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Disease progression of Ascochyta rabiei: sexual and asexual stages in the life cycle. (i) The airborne fungal conidia infect a chickpea plant. (ii) Conidia land on the leaf surface of the chickpea plant and (iii) start germinating through the formation of germ tubes. Later on, the germ tubes form an appressorium‐like structure at the tip of hyphae. (iv) The appressorium punctures the epidermal layer and (v) invades the subepidermal tissues. (vi) At a later stage pycnidia are formed, which contain asexual conidial spores that are dispersed by rain splash. (vii) During the sexual cycle, a specialized structure called the pseudothecium is formed on the infected plant in moist and cool conditions (winter). The pseudothecium is a cup‐like structure with an inner fertile layer called the hymen and an outer narrow opening called the ostiole. (viii) The hymen gives rise to sac‐like structures called asci that each contain eight ascospores. (ix) In spring, the pseudothecium forcefully discharges ascospores, which are carried by wind over distances of up to 10 km.
Source publication
The necrotrophic fungus Ascochyta rabiei causes Ascochyta blight (AB) disease in chickpea. A. rabiei infects all aerial parts of the plant, which results in severe yield loss. At present, AB disease occurs in most chickpea-growing countries. Globally increased incidences of A. rabiei infection and the emergence of new aggressive isolates directed t...
Citations
... The appearance of the pathogen in pods leads to seed infection and dispersal to the next generation. However, the most damaging lesion is on stems, as it can girl and kill plants (Singh et al., 2022;Foresto et al., 2023). ...
... Ascochyta Blight is a black spot disease caused by the necrotrophic fungi Didymella rabiei and is one of the most destructive diseases in most world areas. Ascochyta rabiei goes through both sexual (teleomorphic) and asexual (anamorphic) stages in its life cycle (Singh et al., 2022). The causative agent of this disease also causes damage to broad beans, alfalfa, clover, and beans. ...
Fungal diseases are crucial factors in reducing chickpea production. Ascochyta Blight is caused by the necrotrophic fungi Didymella rabiei and is one of the most destructive diseases in most world areas. Therefore, a completely randomized factorial design with five replications was applied to evaluate the effects of Ascochyta Blight disease fungi on the chickpea plant. The chlorophyll index, the activities of superoxide dismutase isoforms, and evolutionary analyses were performed to get further insights. Also, 2D electrophoresis of chickpea leaf proteins, gene ontology, and protein-protein interactions analysis was performed. The results did not show any significant effect of A. rabiei infection on the wet weight of chickpea seedlings. Chlorophyll index levels significantly decreased with A. rabiei infection in both chickpea lines. Electrophoretic analysis of superoxide dismutase on 8% polyacrylamide gel revealed three isoforms. The activities of superoxide dismutase isoforms significantly increased with A. rabiei disease. Identification of proteins was performed according to their isoelectric points and approximate molecular weights. Leaf proteome analysis of chickpea lines showed that the expression of eight reproducible spots changed significantly under A. rabiei disease condition. Candidate proteins were components of defense and regulation systems. High expression of Dual specificity protein, Peptide methionine sulfoxide reductase B2, and chloroplastic phosphatase 1B (the proteins involved in the defense system) reveals their essential functions under A. rabiei infection. Increased activities of superoxide dismutase enzymes and proteins involved in the defense system can reduce A. rabiei infection effects on chickpea seedlings.
... The exploitation of plant genetic resources with little success is one of the reasons for lack of improvement in productivity and production potential against various stresses (Perrino and Perrino, 2020). However, the creation of useful variation for achieving genetic improvement requires incorporation of elite sources of resistance in breeding schemes Singh et al., 2022). For this reason, the role of wild relatives being the source of resistance to multiple stresses becomes crucial in crop improvement. ...
... Fusarium wilt is a destructive disease caused by fungal soilborne pathogens such as F. oxysporum or F. solani that causes significant losses for many important vegetable and crop plants, including Chickpea, all over the world (Knights and Hobson 2015) causing significant economic losses up to a 100% yield loss. Despite the progress made in recent investigations on pathogen resistance in germplasms, breeding lines, and local chickpea varieties (Sharma and Ghosh 2016), the risk of developing this disease is high (Singh et al. 2022). Fusarium equiseti has received more attention recently about its pathogenicity and its impact on different crops. ...
