scholarly journals Screening of indigenous rhizobacteria as potential biological control against faba bean (Vicia faba L.) gall disease caused by Olpidium viciae

2021 ◽  
Vol 31 (1) ◽  
Author(s):  
Alemayehu Dugassa ◽  
Tesfaye Alemu ◽  
Yitbarek Woldehawariat

Abstract Background Emerged faba bean gall disease attacks the stem and leaves of the plant and results in complete crop losses. This study was initiated to screen multi-trait rhizobacteria for their antagonistic efficacy under in-vitro and in-vivo conditions against Olpidium viciae to control the effect of gall disease on faba bean. Sixty antagonistic isolates were first examined for their morphological, biochemical, and phenotypic traits. Results Pseudomonas fluorescens AAUPF62, P. aeruginosa AAUS31, Bacillus AAUMF42, and Bacillus AAUAm28 showed greater than 68, 62, 57, and 54% suppression of O. viciae in dual culture, volatile metabolites, culture filtrate assay, and detached leaves experiments, respectively. The in-vivo study revealed that early treatment of the crop with P. aeruginosa AAUS31 reduced severity by 63% (in FB-Obse) and 54% (in FB-26869) faba bean varieties. The co-inoculation of P. fluorescens AAUPF62 and P. aeruginosa AAUS31 significantly enhanced the shoot (P = 0.003; mean = 122 cm) and root (P = 0.018; mean = 94 cm) length, increased shoot dry weight by 8 factors (83 g pot −1), and reduced final disease severity by 92% in FB-Obse variety. Conclusions The results revealed that P. fluorescens AAUPF62 and P. aeruginosa AAUS31 strains could be the potential antagonistic agents of gall disease. The use and early treatment of moderately resistant faba bean varieties by co-inoculation of synergistic potential bioagents were recommended.

2017 ◽  
Vol 15 (2) ◽  
pp. e1003 ◽  
Author(s):  
Imen Haddoudi ◽  
Yosra Sendi ◽  
Marwa Batnini ◽  
Samir Ben Romdhane ◽  
Haythem Mhadhbi ◽  
...  

A faba bean rhizospheric Pseudomonas aeruginosa isolate RZ9 was used for studying its antifungal activity and protecting effects of faba bean and common bean against the root pathogen Fusarium culmorum strain MZB47. The dual culture tests showed that RZ9 inhibits MZB47 in vitro growth by 56%. When mixing RZ9 cell suspension with MZB47 macroconidia at equal proportion, the macroconidia viability was reduced with 70%. Pathogenicity tests conducted in sterile conditions showed that MZB47 caused an intense root rotting in faba bean ‘Aquadulce’ plantlets and a slight level in common bean ‘Coco blanc’. This was associated to significant decreases in plant growth only in ‘Aquadulce’, reducing shoot dry weight (DW) by 82% and root DW by 70%. In soil samples, MZB47 caused severe root rotting and induced significant decreases in shoot DW (up to 51%) and root DW (up to 60%) for both beans. It was associated to a decrease in nodule number by 73% and 52% for faba bean and common bean, respectively. Biocontrol assays revealed that the inoculation of RZ9 to MZB47-treated plantlets enhanced shoot DWs (25% and 110%) and root DWs (29% and 67%), in faba bean and common bean, respectively. Moreover, root rotting levels decreased and nodule number increased in treated compared to untreated plantlets. Collected data highlighted the disease severity of F. culmorum and demonstrated the potential of using RZ9 in controlling Fusaria root diseases in beans. Thereby, the current study represents the first report on the biocontrol effectiveness of P. aeruginosa against F. culmorum in beans.


2020 ◽  
Vol 14 (2) ◽  
pp. 178-186
Author(s):  
Lisa Novita Arios ◽  
Dwi Suryanto . ◽  
Kiki Nurtjahja . ◽  
Erman Munir .

