Effects of calcium carbonate on the survival of Ralstonia solanacearum in soil and control of tobacco bacterial wilt

The bacterial wilt pathogen, first known as Bacillus solanacearum, has undergone numerous taxonomic changes since its first description in 1896. The history and significance of this pathogen is covered in this review with an emphasis on the advances in technology that were used to support each reclassification that finally led to the current separation of Ralstonia solanacearum into three genomic species. Frequent name changes occurred as methodology transitioned from phenotypic, biochemical, and molecular studies, to genomics and functional genomics. The diversity, wide host range, and geographical distribution of the bacterial wilt pathogen resulted in its division into three species as genomic analyses elucidated phylogenetic relationships among strains. Current advances in phylogenetics and functional genomics now open new avenues for research into epidemiology and control of the devastating bacterial wilt disease.

Download Full-text

Taxonomy and Phylogenetic Research on Ralstonia solanacearum: A Complex Pathogen with Extraordinary Economic Consequences

10.20944/preprints202009.0182.v1 ◽

2020 ◽

Author(s):

Sujan Paudel ◽

Shefali Dobhal ◽

Anne M. Alvarez ◽

Mohammad Arif

Keyword(s):

Functional Genomics ◽

Bacterial Wilt ◽

Ralstonia Solanacearum ◽

Wilt Disease ◽

Economic Consequences ◽

Bacterial Wilt Disease ◽

Genomic Analyses ◽

Taxonomic Changes ◽

And Control ◽

Name Changes

The bacterial wilt pathogen, first known as Bacillus solanacearum, has undergone numerous taxonomic changes since its first description in 1896. The history and significance of this pathogen is covered in this review with an emphasis on the advances in technology that were used to support each reclassification that finally led to the current separation of Ralstonia solanacearum into three genomic species. Frequent name changes occurred as methodology transitioned from phenotypic, biochemical, and molecular studies, to genomics and functional genomics. The diversity, wide host range and geographical distribution of R. solanacearum has resulted in its inclusion in a “species complex” as genomic analyses of elucidated phylogenetic relationships among strains. Current advances in phylogenetics and functional genomics now open new avenues for research into the epidemiology and control of the devastating bacterial wilt disease.

Download Full-text

Indigenous Bacillus spp. ability to growth promoting activities and control bacterial wilt disease (Ralstonia solanacearum)

Biodiversitas Journal of Biological Diversity ◽

10.13057/biodiv/d180434 ◽

2017 ◽

Vol 18 (4) ◽

pp. 1562-1567

Author(s):

YULMIRA YANTI ◽

TRIMURTI HABAZAR ◽

REFLINALDON REFLINALDON ◽

CHAINUR RAHMAN NASUTION ◽

SRIMANO FELIA

Keyword(s):

Bacterial Wilt ◽

Ralstonia Solanacearum ◽

Wilt Disease ◽

Subtilis Strain ◽

Bacillus Sp ◽

Bacterial Wilt Disease ◽

Bacillus Spp ◽

Growth Promoting ◽

And Control

Yanti Y, Habazar T, Reflinaldon, Nasution CR, Felia S. 2017. Indigenous Bacillus spp. ability to growth promoting activities and control bacterial wilt disease (Ralstonia solanacearum). Biodiversitas 18: 1562-1567. Among the species of Plant Growth Promoting Rhizobacteria, Bacillus spp. has been found to provide beneficial effects to different plant species. Based on our previous research from in planta screeningâ€™s method, we found six indigenous strains of Bacillus spp., which had the ability to control bacterial wilt and increased growth and yields of chili. Those were Bacillus subtilis BSn5,q Bacillus sp. RD-AZPVI-03, Bacillus sp. Y81-1, B.cereus strain C38/15, B.cereus strain APSB-03, and B. subtilis strain CIFT-MFB-4158A. This research aimed to characterize the mechanism of selected Bacillus spp. as biocontrol agents of R. solanacearum and as biofertilizer of chili in vitro. We have observed the biocontrol characters (production of HCN, siderophore, biosurfactant, protease, root colonization, and antibiotic), and biofertilizerâ€™s characters (production of Indole Acetic Acid (IAA), ammonia and phosphate solubilization) of Bacillus spp. All strains had ability to produce variable concentrations of IAA, B.subtilis strain CIFT-MFB-4158A can produce siderophore, all isolates cannot produce HCN and biosurfactant, 4 isolates can produce protease. Based on the ability to colonize roots, B.subtilis strain CIFT-MFB-4158A had the best ability to colonize root surface (4.17 x 105 CFU/g root), while B. subtilis BSn5 had the best ability to colonize internal roots (2.08 x 105 CFU/g), and 2 Bacillus strains can suppress R. solanacearum in vitro.

