Fusarium Wilt Of Chickpea Research Articles

Evaluation of Different Strains of Pseudomonas fluorescens for the Biocontrol of Fusarium Wilt of Chickpea

Evaluation of Different Strains of Pseudomonas fluorescens for the Biocontrol of Fusarium Wilt of Chickpea

Role of salicylic acid in systemic resistance induced by Pseudomonas fluorescens against Fusarium oxysporum f. sp. ciceri in chickpea

Selected isolates of Pseudomonas fluorescens (Pf1-94, Pf4-92, Pf12-94, Pf151-94 and Pf179-94) and chemical resistance inducers (salicylic acid, acetylsalicylic acid, DL-norvaline, indole-3-carbinol and lichenan) were examined for growth promotion and induced systemic resistance against Fusarium wilt of chickpea. A marked increase in shoot and root length was observed in P. fluorescens treated plants. The isolates of P. fluorescens systemically induced resistance against Fusarium wilt of chickpea caused by Fusarium. oxysporum f.sp. ciceri (FocRs1), and significantly (P = 0.05) reduced the wilt disease by 26-50% as compared to control. Varied degree of protection against Fusarium wilt was recorded with chemical inducers. The reduction in disease was more pronounced when chemical inducers were applied with P. fluorescens. Among chemical inducers, SA showed the highest protection of chickpea seedlings against wilting. Fifty two- to 64% reduction of wilting was observed in soil treated with isolate Pf4-92 along with chemical inducers. A significant (P = 0.05; r = -0.946) negative correlation was observed in concentration of salicylic acid and mycelial growth of FocRs1 and at a concentration of 2000 microg ml(-1) mycelial growth was completely arrested. Exogenously supplied SA also stimulated systemic resistance against wilt and reduced the disease severity by 23% and 43% in the plants treated with 40 and 80 microg ml(-1) of SA through root application. All the isolates of P. fluorescens produced SA in synthetic medium and in root tissues. HPLC analysis indicated that Pf4-92 produced comparatively more SA than the other isolates. 1700 to 2000 nanog SA g(-1) fresh root was detected from the application site of root after one day of bacterization whereas, the amount of SA at distant site ranged between 400-500 nanog. After three days of bacterization the SA level decreased and was found more or less equal at both the detection sites.

Induction of an antioxidant enzyme system and other oxidative stress markers associated with compatible and incompatible interactions between chickpea (Cicer arietinum L.) and Fusarium oxysporum f. sp.ciceris

To ascertain if active oxygen species play a role in fusarium wilt of chickpea caused by Fusarium oxysporum f. sp. ciceris, the degree of lipid peroxidation (malondialdehyde formation) and the activity levels of diamine oxidase (DAO), an apoplastic H2O2-forming oxidase, and several antioxidant enzymes, namely ascorbate peroxidase (APX), catalase (CAT), glutathione reductase (GR), guaiacol-dependent peroxidase (GPX) and superoxide dismutase (SOD), were determined spectrophotometrically in roots and stems of ‘WR315’ (resistant) and ‘JG62’ (susceptible) chickpea cultivars inoculated with the highly virulent race 5 of the pathogen. Moreover, APX, CAT, GPX and SOD were also analysed in roots and stems by gel electrophoresis and activity staining; and the protein levels of APX and SOD in roots were determined by Western blotting. In roots, infection by the pathogen increased lipid peroxidation and CAT and SOD activities, although such responses occurred earlier in the incompatible compared with the compatible interactions. APX, GPX and GR activities were also increased in infected roots, but only in the compatible interaction. In stems, infection by the pathogen increased lipid peroxidation and APX, CAT, SOD and GPX activities only in the compatible interaction, and DAO activity only in the incompatible one. In general, electrophoregrams agreed with the activity levels determined spectrophotometrically and did not reveal any differences in isoenzyme patterns between cultivars or between infected and non-infected plants. Further, Western blots revealed an increase in the root protein levels of APX in the compatible interaction and in those of SOD in both compatible and incompatible interactions. In conclusion, whereas enhanced DAO activity in stems, and earlier increases in lipid peroxidation and CAT and SOD activities in roots, can be associated with resistance to fusarium wilt in chickpea, the induction of the latter three parameters in roots and stems along with that of APX, GR (only in roots) and GPX (only in stems) activities are rather more associated with the establishment of the compatible interaction.

