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.

scholarly journals Variabilidad patogénica de Colletotrichum lindemuthianum y resistencia en germoplasma de Phaseolus vulgaris L. de Ecuador

2018 ◽  
Vol 29 (1) ◽  
pp. 19 ◽  
Author(s):  
Diego Rodríguez-Ortega ◽  
Laura Vega-Jiménez ◽  
Ángel Rubén Murillo-Ilbay ◽  
Eduardo Peralta-Idrovo ◽  
Juan Carlos Rosas-Sotomayor
Keyword(s):  
Phaseolus Vulgaris ◽  
Resistance Genes ◽  
Durable Resistance ◽  
Colletotrichum Lindemuthianum ◽  
Phaseolus Vulgaris L ◽  
Sources Of Resistance ◽  
Improved Varieties ◽  
Physiological Races ◽  
Resistant Varieties ◽  
Pathogenic Variability

Anthracnose caused by Colletotrichum lindemuthianum is one of the most economically important diseases of bean (Phaseolus vulgaris L.) cultivation in Ecuador. The best control alternative is the use of resistant varieties. C. lindemuthianum presents great pathogenic variability, which hinders the development of varieties with a lasting resistance, therefore, the knowledge of the presence and distribution of the physiological races of the pathogen and the identification of resistance genes are key to developing varieties with broad and lasting resistance. The objective of this research was to determine the pathogenic variability of C. lindemuthianum and to evaluate the resistance of Ecuadorian bean germplasm. The research was carried out between 2013 and 2014. Seventeen isolates of C. lindemuthianum from northern central Ecuador were characterized by the inoculation of a group of twelve standard differential bean varieties. Among the analyzed samples, thirteen races were identified; five of those races had not been previously reported in the country. The differential G2333 (Co-42, Co-52 and Co-7) presented resistance to every characterized races in Ecuador. In addition, twenty - one improved varieties and elite bean lines were evaluated with sixteen of the seventeen isolates, three genotypes were identified (TB2, TB3 and INIAP 485 Urcuquí) with resistance to the mentioned isolates, which can be used as sources of resistance to Anthracnose. The identified sources of resistance in this study will allow to plan the development of bean varieties with broad and durable resistance to C. lindemuthianum.

scholarly journals Identification of sources of winter barley resistance to smut (Ustilago hordei)

2020 ◽  
pp. 72-76
Author(s):  
N. V. Shishkin ◽  
T. G. Derova ◽  
E. S. Doroshenko ◽  
O. S. Pavlenko
Keyword(s):  
Winter Barley ◽  
Optimal Time ◽  
Artificial Infection ◽  
Good Resistance ◽  
Sources Of Resistance ◽  
Breeding Programs ◽  
Breeding Lines ◽  
Resistant Varieties ◽  
Ustilago Hordei ◽  
Barley Resistance

The current paper presents the 3-year assessment results of domestic and foreign winter barley varieties and lines for smut resistance. The smut pathogen in the Rostov region causes one of the most harmful diseases, which, in addition to direct crop losses (head destruction), causes the so-called hidden losses, which can several times exceed direct ones. An effective way to counteract the disease is to cultivate resistant varieties, and farmers need the reliable sources of resistance to the pathogen. The immunological properties of winter barley varieties were studied in an infectious nursery (2016–2018). Seed infection with spores was carried out by S. Dimitrov’s method (1968) using a nutrient medium. Inoculated seeds were sown at the end of the optimal time. There was estimated a number of infected stems. The variety “Dobrynya 3” was used as a susceptible test-variety, which percentage of infection throughout the years ranged from 20.6 to 71.8%. There were studied 115 domestic and foreign varieties and lines. Among 69 domestic commercial varieties and breeding lines, 11 ones (15.9%) showed good resistance, 21 ones (30.4%) showed weak susceptibility, 30 ones (43.5%) possessed average susceptibility and seven varieties (10.1%) were severely affected by the pathogen. Among foreign varieties, resistance to barley smut has been established in seven German varieties, in three French varieties, in two Swiss varieties, one Czech variety and one Ukrainian variety. The varieties “Rocca”, “Nixe” (Germany), “Metelitsa” (Ukraine) are classified as the best ones in resistance to the pathogen during the artificial infection. The French variety “18513 ЕН11” had no affected plants during the study and was identified as an immune variety. The identified sources of winter barley resistance to smut are recommended for use in breeding programs for immunity.

