Resistance In Chickpea Research Articles

Resistance of Chickpea (Cicer arietinum L.) Varieties to Gram Pod Borer (Helicoverpa armigera) in a Controlled Environment

The research was conducted within the controlled environment of the net house at the Faculty of Agriculture Science and Technology, AKS University, Satna (M.P.), during the Rabi season of 2023-24. Eight diverse chickpea (Cicer arietinum L.) genotypes, viz. JG-63, JG-130, L-2, JG-14, RAJ-128, Narendran-2, Annagiri and RVG-202, were systematically screened to evaluate their resistance to the gram pod borer (Helicoverpa armigera) under protected conditions. The study was meticulously designed using a Completely Randomized Design (CRD) with three replications to ensure robust statistical analysis. Throughout the critical vegetative, flowering and maturity stages, the larval population density of H. armigera was rigorously monitored across all genotypes at regular intervals. The comprehensive data analysis revealed that genotypes RAJ-128 and RVG-202 demonstrated superior resistance, exhibiting the lowest mean larval density of 0.25 and 0.29 larvae per 0.5 m², respectively, indicating their potential for integrated pest management in chickpea cultivation.

Genome-wide association mapping reveals novel genes and genomic regions controlling root-lesion nematode resistance in chickpea mini core collection.

Root-lesion nematodes (RLN) pose a significant threat to chickpea (Cicer arietinum L.) by damaging the root system and causing up to 25% economic losses due to reduced yield. Worldwide commercially grown chickpea varieties lack significant genetic resistance to RLN, necessitating the identification of genetic variants contributing to natural resistance. This study identifies genomic loci responsible for resistance to the RLN, Pratylenchus thornei Sher & Allen, in chickpea by utilizing high-quality single nucleotide polymorphisms from whole-genome sequencing data of 202 chickpea accessions. Phenotypic evaluations of the genetically diverse set of chickpea accessions in India and Australia revealed a wide range of responses from resistant to susceptible. Genome-wide association studies (GWAS) employing Fixed and Random Model Circulating Probability Unification (FarmCPU) and Bayesian-Information and Linkage-Disequilibrium Iteratively Nested Keyway (BLINK) models identified 44 marker-trait associations distributed across all chromosomes except Ca1. Crucially, genomic regions on Ca2 and Ca5 consistently display significant associations across locations. Of 25 candidate genes identified, five genes were putatively involved in RLN resistance response (glucose-6-phosphate dehydrogenase, heat shock proteins, MYB-like DNA-binding protein, zinc finger FYVE protein and pathogenesis-related thaumatin-like protein). One notably identified gene (Ca_10016) presents four haplotypes, where haplotypes 1-3 confer moderate susceptibility, and haplotype 4 contributes to high susceptibility to RLN. This information provides potential targets for marker development to enhance breeding for RLN resistance in chickpea. Additionally, five potential resistant genotypes (ICC3512, ICC8855, ICC5337, ICC8950, and ICC6537) to P. thornei were identified based on their performance at a specific location. The study's significance lies in its comprehensive approach, integrating multiple-location phenotypic evaluations, advanced GWAS models, and functional genomics to unravel the genetic basis of P. thornei resistance. The identified genomic regions, candidate genes, and haplotypes offer valuable insights for breeding strategies, paving the way for developing chickpea varieties resilient to P. thornei attack.

Breeding for Pod Borer and Wilt Resistance in Chickpea (Cicer arietinum L.)

Breeding for Pod Borer and Wilt Resistance in Chickpea (Cicer arietinum L.)

Genetic resources and genes/QTLs for gram pod borer (Helicoverpa armigera Hübner) resistance in chickpea from the Western Himalayas.