Background
Chickpea plant ( Cicer arietinum L.) is an important legume crop that is vulnerable to various fungal pathogens causing significant yield losses. Among them, Fusarium equiseti is a pathogen that has started to raise concern. In contrast, Trichoderma species have been explored for their ability to control such pathogens. In this study, the efficacy of a novel seed treatment formulation was explored for controlling F. equiseti in chickpea plants. The formulation was designated to enhance growth in chickpea plants as well as the ability to protect plants from infection. In addition, this formulation was tested for its effectiveness in maintaining the conidia of the antagonist in the soil after sowing.
Results
Applying the Trichoderma asperellum -based formulation promoted growth, as well as root and aerial biomass. In seedlings derived from treated seeds, the shoot length increased by 36.8%, and the average number of leaves also increased than the control. Following evaluation of disease severity and the foliar alteration index (FAI), a protective effect was noted, as the symptoms of Fusarium were significantly reduced in treated plants than the infected control. Re-isolation from plants infected with F. equiseti was successful in the roots (72.7%), root crown (84.5%), stem (64.4%), and even in petioles (36.1%).
Conclusions
Due to both direct antagonist activity and indirect growth promotion ability, the findings suggested that tested formulation can be a sustainable and eco-friendly alternative to chemical fungicides for managing F. equiseti in chickpea seeds.
... A. rabiei infects all aerial parts of the plant, which results in severe yield loss. At present, AB disease occurs in most chickpea-growing countries [8]. ...
Chickpea is one of the most important legumes in the world, however, it is prone to various diseases that can significantly reduce its yield and quality. Hence, the accurate classification of these diseases are crucial for effective disease management. In this study, we propose a combined approach for chickpea disease classification using GLCM-Color Histogram features with Bilateral filtering and non-local means filtering. Our research comprises three phases: image preprocessing, feature extraction, and classification. To enhance the model’s
robustness and reduce noise, we applied Bilateral filtering, non-local means filtering, and data augmentation
techniques. We utilized a combination of gray-level co-occurrence matrix (GLCM) and Color Histogram for
feature extraction, which can capture the texture and color features important for image classification tasks. The
extracted features were then classified using Multi-Layer Perceptrons (MLPs), Support Vector Machine (SVM), KNearest Neighbors (KNN), and Random Forest (RF). The experimental results indicate that the combined features
extracted using GLCM and Color Histogram with the SVM classifier outperformed individual feature extractors
and classifiers, achieving a testing accuracy of 95.49 %. Our study demonstrates that proper image preprocessing, data augmentation, and feature extraction provide an efficient classification method for identifying
and classifying chickpea disease.
... Talking about the symptoms, A. rabiei affects all aboveground parts of the host plant due to rapid cell collapse and spread of necrotic lesions, defoliation, and breakage followed by death of the plant (Singh et al. 2022a). In the field, it initially appears as small patches (foci) of blighted plants, rapidly spread over night across entire fields under favorable environmental conditions . ...
... During the growing season, conidia formed in pycnidia are assumed to disband over a short distance (~10 m) in a combination of strong wind and rain splashes (Khaliq et al. 2020). Consequently, the disease blowout mainly ensues over the anthropogenic movement of seeds, dissemination of spores via wind and water, and infected chickpea rubble (Singh et al. 2022a) (Fig. 2.1). ...
Chickpea (Cicer arietinum) is cultivated in more than 50 countries and is one of the most valued legumes due to its nutritional content. Ascochyta blight (AB) is a major disease that significantly affects crop yield leading to a large gap between demand and production. Approaches for disease management like cultural practices and chemical control either have limited effectiveness or are not ecofriendly. The only available environment-friendly approach to improve crop resistance with complete efficacy is breeding resistant genotypes. The vital prerequisite for sustainable agricultural production is the development of durable host resistance. Owing to the diversity of the pathogen population and prevalence of partial resistance in known sources of resistance, chickpea is susceptible to several races of Ascochyta rabiei. Hence, it is challenging to breed varieties with effective and stable resistance. Recent advances in the genetic and genomic know-hows have provided better understanding of the complex host-pathogen interactions. In addition, several AB-resistant gene(s)/QTL/genomic regions have been identified on various linkage groups. These genomic resources could be precisely utilized in genomic-assisted breeding by the plant breeders to develop and/or transfer AB-resistant genomic regions to elite cultivars.
