The polyketidederived secondary metabolite ascochitine is produced by species in the didymellaceae family, including but not restricted to ascochyta species pathogens of coolseason food legumes. The disease is widespread in southern australia, but its severity varies considerably from crop to crop and between seasons. P22 peas fungicide timing products for ascochyta control. Use of metabolomics for the chemotaxonomy of legumeassociated ascochyta and allied genera. Several factors were investigated, including amount and concentration of inoculum, period of high humidity and age of leaves. Ascochyta fabae is a major parasite of faba bean causes ascochyta blight disease. The genus was first described in 1830 by marieanne libert, who regarded the spores as minute asci and the cell contents as spherical spore. Seedlings of different cultivars were tested and results compared with available field data. Yield losses can be as high as 90% and losses of 3540% are common. Ascochyta fabae is a seedborne pathogen of all types of vicia faba, including broad beans. Introduction on infected seed occurred in australia and canada in the 1970s, and was probably the means for the.
Clarification on host range of didymella pinodes the. Identification of a polyketide synthase gene responsible. Use a seed treatment registered for ascochyta control. Pdf occurrence of didymella fabae, the teleomorph of ascochyta.
Older leaves proved to be less susceptible than younger leaves. To evaluate the effect of new fungicide management on the ascochyta blight field trial was conducted in 20 cropping season on randomized complete blocks design with three replications. Temperature affected incubation period, lesion expansion, percent leaf damage, audpc and rate of fabaee spot progress on both detached leaf and whole plant tests in faba bean. Breeding for host resistance is an efficient means to combat this disease.
In laboratory tests seed treatment with thiabendazole and benomyl resulted in a significant reduction in the number of seeds giving rise to colonies of a. To understand the composition of fungi associated with this disease in zhejiang. Ascochyta leaf blight results in the rapid development of large irregularly shaped, strawcolored patches on kentucky bluegrass, and occasionally tall rescue and perennial ryegrass during the summer. As a result, seedlings emerging from infected seeds show severe disease development. In recent years this disease has become the most important disease in chickpeas.
May 10, 2017 planting clean, disease free seed is the safest method of control, although seed with up to 5% ascochyta lentis infection will not significantly affect yield as long as soil and weather conditions favor quick germination and good plant vigor. Conidia were collected from colonies grown on v8 agar for 16 d and stained with aniline blue. Management of ascochyta blight of chickpea causal pathogen. The fungus can survive on crop debris, selfsown volunteer plants, and infected seed. Eliminate crop debris and volunteer lentil by deep tillage to reduce pathogen survival.
An update on genetic resistance of chickpea to ascochyta. Here, we identified a polyketide synthase pks gene. Pdf temperature effects on cultural and morphological. Cultural control plant seed free from the aschochyta blight pathogen. Molecular breeding for ascochyta blight resistance in. Ascochyta is a genus of ascomycete fungi, containing several species that are pathogenic to plants, particularly cereal crops. Manual weeding is useful just to avoid spreading of the. With regard to incubation period, xu 46 and xu and robinson 47 noted that the median incubation period was longer at lower and higher temperatures than at intermediate temperature ranges in rose and hawthorn powdery mildew.
Faba bean diseases faba beans are subject to a number of diseases that can reduce yield and quality. To understand the composition of fungi associated with this disease in zhejiang province, china, a total of 65 single. Ascochyta definition is a form genus of imperfect fungi order sphaeropsidales with hyaline 2celled pycnospores formed in pycnidia located in discolored spots in leaves, stems, or fruits. Ascochyta fabae attacks vicia faba and can survive and reproduce in and spread from crop debris or be transported in infected seed. Because the ascochyta fungus is primarily a foliar pathogen, diseased turfgrass usually recovers relatively quickly.
Fungicides management is essential to control this disease. It is yield limiting in the medium and high rainfall areas of the central and southern agricultural regions. Three fungi contribute to the ascochyta blight disease complex of pea pisum sativum. The fungus was initially known in the asexual state, spreading by means of conidia produced in pycnidia. Pdf etude morphologique et physiologique, lutte chimique. Isolates of ascochyta fabae from faba bean vicia faba and a. Ascochyta leaf blight or spot of turfgrasses is caused by more than 80 different fungi which can cause damage to kentucky bluegrass, bentgrasses, italian and perennial ryegrasses, fescues red, meadow, sheep, and tall, redtop, and many other forage, weed, and wild grasses.
Mycosphaerella pinodes causes mycosphaerella blight. However, lentil production is constrained by many factors including biotic stresses, majority of which are fungal diseases such as ascochyta blight ab, fusarium wilt, rust, stemphylium blight, anthracnose. Ascochyta leaf blight of lawns horticulture and home pest news. It is not the same ascochyta species which infects other pulses and is specific to faba beans. Leaves of vicia faba plants naturally or artificially infected with ascochyta fabae. After 2 weeks of growth, the embedded slide with the fungal colony growing on the thin layer of pda about 2 mm in diameter was removed from the plate and dried for 1 h at 65c for maldi imaging analysis. Ascochyta blight is known to occur on droughtstressed turf and also during periods of hot weather preceded by wet conditions. Ascochitine was produced in culture by 18 of 19 isolates of ascochyta fabae. Ascochyta blight, caused by ascochyta fabae, is an important disease of faba beans in victoria, south australia and new south wales. Ascochyta leaf blight symptoms of kentucky bluegrass leaf blades. Aug 08, 2019 the major ones include ascochyta blight ascochyta fabae speg.