Helicoverpa armigera (also known as gram pod borer) is a serious threat to chickpea production in the world. A set of 173 chickpea genotypes were evaluated for H. armigera resistance, including mean larval population (MLP), percentage pod damage (PPD), and pest resistance (PR) for 2 consecutive years (year 2020 and 2021). The same core set was also genotyped with 50K AxiomCicerSNP Array. The trait data and 50,000 single nucleotide polymorphism genotypic data were used together to work out marker-trait associations (MTAs) using different genome-wide association studies models. For MLP, a total of 53 MTAs were identified, including 25 MTAs in year 2020 and 28 MTAs in year 2021. A set of three MTAs was found common in both environments. For PPD, two MTAs in year 2020 and five MTAs in year 2021 were identified. A set of two MTAs were common in both environments. Similarly, for PR, only two MTAs common in both environments were identified. Interestingly, a common MTA (Affx_123255526) on chromosome 2 (Ca2) was found to be associated with all the three component traits (MLP, PPD, and PR) of pod borer resistance in chickpea. Further, we report key genes that encode SCAMPs (that facilitates the secretion of defense-related molecules), quinone oxidoreductase (enables the production of reactive oxygen species that promotes diapause of gram pod borer), and NB-LRR proteins that have been implicated in plant defense against H. armigera. The resistant chickpea genotypes, MTAs, and key genes reported in the present study may prove useful in the future for developing pod borer-resistant chickpea varieties.

Using RNA sequencing to unravel molecular changes underlying the defense response in chickpea induced by Phytophthora medicaginis.

Phytophthora root rot (PRR), caused by Phytophthora medicaginis, is a major soil-borne disease of chickpea in Australia. Breeding for PRR resistance is an effective approach to avoid significant yield loss. Genetic resistance has been identified in cultivated chickpea (Cicer arietinum) and in the wild relative C. echinospermum, with previous studies identifying independent genetic loci associated with each of these sources. However, the molecular mechanisms associated with PRR resistance are not known. RNA sequencing analysis employed in this study identified changes in gene expression in roots of three chickpea genotypes grown hydroponically, early post-infection with P. medicaginis zoospores. Analyses of differentially expressed genes (DEG) identified the activation of a higher number of non-specific R-genes in a PRR-susceptible variety than in the resistant genotypes, suggesting a whole plant resistance response occurring in chickpea against the pathogen. Contrasting molecular changes in signaling profiles, proteolysis and transcription factor pathways were observed in the cultivated and wild Cicer-derived resistant genotypes. DEG patterns supported a hypothesis that increased root elongation and reduced adventitious root formation limit the pathogen entry points in the genotype containing the wild Cicer source of PRR resistance. Candidate resistance genes, including an aquaporin and a maltose transporter in the wild Cicer source and GDSL esterases/lipases in the cultivated source of resistance, were oppositely regulated. Increased knowledge of these genes and pathways will improve our understanding of molecular mechanisms controlling PRR resistance in chickpea, and support the development of elite chickpea varieties through molecular breeding approaches.

Genetic Insights into Fusarium Wilt Resistance in Chickpea: Mechanisms and Sustainable Breeding Strategies

Genetic Insights into Fusarium Wilt Resistance in Chickpea: Mechanisms and Sustainable Breeding Strategies

Expression analysis and characterization of resistance (R) genes in contrasting Fusarium wilt resistant chickpea genotypes