... In a cool and humid environment, the disease appears as necrotic lesions and infects all aerial parts of the host plant. Ascochyta rabiei, which causes blight in chickpea crops, is able to cause yield losses of 10-100% under favorable conditions (Singh et al., 2022). ...
... Lesions can dry out and fall out, giving the leaf a shot-hole appearance. Lesions and blemishes are seen on branch, stem, and pods (Kumar et al., 2022). ...
Pulse crops play an important role in improving the food and nutritional security of the population living in arid regions. Pulse crops use limited soil moisture and nutrients more efficiently than cereal crops, so farmers have chosen them to grow in arid conditions. Chickpea, cowpea, mung bean and moth bean are the pulse crops which is grown in arid and semi-arid conditions of India. These pulse crops are severely affected by biotic and abiotic stresses. Among biotic stress diseases caused by fungal diseases are causing huge yield losses globally. In this chapter, we have covered the major fungal diseases of arid pulses and their management.
... In order to conduct effective management and advice on suitable strategies for ascochyta blight control, it is essential to understand the genetic diversity and population structure of D. rabiei isolates within each chickpea growing region (Bar et al., 2021). This knowledge about pathogen populations, their pathogenicity and mating-type frequency are critical for successful resistance source screening and breeding programs (Farahani et al., 2022;Singh et al., 2022). Phenotypic assessment of variation among fungal pathogen populations might be difficult because of its limited characters, lack of robust discrimination tools and effects of environment conditions (Getaneh et al., 2021). ...
Chickpea is considered as one of the most
important sources of proteins in many developing
countries including Iraq. Didymella rabiei, causing
ascochyta blight disease on chickpea, is a destructive
pathogen on chickpea in the north of the Iraq (Kurdistan
region). Detailed knowledge about the genetic
diversity and pathogenicity of the pathogens is necessary
to adopt appropriate disease control and management
strategies. For the purposes of this study, a combination
of phenotypic and genotypic characterizations
including simple sequence repeat (SSR) fingerprinting,
mating-types distribution and pathogenicity analyses
were used to assess a total of 145 D. rabiei isolates
collected from chickpea fields in the Sulaymaniyah
provincial region of northern Iraq in 2020. Our results
revealed a relatively high level of genetic diversity
(H = 0.66) within populations, with low differentiation
among populations. These findings together with mating
types which were found in a 50:50 ratio, suggest
the role of sexual reproduction in the fungus, primarily
as primary inoculums of D. rabiei which are likely
ascospores (sexual spores). On the contrary, the existence
of gene exchanges through either the movement
of infected seeds or plant debris is most probably the
main mechanism in reduction of differentiation among
populations. Hence, the use of certified chickpea seeds
and removing plant debris are recommended for effective
management of the disease
... Ascochyta Blight (AB) disease is one of the major threats to chickpea production that causes yield losses of up to 100% under wet and cool weather conditions that favor the spread of AB disease . AB disease is caused by a necrotrophic fungus Ascochyta rabiei (Sharma and Ghosh, 2016;Singh et al., 2022a). Integrated disease management strategies, which include the use of resistant cultivars along with fungicide application and cultural practices, are suggested to prevent the outbreak of the AB disease. ...
