Effect of genotype and root colonization in biological control of fusarium wilts in pigeonpea and chickpea byPseudomonas aeruginosaPNA1

2003 ◽  
Vol 49 (2) ◽  
pp. 85-91 ◽  
Author(s):  
Vanamala Anjaiah ◽  
Pierre Cornelis ◽  
Nico Koedam

Pseudomonas aeruginosa PNA1, an isolate from chickpea rhizosphere in India, protected pigeonpea and chickpea plants from fusarium wilt disease, which is caused by Fusarium oxysporum f.sp. ciceris and Fusarium udum. Inoculation with strain PNA1 significantly reduced the incidence of fusarium wilt in pigeonpea and chickpea on both susceptible and moderately tolerant genotypes. However, strain PNA1 protected the plants from fusarium wilt until maturity only in moderately tolerant genotypes of pigeonpea and chickpea. Root colonization of pigeonpea and chickpea, which was measured using a lacZ-marked strain of PNA1, showed tenfold lower root colonization of susceptible genotypes than that of moderately tolerant genotypes, indicating that this plant–bacteria interaction could be important for disease suppression in this plant. Strain PNA1 produced two phenazine antibiotics, phenazine-1-carboxylic acid and oxychlororaphin, in vitro. Its Tn5 mutants (FM29 and FM13), which were deficient in phenazine production, caused a reduction or loss of wilt disease suppression in vivo. Hence, phenazine production by PNA1 also contributed to the biocontrol of fusarium wilt diseases in pigeonpea and chickpea.Key words: biocontrol, fusarium wilts, phenazines, Pseudomonas.

Agronomy ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 385
Author(s):  
Cheng Zhou ◽  
Zhongyou Ma ◽  
Xiaoming Lu ◽  
Lin Zhu ◽  
Jianfei Wang

Soil microbial community changes imposed by the cumulative effects of root-secreted phenolic acids (PAs) promote soil-borne pathogen establishment and invasion under monoculture systems, but the disease-suppressive soil often exhibits less soil-borne pathogens compared with the conducive soil. So far, it remains poorly understood whether soil disease suppressiveness is associated with the alleviated negative effects of PAs, involving microbial degradation. Here, the long-term monoculture particularly shaped the rhizosphere microbial community, for example by the enrichment of beneficial Pseudomonas species in the suppressive soil and thus enhanced disease-suppressive capacity, however this was not observed for the conducive soil. In vitro PA-degradation assays revealed that the antagonistic Pseudomonas species, together with the Xanthomonas and Rhizobium species, significantly increased the efficiency of PA degradation compared to single species, at least partially explaining how the suppressive soil accumulated lower PA levels than the conducive soil. Pot experiments further showed that this consortium harboring the antagonistic Pseudomonas species can not only lower PA accumulation in the 15-year conducive soils, but also confer stronger Fusarium wilt disease suppression compared with a single inoculum with the antagonistic bacteria. Our findings demonstrated that understanding microbial community functions, beyond the single direct antagonism, facilitated the construction of active consortia for preventing soil-borne pathogens under intensive monoculture.


Plants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 222
Author(s):  
Abdulaziz A. Al-Askar ◽  
WesamEldin I. A. Saber ◽  
Khalid M. Ghoneem ◽  
Elsayed E. Hafez ◽  
Amira A. Ibrahim

Presently, the bioprocessing of agricultural residues to various bioactive compounds is of great concern, with the potential to be used as plant growth promoters and as a reductive of various diseases. Lycopersiconesculentum, one of the most consumed crops in the human diet, is attacked by Fusarium wilt disease, so the main aim is to biocontrol the pathogen. Several fungal species were isolated from decayed maize stover (MS). Trichodermaasperellum was chosen based on its organic acid productivity and was molecularly identified (GenBank accession number is MW195019). Citric acid (CA) was the major detected organic acid by HPLC. In vitro, CA of T.asperellum at 75% completely repressed the growth of Fusariumoxysporum f. sp. lycopersici (FOL). In vivo, soaking tomato seeds in CA enhanced the seed germination and vigor index. T. asperellum and/or its CA suppressed the wilt disease caused by FOL compared to control. There was a proportional increment of plant growth and yield, as well as improvements in the biochemical parameters (chlorophyll pigments, total phenolic contents and peroxidase, and polyphenol oxidase activities), suggesting targeting both the bioconversion of MS into CA and biological control of FOL.