Fusarium wilt is one of the most notorious diseases of crop plants. This disease leads to huge crop losses in chickpea with substantial monetary value worldwide. The objective of the current study was to characterise Fusarium oxysporum f. sp. cicris (Foc), the causal agent of chickpea wilt, on morphological basis followed by the assessment of resistance of thirty chickpea germplasm accessions to Foc in a pot experiment. The second objective of this research was to study gene expression and characterisation of specific resistance (R) genes in different Fusarium wilt-resistant chickpea genotypes. The morphological identification and characterization of Foc was done by culturing the fungus potato dextrose agar (PDA) medium. Fusarium wild resistance was assessed by challenging 30 chickpea genotypes to artificial inoculum of Foc by using a pre-defined disease rating scale. Different resistance levels were showed by different chickpea genotypes ranging from highly resistant to highly susceptible. Two accessions demonstrated resistance, 15 were moderately resistant and the rest of the genotypes were moderately susceptible to susceptible. The in-silico expression analysis of R genes showed that two R genes, LOC101499430 and LOC101499568 were upregulated in chickpea roots, indicating their probable role in Fusarium wilt resistance. The genes were further assessed for their expression in response to Fusarium inoculation in contrasting Fusarium wilt resistant and susceptible chickpea genotypes. The resistant genotypes showed significantly higher expression levels of the selected R genes in comparison with susceptible genotypes. This study provides valuable insights into evaluating chickpea germplasm for Fusarium wilt resistance and identification of candidate resistance genes which could be employed for enhancement of Fusarium wilt resistance in chickpea.

The comparison expression of Rare cold inducible 2 (RCI2), some enzymatic antioxidant, and proline in two tolerant and sensitive genotypes chickpea under drought stress

Chickpea (Cicer arietinum L.) is a highly valued crop that its growth and productivity are severely affected by drought stress. At the molecular level, chickpea plants activate genes and signaling pathways involved in drought and salt stress tolerance. One such mechanism involves the expression of rare cold inducible 2 (RCI2) proteins. The aim of this study was to examine the significance of RCI2 expression for drought resistance in chickpea. Hence, seeds of drought-tolerant (MCC877) and sensitive (MCC588) genotypes were evaluated in the three level of drought stress. The results indicated that drought stress reduced significantly total chlorophyll, RWC, and increased electro leakage, MDA, and improved activity of CAT, SOD, and APX. The molecular analysis suggested four RCI2 genes including RCI2A, RCI2B, RCI2B-like, and RCI2F in chickpeas. The comparison between two genotypes of chickpeas, one drought-tolerant and the other sensitive to drought, revealed that the tolerant genotype could enhance the stability of the cell membrane and moderate reactive oxygen species (ROS) content. This is achieved by improving the proline content, the activity of antioxidant enzymes, and especially by increasing the expression of RCI2 genes, compared to the sensitive genotypes. The expression RCI2A, RCI2B, RCI2B-like, and RCI2F genes in drought-tolerant genotypes was about 68 %, 48 %, 27 %, and 42 % higher than drought-sensitive after 16 h of severe water limitation. This suggests that the expression of RCI2 genes in chickpeas might enhance the plant's ability to scavenge ROS, thereby conferring tolerance to drought stresses.

Unveiling the genetic basis of Fusarium wilt resistance in chickpea using GWAS analysis and characterization of candidate genes.

Introduction: Chickpea is a legume crop that thrives in regions with semi-arid or temperate climates. Its seeds are an excellent source of proteins, carbohydrates, and minerals, especially high-quality proteins. Chickpea cultivation faces several challenges including Fusarium wilt (FW), a major fungal disease that significantly reduces productivity. Methods: In this study, a Genome-wide Association Analysis (GWAS) was conducted to identify multiple genomic loci associated with FW resistance in chickpea. We conducted a comprehensive evaluation of 180 chickpea genotypes for FW resistance across three distinct locations (Ethiopia, Tunisia, and Lebanon) during the 2-year span from 2015 to 2016. Disease infection measurements were recorded, and the wilt incidence of each genotype was calculated. We employed a set of 11,979 single nucleotide polymorphisms (SNPs) markers distributed across the entire chickpea genome for SNP genotyping. Population structure analysis was conducted to determine the genetic structure of the genotypes. Results and Discussion: The population structure unveiled that the analyzed chickpea germplasm could be categorized into four sub-populations. Notably, these sub-populations displayed diverse geographic origins. The GWAS identified 11 SNPs associated with FW resistance, dispersed across the genome. Certain SNPs were consistent across trials, while others were specific to particular environments. Chromosome CA2 harbored five SNP markers, CA5 featured two, and CA4, CA6, CA7, and CA8 each had one representative marker. Four SNPs demonstrated an association with FW resistance, consistently observed across a minimum of three distinct environments. These SNPs included SNP5826041, SNP5825086, SNP11063413, SNP5825195, which located in CaFeSOD, CaS13like, CaNTAQ1, and CaAARS genes, respectively. Further investigations were conducted to gain insights into the functions of these genes and their role in FW resistance. This progress holds promise for reducing the negative impact of the disease on chickpea production.

