scholarly journals Bacterial Wilt caused by Ralstonia solanacearum in Ethiopia: StatusaAnd Management Approaches: A Review

2017 ◽  
Vol 5 (3) ◽  
pp. 107-119 ◽  
Author(s):  
Henok Kurabachew ◽  
Getachew Ayana
Keyword(s):  
Disease Management ◽  
Bacterial Wilt ◽  
Ralstonia Solanacearum ◽  
Yield Loss ◽  
Seed Tuber ◽  
Plant Diseases ◽  
Effective Control ◽  
Small Scale ◽  
Potato Seed ◽  
Management Options

Bacterial wilt caused by Ralstonia solanacearum is one of the most devastating plant diseases of economically important crops mainly Solanaceous family such as tomato, potato, pepper and eggplant. These crops play a significant role primarily as sources of income and food security for the small scale farming community in Ethiopia. The occurrence of bacterial wilt disease in Ethiopia was reported in 1956 and is known to cause significant yield loss on different Solanaceous crops in different parts of the country. On the basis of conventional characterization and classification, the strains of R. solanacearum found in Ethiopia have been identified as biovar 1 and 2. Recent characterization of R. solanacearum strains based on phylotype grouping using multiplex PCR and partial endoglucanase gene sequencing identified the occurrences of phylotype II and III. The association of biovar and phylotyping schemes indicated that phylotype II comprises only biovar 2, and phylotype III comprises strains of biovar 1 and biovar 2. The importance of the disease on Solanaceous crop is increasing from time to time specially in potato producing areas of the country. Apart from Solanaceous crops, the disease has also been posing a catastrophic damage to ginger production. Latently infected ginger rhizomes and potato seed tuber and decreasing of land holdings that limit crop rotation have contributed to the wider spread of the disease. In this review attempt has been made to summarize relevant scientific studies on this economically important disease in Ethiopia as well as its different disease management options, challenges and future considerations. Because, there is no single effective control measure against the target pathogen so far, a well-coordinated effort is required to develop an integrated disease management program that will help to minimize the damage and yield loss caused by the disease.

scholarly journals Resistance and Susceptibility of Arabidopsis thaliana to Bacterial Wilt Caused by Ralstonia solanacearum

1998 ◽  
Vol 88 (4) ◽  
pp. 330-334 ◽  
Author(s):  
Chang-Hsien Yang ◽  
Gan-Der Ho
Keyword(s):  
Arabidopsis Thaliana ◽  
Bacterial Wilt ◽  
Ralstonia Solanacearum ◽  
Bacterial Colonization ◽  
Plant Diseases ◽  
Infection Site ◽  
Bacterial Isolation ◽  
Tomato Plants ◽  
Different Strains ◽  
Growth Of Bacteria

Tomato bacterial wilt caused by Ralstonia solanacearum is a model system for studying plant-bacterial interactions, because it is genetically one of the best characterized plant diseases. We demonstrate here that four different strains of R. solanacearum, two from radishes (Rd4 and Rd15) and two from tomato (Ps21 and Ps95), can infect 27 different ecotypes of Arabidopsis thaliana, causing different responses. All ecotypes tested were highly susceptible to strain Rd15, which caused symptoms similar to those observed in tomato plants. For example, leaf drooping and discoloration developed just 3 days after inoculation, and plants completely wilted within 1 week. Strains Rd4 and Ps95 were less infectious than Rd15. With these two strains, a variety of disease responses were observed among different ecotypes at 2 weeks after inoculation; both susceptible and resistant ecotypes of A. thaliana were identified. Ps21 was the least infectious of the four strains and caused almost no symptoms in any of the ecotypes of Arabidopsis tested. Direct bacterial isolation and plant skeleton hybridization analysis from infected plants indicated that bacterial colonization was correlated with the severity of symptoms. Growth of bacteria was limited to the infection site in resistant plants, whereas the bacteria spread throughout susceptible plants by 1 week after inoculation.

scholarly journals Bacterial Wilt Resistance in Tomato, Pepper, and Eggplant: Genetic Resources Respond to Diverse Strains in the Ralstonia solanacearum Species Complex

2011 ◽  
Vol 101 (1) ◽  
pp. 154-165 ◽  
Author(s):  
A. Lebeau ◽  
M.-C. Daunay ◽  
A. Frary ◽  
A. Palloix ◽  
J.-F. Wang ◽  
...  
Keyword(s):  
Bacterial Wilt ◽  
Ralstonia Solanacearum ◽  
Species Complex ◽  
Effective Control ◽  
Economic Losses ◽  
Wilt Resistance ◽  
The Core ◽  
Intermediate Phenotypes ◽  
Vascular Elements ◽  
Pathogen Strains