Management of ascochyta blight ascochyta r abiei in. The effect of four fungicide seed treatments on the control of seedborne ascochyta blight of lentil, caused by a. The primers amplify the internal transcribed spacer its regions of a. Pisum sativum mycosphaerella pinodes ascochyta pisi phoma medicaginis symptomatologie champi. Specific diseases such as leaf and pod spot ascochyta fabae in field beans and pea.
Histopathology of the interaction between ascochyta fabae and. Response of vicia species to ascochyta fabae and uromyces. Lentil is relatively free from any serious infestation of insect pests except. Biological control strategies have not been developed for ascochyta blight of lentil. Ascochyta leaf and pod spot is caused by the fungus ascochyta fabae. Maximum transmission from seeds to seedlings occurs when the soil temperature is approximately 46. High titres were obtained in shake culture but not in still culture unless the surface to volume ratio was large. Histopathology of the interaction between ascochyta fabae and vicia faba. Ascochyta leaf and pod spot of faba bean grains, pulses. Systematic mycology and microbiology laboratory invasive. Ascochyta blight is the most severe disease of coolseason pulses davidson and kimber, 2007. The primary inoculum source that initiates disease epidemics is airborne ascospores released from fungal fruiting bodies pycnidia and perithecia on infested crop debris. Clarification on host range of didymella pinodes the causal.
Ascochyta rabiei michael wunsch, plant pathologist north dakota state university carrington research extension center 9. Transmission of ascochyta blight from infected seed to foliar tissues is favored by cool, moist soil. Diseasefree seed is highly recommended in areas where faba bean is grown commercially. Ascochyta blights occur throughout the world and can be of significant economic importance. Ascochyta leaf blight comes on quickly, causing large brown or bleached patches in lawns when the weather is quickly alternating between very wet and very dry, but the exact environmental trigger is unknown.
In this paper, attempts have been made to summarize the progress made in identifying resistance. Studies on the biology and control of ascochyta fabae on fa ba bean v. Studies on the biology and control of ascochyta fabae on fa. Ascochyta blight of lentil grains, pulses and cereals. Based on comparisons of cultural and morphological traits among isolates of ascochyta fabae the causal agent of ascochyta blight of faba bean and isolates of a. Pdf pseudothecia of didymella fabae, the teleomorph of ascochyta fabae, were first observed on.
The major ones include ascochyta blight ascochyta fabae speg. Two controlled condition experiments were conducted to study the temperature effect on mycelial growth and. While some faba bean diseases may cause little damage, other faba bean diseases can be very damaging and warrant appropriate control. Controlling ascochyta blight what to do for grass with. Ascochitine is structurally similar to the wellknown mycotoxin citrinin and exhibits broadspectrum phytotoxicity and antimicrobial activities. Systematic mycology and microbiology laboratory invasive fungi fact sheets ascochyta blight of broad beansdidymella fabae ascochyta fabae ascochyta blight is the most severe disease of coolseason pulses davidson and kimber, 2007. It is an important source of protein in many parts of central asia and africa. Ascochyta pisi et f8 ascochyta fabae et a30 ascochyta rabiei.
Ascochyta definition of ascochyta by merriamwebster. Ascochyta blight, caused by ascochyta rabiei, is a serious disease of chickpea cicer arietinum and fungicide applications are used to manage the disease in the north central plains 4. Ascochyta blight, an infection caused by a complex of ascochyta pinodes, ascochyta pinodella, ascochyta pisi, andor phoma koolunga, is a destructive disease in many field peas pisum sativum l. Ascochyta blight of chickpeas plant management network. Introduction on infected seed occurred in australia and canada in the 1970s, and was probably the means for the pathogens original spread to countries outside southwestern asia.
The sexual state teleomorph was first reported and described by jellis and punithalingam 1991 on overwintering v. Use of metabolomics for the chemotaxonomy of legume. In this work, we aimed to validate across generations the main quantitative trait loci qtls for ascochyta blight resistance identified in the. The disease is particularly severe under cool and humid weather conditions.
Files are available under licenses specified on their description page. A comparison of clean seed left with ascochyta blight infected lentil seed right. Identification of a polyketide synthase gene responsible for. Ascochyta fabaethe causative agent of ascochyta blight and. To manage the disease, reduce thatch by core aeration at least once a year to allow better water penetration. Aug 25, 2019 the major ones include ascochyta blight ascochyta fabae speg. Furthermore ascochyta leaf blight development is sporadic and rapid. An update on genetic resistance of chickpea to ascochyta blight. High resistance to both diseases was very frequently detected in vicia spp. Qtls for ascochyta blight resistance in faba bean vicia. Even if disease free seed is used and rotations are long, scout your chickpeas carefully for disease. Ascochyta blight is an important disease of faba bean vicia faba l. Histopathology of the interaction between ascochyta fabae.
