Reaction of a range of Brassica species under Australian conditions to the fungus, Leptosphaeria maculans, the causal agent of blackleg

2002 ◽  
Vol 42 (5) ◽  
pp. 587 ◽  
Author(s):  
S. J. Marcroft ◽  
N. Wratten ◽  
A. Purwantara ◽  
P. A. Salisbury ◽  
T. D. Potter ◽  
...  
Keyword(s):  
Seedling Survival ◽  
Leptosphaeria Maculans ◽  
Brassica Species ◽  
Causal Agent ◽  
Adult Plant ◽  
Growth Stages ◽  
Sources Of Resistance ◽  
Breeding Programs ◽  
Resistant Species ◽  
B Genome

A range of Brassica species was screened for resistance to Leptosphaeria maculans, the causal agent of blackleg. The lines were assessed in 8 disease nurseries in 4 canola growing regions of Australia and in 1�glasshouse trial, with a view to identifying alternative sources of resistance to L. maculans for Australian breeding programs. Lines were screened for degree of internal and external blackleg symptoms during both the seedling and adult plant growth stages. Correlation for resistance with ranking between disease nurseries was very strong (0.41-0.98). Brassica carinata and B. nigra were the most resistant species in the disease nurseries, being even more resistant than B. juncea. The 7 European winter B. napus lines tested were significantly more resistant than the 7�Australian spring B. napus lines, with another crucifer, Sinapis alba, being intermediate in resistance between the European and Australian B. napus lines. The same ranking of lines from most to least resistant was also seen when cotyledons and stems were inoculated in the glasshouse with 2 well-characterised Australian isolates. With the exception of the B. napus susceptible control Westar, all lines had similar frequencies of seedling survival in the nurseries. However, mature plants of these lines varied significantly in their degree of resistance. This indicates that screening for seedling survival is not useful in selecting L. maculans resistant lines in Australia. The Brassica lines with the B genome, especially B. carinata, and the winter B. napus types are now being used as sources of resistance in Australian breeding programs.

Mapping genes for resistance to Leptosphaeria maculans in Brassica juncea

Genome ◽  
2006 ◽  
Vol 49 (1) ◽  
pp. 30-41 ◽  
Author(s):  
J A Christianson ◽  
S R Rimmer ◽  
A G Good ◽  
D J Lydiate
Keyword(s):  
Linkage Group ◽  
Brassica Juncea ◽  
Fragment Length Polymorphism ◽  
Leptosphaeria Maculans ◽  
Recessive Gene ◽  
Brassica Species ◽  
Blackleg Disease ◽  
Recessive Resistance ◽  
B Genome ◽  
Restriction Fragment Length

Blackleg disease of crucifers, caused by the fungus Leptosphaeria maculans, is a major concern to oilseed rape producers worldwide. Brassica species containing the B genome have high levels of resistance to blackleg. Brassica juncea F2 and first-backcross (B1) populations segregating for resistance to a PG2 isolate of L. maculans were created. Segregation for resistance to L. maculans in these populations suggested that resistance was controlled by two independent genes, one dominant and one recessive in nature. A map of the B. juncea genome was constructed using segregation in the F2 population of a combination of restriction fragment length polymorphism (RFLP) and microsatel lite markers. The B. juncea map consisted of 325 loci and was aligned with previous maps of the Brassica A and B genomes. The gene controlling dominant resistance to L. maculans was positioned on linkage group J13 based on segregation for resistance in the F2 population. This position was confirmed in the B1 population in which the resistance gene was definitively mapped in the interval flanked by pN199RV and sB31143F. The provisional location of the recessive gene controlling resistance to L. maculans on linkage group J18 was identified using a subset of informative F2 individuals.Key words: blackleg, B genome, phoma, recessive resistance.