Bacterial wilt, caused by strains belonging to the Ralstonia solanacearum species complex, inflicts severe economic losses in many crops worldwide. Host resistance remains the most effective control strategy against this disease. However, wilt resistance is often overcome due to the considerable variation among pathogen strains. To help breeders circumvent this problem, we assembled a worldwide collection of 30 accessions of tomato, eggplant and pepper (Core-TEP), most of which are commonly used as sources of resistance to R. solanacearum or for mapping quantitative trait loci. The Core-TEP lines were challenged with a core collection of 12 pathogen strains (Core-Rs2) representing the phylogenetic diversity of R. solanacearum. We observed six interaction phenotypes, from highly susceptible to highly resistant. Intermediate phenotypes resulted from the plants' ability to tolerate latent infections (i.e., bacterial colonization of vascular elements with limited or no wilting). The Core-Rs2 strains partitioned into three pathotypes on pepper accessions, five on tomato, and six on eggplant. A “pathoprofile” concept was developed to characterize the strain clusters, which displayed six virulence patterns on the whole set of Core-TEP host accessions. Neither pathotypes nor pathoprofiles were phylotype specific. Pathoprofiles with high aggressiveness were mainly found in strains from phylotypes I, IIB, and III. One pathoprofile included a strain that overcame almost all resistance sources.

scholarly journals Bacterial Wilt of Solanaceae Caused by Ralstonia solanacearum Race 1 Biovar 3 in Mali

Plant Disease ◽  
2010 ◽  
Vol 94 (3) ◽  
pp. 372-372 ◽  
Author(s):  
A. T. Thera ◽  
B. J. Jacobsen ◽  
O. T. Neher
Keyword(s):  
Surface Water ◽  
Bacterial Wilt ◽  
Ralstonia Solanacearum ◽  
Solanum Tuberosum L ◽  
Solanum Melongena ◽  
Potato Seed ◽  
Relative Distribution ◽  
Tetrazolium Chloride ◽  
Wide Range ◽  
Race 1

Ralstonia solanacearum (Smith) Yabuuchi et al. causes bacterial wilt worldwide on a wide range of plant species. In Mali, the disease is commonly found on potato (Solanum tuberosum L.), tomato (Lycopersicon esculentum var. esculentum L.), pepper (Capsicum annuum L.), eggplant (Solanum melongena L.), tobacco (Nicotiana tabacum L.), and peanut (Arachis hypogaea L.). Determination of race and biovar is critical for development of potato seed certification programs for management of the disease. Isolates (25) of R. solanacearum were obtained from wilting potato, pepper, eggplant, tobacco, and tomato plants collected from fields near Baguineda, Sonityeni, Sotuba, Sikasso, and Kolikoro. Isolations were made from bacterial streaming by dilution plating on triphenyl tetrazolium chloride medium (TZC) (2). Characteristic colonies were selected and identified by ELISA or Immunostrips (Pathoscreen Rs, Agdia Inc., Elkhart, IN). These isolates were used in host range studies and hypersensitivity (HR) tests on tobacco (cv. xanthi) (3) and tested for their ability to produce acids on Ayers basal media amended with disaccharide and hexose alcohol carbon sources (1). These isolates caused characteristic wilt 40 days postinoculation on greenhouse-grown tobacco (cv. Xanthi), peanut (cv. 4610), and tomato (cv. Roma VF) plants when stems of five plants of each host were syringe inoculated with 0.1 ml of a 1 × 109 CFU/ml of bacteria. Plants inoculated with sterile distilled water remained symptomless and R. solanacearum was reisolated from infected plants on TZC and identified with Immunostrips. All HR tests were negative. Infection of peanut, tobacco, and tomato and the results of the HR tests indicated that all isolates were Race 1 and no significant variation was noted between isolates. Acid was produced from the hexose alcohols: mannitol, sorbitol, and dulcitol; and the disaccharides: cellobiose, lactose, and maltose. This indicated that all isolates were biovar 3, the same as a known Race 1 strain from tobacco (MSU Plant Pathology teaching collection) (1). To assess relative distribution of R. solanacearum, 20 soil samples collected from potato fields in the vicinity of Baguineda, Kati, Koulikoro, and Sikasso were placed in pots (30 × 25 cm) under shade cloth at the IER Station in Sotuba and planted with 30-day-old tobacco plants. After 90 days, infected plants (35 to 100% infection) were found in all soils. Infected plants exhibited classical wilt symptoms and tested positive for R. solanacearum infections as confirmed by Immunostrip tests. Six of nine surface water samples taken near potato fields in Baguineda, Sikasso, Mopti, and Koulikoro tested positive for the presence of R. solanacearum by an Agdia Inc. enrichment kit and ELISA. A weed, Commelina forskalaei (Vahl), collected by Farako creek near Sikasso tested positive in the Immunostrip test even though no symptoms were obvious. No attempt was made to characterize the race, biovar, or phylotype of the soil, water, and weed isolates. To our knowledge, this is the first time that the race and biovar of R. solanacearum from Mali has been reported and the wide distribution of this pathogen in Malian soils and surface water has been demonstrated. It is significant that we did not detect Race 3 biovar 2, which is subject to quarantine and biosecurity regulations. References: (1) A. C. Hayward. J. Bacteriol. 27:265, 1964. (2) A. Kelman. Phytopathology 44:693, 1954. (3) J. Lozano and L. Sequeira. Phytopathology 60:833, 1970.

