Antagonistic Effect of Bacillus spp. against Sugar Beet Pathogens Fusarium Wilt

2017 ◽  
Vol 8 (6) ◽  
pp. 177-181
Author(s):  
Samia Bayoumy ◽  
Aida Afify ◽  
A. El-Sayed ◽  
Samar Elshal
Nematology ◽  
2004 ◽  
Vol 6 (3) ◽  
pp. 375-387 ◽  
Author(s):  
N. Aileen Ryan ◽  
Peter Jones

AbstractSeventy bacteria, isolated from the rhizosphere of the potato cyst nematode (PCN) host plant, potato, were cultured in the presence and absence of potato root leachate (PRL) and the resultant culture filtrates were analysed for their ability to affect the hatch in vitro of the two PCN species. Of the isolates tested, nine had a significant effect on PCN hatch. Six affected Globodera pallida hatch and three affected G. rostochiensis hatch. Five of the isolates significantly increased hatch only when cultured in the presence of PRL. Three of the isolates decreased PCN hatch significantly in PRL. Only one isolate increased hatch significantly in the absence of PRL. No isolate affected the hatch of both species. Six of the nine isolates that significantly affected PCN hatch had been pre-selected by culturing on PRL. Bacterial isolates from PCN non-hosts (14 from wheat, 17 from sugar beet) were also tested for hatching activity. The principal effect of the hatch-active isolates from the PCN non-host plants was to increase PCN hatch in the presence of PRL. In contrast to the host bacteria results, the isolates from non-host plants affected only G. rostochiensis hatch (three wheat isolates and four sugar beet isolates significantly increased G. rostochiensis hatch); no such isolate affected G. pallida hatch significantly in the presence of PRL. Ten isolates (32%) from non-host plants had the ability to increase significantly the hatch of PCN in the absence of PRL (eight of these affected G. rostochiensis hatch and four affected G. pallida hatch), compared to only one bacterial isolate (1%) from a host plant. The majority of the isolates from non-hosts produced PCN species-specific effects, as with the bacteria isolated from potatoes, although two wheat isolates increased the hatch of both species significantly in the absence of PRL. Of 20 hatch-active bacterial isolates (from all three plants) identified, 70% were Bacillus spp. Other genera identified were Arthrobacter , Acinetobacter and Staphylococcus .


2019 ◽  
Vol 65 (1) ◽  
pp. 45-58 ◽  
Author(s):  
Qingrong Li ◽  
Sentai Liao ◽  
Huyu Zhi ◽  
Dongxu Xing ◽  
Yang Xiao ◽  
...  

Fusarium wilt is a devastating soil-borne disease caused mainly by highly host-specific formae speciales of Fusarium oxysporum. Antagonistic microorganisms play a very important role in Fusarium wilt control, and the isolation of potential biocontrol strains is becoming more and more important. We isolated a bacterial strain (SEM-9) from the high-temperature stage of silkworm excrement composting, which had a marked ability to solubilize phosphorus, promote the growth and increase the yield of the small Chinese cabbage, and which also exhibited considerable antagonistic effect towards Fusarium sambucinum and other fungi. The result of physiological and biochemical analyses, as well as genome sequencing, showed that SEM-9 was a strain of Bacillus subtilis. Through genome annotation and analysis, it was found that SEM-9 contained genes related to the regulation of biofilm formation, which may play an important role in colonization, and gene clusters encoding the biosynthesis of antimicrobials, such as surfactin, bacilysin, fengycin, and subtilosin-A. The production of such antifungal compounds may constitute the basis of the mode-of-action of SEM-9 against Fusarium spp. These data suggested that the SEM-9 strain has potential as both a biofertilizer and a biocontrol agent, with the potential to manage Fusarium wilt disease in crops.


2017 ◽  
pp. 261-269 ◽  
Author(s):  
Dragana Bjelic ◽  
Maja Ignjatov ◽  
Jelena Marinkovic ◽  
Nemanja Spremo ◽  
Maja Karaman ◽  
...  