Identifying Genetic Linkage Groups and Markers for Leaf Miner Resistance in Chickpea through QTL Analysis and Field Validation

Chickpea is a commonly grown crop, but it is vulnerable to biotic and abiotic stresses. Leaf miner (Liriomyza cicerina) is a pest that can cause severe yield losses of up to 40% if not properly controlled. This study was conducted at ICARDA (Aleppo, Syria) during the 20112012 growing seasons. Two recombinant inbred lines, ILC 5901 (LM resistant) and ILC 3397 (LM susceptible), were crossed to yield 350 F2 plants, which were then screened for pathogen tolerance. The resistance of the plants was screened using a scale of one to nine, with 1 indicating complete resistance and 9 indicating complete susceptibility. A set of 600 simple sequence repeat (SSR) markers were validated on both parents, and 51 of these markers showed variation and were used to construct a genetic linkage map. QTL analysis was performed to determine the linkage groups responsible for line variations. The QTL analysis found that linkage groups TA37, TA34, and H4F03 were responsible for 22% of line variations, while unmapped NCPRG48 and H1C092 revealed 55.3% and 26.8% of the LIS variance, respectively, and displayed a warped dominance toward the susceptible parent. The H1C092 marker, which is significantly associated with LM, is located on Chr3 near a gene encoding the glutathione S-transferase gene family enzyme, which protects cellular macromolecules from attack by reactive electrophiles. The highly associated markers were field tested for three years to confirm their connection with LM resistance in 200 chickpea genotypes. The study showed marker-associated selection, which could accelerate the conventional breeding of LM-resistant chickpea germplasm. The markers linked to LM resistance and the identification of the protective enzyme gene offer promising avenues for further research. This study represents a significant step forward in understanding the genetics of LM resistance in chickpea and provides valuable information for breeding programs aimed at improving chickpea production.

Rapid and High Throughput Hydroponics Phenotyping Method for Evaluating Chickpea Resistance to Phytophthora Root Rot

Phytophthora root rot (PRR) is a major constraint to chickpea production in Australia. Management options for controlling the disease are limited to crop rotation and avoiding high risk paddocks for planting. Current Australian cultivars have partial PRR resistance, and new sources of resistance are needed to breed cultivars with improved resistance. Field- and glasshouse-based PRR resistance phenotyping methods are labour intensive, time consuming, and provide seasonally variable results; hence, these methods limit breeding programs’ abilities to screen large numbers of genotypes. In this study, we developed a new space saving (400 plants/m2), rapid (<12 days), and simplified hydroponics-based PRR phenotyping method, which eliminated seedling transplant requirements following germination and preparation of zoospore inoculum. The method also provided post-phenotyping propagation all the way through to seed production for selected high-resistance lines. A test of 11 diverse chickpea genotypes provided both qualitative (PRR symptoms) and quantitative (amount of pathogen DNA in roots) results demonstrating that the method successfully differentiated between genotypes with differing PRR resistance. Furthermore, PRR resistance hydroponic assessment results for 180 recombinant inbred lines (RILs) were correlated strongly with the field-based phenotyping, indicating the field phenotype relevance of this method. Finally, post-phenotyping high-resistance genotypes were selected. These were successfully transplanted and propagated all the way through to seed production; this demonstrated the utility of the rapid hydroponics method (RHM) for selection of individuals from segregating populations. The RHM will facilitate the rapid identification and propagation of new PRR resistance sources, especially in large breeding populations at early evaluation stages.