scholarly journals Characterizations of endophytic Bacillus strains from tomato roots as growth promoter and biocontrol of Ralstonia solanacearum

2018 ◽  
Vol 19 (3) ◽  
pp. 906-911 ◽  
Author(s):  
YULMIRA YANTI ◽  
WARNITA WARNITA ◽  
REFLIN REFLIN ◽  
CHAINUR RAHMAN NASUTION
Keyword(s):  
16S Rrna ◽  
Plant Growth ◽  
Bacterial Wilt ◽  
Ralstonia Solanacearum ◽  
Plant Diseases ◽  
Growth Promoter ◽  
Good Ability ◽  
Tomato Roots ◽  
Bacillus Spp ◽  
Bacillus Strains

Yanti Y, Warnita, Reflin, Nasution CR. 2018. Characterizations of endophytic Bacillus strains from tomato roots as growth promoter and biocontrol of Ralstonia solanacearum. Biodiversitas 19: 906-911. Bacterial wilt caused by Ralstonia solanacearum is the most damaging vascular pathogens in tomato and many other crops in tropical, subtropical and warm temperate areas of the world limiting its production. Biological agents such as Plant growth Promoting Rhizobacteria (PGPR) is considered as a potential biological control agent for the suppression of plant diseases such as bacterial wilt. Bacillus spp. are one of the most potential genera of PGPR group used for controlling pathogens and promoting plant growth because of their spore-forming ability which increases their adaptation to the environment. The aims of the research were to isolate Endophytic Bacillus isolates, to characterize its ability as plant growth promoter and pathogen controller, and to identify its molecular genetic using 16S rRNA. Bacillus strains were isolated from healthy tomato roots. All Bacillus spp. strains acquired from isolation were then screened directly on plants in completely randomized design experiments with 3 replications. All potential strains were screened and identified using 16S rRNA with 27F and 1492R primers. Results showed that out of 15 obtained isolates, 6 of them showed a good ability to both promote growth and control R. solanacearum. All isolates were identified as B. Pseudomycoides strain NBRC 101232, B. cereus strain CCM 2010, B. toyonensis strain BCT-7112, B. anthracis strain ATCC 14578, B. cereus strain JCM 2152 and B. cereus ATCC 14579.

scholarly journals Combined use of a microbial restoration substrate and avirulent Ralstonia solanacearum for the control of tomato bacterial wilt

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Xuefang Zheng ◽  
Yujing Zhu ◽  
Jieping Wang ◽  
Ziran Wang ◽  
Bo Liu
Keyword(s):  
Bacterial Wilt ◽  
Ralstonia Solanacearum ◽  
Combined Treatment ◽  
Control Measures ◽  
Effective Control ◽  
Control Effect ◽  
Tomato Production ◽  
Combined Use ◽  
Promote Plant Growth ◽  
Tomato Bacterial Wilt