Reactions of eastern Canada oat genotypes to Puccinia coronata f. sp. avenae

2020 ◽  
Vol 100 (2) ◽  
pp. 209-217
Author(s):  
Allen G. Xue ◽  
Jim Menzies ◽  
Yuanhong Chen ◽  
Weikai Yan ◽  
Bao-luo Ma ◽  
...  
Keyword(s):  
Natural Populations ◽  
Field Trials ◽  
Crown Rust ◽  
Puccinia Coronata ◽  
Adult Plant ◽  
Limiting Factor ◽  
Sources Of Resistance ◽  
Eastern Canada ◽  
Breeding Programs ◽  
Breeding Lines

Crown rust, caused by Puccinia coronata f. sp. avenae (Pca), is the most important disease and yield limiting factor of oat production in eastern Canada. In this study 101 oat genotypes composed of 51 cultivars and 50 breeding lines from eight oat breeding programs across Canada were evaluated for seedling reactions to six common Pca races, as well as reactions to a bulk inoculum of Pca in greenhouse trials and for adult plant resistance (APR) to natural populations of Pca in field trials in 2014 and 2015. Sixty-six genotypes showed resistant reactions to at least one of the six races; of these, 22 were resistant to all six races. These 22 genotypes also showed resistance to the bulk inoculum at the seeding stage and to the natural populations of Pca at the adult plant stage, suggesting that these current and future oat varieties have effective resistance against the common races and Pca populations in the region. Eleven genotypes, including 12ANS03, AAC Bullet, CFA1213, CFA1306, Idaho, OA1301-1w-3, OA1369-5, OA1370-2, OA1371-2, OA1383-2, and Oscar, were susceptible as seedlings but resistant as adult plants. APR is proven to be long lasting and provides broad-spectrum resistance to Pca populations. The 11 oat genotypes identified with APR in the present study are more desirable as sources of resistance for breeding programs developing durable crown rust resistant cultivars for eastern Canada.

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 Strains of Leptosphaeria maculans with the Capacity to Cause Crown Canker on Brassica carinata are Present in Western Australia

Plant Disease ◽  
2006 ◽  
Vol 90 (6) ◽  
pp. 832-832
Author(s):  
R. Khangura ◽  
M. Aberra
Keyword(s):  
Western Australia ◽  
Leptosphaeria Maculans ◽  
Lesion Size ◽  
Hypersensitive Reaction ◽  
Adult Plant ◽  
Conidial Suspension ◽  
Pressure Potential ◽  
Brassica Napus L ◽  
Blackleg Resistance ◽  
B Genome

Blackleg, caused by Leptosphaeria maculans (Desm.) Ces. et de Not., is the most important disease of canola (Brassica napus L.) in Australia, Europe, Canada, and North America (2). During the early 1990s, new cultivars of canola with resistance to blackleg were released in Australia. Despite good adult-plant resistance, these cultivars still suffered significant yield losses from blackleg under high disease pressure. Potential new sources of blackleg resistance such as B. nigra L., B. carinata L., and Sinapis alba L. are being evaluated. B. carinata is believed to be highly resistant to blackleg by virtue of its B-genome. However, some L. maculans isolates that can attack B. carinata have been reported from Germany (1). During the 2003 growing season, 22 isolates of L. maculans were collected from different canola-growing areas of Western Australia and tested for their reaction on 24 seedlings of each of various Brassica genotypes, including B. carinata, in a controlled environment chamber. Twenty-four seeds per genotype were sown in 100-ml plastic pots (12 seeds per pot) and both cotyledons of 10-day-old seedlings were wound inoculated with a conidial suspension (1 × 107 conidia/ml) of each isolate of L. maculans. Disease assessments were made 2 weeks after inoculation. The majority of isolates induced a noninvasive hypersensitive reaction on B. carinata without pycnidial development. However, four of the isolates caused lesions with abundant pycnidia on B. carinata cotyledons. The lesion size ranged between 3 and 7 mm and appeared similar to that on susceptible B. napus cultivars. B. carinata seedlings were grown for another 8 weeks in a glasshouse, and crown cankers were observed from plants inoculated with three of the four seedling virulent isolates. The severity of crown cankers as percent of stem circumference (percent disease index) ranged between 20 and 54%. Twenty-five stem pieces from mature B. carinata plants infected with one of the three isolates were plated on V8 juice agar and L. maculans was recovered from 70% of pieces. Abundant pycnidia were also observed on these stem pieces. These results have important implications for using B. carinata as a source of blackleg resistance in canola breeding. To our knowledge, this is the first report of L. maculans isolates with the capacity to induce crown cankers on B. carinata in Australia. References: (1) C. Sjöidin and K. Glimelius. J. Phytopathol. 123:322, 1988. (2) J. West et al. Plant Pathol. 51:454, 2002.

