Evaluation of the effects of spores and their heat-treated residues from different Bacillus strains on the initial growth of rice plants (original) (raw)
Related papers
Growth and Nutrients Uptake of Rice at Early Seedling Stage as Inoculated with Bacillus SPP
2019
Utilization of plant growth promoting rhizo-bacteria (PGPR) potentially elevates crop productivity. Concurrently, our study was focused on isolating efficient PGPR strains from the rhizosphere of rice plants. This in order to assess its properties under both laboratory and glass house conditions accordingly. Five (5) bacterial isolates were screened out based on sets of qualitative tests. Among the bacterial isolates, UPMRB9 were selected due to higher production of plant growth promoting traits:-1) nitrogen fixation, 2) phosphate and potassium solubilization, 3) indole-3 acetic acid production as well, 4) siderophore and hydrolyzing enzyme production. The isolates were later identified based on 16S rRNA sequence by which known to be Bacillus tequilensis. Subsequently, this potential isolates were inoculated to rice seedlings under control environment (glasshouse conditions). The results amply that seedling biomass was 38.2% (BRR1 dhan67), 38.5% (Putra-1) and 33.9% (MR297) higher in...
Tropical Agricultural Research and Extention, 2024
Sri Lankan rice cultivation has been heavily dependent on the large-scale use of inorganic fertilizers since the introduction of new improved rice varieties to farmers in the 1960s. Excessive use of chemical fertilizers is adverse on human health and the environment. Plant growth-promoting bacteria are recognized as an eco-friendly approach to replace inorganic fertilizer. However, there are a few numbers of reports on efficient biofertilizers for Sri Lankan conditions. Therefore, the objective of this study was to determine the effect of two selected local bacterial isolates (I-I and I-II) under in vitro and greenhouse condition, on commonly grown improved rice varieties in the low country of Sri Lanka. The experiment was carried out in a Completely Randomized Design with three replicates. Bacterial isolates (10 6 colony forming units / millilitre) were inoculated on 2-day old sterile rice seedlings. Sri Lankan improved rice variety Bg 300 inoculated with I-I and I-II reported significant low number of days to flowering (DF) as 74 ±0 and 75±0.11 in contrast to that of control plants (79 ±0.16) and both isolates I-I and I-II significantly increased root length as 10 ±0.4, and 12±0.03 cm respectively, over control plants (7 ±0.2 cm) under in vitro condition. Above experiment was extended under greenhouse condition with three improved rice varieties of Bg 300, Bg 379/2 and At 308 in Faculty of Agriculture, University of Ruhuna, Mapalana, Sri Lanka (in ecological zone WL2 of Low Country Wet Zone) and with Bg 300 in Beliatta, Sri Lanka (in ecological zone IL1b of Low Country Intermediate Zone) under greenhouse condition with four replicates. The bacteria inoculated plants of Bg 379/2 reported significantly lower number of DF of 112.5±0.86 and 114±0.28 in contrast to that of control plants (118.5±1.22). The plants of Bg 300 and Bg 379/2 with I-I, produced the highest number of grains per first panicle (GP) as 134±7.35 and 157±11.2 respectively over those of the control plants of Bg 300 and Bg 379/2 (105.75±6.98 and 132±2.94 respectively). Bacteria inoculation did not affect DF and GP in rice variety At 308 indicating the different responses of variety on inoculation in the experiment at WL2. Bacterial isolate I-I inoculated plants showed significantly higher GP in contrast to control in greenhouse at IL1b. There is a potential for tested bacteria to be developed as a biofertilizer through subsequent field experiments in the future.
Food Control, 2010
A centrifugation-plating method was developed, using amylase and Tween 80 pre-treatment, for detection and enumeration of Bacillus spp. in rice products. The high sensitivity of this method improved detection of a variety of Bacillus species in rice products compared to the spread-plate method. Bacillus spp. were detected in 33 out of 35 raw rice samples with the centrifugation-plating method, but only 13 samples using the spread-plating method, even though 1 mL of a 10 À1 sample dilution was used, to increase sensitivity of the method. Known toxigenic or potentially toxigenic species (Bacillus cereus/Bacillus thuringiensis, Bacillus subtilis, Bacillus licheniformis, and Bacillus pumilus) were those most frequently found in both raw and cooked rice.
