scholarly journals Plant Growth Promotion and Biocontrol Properties of Aneurinibacillus migulanus Isolated from Maize Roots (Zea mays)

Author(s):  
Lynda Kelvin Asogwa ◽  
Frank C. Ogbo

Aims: To isolate Plant Growth Promoting Bacillus strain from maize roots, to evaluate its biocontrol potentials and to characterize the isolate using16S rRNA sequencing. Place and Duration of Study: Department of Applied Microbiology and Brewing, Nnamdi Azikiwe University, Awka, between February 2019 and March 2020. Methodology: The isolation of Plant Growth Promoting Rhizobacteria (PGPR) from maize roots was done using Pikovskaya (PVK) agar. Quantitative determination of phosphate was carried out using PVK broth. Evaluations of other plant growth promoting properties were carried out such as IAA, etc. Fusarium and Enterobacter plant pathogens were isolated from diseased maize plants. The in vitro antagonism effects of the PGPR isolates against the pathogens were analyzed using the dual culture plate technique. The pot experiment was carried out in a completely randomized design. Plant characteristics such as plant height, shoot  and root weight, chlorophyll content, as well as disease assessment were recorded accordingly. The organisms were identified using phenotypic and molecular methods. Results: Seven PGPR bacteria were isolated from maize (Zea mays) roots using PVK agar. Aneurinibacillus migulanus gave the highest solubilization index of 4.21 while isolate IS48 gave the lowest solubilization index of 1.47. A. migulanus produced IAA, ammonia and cellulase enzyme but no hydrogen cyanide. The organism showed antagonism activity against the two tested phytopathogens. In the pot experiment, A. migulanus treated plants showed a statistically insignificant difference in maize plant height at P=0.05 but gave significant increases in shoot and root wet weights. The organism offered 83.33% and 71.43% protection against Enterobacter and Fusarium pathogens respectively in the pot experiment. Conclusion: A. migulanus solubilized phosphate in addition to other plant growth promoting  properties. It showed biocontrol potentials both in vitro and in vivo and thus can be used as substitute for synthetic agrochemicals.

2021 ◽  
Vol 12 ◽  
Author(s):  
Mingma Thundu Sherpa ◽  
Laxuman Sharma ◽  
Niladri Bag ◽  
Sayak Das

Eight rhizospheric bacteria were isolated from the organic paddy fields of Sikkim, India, and identified as Pseudomonas kribbensis KSB, Burkholderia cenocepacia SRD, Kosakonia oryzendophytica YMA7, Pseudomonas rhodesiae SRB, Bacillus sp. ARA, Paenibacillus polymyxa COW3, Bacillus aryabhattai PSB2, and Bacillus megaterium PSB1. They showed plant growth-promoting attributes in rice and have bio-control potential against phytopathogen Colletotrichum gloeosporioides of large cardamom (Amomum subulatum). Burkholderia cenocepacia SRD showed production of indole acetic acid and ammonia and solubilization of phosphate and potassium and also possessed nitrogen fixation potential. It showed antagonistic activity against two other plant pathogens of large cardamom, viz., Curvularia eragrostidis and Pestalotiopsis sp., under in vitro conditions. The liquid bacterial consortium was prepared using the bacterial strains SRB, PSB1, and COW3 (Consortia-1); PSB2, SRD, and COW3 (Consortia-2); and COW3, KSB, and YMA7 (Consortia-3) to increase the growth and yield of rice plants under organic farming conditions. Greenhouse and field studies showed that the Consortia-3 had the highest plant growth-promoting activity. Consortia-3 demonstrated better agronomic performance in terms of root length (9.5 cm),number of leaflets per plant (5.3), grains per panicle (110.6), test grain weight (27.4 g), dry root weight per plant (0.73 g), and total dry biomass per plant (8.26 g).


2017 ◽  
Vol 57 (2) ◽  
pp. 144-151 ◽  
Author(s):  
Arun Karnwal

AbstractThe use of plant growth promoting rhizobacteria is increasing in agriculture and gives an appealing manner to replace chemical fertilizers, pesticides, and dietary supplements. The objective of our research was to access the plant growth promotion traits ofPseudomonas aeruginosa,P. fluorescensandBacillus subtilisisolated from the maize (Zea maysL.) rhizosphere.In vitrostudies showed that isolates have the potential to produce indole acetic acid (IAA), hydrogen cyanide, phosphate solubilisation, and siderophore. RNA analysis revealed that two isolates were 97% identical toP. aeruginosastrain DSM 50071 andP. aeruginosastrain NBRC 12689 (AK20 and AK31), while two others were 98% identical toP. fluorescensstrain ATCC 13525,P. fluorescensstrain IAM 12022 (AK18 and AK45) and one other was 99% identical toB. subtilisstrain NCDO 1769 (AK38). Our gnotobiotic study showed significant differences in plant growth variables under control and inoculated conditions. In the present research, it was observed that the isolated strains had good plant growth promoting effects on rice.