Assay on ability of endophytic bacteria isolated from peanut to inhibit Sclerotium sp. growth in peanut seedlings.   A study on assay of ability of endophytic bacteria to inhibit Sclerotium sp. in peanut seedling has been done. The bacteria were isolated from peanut healthy plants, while Sclerotium sp. was isolated from infected peanaut plant. Antagonistic assay was conducted by dual culture method.  In vivo assay of inhibiting Sclerotium sp. was conducted by dipping peanut seed in bacterial solution, and planting the seed in soil:compost (3:1) growing media. Six endophytic bacterial isolates showed to inhibit the growth of Sclerotium sp. in vitro. LN1 seemed to inhibit more of Sclerotium sp., while LN5 showed to inhibit less. Two potential isolates LN1 of gram-negative and LN2 of gram-positive using for further study showed to decrease more of dumping off. It also seemed that the isolates increased the seedling height, number of leaves, and dry weight.


Weed Science ◽  
1989 ◽  
Vol 37 (6) ◽  
pp. 825-829 ◽  
Author(s):  
S. G. Taylor ◽  
D. G. Shilling ◽  
K. H. Quesenberry ◽  
G. R. Chaudhry

Whole plant and tissue culture experiments were conducted to determine the difference in phytotoxicity of 2,4-D and its metabolite, 2,4-DCP, to red clover. At the whole plant level, the mean concentration of 2,4-DCP (10 mM) required to cause 50% growth inhibition (I50) of shoot dry weight was 24 times greater than for 2,4-D (0.42 mM). Using callus tissue, the I50value for 2,4-DCP (0.28 mM) was 22 times greater than for 2,4-D (0.013 mM) based on dry weights. The callus tissue was 36 and 32 times more sensitive to 2,4-DCP and 2,4-D than shoot tissue based on dry weights, respectively. These data indicate that 2,4-DCP was less phytotoxic than 2,4-D to red clover both in vitro and in vivo.


Nematology ◽  
2015 ◽  
Vol 17 (2) ◽  
pp. 203-212 ◽  
Author(s):  
Eoin P. Lettice ◽  
Peter W. Jones

Three bacterial isolates, SB13 (Acinetobacter sp.), SB14 (Arthrobacter sp.) and SB15 (Bacillus sp.), were previously isolated from the rhizosphere of sugar beet (Beta vulgaris ssp. vulgaris) plants and shown to increase hatch of potato cyst nematodes in vitro. In this study, the three isolates were assayed for rhizosphere competence. Each isolate was applied to seeds at each of four concentrations (105-108 CFU ml−1) and the inoculated seeds were planted in plastic microcosms containing coarse sand. All three isolates were shown to colonise the rhizosphere, although to differing degrees, with the higher inoculation densities providing significantly better colonisation. The isolates increased sugar beet root and shoot dry weight. Isolates SB14 and SB15 were analysed for their ability to induce in vivo hatch of Globodera pallida in non-sterile soil planted with sugar beet. After 4 and 6 weeks, both isolates had induced significantly greater percentage hatch compared to controls.


2024 ◽  
Vol 84 ◽  
Author(s):  
G. S. Isaac ◽  
M. M. El-Deriny ◽  
R. G. Taha

Abstract Root-knot nematode Meloidogyne incognita is among the biotic factors which has greatly affected both the yield and the quality of the tomato crop. The egg parasitic nematode, Purpureocillium lilacinum (Pl) is considered as one of the most promising agents in controlling and overcoming this plant pathogen. The nematicidal effect of the native isolate Pl AUMC 10149 on second stage juvenile’s survival and egg hatching of M. incognita at different times of exposure was tested in vitro. The obtained data showed that Pl gave a maximum percentage of J2 mortality (97.6%) and egg hatching inhibition (79.8%) after 72 hours of exposure. The potentiality of Pl as well as Bio-Nematon to control M. incognita infecting tomato was conducted using different times of application in vivo. Nine treatments with five replicates were used for such bioagents compared with the nematicide Oxamyl. Each seedling was inoculated with 1000 J2s of nematode/pot and 10 mL of Pl (1x1010 CFU/mL) or Bio-Nematon spore suspension (1x108 CFU/mL) 10mL/pot. The results indicated that the most effective treatments in reducing nematode population, number of galls and egg masses of M. incognita in plant roots was performed with treatment by Pl pre-planting and post-infection with Pl (Rf 1.9) giving a significant enhancement in plant length (64.9%), fresh weight (72.52%) and shoot dry weight (163.41%) without negatively impacting environment. Therefore, the present study confirmed that using P. lilacinum AUMC 10149 can be used as a practical supplement to environmentally friendly disease management of root-knot nematodes in Egypt.


