ratios indicating a single dominant gene, designated Pg17.Key words: oat crown rust, oat stem rust, adult plant resistance, seedling resistance


Sign in / Sign up

Export Citation Format

Share Document