Plants ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 2436
Author(s):  
Marika Pellegrini ◽  
Claudia Ercole ◽  
Carmelo Gianchino ◽  
Matteo Bernardi ◽  
Loretta Pace ◽  
...  

Industrial hemp (Cannabis sativa L.) is a multipurpose plant used in several fields. Several phytopathogens attack hemp crops. Fusarium oxysporum is a common fungal pathogen that causes wilt disease in nurseries and in field cultivation and causes high losses. In the present study, a pathogenic strain belonging to F. oxysporum f. sp. cannabis was isolated from a plant showing Fusarium wilt. After isolation, identification was conducted based on morphological and molecular characterizations and pathogenicity tests. Selected plant growth-promoting bacteria with interesting biocontrol properties—Azospirillum brasilense, Gluconacetobacter diazotrophicus, Herbaspirillum seropedicae and Burkholderia ambifaria—were tested against this pathogen. In vitro antagonistic activity was determined by the dual culture method. Effective strains (in vitro inhibition > of 50%) G. diazotrophicus, H. seropedicae and B. ambifaria were combined in a consortium and screened for in planta antagonistic activity in pre-emergence (before germination) and post-emergence (after germination). The consortium counteracted Fusarium infection both in pre-emergence and post-emergence. Our preliminary results show that the selected consortium could be further investigated as an effective biocontrol agent for the management of this pathogen.


2018 ◽  
Vol 3 (1) ◽  
pp. 264-272 ◽  
Author(s):  
Irda Safni ◽  
Widya Antastia

Abstract Plant Growth Promoting Rhizobacteria (PGPR) influence plant growth by a number of direct (producing plant growth promoting substances) and indirect (through prevention of deleterious effects of phytopathogenic microorganisms) mechanisms. Five species of bacteria were isolated from rhizospheric soils of soybean and peanut fields from several locations in North Sumatra. On the basis of morphological and biochemical characteristics, the bacteria were identified as Aeromonas hydrophila, Burkholderia cepacia, Serratia ficaria, Pantoea spp. 2, and Vibrio alginolyticus. These species were tested in vitro against the causal pathogen of collar rot disease of soybean, Athelia rolfsii, which is an important soybean disease in Indonesia. The five species of bacteria were subjected to screening of antagonistic activities against A. rolfsii in vitro with a dual culture-technique. Of the five species, B. cepacia, S. ficaria and V. alginolyticus were the most effective antagonistic bacteria to control A. rolfsii. B. cepacia, S. ficaria and V. algynolitycus produced inhibiting zones against A. rolfsii of 98.35%, 97.83% and 96.97% respectively. All bacterial species showed their antagonistic activity significantly with the inhibiting zone percentage being more than 60%. The experimental results suggested that all bacterial species have a future potency as a biocontrol agent to reduce A. rolfsii collar rot disease of soybean


2020 ◽  
Vol 367 (13) ◽  
Author(s):  
Marika Pellegrini ◽  
Claudia Ercole ◽  
Chiara Di Zio ◽  
Federica Matteucci ◽  
Loretta Pace ◽  
...  

ABSTRACT Potatoes (Solanum tuberosum L.) and tomatoes (Solanum lycopersicum L.), among the main crops belonging to the Solanaceae family, are attacked by several pathogens. Among them Fusarium oxysporum f. sp. radicis-lycopersici and Rhizoctonia solani are very common and cause significant losses. Four plant growth-promoting rhizobacteria, Azospirillum brasilense, Gluconacetobacter diazotrophicus, Herbaspirillum seropedicae and Burkholderia ambifaria were tested against these pathogens. In vitro antagonistic activities of single strains were assessed through dual culture plates. Strains showing antagonistic activity (G. diazotrophicus, H. seropedicae and B. ambifaria) were combined and, after an in vitro confirmation, the consortium was applied on S. lycopersicum and S. tuberosum in a greenhouse pot experiment. The bioprotection was assessed in pre-emergence (infection before germination) and post-emergence (infection after germination). The consortium was able to successfully counteract the infection of both F. oxysporum and R. solani, allowing a regular development of plants. The biocontrol of the fungal pathogens was highlighted both in pre-emergence and post-emergence conditions. This selected consortium could be a valid alternative to agrochemicals and could be exploited as biocontrol agent to counteract losses due to these pathogenic fungi.