scholarly journals Development of Plant–Fungal Endophyte Associations to Suppress Phoma Stem Canker in Brassica

2021 ◽  
Vol 9 (11) ◽  
pp. 2387
Author(s):  
Davood Roodi ◽  
James P. Millner ◽  
Craig R. McGill ◽  
Richard D. Johnson ◽  
Shen-Yan Hea ◽  
...  
Keyword(s):  
Endophytic Fungi ◽  
Fungal Endophytes ◽  
Leptosphaeria Maculans ◽  
Brassica Species ◽  
Stem Canker ◽  
Fungal Endophyte ◽  
Plant Diseases ◽  
Growth Stages ◽  
Phoma Stem Canker ◽  
Pests And Diseases

Endophytic microorganisms are found within the tissues of many plants species, with some conferring several benefits to the host plant including resistance to plant diseases. In this study, two putative endophytic fungi that were previously isolated from wild seeds of Brassica, identified as Beauveria bassiana and Pseudogymnoascus pannorum, were inoculated into cultivars of three Brassica species—Brassica napus, Br. rapa and Br. oleracea. Both fungal endophytes were reisolated from above- and below-ground tissues of inoculated plants at four different plant-growth stages, including cotyledon, one-leaf, two-leaf, and four-leaf stages. None of the plants colonised by these fungi exhibited any obvious disease symptoms, indicating the formation of novel mutualistic associations. These novel plant–endophyte associations formed between Brassica plants and Be. bassiana significantly inhibited phoma stem canker, a devastating disease of Brassica crops worldwide, caused by the fungal pathogen Leptosphaeria maculans. The novel association formed with P. pannorum significantly suppressed the amount of disease caused by L. maculans in one out of two experiments. Although biological control is not a new strategy, endophytic fungi with both antiinsect and antifungal activity are a highly conceivable, sustainable option to manage pests and diseases of economically important crops.

scholarly journals Mining Vavilov’s Treasure Chest of Wheat Diversity for Adult Plant Resistance to Puccinia triticina

Plant Disease ◽  
2017 ◽  
Vol 101 (2) ◽  
pp. 317-323 ◽  
Author(s):  
Adnan Riaz ◽  
Naveenkumar Athiyannan ◽  
Sambasivam Periyannan ◽  
Olga Afanasenko ◽  
Olga Mitrofanova ◽  
...  
Keyword(s):  
Plant Resistance ◽  
Adult Plant Resistance ◽  
Control Method ◽  
Plant Genetic Resources ◽  
Puccinia Triticina ◽  
Future Research ◽  
Adult Plant ◽  
Growth Stages ◽  
Sources Of Resistance ◽  
Adult Growth