Biocontrol using plant growth-promoting rhizobacteria (PGPR) represents an alternative approach to disease management, since PGPR are known to promote growth and reduce diseases in various crops. Among the different PGPR, members of the genus Bacillus are prefered for most biotechnological uses due to their capability to form extremely resistant spores and produce a wide variety of metabolites with antimicrobial activity. The objective of this research was to identify antagonistic bacteria for management of the plant diseases. Eleven isolates of Bacillus spp. were obtained from the soil samples collected from different localities in the Province of Vojvodina. The antifungal activity of bacterial isolates against five fungal species was examined using a dual plate assay. Bacillus isolates exhibited the highest antifungal activity against Fusarium proliferatum, Fusarium oxysporum f. sp. cepae and Alternaria padwickii, while they had the least antagonistic effect on Fusarium verticillioides and Fusarium graminearum. Molecular identification showed that effective bacterial isolates were identified as Bacillus safensis (B2), Bacillus pumilus (B3, B11), Bacillus subtilis (B5, B7) and Bacillus megaterium (B8, B9). The highest antagonistic activity was exhibited by isolates B5 (from 39% to 62% reduction in fungal growth) and B7 (from 40% to 71% reduction in fungal growth). These isolates of B. subtilis could be used as potential biocontrol agents of plant diseases.


2017 ◽  
Vol 8 (11) ◽  
pp. 271-275
Author(s):  
Aida Afify ◽  
Samia Bayoumy ◽  
A. El-Sayed ◽  
Samar Elshal

2018 ◽  
Vol 33 (1) ◽  
pp. 9-18 ◽  
Author(s):  
Svetlana Milijasevic-Marcic ◽  
Vesna Todorovic ◽  
Olja Stanojevic ◽  
Tanja Beric ◽  
Slavisa Stankovic ◽  
...  

In vitro antagonistic potential of eleven isolates of Bacillus spp. against two phytopathogenic bacteria and one fungus was tested in order to identify potential biocontrol agents in vegetable crops. The Bacillus spp. isolates demonstrated different levels of antagonistic effect against the tested pathogenic microorganisms. Data in the study proved Xanthomonas vesicatoria to be more sensitive to Bacillus spp. strains than Clavibacter michiganensis subsp. michiganensis. Ten B. subtilis strains induced growth inhibition of X. vesicatoria, while a strain of B. pumilus did not affect the growth of that bacterium. The largest inhibition zones against X. vesicatoria were induced by strains B-319, B-325 and B-358. The pathogenic strain C. michiganensis subsp. michiganensis was most inhibited by two B. subtilis strains (B-338 and B-348) with mean inhibition zone diameters of up to 20 mm. B. subtilis strain B-319 which was the best in inhibiting X. vesicatoria, showed the lowest inhibitory effect on C. michiganensis subsp. michiganensis. The largest growth inhibition percentage of Verticillium sp. (PGI approximately 70%) was induced by B. subtilis strains B-310 and B-322. The other B. subtilis strains showed PGI values ranging from 45% to 68%, while B. pumilus strain B-335 had the least antagonistic potential (PGI =34.43%) against the pathogen. This study identified at least one suitable biocontrol candidate, B. subtilis strain B-358, as effective in vitro against all three vegetable pathogens.


2021 ◽  
Vol 21 (no 1) ◽  
Author(s):  
K. Vignesh ◽  
K. Rajamohan ◽  
P. Balabaskar ◽  
R. Anandan

Tomato (Solanum lycopersicum L.) is one of the most important, commercial and widely grown vegetable crop in the world. Tomato plays a critical role in nutritional food requirements, income and employment opportunities for the people. However, its production is threatened by the Fusarium wilt caused by Fusarium oxysporum f.sp. lycopersici and production losses between 30%to40%. In the present investigation an attempt has been made to study the in vitro efficacy of Pseudomonas fluorescens against Fusarium oxysporum f.sp. lycopersici. The antagonistic effect of Pseudomonas fluorescens were observed by the Dual culture technique and Agarwell method under the in vitro conditions.Among the ten isolates of Pseudomonas fluorescens, isolate Pf5 found to show the maximum percent inhibition over control (58.75%) and least mycelial growth (37.12mm) in dual culture technique against Fusarium oxysporum f.sp. lycopersici. In Agar well method isolate Pf5 proved out the maximum inhibition zone (17.47mm)against Fusarium oxysporumf.sp. lycopersici and percent inhibition over control (80.97%) at 30% concentration level.