Ascochyta blight (AB) disease caused by the fungus Ascochyta rabiei is a major threat to global chickpea production. Molecular breeding for improved AB resistance requires the identification of robust fine-mapped QTLs/candidate genes and associated markers. Earlier, we identified three QTLs (qABR4.1, qABR4.2, and qABR4.3) for AB resistance on chickpea chromosome 4 by employing multiple quantitative trait loci sequencing strategy on an intra-specific (FLIP84–92C x PI359075) and an inter-specific (FLIP84–92C x PI599072) crosses derived recombinant inbred lines. Here, we report the identification of AB resistance providing candidate genes under the fine mapped qABR4.2 and qABR4.3 genomic region by combining genetic mapping, haplotype block inheritance, and expression analysis. The qABR4.2 region was narrowed down from 5.94 Mb to ∼800 kb. Among 34 predicted gene models, a secreted class III peroxidase encoding gene showed higher expression in AB-resistant parent after A. rabiei conidia inoculation. Under qABR4.3, we identified a frame-shift mutation in a cyclic nucleotide-gated channel CaCNGC1 gene leading to the truncated N-terminal domain in resistant accession of chickpea. The extended N-terminal domain of CaCNGC1 interacts with chickpea calmodulin. Thus, our analysis has revealed narrowed genomic regions and their associated polymorphic markers, namely CaNIP43 and CaCNGCPD1. These co-dominant markers significantly associate with AB resistance on qABR4.2 and qABR4.3 regions. Our genetic analysis revealed that the presence of AB-resistant alleles at two major QTLs (qABR4.1 and qABR4.2) together provide AB resistance in the field while minor QTL qABR4.3 determines the degree of resistance. The identified candidate genes and their diagnostic markers will assist in the biotechnological advancement and introgression of AB resistance into locally adapted chickpea varieties used by farmers.
... A major constraint limiting the chickpea production in more than 40 countries is Ascochyta blight (AB) disease that can cause a yield loss of 10-100% (Singh et al., 2022). AB is caused by the fungus Ascochyta rabiei (Pass.) ...
... So far, a number of quantitative trait loci (QTL) associated with AB resistance with low-to-moderate effects have been identified and located in all linkage groups (LG) of chickpea (Singh et al., 2022). Among the identified QTLs, two major ones (QTL AR1 and QTL AR2 ) have recurrently appeared in different crosses on LG4 (Santra et al., 2000;Flandez-Galvez et al., 2003;Millan et al., 2003;Udupa and Baum, 2003;Cho et al., 2004;Tekeoglu et al., 2004;Iruela et al., 2006;Tar'an et al., 2007;Madrid et al., 2012;Labdi et al., 2013;Sabbavarapu et al., 2013;Stephens et al., 2014). ...
... The availability of robust markers for faster development of resistant cultivars plays a key role in chickpea breeding programs but is a difficult procedure due to the polygenic nature of AB resistance and the different genetic backgrounds across cultivars. In the last decade, numerous AB resistance QTLs contributing to the expression of AB resistance have been identified and markers associated to those genomic regions have been developed (Sharma and Ghosh, 2016;Ilyas et al., 2022;Singh et al., 2022). However, the use of markers remains low as inferred from publications regarding new varieties of chickpea (Singh et al., 2022). ...
Ascochyta blight, caused by the fungal pathogen Ascochyta blight, caused by the fungal pathogen Ascochyta rabiei , is a devastating biotic stress that poses a significant threat to chickpea cultivation worldwide. To combat this disease, breeding programs have focused on developing cultivars with resistance to Ascochyta blight. However, a comprehensive understanding of the underlying plant defense mechanism is still lacking. To identify genomic regions associated with resistance, a recombinant inbred line (RIL) population was created by crossing ILC3279 (kabuli, resistant) and WR315 (desi, susceptible), which was then phenotyped and sequenced using a tuneable genotyping-by-sequencing (tGBS) protocol to obtain single nucleotide polymorphisms (SNPs). We further validated the association of genomic regions with Ascochyta blight resistance in a second recombinant inbred line\population derived from the cross between JG62 (desi, susceptible) and ILC72 (kabuli, resistant). Our analysis identified four genomic regions associated with Ascochyta blight resistance in chromosomes 2 and 4, among which a region spanning from 3.52 to 8.20 Mb in chromosome 4 was the most robust candidate for resistance, being associated with resistance in both years and populations. A total of 30 genes from the identified regions were selected as robust candidates, and LOC101507066, which encodes a leucine-rich repeat receptor-like protein kinase, was the most robust candidate gene, as it plays critical roles in plant stress responses and immunity. Our findings have potential to accelerate marker-assisted genetic improvement and facilitate the development of integrated strategies for crop protection.