AbstractTomato bacterial wilt (BW) caused by Ralstonia solanacearum seriously restricts tomato production and no effective control measures are available. A microbial restoration substrate (MRS) had been proved to be effective control of tomato BW in a greenhouse cultivation. In this study, MRS was combined with an avirulent Ralstonia solanacearum (aRS) strain to control the disease under an open field condition. In the two consecutive year (2017 and 2018) trials, the combined use of aRS and MRS resulted in better disease control compared with either aRS or MRS alone. Moreover, the combined treatment was more effective than expected and suggesting a synergistic control effect. Compared with control (CK, non-aRS or MRS), the application of aRS and MRS treatments alone or in combination could all promote plant growth, increase root activity and yield (e.g. the yield for the treatment of aRS + MRS increased by 463.64% in 2017). Soil nutrients, including soil organic carbon, total nitrogen, total phosphorus and total potassium contents were also significantly increased by the application of aRS and MRS treatments alone or in combination (P < 0.05). The application of MRS or in combination with aRS changed the soil from acidic to neutral, which is one of the key factors for controlling BW. The soil enzymatic activities were notably influenced by the combined use of aRS and MRS, which increased urease (87.37% in 2017 and 60.89% in 2018), catalase (93.67% in 2017 and 279.37% in 2018) and alkaline phosphatase activities (193.77% in 2017 and 455.73% in 2018). These results suggest that the combination of MRS and aRS could effectively control tomato BW and thus represents a promising new tool to control this disease.

scholarly journals A Single Locus Leads to Resistance of Arabidopsis thaliana to Bacterial Wilt Caused by Ralstonia solanacearum Through a Hypersensitive-like Response

1999 ◽  
Vol 89 (8) ◽  
pp. 673-678 ◽  
Author(s):  
Gan-Der Ho ◽  
Chang-Hsien Yang
Keyword(s):  
Arabidopsis Thaliana ◽  
Bacterial Wilt ◽  
Ralstonia Solanacearum ◽  
Northern Blot Analysis ◽  
Plant Diseases ◽  
Glutathione S Transferase ◽  
Solanacearum Strain ◽  
Whole Plant ◽  
Pathogenesis Related Protein ◽  
Pathogenesis Related

Strains of Ralstonia solanacearum have been shown to cause bacterial wilt in some, but not all, ecotypes of Arabidopsis thaliana. We demonstrate here that after inoculation of the leaves of resistant ecotype S96 with R. solanacearum strain Ps95 necrosis around the inoculation site rapidly appeared and no further symptoms developed in the plant. Leaves of susceptible ecotype N913 completely wilted 7 days after inoculation with Ps95, and symptoms spread systemically throughout the whole plant within 2 weeks after inoculation. These results suggest that the resistance of Arabidopsis S96 to R. solanacearum is due to a response similar to the hypersensitive response (HR) observed in other plant diseases. Northern blot analysis of the expression of defense-related genes, known to be differentially induced during the HR in Arabidopsis, indicated that pathogenesis-related protein PR-1, glutathione S-transferase (GST1), and Cu, Zn superoxide dismutase (SOD) mRNAs increased significantly in S96 leaves between 3 to 12 h after infiltration with Ps95. The induction of these genes in susceptible ecotype N913 by Ps95 was clearly delayed. Genetic analysis of crosses between resistant ecotype S96 and susceptible ecotype N913 indicated that resistance to Ps95 is due to a single dominant locus.

scholarly journals On the assessment of the sources of inoculum of bacterial wilt in Brazil.

2021 ◽  
Author(s):  
Eduardo S. G. Mizubuti ◽  
Jaqueline K. Yamada ◽  
Thais R. Santiago ◽  
Carlos A. Lopes
Keyword(s):  
Bacterial Wilt ◽  
Seed Tuber ◽  
Selective Medium ◽  
Soil Samples ◽  
Potato Seed ◽  
Bidens Pilosa ◽  
Inoculum Sources ◽  
Mata Atlântica ◽  
Two Samples ◽  
Mata Atlantica

Dispersal of Ralstonia spp. cells by water and contaminated plant material and the importance of weeds as inoculum sources have been poorly investigated. Water of rivers, soil from fields of diverse crops and areas of natural vegetation both from the Amazonia, Cerrado and Mata Atlantica biomes, besides soil of the rhizosphere of weeds present in tomato fields with records of bacterial wilt were sampled and analyzed to detect Ralstonia spp. Seeds of tomato plants artificially and naturally infected with Ralstonia spp. were also processed. All samples were enriched a priori in selective medium South Africa (SMSA) and colonies were isolated in plates containing solid SMSA. Detection of Ralstonia spp. was confirmed by polymerase chain reaction with specific primers. The Co-operational PCR (CO-PCR) was also used to detect Ralstonia spp. Colonies were obtained from soil samples and from a commercial substrate sample. Five soil samples from eggplant fields, one from coffee field, one substrate from potato seed tuber production, two soil samples from the rhizosphere of Amaranthus spp., one from Bidens pilosa and one from Solanum americanum tested positive for Ralstonia spp. Besides these soil samples, five water samples of rivers were positive for CO-PCR detection: two samples from Amazonia, one from Cerrado and two samples from irrigation water collected from tomato fields located in the Mata Atlantica biome. Ralstonia spp. were not detected in tomato seeds. These results revealed potential inoculum sources, especially weeds, in areas with historical records of bacterial wilt. Additionally, rivers may act as dispersal agents of inoculum of Ralstonia spp.