Plant defence reactions against fusarium wilt in chickpea induced by incompatible race 0 of Fusarium oxysporum f.sp. ciceris and nonhost isolates of F. oxysporum

Germinated seeds of ‘kabuli’ chickpea cv. ICCV 4 were inoculated with a conidial suspension of the incompatible race 0 of Fusarium oxysporum f.sp. ciceris (Foc) or of nonhost F. oxysporum resistance ‘inducers’, and 3 days later were challenged by root dip with a conidial suspension of highly virulent Foc race 5. Prior inoculation with inducers delayed the onset of symptoms and/or significantly reduced the final amount of fusarium wilt caused by race 5. However, the extent of disease suppression varied with the nature of the inducing agent; the nonhost isolates of F. oxysporum were more effective at disease suppression than the incompatible Foc race 0. Inoculation with the inducers gave rise to synthesis of maackiain and medicarpin phytoalexins in inoculated seedlings; these did not accumulate in plant tissues but were released into the inoculum suspension. Inoculation with inducers also resulted in accumulation of chitinase, β‐1,3‐glucanase and peroxidase activities in plant roots. These defence‐related responses were induced more consistently and intensely by nonhost isolates of F. oxysporum than by incompatible Foc race 0. The phytoalexins and, to a lesser extent, the antifungal hydrolases, were also induced after challenge inoculation with Foc race 5. However, in this case the defence responses were induced in both preinduced and noninduced plants infected by the pathogen. It is concluded that the suppression of fusarium wilt in this study possibly involved an inhibitory effect on the pathogen of preinduced plant defences, rather than an increase in the expression of defence mechanisms of preinduced plants following a subsequent challenge inoculation.

Sources of resistance to Fusarium wilt of chickpea in Sudan

A total of 330 chickpea genotypes were screened for resistance to Fusarium wilt caused by Fusarium oxysporum f. sp. ciceris in a wilt-infected plot at Hudeiba Research Station, Ed-Damer, Sudan. The released kabuli cv. Shendi (NEC 2491/ILC 1335) and Jebel Marra-1 (ILC 915), and the widely-grown kabuli cv. Baladi were highly susceptible to Fusarium wilt. Conversely, kabuli cv. ICCV 2 and UC 15, and desi genotypes FLIP 85-20C, FLIP 85- 29C and FLIP 85-30C were highly resistant to the disease with less than 10% wilt incidence. ‘ICCV 2’ matured about 4 to 5 weeks earlier than the other four resistant chickpea genotypes. Two field trials were also conducted to verify the resistance of cv. ICCV 2 and the efficacy of the seed-dressing fungicides Tecto-TM and Quinolate Pro for control of Fusarium wilt. One trial was carried out in the wilt-infected plot and the other in farmers’ fields with a history of high disease incidence. In both trials, cv. ICCV 2 showed a good level of resistance to wilt and produced twice the grain yield of cv. Baladi in farmers’ fields. Both seed-dressing fungicides significantly increased seedling emergence in the wilt-infected plot, but neither significantly decreased the final incidence of dead plants, or increased the grain yield in the infected plot or the farmers’ fields. Results of this study indicate that cv. ICCV 2 is a potential variety for release in the traditional chickpea-producing areas of Sudan where Fusarium wilt and late-season soil moisture stress are major constraints to production.

Gene genealogies support Fusarium oxysporum f. sp. ciceris as a monophyletic group

Fusarium oxysporum f. sp. ciceris (Foc), the causal agent of fusarium wilt of chickpea, consists of two pathotypes (yellowing and wilting) and eight races (races 0, 1B/C, 1A and 2–6) of diverse geographical distribution. Six Foc isolates, one each of races 0, 1B/C, 1A, 4, 5 and 6, representing the two pathotypes and the geographical range of the pathogen, showed identical sequences in introns of the genes for translation elongation factor 1α (EF1α), β‐tubulin, histone 3, actin and calmodulin. Eleven additional Foc isolates representative of all races, pathotypes and geographical range, and three isolates of F. oxysporum (Fo) nonpathogenic to chickpea were further analysed for sequence variation in the EF1α gene. All isolates pathogenic to chickpeas shared an identical EF1α gene sequence, which differed from that shared by the three Fo isolates nonpathogenic to chickpea. EF1α gene sequences from the 17 Foc isolates and the three Fo isolates were compared with 24 EF1α gene sequences in GenBank from isolates of 11 formae speciales of F. oxysporum by parsimony analysis. Foc isolates formed a grouping distinct from other formae speciales and nonpathogenic isolates. These results indicate that F. oxysporum f. sp. ciceris is monophyletic.

