Identifying resistance genes to Leptosphaeria maculans in Australian Brassica napus cultivars based on reactions to isolates with known avirulence genotypes

2012 ◽  
Vol 63 (4) ◽  
pp. 338 ◽  
Author(s):  
Steve J. Marcroft ◽  
Vicki L. Elliott ◽  
Anton J. Cozijnsen ◽  
Phillip A. Salisbury ◽  
Barbara J. Howlett ◽  
...  
Keyword(s):  
Brassica Napus ◽  
Resistance Genes ◽  
Adult Plant Resistance ◽  
Leptosphaeria Maculans ◽  
Mortality Data ◽  
Adult Plant ◽  
Blackleg Disease ◽  
Seedling Resistance ◽  
Breeding Lines ◽  
Fungal Populations

Blackleg disease, caused by the fungus Leptosphaeria maculans, is the major disease of canola (Brassica napus) worldwide. A set of 12 Australian L. maculans isolates was developed and used to characterise seedling resistance in 127 Australian cultivars and advanced breeding lines. Plant mortality data used to assess the effectiveness of seedling resistance in canola growing regions of Australia showed that Rlm3 and Rlm4 resistance genes were less effective than other seedling resistance genes. This finding was consistent with regional surveys of the pathogen, which showed the frequency of Rlm4-attacking isolates was >70% in fungal populations over a 10-year period. Differences in adult plant resistance were identified in a subset of Australian cultivars, indicating that some adult gene resistance is isolate-specific.

scholarly journals Insights into fighting against blackleg disease of Brassica napus in Canada

2018 ◽  
Vol 69 (1) ◽  
pp. 40 ◽  
Author(s):  
Xuehua Zhang ◽  
W. G. Dilantha Fernando
Keyword(s):  
Brassica Napus ◽  
Disease Control ◽  
Resistance Genes ◽  
Leptosphaeria Maculans ◽  
Western Canada ◽  
R Genes ◽  
Blackleg Disease ◽  
Evolutionary Potential ◽  
Fungal Populations ◽  
Major Resistance Genes

Blackleg disease, caused by the ascomycete fungal pathogen Leptosphaeria maculans, is a devastating disease of canola (Brassica napus) in Australia, Canada and Europe. Although cultural strategies such as crop rotation, fungicide application, and tillage are adopted to control the disease, the most promising disease control strategy is the utilisation of resistant canola varieties. However, field populations of L. maculans display a high evolutionary potential and are able to overcome major resistance genes within a few years, making disease control relying on resistant varieties challenging. In the early 1990s, blackleg resistance gene Rlm3 was introduced into Canadian canola varieties and provided good resistance against the fungal populations until the early 2000s, when moderate to severe blackleg outbreaks were observed in some areas across western Canada. However, the breakdown of Rlm3 resistance was not reported until recently, based on studies on R genes present in Canadian canola varieties and the avirulence allele frequency in L. maculans populations in western Canada. The fact that Rlm3 was overcome by the evolution of fungal populations demands canola breeding programs in Canada to be prepared to develop canola varieties with diversified and efficient R genes. In addition, frequent monitoring of fungal populations can provide up-to-date guidance for proper resistance genes deployment. This literature review provides insights into the outbreaks and management of blackleg disease in Canada.

Transfer of leaf and stripe rust resistance genes Lr19 and Yr15 in to a susceptible wheat cultivar HS295

2019 ◽  
Vol 79 (3) ◽  
Author(s):  
Pratima Sharma ◽  
Madhu Patial ◽  
Dharam Pal ◽  
S. C. Bhardwaj ◽  
Subodh . Kumar ◽  
...  
Keyword(s):  
Rust Resistance ◽  
Ssr Marker ◽  
Scar Marker ◽  
Adult Plant Resistance ◽  
Wheat Cultivar ◽  
Stripe Rust Resistance ◽  
Adult Plant ◽  
Potential Donor ◽  
Seedling Resistance ◽  
Breeding Lines

The present study was conducted to transfer multiple rust resistance in a popular but rust susceptible wheat cultivar HS295. Selected derivatives WBM3632 and WBM3635 have been developed from a cross, HS295*2/FLW20//HS295*2/ FLW13 using bulk-pedigree method of breeding. Advance line WBM3697 selected from a breeding line WBM3532 was named as HS661. This line was evaluated for seedling resistance to a wide array of rust pathotypes and found to possess resistance to all the three rusts. HS661 was also tested under field conditions and showed adult plant resistance to leaf rust (AC1=0.6), stem rust (ACI=2.7) and strpe rust (AC1=3.8). Among 34 F3 lines, 28 were tested positive for SSR marker Xwmc221 indicating the presence of Lr19/Sr25. Out of 14 selected F4 lines from F3, nine were homozygous positive for Lr19/Sr25. The advanced breeding lines viz., WBM3632 (WBM3697) and WBM3635 were also positive for Lr19/Sr25 with SCAR marker SCS265512. SSR marker Xgwm1 producing 215 bp band in Avst-15, FLW13 and HS661 confirmed the presence of Yr15 . Agronomically, HS661 was comparable with recipient variety HS295 and superior to a standard check HS490 under late sown restricted irrigation production conditions of NHZ. HS661 may serve as a potential donor for creating new usable variability against all the three rusts.