Ascochyta blight is seedborne and infected seed is an important source of primary inoculum in the field 18, 19. Screening faba beans for resistance to ascochyta fabae by. Turfgrass usually recovers completely after a couple of weeks. Ascochyta blight ascochyta fabae occurs in all faba bean growing areas of western australia. The amplicon from this pcr reaction, when digested with the restriction enzymes nla iv and sau 96i, gives a distinct banding pattern that can be used to.
This page was last edited on 17 august 2018, at 03. Although several fungicides will inhibit ascochyta growth, they can be expensive and difficult to apply. Planting clean, disease free seed is the safest method of control, although seed with up to 5% ascochyta lentis infection will not significantly affect yield as long as soil and weather conditions favor quick germination and good plant vigor. Ascochyta blight of pea bugwood center for invasive. It is not the same ascochyta species which infects other pulses and is specific to faba.
Ascochyta blight is the ethiopias most important disease of chickpea that affects the quantitative and qualitative chickpea yield. Effect of weather conditions on yield and health status of. A field was only considered positive for ascochyta blight if the causal pathogen was isolated from symptomatic lentil tissues collected in that field. Etude morphologique et physiologique, lutte chimique, polymorphisme. An extended period of leaf wetness is required for disease. Gent, martha mikkelson,and jack riesselman identification and life cycle ascochyta blight is caused by the fungus ascochyta fabae f. The species didymella fabae anamorph ascochyta fabae that attacks vicia faba can survive and reproduce. The conidial stage is and is especially prevalent in spring on crops grown through the winter in mild climates such as western washington bailey et al.
Studies on the biology and control of ascochyta fabae on. Systematic mycology and microbiology laboratory invasive fungi fact sheets ascochyta blight of broad beansdidymella fabaeascochyta fabae ascochyta blight is the most severe disease of coolseason pulses davidson and kimber, 2007. Ascospores germinate and infect pea over a range of tempatures 40 to 95. Ascochyta blight is primarily a leaf and not a root or crown disease so it rarely causes plant mortality. It is considered that other primary sources of inoculum, sucli as host material buried in the soil, are of minor significance in the establishment of the disease. Distribution of ascochyta blight in north dakota and eastern montana lentil production fields in 2011.
Ascochyta blight, or leaf and pod spot, of vicia faba is caused by d. The minor, usually nonyield limiting diseases alternaria and cercospora can both be confused with ascochyta blight. Although there have been a large number of trials looking at fungicide control of ascochyta, they have. Ascochyta leaf and pod spot of faba bean grains, pulses and. Apr 12, 2016 ascochyta blight, an infection caused by a complex of ascochyta pinodes, ascochyta pinodella, ascochyta pisi, andor phoma koolunga, is a destructive disease in many field peas pisum sativum l. A method was developed for screening faba bean seedlings for resistance to ascochyta fabae. The reasons for poor yields are not clear and probably vary markedly from site to site. Ascochyta leaf blight of lawns horticulture and home. Variation in the production of ascochitine by ascochyta fabae. You can positively identify an ascochyta leaf blight infection by examining damaged grass blades with a hand magnifying glass. It occurs everywhere faba bean is grown in western canada and can be stubble or seedborne. Ascochyta blight ab caused by ascochyta rabiei pass. Ascochyta blight of chickpeas is caused by the fungal pathogen phoma rabiei formerly known as ascochyta rabiei which is specific to chickpeas. Peas fill an important role as a break crop for new zealand growers, but in some situations it is not a profitable crop option.
Ascochyta leaf and pod spot is caused by ascochyta fabae. Ascochyta blight is currently is the most common disease of lentils in the northern hemisphere. The line 29h is one of the most resistant accessions to the pathogen ascochyta fabae speg. It may be beneficial to utilize an integrated weed management strategy, combining both herbicides and cultural control methods. Under the condition when disease free seed is not available, foliar spray is preferable to prevent spread of the disease. Controlling ascochyta blight what to do for grass with leaf. Practice a threeyear or longer crop rotation to nonhosts such as small grains or corn.
Inoculation was made on mnpda medium for sporulation evaluation. Ascochyta blight is favored by cool, moist weather. Ascochyta damaged turf where spores might have been spread by the mower. All structured data from the file and property namespaces is available under the creative commons cc0 license. Galway the optimum temperature for radial growth of ascochyta fabae mycelium on agar and for fungal infection of erfordia faba bean vicia faba was 20c. Studies on the control of ascochyta blight in field peas. Ascochyta blight is a seedborne or residueborne disease of faba beans in western canada. The disease usually becomes established when spores of the fungus, produced on old bean stubble, are carried into the new crop. Faba beans are a poor competitor, so good weed control is essential and often the most important consideration for profitable faba bean production. The fungal pathogen ascochyta lentis that causes ascochyta blight can survive in infected seed, and in previously infected lentil stubble.
1093 446 1507 307 890 798 596 1228 999 650 995 943 1112 468 571 440 996 980 1476 1426 572 207 451 1385 874 764 799 367 1453 1413 1032 20