Influence of Temperature and Inoculum Density of Fusarium oxysporum f. sp. ciceris on Suppression of Fusarium Wilt of Chickpea by Rhizosphere Bacteria

The effects of temperature and inoculum density of Fusarium oxysporum f. sp. ciceris race 5 on suppression of Fusarium wilt in chickpea (Cicer arietinum) cv. PV 61 by seed and soil treatments with rhizobacteria isolated from the chickpea rhizosphere were studied in a model system. Disease development over a range of temperatures (20, 25, and 30 degrees C) and inoculum densities (25 to 1,000 chlamydospores per gram of soil) was described by the Gompertz model. The Gompertz relative rate of disease progress and final amount of disease increased exponentially and monomolecularly, respectively, with increasing inoculum densities. Disease development was greater at 25 degrees C compared with 20 and 30 degrees C. At 20 and 30 degrees C, disease development was greater at 250 to 1,000 chlamydospores per gram of soil compared with 25 to 100 chlamydospores per gram of soil. At 25 degrees C, increasing inoculum densities of the pathogen did not influence disease. Nineteen Bacillus, Paenibacillus, Pseudomonas, and Stenotrophomonas spp. out of 23 bacterial isolates tested inhibited F. oxysporum f. sp. ciceris in vitro. Pseudomonas fluorescens RGAF 19 and RG 26, which did not inhibit the pathogen, showed the greatest Fusarium wilt suppression. Disease was suppressed only at 20 or 30 degrees C and at inoculum densities below 250 chlamydospores per gram of soil. Bacterial treatments increased the time to initial symptoms, reduced the Gompertz relative rate of disease progress, and reduced the overall amount of disease developed.

Yield Loss in Chickpeas in Relation to Development of Fusarium Wilt Epidemics

ABSTRACT Development of 108 epidemics of Fusarium wilt of chickpea caused by Fusarium oxysporum f. sp. ciceris were studied on cvs. P-2245 and PV-61 in field microplots artificially infested with races 0 and 5 of F. oxysporum f. sp. ciceris in 1986 to 1989. Disease progression data were fitted to the Richards model using nonlinear regression. The shape parameter was influenced primarily by date of sowing and, to a lesser extent, by chick-pea cultivars and races of F. oxysporum f. sp. ciceris. Fusarium wilt reduced chickpea yield by decreasing both seed yield and seed weight. These effects were related to sowing date, chickpea cultivar, and virulence of the prevalent F. oxysporum f. sp. ciceris race. Regression models were developed to relate chickpea yield to Fusarium wilt disease intensity with the following independent variables: time to initial symptoms (t(is)), time to inflection point (t(ip)) of the disease intensity index (DII) progress curve, final DII (DII(final)), standardized area under DII progress curve (SAUDPC), and the Richards weighted mean absolute rate of disease progression (rho). Irrespective of the chickpea cultivar x pathogen race combination, the absolute and relative seed yields decreased primarily by delayed sowing. The relative seed yield increased with the delay in t(is) and t(ip) and decreased with increasing DII(final), SAUDPC, and rho. A response surface as developed in which seed yield loss decreased in a linear relationship with the delay in t(is) and increased exponentially with the increase of rho.

Inheritance and Linkage of Two Genes that Confer Resistance to Fusarium Wilt in Chickpea

Fusarium oxysporum Schlechtend.: Fr. f. sp. ciceris (Padwick) causes a vascular wilt of chickpea (Cicer arietinum L.) and significantly limits production worldwide. The objectives of this study were (i) to determine the inheritance of resistance to races 0 and 5 of fusarium wilt and the genetic map positions of the resistance genes and (ii) to assess the linkage relationships between these two genes and other known wilt resistance genes in chickpea. Seedlings of 131 F6‐derived recombinant inbred lines (RILs) were tested for reaction to races 0 and 5. A 1 resistant:1 susceptible segregation ratio was observed for both races, indicating that resistance to each race is controlled by a single gene. Linkage analysis indicated that the genes for resistance to races 4 and 5 were in the same linkage group and were separated by 11.2 centiMorgans (cM). The gene for resistance to race 0 was not linked to the race 4 and 5 resistance genes. In addition, an allele‐specific associated primer (ASAP) product (CS‐27R/CS‐27F), developed from the CS‐27 primer, was located between the two resistance genes and was 7.2 and 4 cM from the genes for resistance to races 4 and 5, respectively. Map positions of these two race‐specific resistance genes and the marker reported to be linked to the genes for resistance to races 1 and 4 support the hypothesis that wilt resistance genes are clustered on the same chromosome. Since the gene conferring resistance to race 0 is found in a different region of the genome, other genomic regions may be responsible for resistance to wilt pathogens. The gene symbols foc‐0, foc‐4, and foc‐5 are proposed for the genes for resistance to races 0, 4, and 5 of the pathogen, respectively. Identification and further evaluation of disease resistance gene clusters would improve our understanding of wilt resistance in chickpea and facilitate the transfer of resistance genes to new cultivars.