Identifying seedling and adult plant resistance of Chinese Brassica napus germplasm to Leptosphaeria maculans

2016 ◽  
Vol 66 (5) ◽  
pp. 752-762 ◽  
Author(s):  
X. Zhang ◽  
G. Peng ◽  
P. Parks ◽  
B. Hu ◽  
Q. Li ◽  
...  
Keyword(s):  
Brassica Napus ◽  
Plant Resistance ◽  
Adult Plant Resistance ◽  
Leptosphaeria Maculans ◽  
Adult Plant

scholarly journals Seedling and Adult Plant Resistance to Powdery Mildew in Chinese Bread Wheat Cultivars and Lines

Plant Disease ◽  
2005 ◽  
Vol 89 (5) ◽  
pp. 457-463 ◽  
Author(s):  
Z. L. Wang ◽  
L. H. Li ◽  
Z. H. He ◽  
X. Y. Duan ◽  
Y. L. Zhou ◽  
...  
Keyword(s):  
Powdery Mildew ◽  
Bread Wheat ◽  
Resistance Genes ◽  
Plant Resistance ◽  
Adult Plant Resistance ◽  
The United States ◽  
Adult Plant ◽  
Wheat Cultivars ◽  
Seedling Resistance ◽  
Progress Curve

Powdery mildew, caused by Blumeria graminis f. sp. tritici, is a widespread wheat disease in China. Identification of race-specific genes and adult plant resistance (APR) is of major importance in breeding for an efficient genetic control strategy. The objectives of this study were to (i) identify genes that confer seedling resistance to powdery mildew in Chinese bread wheat cultivars and introductions used by breeding programs in China and (ii) evaluate their APR in the field. The results showed that (i) 98 of 192 tested wheat cultivars and lines appear to have one or more resistance genes to powdery mildew; (ii) Pm8 and Pm4b are the most common resistance genes in Chinese wheat cultivars, whereas Pm8 and Pm3d are present most frequently in wheat cultivars introduced from CIMMYT, the United States, and European countries; (iii) genotypes carrying Pm1, Pm3e, Pm5, and Pm7 were susceptible, whereas those carrying Pm12, Pm16, and Pm20 were highly resistant to almost all isolates of B. graminis f. sp. tritici tested; and (iv) 22 genotypes expressed APR. Our data showed that the area under the disease progress curve, maximum disease severity on the penultimate leaf, and the disease index are good indicators of the degree of APR in the field. It may be a good choice to combine major resistance genes and APR genes in wheat breeding to obtain effective resistance to powdery mildew.

Usefulness of winter canola (Brassica napus) race-specific resistance genes against blackleg (causal agent Leptosphaeria maculans) in southern Australian growing conditions

2011 ◽  
Vol 62 (2) ◽  
pp. 162 ◽  
Author(s):  
K. A. Light ◽  
N. N. Gororo ◽  
P. A. Salisbury
Keyword(s):  
Disease Resistance ◽  
Resistance Genes ◽  
Leptosphaeria Maculans ◽  
Brassica Species ◽  
Superior Performance ◽  
Adult Plant ◽  
Control Line ◽  
Blackleg Disease ◽  
Blackleg Resistance ◽  
Spring Canola

Studies on the blackleg resistance of Brassica lines containing known race-specific, Rlm resistance genes can provide information on the potential use of these genes in the genetic improvement of Australian spring canola lines. Lines of four Brassica species (winter B. napus, B. nigra, B. juncea, B. rapa) containing one or more known specific Rlm genes were assessed for seedling and adult plant survival, on infected stubble derived from crops of both polygenic and B. rapa ssp. sylvestris resistance types, to determine their potential usefulness as sources of blackleg disease resistance in diverse environments in southern Australia. Seedling and adult plant resistance of lines differed depending on the stubble type used. The seedling and adult plant blackleg resistance of several lines containing the resistance genes Rlm1, Rlm1/Rlm3, Rlm7, and Rlm10 was consistently higher than the control line, AV-Sapphire, which carries polygenic resistance. The superior performance of these lines indicates that winter B. napus and B. nigra lines have outstanding potential for improving blackleg disease resistance under Australian conditions.

scholarly journals A Cluster of Major Specific Resistance Genes to Leptosphaeria maculans in Brassica napus

2004 ◽  
Vol 94 (6) ◽  
pp. 578-583 ◽  
Author(s):  
R. Delourme ◽  
M. L. Pilet-Nayel ◽  
M. Archipiano ◽  
R. Horvais ◽  
X. Tanguy ◽  
...  
Keyword(s):  
Brassica Napus ◽  
Resistance Genes ◽  
Specific Resistance ◽  
Quantitative Resistance ◽  
Specific Interaction ◽  
Leptosphaeria Maculans ◽  
Field Resistance ◽  
Genetic Identification ◽  
Adult Plant ◽  
Avirulence Genes