2017 ◽  
Vol 63 (No. 6) ◽  
pp. 277-281
Author(s):  
Patkowska Elżbieta ◽  
Błażewicz-Woźniak Marzena ◽  
Wach Dariusz

The purpose of the present studies was to determine the antagonistic effect of bacteria Bacillus spp. and Pseudomonas spp. towards selected fungi from the soil environment of carrot. Oats (Avena sativa L.), tansy phacelia (Phacelia tanacetifolia Bentham) and vetch (Vicia satica L.) were used as cover crops in the cultivation of this plant. In the traditional cultivation of carrot the population of bacteria was the smallest, while after the application of oats it was the largest. Laboratory tests showed that cover crops promoted the development of antagonistic Bacillus spp. and Pseudomonas spp. Irrespective of the experimental treatment, those bacteria were the most effective in limiting the growth and development of Fusarium oxysporum and Thanatephorus cucumeris (syn. Rhizoctonia solani), while being less effective towards Altenaria dauci and Alternaria radicina, and the least towards Sclerotinia sclerotiorum. The best total antagonistic effect of Pseudomonas spp. and Bacillus spp. towards the tested fungi was found after using oats and vetch, while the worst – in the traditional cultivation of carrot.


Author(s):  
Anju Sehrawat ◽  
Aakanksha Khandelwal ◽  
Satyavir Singh Sindhu

Mesorhizobium sp. indirectly promote the growth of plants as a biocontrol agent by inhibiting the growth of pathogens particularly Fusarium wilt of chickpea. Out of 24 Mesorhizobium isolates obtained from chickpea nodules, eight isolates showed antagonistic effect against Fusarium oxysporum. Salinity stress severely affects growth, nodulation and yield of chickpea. Mesorhizobium isolates were tested for their salt tolerance capacity at 1, 2, 4, 6 and 8% NaCl concentrations. Only two Mesorhizobium isolates MCA5 and MCA22 were found salt-tolerant upto 8% of salt concentration. Maximum increase (45.5%) in shoot dry weight was observed by inoculation of isolate MCA20 at 40 days of chickpea growth under chillum jar conditions, whereas isolate MCA23 resulted in 166.2% increase in root dry weight. Likewise, 112.6% increase in shoot dry weight was observed on inoculation of MCA14 isolate at 80th day of observation. Further extensive research is required to understand the mechanism of potential Mesorhizobium isolates of chickpea in controlling Fusarium wilt disease and salt tolerance. Selection of mesorhizobia with twin functional traits (plant growth promoting and biocontrol agent) can be exploited as future biofertilizer in chickpea.


2020 ◽  
Vol 66 (6) ◽  
pp. 401-412
Author(s):  
Qingrong Li ◽  
Sentai Liao ◽  
Junhong Wei ◽  
Dongxu Xing ◽  
Yang Xiao ◽  
...  

Fusarium wilt is a devastating soil-borne disease mainly caused by highly host-specific formae speciales of Fusarium spp. Antagonistic microorganisms play a very important role in Fusarium wilt control. Isolation of potential biocontrol strains has become increasingly important. Bacterial strain SEM-2 was isolated from the high-temperature stage of silkworm excrement composting. SEM-2 exhibited a considerable antagonistic effect against Fusarium graminearum mycelial growth and spore germination. The results of pot experiments suggested that SEM-2 has a better inhibitory effect on the early stage of disease occurrence. The green fluorescent protein labelled SEM-2 coated on the surface of tomato seeds colonised the roots of tomato plants in 15 days. Genome sequencing identified SEM-2 as a new strain of Bacillus subtilis, and genome annotation and analysis determined gene clusters related to the biosynthesis of antimicrobials, such as bacillaene, fengycin, bacillibactin, subtilosin A, surfactin, and bacilysin. Interestingly, liquid chromatography – quadrupole time-of-flight mass spectrometry revealed that metabolites in pathways associated with the synthesis of secondary metabolites and antibiotics were highly differentially expressed. These findings may help to explain the mode of action of B. subtilis SEM-2 against Fusarium spp.


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