A second gene for resistance to race 4 of Fusarium wilt in chickpea and linkage with a RAPD marker

Fusarium wilt caused by Fusarium oxysporum Schlechtend.: Fr f. sp. ciceris (Padwick) Matuo & Sato is a devastating disease of chickpea. The current study was conducted to determine the inheritance of the gene(s) for resistance to race 4 of fusarium wilt and to identify linked RAPD markers using an early wilting line, JG-62, as a susceptible parent. Genetic analysis was performed on the F1s, F2s and F3 families from the cross of JG-62 × Surutato-77. The F3 families were inoculated with a spore suspension of the race 4 wilt pathogen and the results were used to infer the genotypes of the parent F2 plants. Results indicated that two independent genes controlled resistance to race 4. Linkage analysis of candidate RAPD marker, CS-27700, and the inferred F2 phenotypic data showed that this marker locus is linked to one of the resistance genes. Allelism indicated that the two resistance sources, Surutato-77 and WR-315, shared common alleles for resistance and the two susceptible genotypes, C-104 and JG-62, carried alleles for susceptibility. The PCR-based marker, CS-27700, was previously reported to be linked to the gene for resistance to race 1 in a different population which suggested that the genes for resistance to races 1 and 4 are in close proximity in the Cicer genome.

A Simple PCR-based Method for the Detection of the Chickpea-wilt Pathogen Fusarium oxysporum f.sp. ciceris in Artificial and Natural Soils

A fast and simple polymerase chain reaction method has been developed for the detection of Fusarium oxysporum f.sp. ciceris, the causal agent of Fusarium wilt of chickpea, in natural and artificial soils. The method involves the disruption of fungal biomass by grinding dry soil, using its abrasive properties, in the presence of skimmed milk powder. The latter prevents loss of DNA by adsorption to soil particles or by degradation and reduces the co-extraction of PCR inhibitors with the DNA. After phenol/chloroform extraction, the DNA is suitable for direct PCR amplification without a precipitation step. For the efficient detection of small amounts of DNA extracted from soil, a two step amplification with nested primers was used. The dilution step reduced the effect of Taq-polymerase inhibitors. The specificity of the amplification, and consequently the yield of specific product, was increased by the use of a modified ‘touch down’ process during the annealing step. The method has been applied to the specific detection of wilt-inducing isolates of the pathogen in a variety of natural and artificial soils. The amplification was improved by the use of increased concentrations of skimmed milk powder in soils with high organic or clay contents.

Effect of Sowing Date, Host Cultivar, and Race of Fusarium oxysporum f. sp. ciceris on Development of Fusarium Wilt of Chickpea

ABSTRACT Microplots experiments were carried out at Córdoba, southern Spain, from 1986 to 1989 to determine the effects of sowing date in the management of Fusarium wilt of chickpea as influenced by virulence of the pathogen race and by cultivar susceptibility. A total of 108 epidemics of the disease were described, analyzed, and compared to assess the degree of disease control. The epidemics were characterized by five curve elements: final disease intensity index (DII), standardized area under DII progress curve, time to epidemic onset, time to inflection point (t(ip)), and the DII value at t(ip), the last two parameters being estimates from the Richards function adjusted by nonlinear regression analysis. The structure of Fusarium wilt epidemics was examined by conducting multivariate principal components and cluster analyses. From these analyses, three factors accounting for 98 to 99% of the total variance characterized the DII progress curves and provided plausible epidemiological interpretations. The first factor included the t(ip) and the time to disease onset and can be interpreted as a positional factor over time. This factor accounted for the largest proportion of the total variance and may, therefore, be considered as the main factor for analysis of Fusarium wilt epidemics. The second factor concerns the standardized area under DII progress curves and the final DII of the epidemics. The third factor identified the uniqueness of the estimated value for the point of inflection of the DII progress curve over time. Our results indicate that for each year of experiment epidemic development was related mainly to the date of sowing. Thus, for chickpea crops in southern Spain, advancing the sowing date from early spring to early winter can slow down the development of Fusarium wilt epidemics, delay the epidemic onset, and minimize the final amount of disease. However, the net effect of this disease management practice may also be influenced, though to a lesser extent, by the susceptibility of the chickpea cultivar and the virulence and inoculum density of the Fusarium oxysporum f. sp. ciceris race.

A Vascular Wilt of Turnsole Caused by Fusarium oxysporum.