Four haplotype blocks linked to Ascochyta blight disease resistance in chickpea under Mediterranean conditions

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.

Transcriptome profiling reveals the expression and regulation of genes associated with Fusarium wilt resistance in chickpea (Cicer arietinum L.).

Fusarium wilt (FW) is one of the most significant biotic stresses limiting chickpea production worldwide. To dissect the molecular mechanism of FW resistance in chickpea, comparative transcriptome analyses of contrasting resistance sources of chickpea genotypes under control and Fusarium oxysporum f. sp. ciceris (Foc) inoculated conditions were performed. The high-throughput transcriptome sequencing generated about 1137 million sequencing reads from 24 samples representing two resistant genotypes, two susceptible genotypes, and two near-isogenic lines under control and stress conditions at two-time points (7th- and 12th-day post-inoculation). The analysis identified 5182 differentially expressed genes (DEGs) between different combinations of chickpea genotypes. Functional annotation of these genes indicated their involvement in various biological processes such as defense response, cell wall biogenesis, secondary metabolism, and disease resistance. A significant number (382) of transcription factor encoding genes exhibited differential expression patterns under stress. Further, a considerable number of the identified DEGs (287) co-localized with previously reported quantitative trait locus for FW resistance. Several resistance/susceptibility-related genes, such as SERINE/THREONINE PROTEIN KINASE, DIRIGENT, and MLO exhibiting contrasting expression patterns in resistant and susceptible genotypes upon Foc inoculation, were identified. The results presented in the study provide valuable insights into the transcriptional dynamics associated with FW stress response in chickpea and provide candidate genes for the development of disease-resistant chickpea cultivars.

Use of Ganoderma lucidum extract to elevate the resistance in chickpea against the Fusarium oxysporum f. sp. ciceris

Biological based formulation for inducing systematic resistance in the crop is a sustainable measure to control plant disease by utilizing the natural defence system of the host plant and meet the strategic needs of pesticide application for agricultural products worldwide. The crude extract of Ganoderma lucidum was used to induce systematic resistant in the chickpeas against the Fusarium wilt caused by soil-borne fungus Fusarium oxysporum (Schletend: Fr) f. sp. ciceri (Padwick) (FOC). The formulation was made using a crude extract of Ganoderma lucidum and an emulsion (water in oil: W/O); different dilutions of the formulation were made and applied to the chickpea and then challenged with the FOC. After the incubation with FOC, the chickpea was assayed for the enzyme involved in Phenylpropanoid pathways, i.e. Peroxidase (PO), Polyphenol oxidase (PPO) and Phenylalanine ammonia-lyase (PAL). The activity levels of these enzymes were changed in chickpea treated with the formulations as compared to the control (water treated chickpea). The GC-MS analysis confirmed bioactive compounds responsible for the enhanced level of enzyme in chickpea. The findings of the study would lead to the development of a bio-formulation based inducer of resistance molecules in the chickpea against the Fusarium wilt.

Breeding and Genomic Approaches towards Development of Fusarium Wilt Resistance in Chickpea.

Chickpea is an important leguminous crop with potential to provide dietary proteins to both humans and animals. It also ameliorates soil nitrogen through biological nitrogen fixation. The crop is affected by an array of biotic and abiotic factors. Among different biotic stresses, a major fungal disease called Fusarium wilt, caused by Fusarium oxysporum f. sp. ciceris (FOC), is responsible for low productivity in chickpea. To date, eight pathogenic races of FOC (race 0, 1A, and 1B/C, 2-6) have been reported worldwide. The development of resistant cultivars using different conventional breeding methods is very time consuming and depends upon the environment. Modern technologies can improve conventional methods to solve these major constraints. Understanding the molecular response of chickpea to Fusarium wilt can help to provide effective management strategies. The identification of molecular markers closely linked to genes/QTLs has provided great potential for chickpea improvement programs. Moreover, omics approaches, including transcriptomics, metabolomics, and proteomics give scientists a vast viewpoint of functional genomics. In this review, we will discuss the integration of all available strategies and provide comprehensive knowledge about chickpea plant defense against Fusarium wilt.