Leaf rust (LR) caused by Puccinia triticina, is among the most important diseases of wheat (Triticum aestivum L.) crops globally. Deployment of cultivars incorporating genetic resistance, such as adult plant resistance (APR) or all-stage resistance, is considered the most sustainable control method. APR is preferred for durability because it places lower selection pressure on the pathogen and is often polygenic. In the search for new sources of APR, here we explored a diversity panel sourced from the N. I. Vavilov Institute of Plant Genetic Resources. Based on DNA marker screening, 83 of the 300 lines were deemed to carry known APR genes; namely, Lr34, Lr46, and Lr67. Interestingly, lines carrying Lr67 were mostly landraces from India and Pakistan, reconfirming the likely origin of the gene. Rapid phenotypic screening using a method that integrates assessment at both seedling and adult growth stages under accelerated growth conditions (i.e., constant light and controlled temperature) identified 50 lines carrying APR. Levels of APR corresponded well with phenotypes obtained in a field nursery inoculated using the same pathotype (R2 = 0.82). The second year of field testing, using a mixture of pathotypes with additional virulence for race-specific APR genes (Lr13 and Lr37), identified a subset of 13 lines that consistently displayed high levels of APR across years and pathotypes. These lines provide useful sources of resistance for future research. A strategy combining rapid generation advance coupled with phenotyping under controlled conditions could accelerate introgression of these potentially novel alleles into adapted genetic backgrounds.

Blackleg disease on oilseed Brassica in Australia: a review

1995 ◽  
Vol 35 (5) ◽  
pp. 665 ◽  
Author(s):  
PA Salisbury ◽  
DJ Ballinger ◽  
N Wratten ◽  
KM Plummer ◽  
BJ Howlett
Keyword(s):  
Leptosphaeria Maculans ◽  
Effective Control ◽  
Blackleg Disease ◽  
Varietal Resistance ◽  
Sources Of Resistance ◽  
Breeding Programs ◽  
Previous Season ◽  
Resistant Varieties ◽  
Cropping Seasons ◽  
Pathogenic Variability

Blackleg, caused by the fungus Leptosphaeria maculans, is the major disease of canola (Brassica napus) in Australia. The development of blackleg-resistant B. napus varieties has been a major factor in the resurgence of the industry nationwide. The main sources of resistance used in Australian public breeding programs are Japanese spring varieties and French winter varieties. In these programs, all early generation material is screened in field blackleg nurseries sown on, or adjacent to, infested canola stubble from the previous season. Little is known about the genetic control of resistance, and the mechanisms responsible for generating pathogenic variability of L. maculans isolates in Australia is largely uncharacterised. Australian B. napus varieties are the most blackleg-resistant spring varieties in the world. Apart from growing blackleg-resistant varieties, other strategies that minimise infection and delay any breakdown in varietal resistance include growing canola on the same area only once every 3 years, destroying stubble, and eradicating volunteer plants between cropping seasons. Additionally, strategic use of chemicals can provide effective control to supplement varietal resistance in areas prone to severe blackleg infestation.

Seedling and adult plant evaluation of race variability in Leptosphaeria maculans on Brassica species in Australia

1996 ◽  
Vol 36 (4) ◽  
pp. 485 ◽  
Author(s):  
DJ Ballinger ◽  
PA Salisbury
Keyword(s):  
Plant Resistance ◽  
Adult Plant Resistance ◽  
Leptosphaeria Maculans ◽  
Brassica Species ◽  
Adult Plant ◽  
Host Pathogen Interactions ◽  
Differential Host ◽  
Host Pathogen ◽  
Napus Line ◽  
Plant Evaluation

Seedling and adult plant studies were used to identify the race structure of Leptosphaeria maculans (the cause of blackleg) on oilseed Brassica species in Australia. Host-pathogen interactions using a set of 12 differential host lines identified 14 seedling relationship, however, between seedling and adult plant reactions to individual isolates, indicating that seedling and adult plant resistance are under different genetic control. While non-specific adult plant resistance was observed in the B. napus line Jet Neuf, host-pathogen interactions confirmed the existence of race-specific adult plant resistances in other differential lines.

scholarly journals Pathogenicity of Leptosphaeria maculans Isolates on a Brassica napus-B. juncea Recombinant Line