Turnsole (Chrozophora tinctoria) is a common spring-summer weed in chickpea (Cicer arietinum) and other dry-land crop production areas in southern Spain. Under field conditions, this weed often develops a general wilt and eventual death associated with a vascular discoloration of stems and roots. Diseased turnsole plants frequently occurred together with chickpea plants affected by Fusarium wilt caused by Fusarium oxysporum f. sp. ciceris, a major disease of chickpea crops in southern Spain (1). Isolations from roots, stems and leaf petioles of turnsole plants consistently yielded F. oxysporum, and it was morphologically similar to F. oxysporum f. sp. ciceris. To test the pathogenicity of this fungus, germinated and previously surface-sterilized seeds of turnsole and chickpea cultivar Blanco Lechoso were planted in a greenhouse soil mixture artificially infested with four isolates of F. oxysporum from turnsole and two isolates of F. oxysporum f. sp. ciceris, one of them inducing the wilt syndrome and the other causing yellowing (1). Pathogenicity tests were conducted following the standard inoculation method used for F. oxysporum in chickpea (1). Inoculated and control plants were maintained in a greenhouse at 15 to 30°C. Isolates of F. oxysporum from turnsole caused wilt symptoms and death of turnsole plants within 2 months, but chickpea isolates did not affect turnsole. Conversely, chickpea plants were affected only by the two isolates of F. oxysporum f. sp. ciceris from chickpea. All diseased chickpea and turnsole plants exhibited typical vascular discoloration. F. oxysporum was consistently reisolated from the vascular tissues of roots, stems, and leaf petioles of affected plants. Based on these results, the fungus causing wilt of turnsole was identified as a forma specialis of F. oxysporum different from the chickpea wilt pathogen. Since the Fusarium wilt diseases of turnsole and chickpea are caused by different pathogens, the occurrence of F. oxysporum causing wilt of turnsole in the field can not be used to forecast Fusarium wilt of chickpea, but it may be considered as a potential biocontrol agent of this weed under field conditions. This is the first report of F. oxysporum causing wilt of turnsole. Reference: (1) A. Trapero-Casas and R. M. Jiménez-Díaz. Phytopathology 75:1146, 1985.

Involvement of Phenazines and Anthranilate in the Antagonism of Pseudomonas aeruginosa PNA1 and Tn5 Derivatives Toward Fusarium spp. and Pythium spp.

Pseudomonas aeruginosa PNA1, isolated from the rhizosphere of chickpea in India, suppressed Fusarium wilt of chickpea, caused by Fusarium oxysporum f. sp. ciceris, and Pythium damping-off of bean, caused by Pythium splendens. When grown in culture, PNA1 produced the phenazine antibiotics phenazine-1-carboxylic acid and oxychloraphine, and inhibited mycelial growth of F. oxysporum f. sp. ciceris, P. splendens, and certain other phytopathogenic fungi. Two mutants (FM29 and FM13) deficient in phenazine production were obtained following transposon mutagenesis of PNA1. The transposon in the genome of FM29 was localized to phnA, which is thought to encode a subunit of anthranilate synthase II involved in the phenazine biosynthesis. The FM13 mutation was complemented by trpC, which encodes indole glycerol phosphate synthase in the tryptophan biosynthesis pathway; consequently, FM13 could not grow on a minimal medium in the absence of tryptophan. Neither FM29 nor FM13 suppressed Fusarium wilt of chickpea to the level achieved by the wild-type strain, indicating that phenazine production contributed to the biocontrol of this disease by P. aeruginosa PNA1. FM29 was also less effective than the phenazine-producing parental strain in biological control of Pythium damping-off of bean, but FM13 was as effective as the parental strain in suppressing this disease. Anthranilate, an intermediate in the tryptophan biosynthesis pathway, suppressed mycelial growth of Pythium spp. in culture and Pythium damping-off of bean and lettuce. Anthranilate, excreted by FM13 as a consequence of the trpC mutation, may have contributed to the suppression of Pythium damping-off by the mutant.

Inheritance of resistance to fusarium wilt in chickpea

AbstractThis preliminary study indicated that the resistance to race 2 of fusarium wilt is controlled by two genes, the first of which must be present in the homozygous recessive form, and the other in the dominant form, whether homozygous or heterozygous for complete resistance. Early wilting results if the other gene is homozygous recessive. Late wilting occurs if both loci are dominant. The existence of differences among chickpea cultivars in the time taken to express the initial symptoms of fusarium wilt were observed.

Inheritance of Resistance to Fusarium Wilt in Chickpea

Inheritance of Resistance to Fusarium Wilt in Chickpea

Inheritance of Resistance to Fusarium Wilt in Chickpea

Inheritance of Resistance to Fusarium Wilt in Chickpea