Identification of multi-race Fusarium wilt resistance in chickpea (Cicer arietinum L.) using rapid hydroponic phenotyping

Fusarium wilt, caused by Fusarium oxysporum f. sp. ciceris (Padwick) Matuo and K. Sato is a major cause for low productivity of chickpea. Presence of multiple pathogenic races makes it difficult for the breeder to screen for Fusarium wilt resistance. Twenty-two chickpea genotypes were grown in Hoagland solution and inoculated with five different F. oxysporum races two isolates of each race), including host and pathogens from the major chickpea growing region of India. The resistant chickpea line “WR 315” showed a “highly resistant” reaction, and the susceptible line “JG 62” showed a “highly susceptible” reaction across all pathogen races and isolates. However, the parent lines “Pusa 372” and “JG 11” showed “susceptible” reactions, while the marker-assisted backcrossing (MABC) lines of “Pusa 372” (IL.11,12,14) and “JG 11” (IL.15,16,17) were superior for assessed characters (lengths of roots and shoots, fresh and dry weights), and were highly resistant to most races. This is the first study to use race specific screening of MABC lines using hydroponic host culture in chickpea.

Multi-locus genome-wide association study of chickpea reference set identifies genetic determinants of Pratylenchus thornei resistance.

Pratylenchus thornei is an economically important species of root-lesion nematode adversely affecting chickpea (Cicer arietinum) yields globally. Integration of resistant crops in farming systems is recognised as the most effective and sustainable management strategy for plant-parasitic nematodes. However, breeding for P. thornei resistance in chickpea is limited by the lack of genetic diversity. We deployed a genome-wide association approach to identify genomic regions and candidate genes associated with P. thornei resistance in 285 genetically diverse chickpea accessions. Chickpea accessions were phenotyped for P. thornei resistance in replicated glasshouse experiments performed for two years (2018 and 2020). Whole genome sequencing data comprising 492,849 SNPs were used to implement six multi-locus GWAS models. Fourteen chickpea genotypes were found to be resistant to P. thornei. Of the six multi-locus GWAS methods deployed, FASTmrMLM was found to be the best performing model. In all, 24 significant quantitative trait nucleotides (QTNs) were identified, of which 13 QTNs were associated with lower nematode population density and 11 QTNs with higher nematode population density. These QTNs were distributed across all of the chickpea chromosomes, except chromosome 8. We identified, receptor-linked kinases (RLKs) on chromosomes 1, 4 and 6, GDSL-like Lipase/Acylhydrolase on chromosome 3, Aspartic proteinase-like and Thaumatin-like protein on chromosome 4, AT-hook DNA-binding and HSPRO2 on chromosome 6 as candidate genes for P. thornei resistance in the chickpea reference set. New sources of P. thornei resistant genotypes were identified that can be harnessed into breeding programs and putative candidate P. thornei resistant genes were identified that can be explored further to develop molecular markers and accelerate the incorporation of improved P. thornei resistance into elite chickpea cultivars.

Integrated Application of Salicylic Acid and PGPRs to Control Fusarium Wilt of Chickpea