1976 ◽  
Vol 54 (8) ◽  
pp. 752-757 ◽  
Author(s):  
Frank L. Caruso ◽  
Terry A. Tattar ◽  
Mark S. Mount ◽  
Margaret E. Malia

Decreases in electrical resistance (ER) of tomato taproots were correlated with the progression of Fusarium wilt disease. Production of polygalacturonase (PG) from four isolates of Fusarium oxysporum f. sp. lycopersici, as determined from ammonium sulfate fractions, was correlated with the degree of virulence of each isolate. A drop in ER in tomato plant taproots at 6 cm below the soil level was noticed within 2 h after separate inoculation with all strains. These drops in ER preceded foliar symptom development by 20 h. Measurement of ER in the stems of inoculated tomato plants, however, was found to be no different from that of uninoculated plants. The rate of ER decrease was correlated with the in vitro production of PG by these isolates; the higher the PG activity, the greater the decrease in ER.


2018 ◽  
Vol 10 (9) ◽  
pp. 373
Author(s):  
Jose R. M. Campos Neto ◽  
Leonardo de J. M. G. de Oliveira ◽  
Nathalia B. Diniz ◽  
Ivaneide de O. Nascimento ◽  
Antonia Alice C. Rodrigues

To study the effects of resistance inducers used to control fusarium wilt in tomatoes due to the fungus Fusarium oxysporum Schlecht f. sp. lycopersici, we evaluated the effects of ASM (acibenzolar-S-methyl), Agro-Mos, chitosan, Biopirol and neem oil on F. oxysporum f. sp. lycopersici mycelial growth and sporulation and systemic resistance in tomatoes. In vitro experiments comprised evaluations of the products’ effects on the mycelial growth and sporulation of the PDA (potato dextrose agar) growth medium-cultured pathogen. In vivo experiments included product application to tomato plants of the Santa Cruz cultivar that were grown for 25 days on autoclaved soil, followed by determinations of disease severity and peroxidase, polyphenol oxidase and Beta-1,3-glucanase enzyme activity levels, which are related to the process of resistance induction. Pathogen inoculation occurred after 5 days at a concentration of 106 conidia/mL. We evaluated the disease according to a rating scale. Enzymatic activity was determined according to specific protocols. Neem oil controlled pathogen mycelial growth and sporulation, while ASM influenced sporulation. The products reduced the severity of wilt in the plants. We highlight neem oil, Agro-Mos and Biopirol due to their ability to induce significant peroxidase, polyphenol oxidase and Beta-1,3-glucanase expression, respectively.


2017 ◽  
Vol 57 (2) ◽  
pp. 185-193 ◽  
Author(s):  
Zeinab Fotoohiyan ◽  
Saeed Rezaee ◽  
Gholam Hosein Shahidi Bonjar ◽  
Amir Hossein Mohammadi ◽  
Mohammad Moradi