scholarly journals New sources of powdery mildew resistance among winter bread wheat for adjusting the breeding immunological programs in the Agricultural Research Center “Donskoy”

2021 ◽  
pp. 82-87
Author(s):  
Т. G. Derova ◽  
N. V. Shishkin ◽  
О. S. Kononenko
Keyword(s):  
Powdery Mildew ◽  
Winter Wheat ◽  
Agricultural Research ◽  
Research Center ◽  
Artificial Infection ◽  
Sources Of Resistance ◽  
Wheat Varieties ◽  
Breeding Programs ◽  
Winter Bread Wheat ◽  
Resistant Varieties

Systematic work on the development of winter wheat varieties possessing resistance to a complex of the most harmful diseases has been carried out in the Agricultural Research Center “Donskoy” since the early 1970s. During this period, there has been created a large number of varieties that possess resistance to 3–4 diseases in conditions of infectious backgrounds of pathogens. Due to the analysis of varieties, there was identified a small number of varieties resistant to powdery mildew. Powdery mildew, caused by the fungus Blumeria graminis (DC) Speer, annually occurs on wheat, affecting all aboveground plant organs. Earlier the FSBSI “ARC “Donskoy” developed and widely cultivated the medium-resistant varieties ‘Tanais’ (2006), ‘Nakhodka’ (2015), ‘Etyud’, ‘Shef’, ‘Lilit’ (2016), ‘Volnitsa’ (2017), ‘Polina’, Yubiley Dona’ , ‘Podarok Krymu’ (2018), ‘Niva Dona’ (2019). In recent years, breeders have developed such varieties with high resistance to the pathogen as ‘Donskaya Step’ (2016), ‘Premiera’, ‘Univer’ (2018), ‘Priazovye’, ‘Zolotoy Kolos’ (2020). But the breeding process of varieties for resistance to powdery mildew is difficult, since it is explained by the small number of effective resistance genes and their sources. Therefore, the purpose of the current study was to identify new sources of resistance to the pathogen. Under the conditions of artificial infection, during last 10 years there was conducted a testing of 302 varieties and samples of winter wheat of domestic and foreign breeding. There have not been identified immune varieties. There was identified a small percentage (15.2) of varieties that were resistant to the pathogen. Among the Russian varieties they were ‘L 3191 k-5-8’, ‘Akhmat’, ‘Alievich’, ‘Barier’, ‘Ulyasha’, ‘Knyaginya Olga’, which were not attacked by the disease over the years of testing. Among foreign varieties, the varieties ‘Bombus’, ‘Sailor’ (France), ‘Etana’, ‘Rotax’, ‘KVS-Emil’ (Germany), ‘Fidelius’ (Austria), ‘MV 09-04’ (Hungary) were identified as the best ones in their resistance to powdery mildew. All identified sources of resistance have been recommended in breeding programs for immunity.

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.

scholarly journals Responses of African yam bean (Sphenostylis stenocarpa [Hochst. Ex A. Rich]) accessions to viral diseases and serological identification of the associated viruses

2020 ◽  
Vol 37 (1) ◽  
pp. 85-93
Author(s):  
O.M. Ogunsanya ◽  
C.G. Afolabi ◽  
M.O. Otusanya ◽  
M.A. Adebisi
Keyword(s):  
Field Experiments ◽  
Natural Infection ◽  
Block Design ◽  
Viral Diseases ◽  
Sources Of Resistance ◽  
Pests And Diseases ◽  
African Yam Bean ◽  
Resistant Varieties ◽  
Cropping Seasons ◽  
Sphenostylis Stenocarpa