1999 ◽  
Vol 89 (2) ◽  
pp. 169-175 ◽  
Author(s):  
Irénée Somda ◽  
Régine Delourme ◽  
Michel Renard ◽  
Hortense Brun
Keyword(s):  
Brassica Napus ◽  
Plant Breeding ◽  
Leptosphaeria Maculans ◽  
The Other ◽  
Interspecific Crosses ◽  
Sources Of Resistance ◽  
Recombinant Line ◽  
B Genome ◽  
Cotyledon Stage ◽  
Breeding Schemes

The Brassica napus-B. juncea recombinant line (MX), resistant to Leptosphaeria maculans, was produced by interspecific crosses and bears one gene (Jlm1) from the B. juncea B genome. We investigated whether this new resistance was race specific by characterizing protection against a large sample of L. maculans isolates. The pathogenicity of 119 isolates of L. maculans comprising 105 A-group isolates and 14 B-group isolates was studied at the cotyledon stage under controlled conditions using the MX line, the susceptible B. napus cultivar Westar, and the resistant B. juncea cultivar Picra. All but one of the isolates were pathogenic on ‘Westar’. Only 3 of the 105 A-group isolates caused very mild symptoms on ‘Picra’. Two of these strains were isolated from the MX line and the other from Sinapis arvensis. The other 102 strains caused hypersensitive-type responses. Most B-group isolates were pathogenic on ‘Picra’. There were differences in pathogenicity among A-group isolates tested on the MX line, whereas all B-group isolates were pathogenic on this line. A-group isolates obtained from the MX line were more frequently pathogenic on the MX line than those obtained from B. napus cultivars. One isolate from S. arvensis infected the MX line. These results suggest that the resistance of the MX line is unlikely to be durable. Thus, the new resistance gene Jlm1 should probably be used in association with other sources of resistance, in plant breeding schemes, to prevent the breakdown of this resistance.

Resistance in maize (Zea mays) to isolates of Puccinia sorghi from Eastern Australia

2021 ◽  
Author(s):  
Aurelie Quade ◽  
Gavin J Ash ◽  
Robert F Park ◽  
Ben John Stodart
Keyword(s):  
Resistance Genes ◽  
Sweet Corn ◽  
Adult Plant ◽  
Maize Breeding ◽  
Sources Of Resistance ◽  
Breeding Programs ◽  
Puccinia Sorghi ◽  
Eastern Australia ◽  
The Us ◽  
Infection Types

The causal agent of maize common rust (CR), Puccinia sorghi Schwein., has increased in incidence and severity in Australia in recent years, prompting the assessment of sources of resistance and a preliminary survey of the diversity of P. sorghi populations. The maize commercial hybrids tested carried no resistance to 14 isolates of P. sorghi and had infection types (IT) comparable to that of a susceptible check. The resistance gene Rp1_D that remained effective in the US for 35 years, was ineffective against seven of the 14 isolates. Maize lines carrying known Rp genes were inoculated with the five isolates considered most diverse based on year of collection (2018/2019), location (Queensland/Victoria), and host from which they were isolated (maize/sweet corn). Lines carrying the resistance genes RpG, Rp5, Rp1_E, Rp1_I, Rp1_L, RpGDJ, RpGJF and Rp5GCJ were resistant to all five isolates and to isolates collected in many agro-ecological regions. These lines were recommended as donors of effective resistance for maize breeding programs in Australia. Lines carrying no known resistance or resistance genes Rp8_A, Rp8_B, Rp1_J, Rp1_M, Rp7 and Rpp9 (conferring resistance to P. polysora Underw.) were susceptible to all five isolates. Differential lines carrying the resistance genes Rp1_B, Rp1_C, Rp1_D, Rp1_F, Rp1_K, Rp3_D, or Rp4_A were either resistant or susceptible depending upon the isolate used, showing that the isolates varied in virulence for these genes. Urediniospore production was reduced on adult compared to juvenile plants, presumably due to changes in plant physiology associated with age or the presence of adult plant resistance.

Sign in / Sign up

Export Citation Format

Share Document