Two types of genetic resistance to Leptosphaeria maculans usually are distinguished in Brassica napus: qualitative, total resistance expressed at the seedling stage and quantitative, partial resistance expressed at the adult plant stage. The latter is under the control of many genetic factors that have been mapped through quantitative trait loci (QTL) studies using ‘Darmor’ resistance. The former usually is ascribed to race-specific resistance controlled by single resistance to L. maculans (Rlm) genes. Three B. napus-originating specific Rlm genes (Rlm1, Rlm2, and Rlm4) previously were characterized. Here, we report on the genetic identification of two novel resistance genes, Rlm3 and Rlm7, corresponding to the avirulence genes AvrLm3 and AvrLm7. The identification of a novel L. maculans- B. napus specific interaction allowed the detection of another putative new specific resistance gene, Rlm9. The resistance genes were mapped in two genomic regions on LG10 and LG16 linkage groups. A cluster of five resistance genes (Rlm1, Rlm3, Rlm4, Rlm7, and Rlm9) was strongly suggested on LG10. The relation between all these specific resistance genes and their potential role in adult-plant field resistance is discussed. These two Rlm-carrying regions do not correspond to major QTL for Darmor quantitative resistance.

Seedling and adult plant resistance to blackleg (Leptosphaeria maculans (Desm.) Ces. et de Not.) in spring rape (Brassica napus L.)

1980 ◽  
Vol 31 (1) ◽  
pp. 37 ◽  
Author(s):  
LA Cargeeg ◽  
N Thurling
Keyword(s):  
Brassica Napus ◽  
Leptosphaeria Maculans ◽  
Adult Plant ◽  
Selection Line ◽  
Selected Lines ◽  
Brassica Napus L ◽  
Seedling Resistance ◽  
Causal Organism ◽  
Resistant Lines ◽  
The Mean

In a glasshouse test with a large number of lines derived by self-pollination of rape plants (Brassica napus L.) randomly selected from each or four spring cultivars, considerable variation in the responses of seedlings to blackleg infection (causal organism Leptosphaeria maculans (Desm.) Ces. et de Not.) was observed between and within cultivars. Although the mean disease scores of lines within each cultivar ranged between the extremes of susceptibility and resistance, a much higher frequency of resistant lines were detected in the cultivar Nosovsky than in Ceska and Zollerngold. The lines used in this initial test provided a basis for developing a susceptible and resistant line from each cultivar, and these were tested together with six other lines previously rated as being resistant in the field, under both glasshouse and field conditions. Responses to seedling infection in four different glasshouse environments showed only three field-selected lines (Wesreo, Mutu and R46) to have adequate seedling resistance. All glasshouse-selected lines were susceptible in these glasshouse tests, and the resistant selections were In all cases slightly more susceptible than the corresponding susceptible selections. In the field test, the field-selected lines as a group were clearly more resistant than any of the glasshouse-selected lines except the Nosovsky resistant selection line. The Ceska and Zollerngold resistant selections, although susceptible in comparison with the field selections, were more resistant than the corresponding susceptible selections. Considerable variation in the mean disease scores of individual plants obtained at maturity was observed within all lines except the two Tower glasshouse selections. The frequency of resistant plants was fairly high in all field-selected lines except 73N22-1 and very low in all glasshouse-selected lines except the Nosovsky resistant selection. Coefficients of correlation between disease scores at maturity in the field and scores of young plants in each of four different glasshouse environments were significant for all but one environment. The highest correlation was observed in the case of the procedure involving a single inoculation 10 days after sowing and growth of seedlings under a daily temperature regime of 25/20�C. The five lines ranked most resistant in this test were also the five most resistant lines in the field.

Development of an agronomically superior blackleg resistant canola cultivar in Brassica napus L. using doubled haploidy

1995 ◽  
Vol 75 (2) ◽  
pp. 437-439 ◽  
Author(s):  
G. R. Stringam ◽  
V. K. Bansal ◽  
M. R. Thiagarajah ◽  
D. F. Degenhardt ◽  
J. P. Tewari
Keyword(s):  
Brassica Napus ◽  
Doubled Haploid ◽  
Leptosphaeria Maculans ◽  
Resistance Breeding ◽  
Breeding Method ◽  
Brassica Napus L ◽  
Breeding Lines ◽  
University Of Alberta ◽  
Blackleg Resistance ◽  
The University

The doubled haploid breeding method and greenhouse screening using cotyledon bio-assay were successfully applied to transfer blackleg resistance from the Australian cultivar Maluka (Brassicas napus), into susceptible advanced B. napus lines from the University of Alberta. This approach for blackleg resistance breeding was effective and efficient as several superior blackleg resistant breeding lines were identified within 4 yr from the initial cross. One of these lines (91–21864NA) was entered in the 1993 trials of the Western Canada Canola/Rapeseed Recommending Committee. Key words: Blackleg resistance, Leptosphaeria maculans, doubled haploid, Brassica napus

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