Evaluation of rice associated Bacillus spp. against sheath blight and bacterial blight of rice
Journal of Biological Control
Bacterial antagonist, Bacillus spp. cultures were isolated from different places of Kuttanad region. Three effective endophytic Bacillus strains viz., B 15, B 17 and B 33 were tested in the separate field experiments against sheath blight and bacterial blight diseases of rice during Kharif 2017, Rabi 2018-19, Kharif 2019 and Kharif 2020. In the field study, the Bacillus cultures were treated as standard bioagent application methods of seed (10 g/kg), soil (1 kg/acre) and foliar (20 g/litre of water) spraying against the major diseases in rice. The rice associated native Bacillus cultures B 15, B 17 and B 33 were found equally effective for the sheath blight and bacterial blight diseases management. All the three native Bacillus species can be used as potential biopesticides against rice sheath blight and bacterial diseases in Kuttanad region.
Pathogens
Rice (Oryza sativa L.) is a major cereal and staple food crop worldwide, and its growth and production are affected by several fungal and bacterial phytopathogens. Bacterial blight (BB) is one of the world’s most devastating rice diseases, caused by Xanthomonas oryzae pv. oryzae (Xoo). In the current study, Bacillus atrophaeus FA12 and B. cabrialesii FA26 were isolated from the rice rhizosphere and characterized as having broad-range antifungal and antibacterial activities against various phytopathogens, including Xoo. In addition, the selected strains were further evaluated for their potent rice growth promotion and suppression efficacy against BB under greenhouse conditions. The result shows that FA12 and FA26, applied as seed inoculants, significantly enhanced the vigor index of rice seedlings by 78.89% and 108.70%, respectively. Suppression efficacy against BB disease by FA12 and FA26 reached up to 59.74% and 54.70%, respectively, in pot experiments. Furthermore, MALDI-TOF MS an...
Microbiological research, 2018
Rice blast is a severe threat for agricultural production. Plant growth promoting rhizobacteria could be suitable biocontrol agents to reduce the disease incidence. In this study, Bacillus spp. KFP-5, KFP-7, KFP-17 significantly reduced disease severity by 40-52% with grain yield of 3.2-3.9 t hain two rice varieties i.e., basmati super and basmati 385. Bacillus spp. significantly colonized the rice rhizosphere with a cell population of 2.40E+06-5.6E+07CFU. Rice plants treated with antagonistic bacterial suspension followed by challenge inoculation with P. oryzae were found to have higher activities of antioxidant enzymes such as superoxide dismutase (308-266 Ug FW), peroxidase (change in absorbance (ΔA) = 0.20-0.71 min g FW), polyphenol oxidase (ΔA = 0.29-0.58 min g FW) and phenylalanine ammonia lyase (ΔA = 0.32-0.59 min g FW). A consistency in the performance of strains was observed in the consecutive years 2013-2014. These findings suggest that indigenous Bacillus spp. could be a ...
Controlling and Defence-related Mechanisms of Bacillus Strains Against Bacterial Leaf Blight of Rice
Journal of Phytopathology, 2016
Bacillus strains are broadly studied for their beneficial role in plant growth and biological control of plant disease and pest; however, little is known about their underlying mechanisms. In this study, we assessed the controlling and defence-related mechanisms of three Bacillus strains including rice seed-associated strain B. subtilis A15, rhizobacterial strains B. amyloliquefaciens D29 and B. methylotrophicus H8, all of which are against bacterial leaf blight (BLB) caused by Xanthomonas oryzae pv. oryzae. Results indicated that all three strains showed strong biofilm formation ability. The culture filtrates of each strain significantly suppressed the growth and biofilm formation of X. oryzae, while changes in bacterial cell morphology such as cell swell and severe cell wall alterations were observed through the transmission electron microscopy images. PCR analysis revealed that all three strains harbour the antimicrobial-associated genes that are responsible for biosynthesis of bacillomycin, fengycin, iturin and surfactin. Subsequent real-time qPCR analysis revealed the upregulated expression of fenD and srfAA genes in D29 and H8, and fenD and ituC genes in A15 during their in vitro interaction with X. oryzae. It suggests that the antibacterial mechanisms of the three strains may be at least partially associated with their ability to secrete corresponding lipopeptides. Interestingly, the applications of the three strains in greenhouse conditions were found to be effective in controlling the BLB disease, which was achieved through the activation of inducing systemic resistance resulted from the enhanced activities of defence-related enzymes. This is the first report of demonstration of the mode of antibacterial effect of Bacillus strains against X. oryzae. Overall, data from the current study provide valuable information for biological control of BLB disease in rice.