Download Full-text

Control of Ralstonia solanacearum on Selected Solaneceous Crops in Greenhouse by Selected Soil Amendments

Journal of Agriculture and Ecology Research International ◽

10.9734/jaeri/2019/v19i230081 ◽

2019 ◽

pp. 1-12

Author(s):

E. K. Kago ◽

Z. M. Kinyua ◽

J. M. Maingi ◽

P. O. Okemo

Keyword(s):

Bacterial Wilt ◽

Ralstonia Solanacearum ◽

Soil Amendments ◽

Block Design ◽

Orange Peel ◽

Bacterial Isolates ◽

Randomized Complete Block Design ◽

And Control ◽

Split Pot ◽

Metham Sodium

Aims: The aim of this study was to establish the effect of selected soil amendments on Ralstonia solanacearum isolates in greenhouse on selected solaneceous crops. Study Design: The study was laid out as randomized complete block design (RCBD) in split pot arrangement for two seasons in the greenhouse. Place and Duration of Study: The experiment was carried out in Kenyattta University situated in Kiambu County about 20 km from Nairobi city along Nairobi-Thika road between July, 2017- September, 2017 and between November, 2017- January, 2018. Methodology: The three host crops of interest (potatoes, tomatoes and capsicum) were inoculated with prepared pure bacterial isolates; 18 (2T-Kiambu-Low Land), 71(2A-Nyeri-Low Land), 67 (2A-Nyeri-High Land), 83 (2T-Kirinyaga-Highland) and MX (18/71/67/83). Potatoes, tomatoes and capsicum were planted in pots each with a radius of 0.07 m (area 0.015 m2).The experiment had a total of 450 pots having a total area of 6.93 m2. The treatments were ChalimTM, Super-hydro-grow polymer + Metham sodium, Metham sodium, Metham sodium & Orange peel, Super-hydro-grow polymer, Brassica tissues, ChalimTM + Super-hydro-grow polymer, Brassica tissue + Orange peel, Metham sodium + Super-hydro-grow polymer and Control (no amendments). Results: There were significant differences (P≤0.05) in the bacterial wilt incidences in selected solaneceous crops between control and all the soil amendments used in season 1 and 2. Brassica tissue + Super-hydro-grow polymer was superior in reducing bacterial wilt incidences in selected solaneceous crops in all the R. solanacearum isolates from Kenyan highlands and lowlands both in season 1 and 2. Conclusion: Organic and inorganic soil amendments could serve as a viable control of bacterial wilt in solaneceous crops caused by R. solanacearum in the greenhouse.

Download Full-text

Distributional variability of bacterial wilt of chili incited by Ralstonia solanacearum in eight agro-ecological zones of Pakistan

10.7287/peerj.preprints.26668v1 ◽

2018 ◽

Author(s):

Muhammad N Aslam ◽

Tariq Mukhtar

Keyword(s):

Bacterial Wilt ◽

Ralstonia Solanacearum ◽

Disease Incidence ◽

Control Measures ◽

Yield Losses ◽

Ecological Zones ◽

Sindh Province ◽

Indus Delta ◽

And Control ◽

Agro Ecological Zones

Background. Bacterial wilt caused by Ralstonia solanacearum is one of the major constraints in the production of chilies in Pakistan. As the information regarding distribution and prevalence of R. solanacearum is exiguous, the present studies were conducted during 2014-15 to determine the incidence and prevalence of R. solanacearum in the major chili growing areas from different agro-ecological zones of Pakistan. Results. The overall incidence and prevalence of R. solanacearum in the country was found to be 10% and 76% respectively. Of the four provinces, maximum disease incidence of 16.4% was recorded in Sindh province followed by Punjab and Khyber Pakhtoonkhwa showing 11.4% and 7% disease incidences respectively and the minimum incidence of 4.9% was observed in the province of Baluchistan. As regards prevalence, the same pattern was observed. Out of 8 agro-ecological zones the maximum disease incidence of 19.5% was observed in Indus delta followed by Sandy deserts (14.1%) while the minimum disease incidence of 5% was found in Western dry mountains. The disease incidence in other zones ranged between 5.4 and 14.1%. Similar trend was noticed regarding prevalence being the maximum in Indus delta (100%) followed by Southern irrigated plains (90%). Out of 114 R. solanacearum strains, 92 (81%) were identified as Biovar 3 while the remaining 22 (19%) were recognized as Biovar 4. Biovar 3 was recorded from all the four provinces and was found to be predominant in all the provinces while Biovar 4 was found in the Punjab and Sindh provinces only. Similarly, biovar 3 was observed from all the eight agro ecological zones and found to be predominant. On the other hand, biovar 4 was recorded from four agro ecological zones. Conclusions. The study provides first comprehensive report about the distribution of bacterial wilt of chilies in all the agro ecological zones of the country. The disease has been found fairly distributed in the country with varying intensities warranting stringent surveillance and control measures to minimize yield losses.