Abstract Verticillium wilt caused by Verticillium dahliae, is one of the most devastating diseases in pistachio orchards in the world including Iran. In search for an effective non-chemical strategy for the management of this disease, we evaluated the biocontrol potential of Trichoderma harzianum isolates obtained from the rhizosphere of healthy pistachio trees in different locations of the Kerman province of Iran against V. dahliae under laboratory and greenhouse conditions. Dual culture tests in the laboratory were conducted in a completely randomized design using 72 T. harzianum isolates. Twenty isolates showed the highest in vitro antagonistic activity. The results indicated that all 20 isolates were capable of inhibiting the mycelial growth of V. dahliae significantly. Among them, isolates Tr8 and Tr19 were the most effective by 88.89% and 85.12% inhibition, respectively. Extracted cell free metabolites of all effective isolates also inhibited the growth of V. dahliae in the culture medium significantly. According to the results, isolates Tr4 and Tr6 inhibited fungal pathogen growth by 94.94% and 88.15% respectively, through production of non-volatile metabolites. In the evaluation of volatile metabolites, isolates Tr5 and Tr4 were the most effective by 26.27% and 24.49% growth inhibition, respectively. Based on the results of the in vitro experiments, the five most effective isolates were selected for evaluation under greenhouse conditions for their biocontrol potential in controlling Verticillium wilt of pistachio. Results of the greenhouse, (in vivo) experiments were positive and indicated that the occurrence of wilt disease in plants treated with the antagonists alone or in combination with pathogenic fungus was lower than in plants inoculated with pathogen alone. The overall results of this study suggest that Trichoderma fungal antagonist may be an effective biocontrol agent for the control of Verticillium wilt of pistachio.


2020 ◽  
Vol 8 (4) ◽  
pp. 544 ◽  
Author(s):  
Maria E. Constantin ◽  
Babette V. Vlieger ◽  
Frank L. W. Takken ◽  
Martijn Rep

Root colonization by Fusarium oxysporum (Fo) endophytes reduces wilt disease symptoms caused by pathogenic Fo strains. The endophytic strain Fo47, isolated from wilt suppressive soils, reduces Fusarium wilt in various crop species such as tomato, flax, and asparagus. How endophyte-mediated resistance (EMR) against Fusarium wilt is achieved is unclear. Here, nonpathogenic colonization by Fo47 and pathogenic colonization by Fo f.sp. lycopersici (Fol) strains were assessed in tomato roots and stems when inoculated separately or coinoculated. It is shown that Fo47 reduces Fol colonization in stems of both noncultivated and cultivated tomato species. Conversely, Fo47 colonization of coinoculated tomato stems was increased compared to single inoculated plants. Quantitative PCR of fungal colonization of roots (co)inoculated with Fo47 and/or Fol showed that pathogen colonization was drastically reduced when coinoculated with Fo47, compared with single inoculated roots. Endophytic colonization of tomato roots remained unchanged upon coinoculation with Fol. In conclusion, EMR against Fusarium wilt is correlated with a reduction of root and stem colonization by the pathogen. In addition, the endophyte may take advantage of the pathogen-induced suppression of plant defences as it colonizes tomato stems more extensively.


2015 ◽  
Vol 95 (4) ◽  
pp. 689-701 ◽  
Author(s):  
Samia Ageeb Akladious ◽  
George Saad Isaac ◽  
Medhat Ahmed Abu-Tahon

Akladious, S. A., Isaac, G. S. and Abu-Tahon, M. A. 2015. Induction and resistance against Fusarium wilt disease of tomato by using sweet basil (Ocimum basilicum L) extract. Can. J. Plant Sci. 95: 689–701. The antifungal activity of Ocimum basilicum (sweet basil) extract against Fusarium oxysporum f. sp. lycopersici race 3 the causal agent of tomato wilt and its ability in inducing disease resistance were studied in vivo using seed-soaking treatment before sowing. Plants were harvested at 45 and 105 d (vegetative and flowering stages) after sowing. Treatment with O. basilicum extract decreased the disease incidence from 94.70 to 18.00%. Results revealed that growth parameters and photosynthetic pigments were markedly inhibited in tomato plants in response to Fusarium wilt disease, whereas the contents of non-enzymatic and enzymatic antioxidants were increased as compared with healthy control plants. Moreover, presoaking in basil extract enhanced all the mentioned parameters in both healthy and infected plants. SDS-PAGE analysis of tomato leaves revealed that seed treated with basil extract resulted in an induction of novel protein bands during the vegetative stage. These new proteins were not detected in untreated healthy or infected control plants. Electrophoretic studies of polyphenol oxidase, esterase and malate dehydrogenase isoenzymes showed wide variations in their intensities and densities among all treatments. It seems that O. basilicum extract was able to enhance the biological control of Fusarium wilt disease of tomato.


