scholarly journals On the potential of Bacillus aryabhattai KMT-4 against Meloidogyne javanica

2021 ◽  
Vol 31 (1) ◽  
Author(s):  
Sonam Antil ◽  
Rakesh Kumar ◽  
D. V. Pathak ◽  
Anil Kumar ◽  
Anil Panwar ◽  
...  

Abstract Background Nematodes (Meloidogyne spp.) are a major reason behind the global crop yield reduction. The bacterial strain KMT-4 was isolated from nematode-affected tomato (Solanum lycopersicum) rhizosphere at research farms, Hisar, India, and screened for its biocontrol potential against root-knot nematode Meloidogyne javanica as well as checked for its effect on plant growth and yield. Results The bacterium KMT-4 was identified as Bacillus aryabhattai based on phenotypic characters and 16S rRNA sequence analysis. During in vitro studies, hatching and mortality of M. javanica were significantly affected due to the antagonistic behavior exhibited by the bacterium. In addition to this, KMT-4 also displayed various direct as well as indirect plant growth-promoting attributes like siderophore production, growth hormone (IAA) production, ammonia excretion, hydrogen cyanide production, and chitinase activity. A pot house experiment conducted on brinjal resulted in nearly 73% reduction in eggs, while 80% reduction in galls in the plant root compared to the untreated and chemically treated plants. The final nematode population also reduced significantly in KMT-4 treatment. It was 1141.6 J2/200cc soil in control and reduced to 108 J2/200 cc soil inoculated with KMT-4. Similar results were obtained in field experiments on brinjal and cucumber conducted in years 2018 and 2019, respectively. Also, a notable enhancement in the plant growth was observed in both pot house experiment and field trials. Conclusion The possession of nematicidal activity along with plant growth-promoting properties in B. aryabhattai KMT-4 warrants its employment as a potent biological control agent against M. javanica and a promising substitute of chemical nematicides.

HortScience ◽  
2013 ◽  
Vol 48 (5) ◽  
pp. 563-567 ◽  
Author(s):  
Huseyin Karlidag ◽  
Ertan Yildirim ◽  
Metin Turan ◽  
Mucahit Pehluvan ◽  
Figen Donmez

The effect of selected plant growth-promoting rhizobacteria (PGPR) on the growth, chlorophyll content, nutrient element content, and yield of strawberry plants under natural field salinity conditions stress was investigated. Field experiments were conducted using a randomized complete block design with five PGPRs (Bacillus subtilis EY2, Bacillus atrophaeus EY6, Bacillus spharicus GC subgroup B EY30, Staphylococcus kloosii EY37, and Kocuria erythromyxa EY43) and a control (no PGPR) in 2009 and 2010. PGPR inoculations significantly increased the growth, chlorophyll content, nutrient element content, and yield of strawberry plants. PGPR treatments lowered electrolyte leakage of plants under saline conditions. The leaf relative water content (LRWC) of plants rose with bacterial inoculation. All nutrient element contents of leaves and roots investigated were significantly increased with PGPR inoculations with the exception of sodium (Na) and chlorine (Cl). The highest efficiency to alleviate salinity stress on the yield and nutrient uptake of strawberry plants was obtained from EY43 (228 g per plant) and EY37 (225 g per plant) treatment and the yield increasing ratio of plants was 48% for EY43 and 46% for EY 37 compared with the control treatment (154 g per plant). The highest nitrogen (N), potassium (K), phosphorus (P), calcium (Ca), magnesium (Mg), sulfur (S), manganese (Mn), copper (Cu), and iron (Fe) concentrations were obtained from EY43 and followed by E6, E37, and E30, and increasing ratio of leaves and root N, P, K, Ca, Mg, S, Mn, Cu, and Fe contents were 22% to 33%, 34% to 8.8%, 89% to 11%, 11.0% to 7.2%, 5.1% to 6.2%, 97% to 65%, 120% to 140%, 300% to 15%, and 111% to 9.0%, respectively. The results of the study suggested that PGPR inoculations could alleviate the deleterious effects of salt stress conditions on the growth and yield of strawberry plants under salinity conditions.