2020 ◽  
Vol 55 (1) ◽  
pp. 27-34
Author(s):  
G. Zadehdabagh ◽  
K. Karimi ◽  
M. Rezabaigi ◽  
F. Ajamgard

The northern of Khuzestan province in Iran is mainly considered as one of the major areas of miniature rose production. Blossom blight caused by Botrytis cinerea has recently become a serious limiting factor in rose production in pre and post-harvest. In current study, an attempt was made to evaluate the inhibitory potential of some local Trichoderma spp. strains against B. cinerea under in vitro and in vivo conditions. The in vitro results showed that all Trichoderma spp. strains were significantly able to reduce the mycelial growth of the pathogen in dual culture, volatile and non-volatile compounds tests compared with control, with superiority of T. atroviride Tsafi than others. Under in vivo condition, the selected strain of T. atroviride Tsafi had much better performance than T. harzianum IRAN 523C in reduction of disease severity compared with the untreated control. Overall, the findings of this study showed that the application of Trichoderma-based biocontrol agents such as T. atroviride Tsafi can be effective to protect cut rose flowers against blossom blight.


Author(s):  
Mahmoud Ahmed Touny El-Dabaa ◽  
Hassan Abd-El-Khair

Abstract Background Orobanche crenata is an obligate root parasite belonging to Orbanchaceae. Broomrape causes great damage to the faba bean. Several attempts were applied for controlling parasitic weeds. So, the aim of this work is to study the application of Trichoderma spp. as well as three rhizobacteria species in comparison to herbicidal effect of Glyphosate (Glialka 48% WSC) for controlling broomrape infesting faba bean (Vicia faba). Materials and methods Three pot experiments were carried out in the greenhouse of the National Research Centre, Dokki, Giza, Egypt during two successive winter seasons. Trichoderma inocula were adjusted to 3.6 × 108 propagules/ml and the bacterium inocula were adjusted at 107–109 colony-forming unit (CFU)/ml. All treatments were applied, before 1 week of sowing, at rate of 50 ml per pot in experiments I and II, while 100 ml per pot in experiment III. Results Trichoderma spp. (T. harzianum, T. viride and T. vierns) as well as three rhizobacteria species (Pseudomonas fluorescens, Bacillus subtilis and Bacillus pumilus) enhanced the growth parameters in faba bean plants, i.e. shoot length, shoot fresh weight, shoot dry weight and leaf number in the first experiment when applied without O. crenata infection. In the second experiment, all bio-control could protect plants against O. crenata infection, where it had better juvenile number reduction, than glyphosate after 2 months of application. Both B. subtilis and B. pumilus had the highest reduction to juvenile fresh weight, while their effect was equal to herbicide for juvenile dry weight, respectively. The bio-control agents had high effects until the 4th month, but it was less than that of the herbicide. In experiment III, the bio-control agents could highly reduce the juvenile parameters after 2 months, as well as juvenile fresh weight and juvenile dry weight after 4 months, than the herbicide, respectively. The bio-control agents were effective until 6 months, but less than the herbicide effect. All bio-control treatments highly increased the plant growth parameters, than the herbicide. Conclusion The application of Trichoderma spp. as well as rhizobacteria species could play an important role in controlling broomrape in faba bean as a natural bioherbicide.


2014 ◽  
Vol 40 (2) ◽  
pp. 141-146 ◽  
Author(s):  
Zayame Vegette Pinto ◽  
Matheus Aparecido Pereira Cipriano ◽  
Amaury da Silva dos Santos ◽  
Ludwig Heinrich Pfenning ◽  
Flávia Rodrigues Alves Patrício