2019 ◽  
pp. 1-7 ◽  
Author(s):  
M. Ravi Teja ◽  
K. Vijay Krishna Kumar ◽  
H. Sudini

Aflatoxin contamination is a qualitative problem in groundnut (Arachis hypogaea L.) occurring at both pre-and post-harvest stages. These aflatoxins are secondary metabolites produced by Aspergillus flavus and A. parasiticus and have carcinogenic, hepatotoxic, teratogenic and immuno-suppressive effects. Use of plant growth-promoting rhizobacteria (PGPR) is a viable and sustainable option in managing aflatoxin problem in groundnut. Our present study is aimed at identifying a plant growth-promoting rhizobacteria (PGPR) strain with superior antagonistic abilities on A. flavus infection, aflatoxin contamination and to determine its mode of action. Ten native P. fluorescens isolates were isolated from groundnut rhizosphere and screened against A. flavus by dual culture and in vitro seed colonization (IVSC) assays. In dual culture and IVSC studies, Pf7 exhibited higher degree of antagonism on A. flavus (54% inhibition), inhibited its colonization and reduced aflatoxin contamination (27.8 µg kg-1) in kernels.


Author(s):  
Peguy Flora Djuidje Kouomou ◽  
Cécile Annie Ewane ◽  
Sylvain Lerat ◽  
Denis Omokolo Ndoumou ◽  
Carole Beaulieu ◽  
...  

The focus of this study was to isolate, evaluate and characterize cocoyam rhizospheric actinobacteria collected from Mount Cameroon for their potential antagonistic activities against Pythium myriotylum, the causative agent of cocoyam root rot disease, and/or their ability to promote plant growth. Actinobacteria were isolated from soil samples by using serial dilution method. Dual culture assay was used to screen the isolates against fungal phytopathogens including P. myriotylum. The selected isolates were characterized morphologically, physiologically, biochemically and genetically. Furthermore, these isolates were subjected to in vitro production of various plant growth promoting (PGP) traits. Among the 287 isolates distributed into 12 distinct groups, PFK4, PFBOT7 and PFEL2 had high antagonistic effects against P. myriotylum and they were regarded as promising candidates for further study of their biocontrol ability. The identification of actinobacterial isolates was done using universal PCR of partial 16S rRNA sequences combined with bioinformatics and phylogenetic procedures. The results revealed that all these isolates belong to the genus Streptomyces spp. The isolate PFK4 showed 99% similarity with Streptomyces albulus while PFBOT7 showed 99% similarity with Streptomyces albus and PFEL2 showed 98% similarity with Streptomyces gandoceansis based on their 16S rRNA gene sequences. In this study for the first time, we report S. gandocaensis strain for the biological control of Pythium myriotylum. The role of these isolates in Plant Growth Promotion (PGP) by in vitro production of PGP traits such as phosphate solubilisation, siderophore, indole-3-acetic acid (IAA), ACC deaminase and cell wall degrading enzymes production were also evaluated and showed as potential PGP agents. Concurrent production of PGP substances coupled with broad spectrum of antifungal and antibacterial activities of these three strains suggest their potential use as promising biocontrol and PGP tools for the development of an alternative control method for cocoyam cultivation.


2021 ◽  
Vol 12 ◽  
Author(s):  
Claudia Petrillo ◽  
Stefany Castaldi ◽  
Mariamichela Lanzilli ◽  
Matteo Selci ◽  
Angelina Cordone ◽  
...  

Massive application of chemical fertilizers and pesticides has been the main strategy used to cope with the rising crop demands in the last decades. The indiscriminate use of chemicals while providing a temporary solution to food demand has led to a decrease in crop productivity and an increase in the environmental impact of modern agriculture. A sustainable alternative to the use of agrochemicals is the use of microorganisms naturally capable of enhancing plant growth and protecting crops from pests known as Plant-Growth-Promoting Bacteria (PGPB). Aim of the present study was to isolate and characterize PGPB from salt-pans sand samples with activities associated to plant fitness increase. To survive high salinity, salt-tolerant microbes produce a broad range of compounds with heterogeneous biological activities that are potentially beneficial for plant growth. A total of 20 halophilic spore-forming bacteria have been screened in vitro for phyto-beneficial traits and compared with other two members of Bacillus genus recently isolated from the rhizosphere of the same collection site and characterized as potential biocontrol agents. Whole-genome analysis on seven selected strains confirmed the presence of numerous gene clusters with PGP and biocontrol functions and of novel secondary-metabolite biosynthetic genes, which could exert beneficial impacts on plant growth and protection. The predicted biocontrol potential was confirmed in dual culture assays against several phytopathogenic fungi and bacteria. Interestingly, the presence of predicted gene clusters with known biocontrol functions in some of the isolates was not predictive of the in vitro results, supporting the need of combining laboratory assays and genome mining in PGPB identification for future applications.


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