scholarly journals First Report of Bacterial Wilt Caused by Ralstonia solanacearum on Ageratum conyzoides in China

Plant Disease ◽  
2013 ◽  
Vol 97 (3) ◽  
pp. 418-418
Author(s):  
X.-M. She ◽  
Z.-F. He ◽  
F.-F. Luo ◽  
H.-P. Li
Keyword(s):  
16S Rdna ◽  
Bacterial Wilt ◽  
Ralstonia Solanacearum ◽  
Vascular Tissue ◽  
Negative Control ◽  
Plant Diseases ◽  
Bacterial Isolates ◽  
Ageratum Conyzoides ◽  
First Report ◽  
Initial Symptoms

Ageratum conyzoides L. is believed to act as reservoir host for many plant diseases. In June 2011, a 30% incidence of bacterial wilt on A. conyzoides was observed in a field of Rhizoma kaempferiae in Yangchun city of Guangdong province. The initial symptoms were wilting of the apical leaves during the day, which recovered at night. After 4 to 6 days, the leaves became totally necrotic. The basal stems of the diseased plants were blackened and the vascular tissue turned brown. To investigate the disease etiology before understanding the disease link between A. conyzoides and R. kaempferiae, 10 plants with typical wilting symptoms were collected from the field. A total of 10 bacterial isolates were isolated from the vascular tissue of each diseased plant on tripheny tetrazolium chloride (TZC) medium. After incubation at 30°C for 2 days, the plates had large, irregular round, fluidal, white colonies with a pink center. Thirty healthy A. conyzoides plants at the four- to six-leaf growth stage were inoculated by injuring the roots and soaking them in a bacterial suspension (1 × 108 cfu/ml) for 20 min with the 10 bacterial isolates separately, and planted in 10-cm pots with sterile gardening soil in a glasshouse (28 to 35°C). Sterile water was used as a negative control. Five days after inoculation, a few leaves of the inoculated plants began to exhibit wilting. The inoculated plants eventually showed the same symptoms as those in the field. The same bacterium was reisolated from inoculated plants. The 30 negative control plants did not have wilt symptoms. With the same inoculation procedure, the bacterium also caused wilting on tomato (25 of 30), pepper (10 of 30), eggplant (2 of 30), ginger (11 of 15), and R. kaempferiae (8 of 15). Using the universal bacterial 16S rDNA primer set 27f/1541R (3), approximately 1,400 bp-fragments were amplified from the 10 isolates, respectively. The sequences for the 10 fragments (GenBank Accession Nos. JX294065 to JX294074) were identical and had 100% sequence identity with 16S rDNA of R. solanacearum GMI1000 (AL646052). The 10 isolates were able to oxidize disaccharides (lactose, maltose, and cellobiose) and hexose alcohols (mannitol, dulcitol, and sorbitol). According to Hayward's classification, all isolates were biovar 3 (2). Based on the pathogenicity tests, carbohydrate utilization, and near full-length 16S rDNA sequences, the bacterial isolates from the diseased A. conyzoides belonged to race 4 and biovar 3 of R. solanacearum. Furthermore, the specific 280-bp and 140-bp fragments were respectively amplified from all 10 isolates by using the multiplex PCR (1). In addition, specific 165-bp fragments were amplified from all the isolates using the specific primers AKIF/AKIR (3), which indicates the bacterium belongs to R. solanacearum Phylotype I. To our knowledge, this is the first report of a disease caused by R. solanacearum on A. conyzoides in China. References: (1) M. Fegan and P. Prior. Page 449 in: Bacterial Wilt Disease and the Ralstonia solanacearum Species Complex. C. Allen et al., eds. The American Phytopathological Society. St. Paul, MN, 2005. (2) A. C. Hayward. J. Appl. Bacteriol. 27:265, 1964. (3) M. Horita et al. J. Gen. Plant Pathol. 70:278, 2004.

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