Bottom rot, caused by Rhizoctonia solani AG 1-IB, is an important disease affecting lettuce in Brazil, where its biological control with Trichoderma was not developed yet. The present study was carried out with the aim of selecting Trichoderma isolates to be used in the control of lettuce bottom rot. Forty-six Trichoderma isolates, obtained with baits containing mycelia of the pathogen, were evaluated in experiments carried out in vitro and in vivo in a greenhouse in two steps. In the laboratory, the isolates were evaluated for their capabilities of parasitizing and producing toxic metabolic substances that could inhibit the pathogen mycelial growth. In the first step of the in vivo experiments, the number and the dry weight of lettuce seedlings of the cultivar White Boston were evaluated. In the second step, 12 isolates that were efficient in the first step and showed rapid growth and abundant sporulation in the laboratory were tested for their capability of controlling bottom rot in two repeated experiments, and had their species identified. The majority of the isolates of Trichoderma spp. (76%) showed high capacity for parasitism and 50% of them produced toxic metabolites capable of inhibiting 60-100% of R. solani AG1-IB mycelial growth. Twenty-four isolates increased the number and 23 isolates increased the dry weight of lettuce seedlings inoculated with the pathogen in the first step of the in vivo experiments.In both experiments of the second step, two isolates of T. virens, IBLF 04 and IBLF 50, reduced the severity of bottom rot and increased the number and the dry weight of lettuce seedlings inoculated with R. solani AG1-IB. These isolates had shown a high capacity for parasitism and production of toxic metabolic substances, indicating that the in vitro and in vivo steps employed in the present study were efficient in selecting antagonists to be used for the control of lettuce bottom rot.


2017 ◽  
Vol 7 (1) ◽  
pp. 10
Author(s):  
Tatsuya Ohike ◽  
Minori Maeda ◽  
Tetsuya Matsukawa ◽  
Masahiro Okanami ◽  
Shin’ichiro Kajiyama ◽  
...  

Rhizoctonia solani is fungal plant pathogen that infects many different host plants. Recently, biological control agents that are friendly to the environment and ecosystems have attracted much attention as an alternative to the use of chemical fungicide which have been used worldwide to control soil borne pathogens including R. solani. In this study, 53 strains of actinomycetes isolated from environmental soils, and antifungal activities of them were assessed by the dual culture assay. Strain KT showed strong inhibitory activities against 8 phytopathogenic fungi. A great suppressive effect on R. solani growth was observed in the inoculation test of plants using cucumber and chin-geng-sai. In addition, infection of Bipolaris oryzae also could be suppressed in the detached leaf assay using oats. As a result of genetic analysis, it was shown that KT was a species closely related to Streptomyces lavenduligriseus NRRL B-3173T. However, as far as we know, there is no report for biological control agents using S. lavenduligriseus. This study suggests that the strain KT may useful as biological control agents to suppress various crop diseases.


2010 ◽  
Vol 76 (21) ◽  
pp. 7217-7225 ◽  
Author(s):  
Daniel P. MacEachran ◽  
M. E. Prophete ◽  
A. J. Sinskey

ABSTRACT Generally, prokaryotes store carbon as polyhydroxyalkanoate, starch, or glycogen. The Gram-positive actinomycete Rhodococcus opacus strain PD630 is noteworthy in that it stores carbon in the form of triacylglycerol (TAG). Several studies have demonstrated that R. opacus PD630 can accumulate up to 76% of its cell dry weight as TAG when grown under nitrogen-limiting conditions. While this process is well studied, the underlying molecular and biochemical mechanisms leading to TAG biosynthesis and subsequent storage are poorly understood. We designed a high-throughput genetic screening to identify genes and their products required for TAG biosynthesis and storage in R. opacus PD630. We identified a gene predicted to encode a putative heparin-binding hemagglutinin homolog, which we have termed tadA (triacylglycerol accumulation deficient), as being important for TAG accumulation. Kinetic studies of TAG accumulation in both the wild-type (WT) and mutant strains demonstrated that the tadA mutant accumulates 30 to 40% less TAG than the parental strain (WT). We observed that lipid bodies formed by the mutant strain were of a different size and shape than those of the WT. Characterization of TadA demonstrated that the protein is capable of binding heparin and of agglutinating purified lipid bodies. Finally, we observed that the TadA protein localizes to lipid bodies in R. opacus PD630 both in vivo and in vitro. Based on these data, we hypothesize that the TadA protein acts to aggregate small lipid bodies, found in cells during early stages of lipid storage, into larger lipid bodies and thus plays a key role in lipid body maturation in R. opacus PD630.


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