Author(s):  
R. Thamizh Vendan ◽  
D. Balachandar

Background: Symbiotic associations between legumes and Rhizobia are ancient and fundamental. However, the plant growth-promoting endophytes other than Rhizobia are not yet fully explored for pulses productivity. The present study was aimed to isolate efficient endophytic bacteria from pulses, assess their diversity, screen their plant growth-promoting activities and to test their potential as bio inoculants for pulses.Methods: We have isolated several endophytic bacteria from pulse crops more specifically from blackgram (Vigna mungo) and greengram (Vigna radiata). After careful screening, 15 promising endophytic isolates were selected for this study. The identification of endophytic bacterial isolates was performed by 16S rRNA gene sequencing. The isolates were tested for their potential for the plant growth-promoting traits such as nitrogen fixation, phosphate solubilization, indole-3-acetic acid production, siderophore secretion and antifungal activity. Pot culture experiments were conducted with the screened potential endophytic cultures.Result: The 16S rRNA gene sequencing revealed that species of Enterobacter, Bacillus, Pantoea, Pseudomonas, Acromobacter, Ocrobacterium were found as endophytes in blackgram and greengram. The in vitro screening identified Bacillus pumilus (BG-E6), Pseudomonas fluorescens (BG-E5) and Bacillus licheniformis (BG-E3) from blackgram and Pseudomonas chlororaphis (GG-E2) and Bacillus thuringiensis (GG-E7) from greengram as potential plant growth-promoting endophytes. These strains showed antagonism against plant pathogenic fungi. Upon inoculation of these endophytic PGPR strains, the blackgram and greengram growth and yield got increased. Among the strains, BG-E6 recorded 14.7% increased yield in blackgram and GG-E2 accounted for a 19.5% yield increase in greengram compared to respective uninoculated control. The experimental results showed that there was a host specificity found among the endophytic bacterial cultures with pulses. The cross inoculation of endophytic strains did not perform well to enhance the growth and yield of their alternate hosts. 


Soil Systems ◽  
2022 ◽  
Vol 6 (1) ◽  
pp. 10
Author(s):  
Anithadevi Kenday Sivaram ◽  
Logeshwaran Panneerselvan ◽  
Kannappar Mukunthan ◽  
Mallavarapu Megharaj

Pyroligneous acid (PA) is often used in agriculture as a plant growth and yield enhancer. However, the influence of PA application on soil microorganisms is not often studied. Therefore, in this study, we investigated the effect of PA (0.01–5% w/w in soil) on the microbial diversity in two different soils. At the end of eight weeks of incubation, soil microbial community dynamics were determined by Illumina-MiSeq sequencing of 16S rRNA gene amplicons. The microbial composition differed between the lower (0.01% and 0.1%) and the higher (1% and 5%) concentration in both PA spiked soils. The lower concentration of PA resulted in higher microbial diversity and dehydrogenase activity (DHA) compared to the un-spiked control and the soil spiked with high PA concentrations. Interestingly, PA-induced plant growth-promoting bacterial (PGPB) genera include Bradyrhizobium, Azospirillum, Pseudomonas, Mesorhizobium, Rhizobium, Herbaspiriluum, Acetobacter, Beijerinckia, and Nitrosomonas at lower concentrations. Additionally, the PICRUSt functional analysis revealed the predominance of metabolism as the functional module’s primary component in both soils spiked with 0.01% and 0.1% PA. Overall, the results elucidated that PA application in soil at lower concentrations promoted soil DHA and microbial enrichment, particularly the PGPB genera, and thus have great implications for improving soil health.


2015 ◽  
Vol 3 (4) ◽  
pp. 609-618 ◽  
Author(s):  
Azza M. Abdel-fattah ◽  
EL-Shahat H. A. Nashy ◽  
El-Tahir A. Sabiel ◽  
Manal M. Hussien ◽  
Ahmed S. Attia

Two field experiments had been conducted in Nubaria sandy soil, Behaira Governate, Egypt to show the effect of keratinase enzyme produced by the novel microbial isolate (Cyberlindnera fabianii NRC3 Aza) on plants.The trials had been conducted in the two successive summer seasons (2011/2012 and 2012/2013) to show the effect of keratinase enzyme from degraded feather–waste on the morphology and chemical composition of peas pods (Pisumsativum L.)–family Fabaceae (Leguminasae). In 2011/2012 season, only the chemical analysis of the dried powdered beads was studied. In 2012/2013 season, the morphological studies of the yield were considered beside the chemical ones. The results depicted significant effects of the sprayed enzyme (keratinase) on peas as plant growth promoting agent (PGPA), compared with the blank (sprayed with water). Electrophoreses and amino acid analysis were carried out for the characterization of the partial pure keratinase enzyme. Int J Appl Sci Biotechnol, Vol 3(4): 609-618


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