African yam bean (Sphenostylis stenocarpa) is an orphan crop with lofty nutraceutical benefits grown in Africa. However, pests and diseases often hinder its productivity. Twenty accessions of African yam bean (AYB) were screened for resistance to viral diseases and symptomatic leaves were indexed for the presence of viruses. The Field experiments were conducted during the 2015/2016 cropping seasons (wet and dry seasons). The twenty accessions were grown in triplicates in a randomized complete block design (RCBD) on the field under natural infection and the resistance or susceptibility responses were recorded using visual symptom expression. The characteristic symptoms that were highly prevalent were leaf mosaic and leaf distortion. In both seasons, there were significant (P< 0.05) differences in the severity of these viral symptoms. Also, based on the severity of the symptoms observed in this study, 2 accessions were classified as resistant, 16 as susceptible and 2 accessions as highly susceptible. Two viruses were identified serologically namely Cowpea Mild Mottle Virus (CPMMV) and Blackeye Cowpea Mosaic Virus (BlCMV). The sources of resistance identified in this study would be useful for breeders in developing virus resistant varieties for African yam bean improvement. Keywords: African yam bean, Virus, Symptoms, ACP-Elisa, Screening.

INHERITANCE OF RESISTANCE TO NET BLOTCH IN BARLEY. I. FACTORS AFFECTING THE PENETRANCE AND EXPRESSIVITY OF GENE(S) CONDITIONING HOST RESISTANCE

1969 ◽  
Vol 11 (3) ◽  
pp. 587-591 ◽  
Author(s):  
T. N. Khan
Keyword(s):  
Environmental Conditions ◽  
Net Blotch ◽  
Host Reaction ◽  
Susceptible Parent ◽  
Breeding Programs ◽  
Genetic Studies ◽  
Factors Affecting ◽  
Drechslera Teres ◽  
Resistant Varieties ◽  
High Level

Variability in the host-reaction of barley to infection by Drechslera teres was examined in the parents and progeny of selected crosses under different environmental conditions of testing.The Ethiopian variety C.I. 5791 exhibits a consistently high level of resistance under a range of environmental conditions, which is in contrast to the Manchurian variety C.I. 2330. The sensitivity of the genes for resistance possessed by these varieties to environmental modifications is considered to depend upon their respective genetic backgrounds. Furthermore, variability of host reaction in the progeny of these resistant varieties was shown to be influenced by the genetic background of the susceptible parent used.The implications of these findings in the conduct and interpretation of genetic studies and in backcross breeding programs is discussed.

A Review of Corynespora cassiicola and Its Increasing Relevance to Tomato in Florida

2018 ◽  
Vol 19 (4) ◽  
pp. 303-309 ◽  
Author(s):  
Keevan J. MacKenzie ◽  
Leilani G. Sumabat ◽  
Katia V. Xavier ◽  
Gary E. Vallad
Keyword(s):  
Fungal Pathogen ◽  
Effective Control ◽  
Corynespora Cassiicola ◽  
Varietal Resistance ◽  
Vegetable Crop ◽  
Fresh Market ◽  
Resistance Development ◽  
Pathogen Diversity ◽  
Target Spot ◽  
Insight Into

Corynespora cassiicola is a highly diverse fungal pathogen that can infect more than 500 species of plants, including many economically important crops such as cotton, soybean, tomato, and cucumber. In Florida, the number one vegetable crop by market value are fresh-market tomatoes, which generate nearly half a billion dollars annually. Florida’s subtropical to tropical climate is conducive to infection and development of the target spot pathogen on tomato caused by C. cassiicola. There is no varietal resistance available for target spot of tomato, and preventative fungicide treatments are the primary method for control. In the last decade, C. cassiicola has been more frequently reported by Florida tomato growers, appearing not only more aggressive but also increasingly insensitive to various fungicides. This review brings together the most recent C. cassiicola literature, providing a history and understanding of the immense pathogen diversity and its relevance to tomato. It also provides insight into fungicide resistance development and pathogen survivability, which are important factors in providing effective control recommendations and in understanding the epidemiology of this disease, respectively.