Download Full-text

Distributional variability of bacterial wilt of chili incited by Ralstonia solanacearum in eight agro-ecological zones of Pakistan

10.7287/peerj.preprints.26668 ◽

2018 ◽

Author(s):

Muhammad N Aslam ◽

Tariq Mukhtar

Keyword(s):

Bacterial Wilt ◽

Ralstonia Solanacearum ◽

Disease Incidence ◽

Control Measures ◽

Yield Losses ◽

Ecological Zones ◽

Sindh Province ◽

Indus Delta ◽

And Control ◽

Agro Ecological Zones

Background. Bacterial wilt caused by Ralstonia solanacearum is one of the major constraints in the production of chilies in Pakistan. As the information regarding distribution and prevalence of R. solanacearum is exiguous, the present studies were conducted during 2014-15 to determine the incidence and prevalence of R. solanacearum in the major chili growing areas from different agro-ecological zones of Pakistan. Results. The overall incidence and prevalence of R. solanacearum in the country was found to be 10% and 76% respectively. Of the four provinces, maximum disease incidence of 16.4% was recorded in Sindh province followed by Punjab and Khyber Pakhtoonkhwa showing 11.4% and 7% disease incidences respectively and the minimum incidence of 4.9% was observed in the province of Baluchistan. As regards prevalence, the same pattern was observed. Out of 8 agro-ecological zones the maximum disease incidence of 19.5% was observed in Indus delta followed by Sandy deserts (14.1%) while the minimum disease incidence of 5% was found in Western dry mountains. The disease incidence in other zones ranged between 5.4 and 14.1%. Similar trend was noticed regarding prevalence being the maximum in Indus delta (100%) followed by Southern irrigated plains (90%). Out of 114 R. solanacearum strains, 92 (81%) were identified as Biovar 3 while the remaining 22 (19%) were recognized as Biovar 4. Biovar 3 was recorded from all the four provinces and was found to be predominant in all the provinces while Biovar 4 was found in the Punjab and Sindh provinces only. Similarly, biovar 3 was observed from all the eight agro ecological zones and found to be predominant. On the other hand, biovar 4 was recorded from four agro ecological zones. Conclusions. The study provides first comprehensive report about the distribution of bacterial wilt of chilies in all the agro ecological zones of the country. The disease has been found fairly distributed in the country with varying intensities warranting stringent surveillance and control measures to minimize yield losses.

Download Full-text

Ralstonia solanacearum Needs Motility for Invasive Virulence on Tomato

Journal of Bacteriology ◽

10.1128/jb.183.12.3597-3605.2001 ◽

2001 ◽

Vol 183 (12) ◽

pp. 3597-3605 ◽

Cited By ~ 201

Author(s):

Julie Tans-Kersten ◽

Huayu Huang ◽

Caitilyn Allen

Keyword(s):

Bacterial Wilt ◽

Ralstonia Solanacearum ◽

Soft Agar ◽

Cell Protein ◽

In Planta ◽

Tomato Plants ◽

Bacterial Wilt Disease ◽

Virulence Assay ◽

Flagellar Filament

ABSTRACT Ralstonia solanacearum, a widely distributed and economically important plant pathogen, invades the roots of diverse plant hosts from the soil and aggressively colonizes the xylem vessels, causing a lethal wilting known as bacterial wilt disease. By examining bacteria from the xylem vessels of infected plants, we found thatR. solanacearum is essentially nonmotile in planta, although it can be highly motile in culture. To determine the role of pathogen motility in this disease, we cloned, characterized, and mutated two genes in the R. solanacearum flagellar biosynthetic pathway. The genes for flagellin, the subunit of the flagellar filament (fliC), and for the flagellar motor switch protein (fliM) were isolated based on their resemblance to these proteins in other bacteria. As is typical for flagellins, the predicted FliC protein had well-conserved N- and C-terminal regions, separated by a divergent central domain. The predicted R. solanacearum FliM closely resembled motor switch proteins from other proteobacteria. Chromosomal mutants lackingfliC or fliM were created by replacing the genes with marked interrupted constructs. Since fliM is embedded in the fliLMNOPQR operon, the aphAcassette was used to make a nonpolar fliM mutation. Both mutants were completely nonmotile on soft agar plates, in minimal broth, and in tomato plants. The fliC mutant lacked flagella altogether; moreover, sheared-cell protein preparations from the fliC mutant lacked a 30-kDa band corresponding to flagellin. The fliM mutant was usually aflagellate, but about 10% of cells had abnormal truncated flagella. In a biologically representative soil-soak inoculation virulence assay, both nonmotile mutants were significantly reduced in the ability to cause disease on tomato plants. However, the fliC mutant had wild-type virulence when it was inoculated directly onto cut tomato petioles, an inoculation method that did not require bacteria to enter the intact host from the soil. These results suggest that swimming motility makes its most important contribution to bacterial wilt virulence in the early stages of host plant invasion and colonization.

Download Full-text