Fusarium wilt and Ascochyta blight are the most important diseases of chickpea. The current study was designed to investigate the individual and combined effect of salicylic acid (SA) with Pseudomonas stutzeri and Pseudomonas putida to suppress Fusarium wilt and promote growth of chickpea varieties: Thal-2006 and Punjab-2008. At the time of sowing, inoculum of Fusarium oxysporum was applied to the soil and the incidence of Fusarium wilt was recorded after 60 days. The seeds were inoculated with Pseudomonas stutzeri and Pseudomonas putida prior to sowing. Chickpea plants were treated with salicylic acid at seedling stage. The combination of P. stutzeri and SA significantly increased root length (166% and 145%), shoot height (50% and 47%) and shoot biomass (300% and 233%) in cv. Thal-2006 and cv. Punjab-2008, respectively, in infected plants. Similarly, the combined treatment of P. putida + SA, also enhanced the plant growth parameters of chickpea varieties. Maximum reduction in disease severity was observed in both P. stutzeri + SA (90% and 84%) and P. putida + SA (79% and 77%) treatments in cv. Thal-2006 and Punjab-2008, respectively. Both P. putida + SA and P. stutzeri + SA treatments resulted in increased leaf relative water and total protein content, peroxidase, superoxide dismutase, phenylalanine ammonia-lyase and polyphenol oxidase activities in both resistant (cv. Thal-2006) and susceptible (cv. Punjab-2008) cultivars. Both treatments also significantly reduced malondialdehyde (MDA) and proline content in cv. Thal-2006 and Punjab-2008. Cultivar Thal-2006 was more effective than cv. Punjab-2008. The results suggested that, in combination, salicylic acid and P. stutzeri may play an important role in controlling Fusarium wilt diseases by inducing systemic resistance in chickpea.

Unravelling the mechanism of Fusarium wilt resistance in chickpea seedlings using biochemical studies and expression analysis of NBS-LRR and WRKY genes

The yield potential of chickpea is highly compromised because of Fusarium wilt stress. Plant employs a series of physiological, biochemical and molecular changes to restrict pathogen spread. To understand the biochemical basis of resistance in chickpea against Fusarium oxysporum f.sp. ciceri (Foc), the temporal changes in antioxidant enzyme activity profiles were investigated. We documented guaiacol peroxidase, catalase, ascorbate peroxidase, and superoxide dismutase enzyme activities in resistant (WR 315) and susceptible (JG 62) chickpea genotypes under control and wilt stress conditions at two time points, 2- and 10- days post inoculation. Biochemical studies suggest that early and rapid defense responses, against pathogen attack, restrict pathogen spread in resistant cultivar while a weak and slow response by susceptible genotype leads to aggressive colonization by the pathogen. We have identified a set of wilt stress responsive nucleotide binding site and leucine rich repeat (NBS-LRR) resistance (R) and WRKY genes, known to be involved in plant defense, based on their co-localization with previously reported major Foc resistance QTLs and expression profiles. Sixteen NBS-LRR and eleven WRKY genes were co-localized to previously reported ten major Foc-QTLs present in chromosome 2 and 6. Interestingly, majority of these genes were co-localized to chromosome 2 which is also considered as a hotspot for Fusarium wilt resistance. The gene expression analysis in contrasting chickpea genotypes in response to Foc infection identified fourteen NBS-LRR and nine WRKY genes that showed differential expression suggesting their involvement in Fusarium wilt resistance. Our study provides new insights into biochemical and molecular mechanisms underlying resistance and susceptibility in chickpea against Fusarium oxysporum infection.

STMS markers related to Ascochyta blight resistance in chickpea

Chickpea (Cicer arietinum L.) is one of the important legume crops and is cultivated in large-scale throughout Türkiye as well as the world. Ascochyta blight, caused by the fungal phytopathogen Ascochyta rabiei, is the leading reason for the highest yield losses among the diseases known for chickpea. The pathogen exhibits high genetic diversity in Türkiye. Therefore, resistancy using Sequence Tagged Microsatellite Site (STMS) markers related with the genes that provide resistant against Ascochyta blight was investigated for the 205 chickpea breeding lines grown in different parts of Türkiye. The analysis for Ascochyta blight resistance was performed using Ta2, Ta146 and Ts54. It was demonstrated that Ta2, Ts54 and Ta146 were the STMS markers having distinguishable features for the detection of Ascochyta blight resistance and were shown to be used in credible fashion for the selection of resistant chickpea breeding lines.