Identification of Resistance to Powdery Mildew in Publicly Available Male Hop Germplasm

2018 ◽  
Vol 19 (3) ◽  
pp. 258-264
Author(s):  
David H. Gent ◽  
Briana J. Claassen ◽  
Megan C. Twomey ◽  
Sierra N. Wolfenbarger
Keyword(s):  
United States ◽  
Powdery Mildew ◽  
Pacific Northwest ◽  
Western United States ◽  
R Genes ◽  
Sources Of Resistance ◽  
Department Of Agriculture ◽  
Breeding Programs ◽  
The Pacific ◽  
The U.S

Powdery mildew (caused by Podosphaera macularis) is one of the most important diseases of hop in the western United States. Strains of the fungus virulent on cultivars possessing the resistance factor termed R6 and the cultivar Cascade have become widespread in the Pacific Northwestern United States, the primary hop producing region in the country, rendering most cultivars grown susceptible to the disease at some level. In an effort to identify potential sources of resistance in extant germplasm, 136 male accessions of hop contained in the U.S. Department of Agriculture collection were screened under controlled conditions. Iterative inoculations with three isolates of P. macularis with varying race identified 23 (16.9%) accessions with apparent resistance to all known races of the pathogen present in the Pacific Northwest. Of the 23 accessions, 12 were resistant when inoculated with three additional isolates obtained from Europe that possess novel virulences. The nature of resistance in these individuals is unclear but does not appear to be based on known R genes. Identification of possible novel sources of resistance to powdery mildew will be useful to hop breeding programs in the western United States and elsewhere.

scholarly journals A linkage of gene of resistance to a broomrape race G with microsatellite loci of a sunflower linedonor RGP1 of VNIIMK’s breeding

2021 ◽  
Vol 186 (2) ◽  
pp. 3-9
Author(s):  
S.Z. Guchetl ◽  
◽  
D.L. Savichenko ◽  
Keyword(s):  
Microsatellite Loci ◽  
Physical Map ◽  
Pcr Analysis ◽  
Sources Of Resistance ◽  
Resistant Varieties ◽  
Literary Sources ◽  
Ssr Loci ◽  
Environmentally Safe ◽  
Yield Formation ◽  
Sunflower Genome

Broomrape (Orobanche cumana Wallr.) is one of the main biotic factors limiting high sunflower yield formation. The most effective and environmentally safe method of protection is cultivation of resistant varieties and hybrids of sunflower. Development of resistant sunflower genotypes includes search and usage of sources of resistance in breeding process as well as accurate and productive procedures of material assessment. The purpose of the research is to analyze a linkage of a gene Or7 with microsatellite loci of the line-donor of resistance to broomrape race G from the VNIIMK’s collection. The objects of the research are the line RGP1 – a donor of resistance to broomrape race G and a susceptible to this race line VR 678 from the VNIIMK’s collection. Sunflower plants were crossed in field to produce F1. Also we conducted self-pollination of F1 plants to obtain F2 progeny. Plants were tested in a greenhouse in soil infected with seeds of broomrape race G using a method of early diagnostic. Sunflower DNA was extracted from the top leaves of the young sprouts of the vegetative plants. For PCR-analysis we used three SSR-primers demonstrated polymorphism in parental lines: ORS 683, ORS 1040, and ORS 1112. We tested joint inheritance of the gene Or7 and these loci, and inheritance between SSR-loci. An independent inheritance of the gene Or7 with DNA-loci ORS 683, ORS 1040, and ORS 1112, as well as SSR-loci between ORS 1040 and ORS 1112, ORS 1040 and ORS 683 was showed. Loci ORS683 – ORS 1112 are linked with a frequency of recombination of 0.27 ± 0.41 (27 cM). As a result of our research location of the gene Or7 in the nearest area to microsatellite loci ORS 683, ORS 1040, and ORS 1112 was excluded. Basing on studied literary sources and a representative sunflower genome HanXRQr2.0-SUNRISE we made a partial physical map LG3 for determination of an area for the further search of a localization of the Or7 and DNAmarkers co-segregating with this gene.

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