Interactions of rice seedlings with bacteria isolated from rice roots
Australian Journal of Plant Physiology, 1999
The interactions between two groups of rice endophytic bacterial strains and several rice cultivars were investigated. Various strains of Rhizobium leguminosarum bv. trifolii, originally isolated from rice plants grown in Egypt, comprise one group. The second group of bacterial strains was isolated from rice cultivars grown in the Philippines. Inoculation experiments with rice seedlings showed that specific isolates of these rice-associating bacteria could either promote, inhibit, or have no influence on rice plant growth. Furthermore, these growth effects were greatly influenced by the environmental growth conditions used. Studies to examine root colonisation patterns, using Rhizobium strains into which a plasmid expressing the green fluorescent protein has been placed, showed that the bacteria preferentially colonise rice seedling surfaces mainly in clumps. This occurs along grooves on the rice root surface, or at the emerging lateral root zones and at the root tips. However, rhiz...
Controlling and Defence-related Mechanisms of Bacillus Strains Against Bacterial Leaf Blight of Rice
Journal of Phytopathology, 2016
Bacillus strains are broadly studied for their beneficial role in plant growth and biological control of plant disease and pest; however, little is known about their underlying mechanisms. In this study, we assessed the controlling and defence-related mechanisms of three Bacillus strains including rice seed-associated strain B. subtilis A15, rhizobacterial strains B. amyloliquefaciens D29 and B. methylotrophicus H8, all of which are against bacterial leaf blight (BLB) caused by Xanthomonas oryzae pv. oryzae. Results indicated that all three strains showed strong biofilm formation ability. The culture filtrates of each strain significantly suppressed the growth and biofilm formation of X. oryzae, while changes in bacterial cell morphology such as cell swell and severe cell wall alterations were observed through the transmission electron microscopy images. PCR analysis revealed that all three strains harbour the antimicrobial-associated genes that are responsible for biosynthesis of bacillomycin, fengycin, iturin and surfactin. Subsequent real-time qPCR analysis revealed the upregulated expression of fenD and srfAA genes in D29 and H8, and fenD and ituC genes in A15 during their in vitro interaction with X. oryzae. It suggests that the antibacterial mechanisms of the three strains may be at least partially associated with their ability to secrete corresponding lipopeptides. Interestingly, the applications of the three strains in greenhouse conditions were found to be effective in controlling the BLB disease, which was achieved through the activation of inducing systemic resistance resulted from the enhanced activities of defence-related enzymes. This is the first report of demonstration of the mode of antibacterial effect of Bacillus strains against X. oryzae. Overall, data from the current study provide valuable information for biological control of BLB disease in rice.
Microorganisms
Multifarious plant growth-promoting Bacillus strains recovered from rhizospheric soils of the Indo Gangetic plains (IGPs) were identified as Bacillus licheniformis MNNITSR2 and Bacillus velezensis MNNITSR18 based on their biochemical characteristics and 16S rDNA gene analysis. Both strains exhibited the ability to produce IAA, siderophores, ammonia, lytic enzymes, HCN production, and phosphate solubilization capability and strongly inhibited the growth of phytopathogens such as Rhizoctonia solani and Fusariun oxysporum in vitro. In addition, these strains are also able to grow at a high temperature of 50 °C and tolerate up to 10–15% NaCl and 25% PEG 6000. The results of the pot experiment showed that individual seed inoculation and the coinoculation of multifarious plant growth promoting (PGP) Bacillus strains (SR2 and SR18) in rice fields significantly enhanced plant height, root length volume, tiller numbers, dry weight, and yield compared to the untreated control. This indicates ...