1998 ◽  
Vol 44 (6) ◽  
pp. 528-536 ◽  
Author(s):  
V K Sharma ◽  
J Nowak

The potential utilization of a plant growth promoting rhizobacterium, Pseudomonas sp. strain PsJN, to enhance the resistance of tomato transplants to verticillium wilt was investigated. Plant growth and disease development were tested on the disease-susceptible cultivar Bonny Best after Verticillium dahliae infection of tissue culture plantlets bacterized in vitro (by co-culturing with the bacterium) and seedlings bacterized in vivo (after 3 weeks growth in the greenhouse). Significant differences in both disease suppression and plant growth were obtained between in vitro bacterized and nonbacterized (control) plants. The degree of protection afforded by in vitro bacterization depended on the inoculum density of V. dahliae; the best and worst protection occurred at the lowest (103 conidia ·mL-1) and highest (106 conidia ·mL-1) levels, respectively. In contrast, the in vivo bacterized tomatoes did not show plant growth promotion when compared to the nonbacterized control plants. When challenged with Verticillium, significant growth differences between in vivo bacterized plants (26.8% for shoot height) and nonbacterized controls were only seen at the 3rd week after inoculation. Compared with the in vitro inoculation, there was no delay in the verticillium wilt symptom expression, even at the lowest concentration of V. dahliae, by in vivo PsJN inoculation. These results suggest that endophytic colonization of tomato tissues is required for the Verticillium-resistance responses. Plant growth promotion preceeds the disease-resistance responses and may depend on the colonization thresholds and subsequent sensitization of hosts.Key words: Pseudomonas sp., plant growth promoting rhizobacterium, Verticillium dahliae, tomato, colonization, plant growth promotion, disease suppression.


1993 ◽  
Vol 71 (8) ◽  
pp. 1080-1086 ◽  
Author(s):  
Mohamed S. El-Abyad ◽  
Mostafa A. El-Sayed ◽  
Abdel-Reheem El-Shanshoury ◽  
Nadia H. El-Batanouny

The purpose of this investigation was to produce improved mutants of Streptomyces corchorusii and Streptomyces spiroverticillatus, using a UV-irradiation regime, which are effective against the causal pathogens of the Fusarium wilt of French bean and the bacterial wilt of banana, respectively. Seven out of the 11 mutants obtained from S. corchorusii were active antagonists against Fusarium oxysporum f.sp. phaseoli; mutant 155 was the most effective. All five mutants obtained from S. spiroverticillatus showed inhibitory effects against Pseudomonas solanacearum; mutant 281 was the most potent. Spore germination, germ-tube elongation, growth, and sporulation of F. oxysporum f.sp. phaseoli were significantly inhibited in the different concentrations of filtrates of either wild or mutant 155 of S. corchorusii in vitro with the mutant being more effective; maximum inhibition was at 80% concentration. The filtrate of either wild or mutant 281 of S. spiroverticillatus sharply decreased the number of colonies of P. solanacearum as its concentration increased up to 80%, at which no growth was obtained. The in vivo utilization of S. corchorusii in the biocontrol of Fusarium wilt of French bean revealed that soaking seeds in filtrate of the antagonistic strain prior to sowing was the most effective treatment and that mutant 155 reduced disease incidence by 83.4% (43.3% for the wild type) compared with the untreated control, in addition to improving plant growth. Key words: antagonism, UV irradiation, mutation, Streptomyces spp., Fusarium wilt, bacterial wilt, French bean, banana.


Sign in / Sign up

Export Citation Format

Share Document