Criblage de variétés de tomate pour de la résistance au flétrissement bactérien causé par Ralstonia solanacearum au Togo

Objectifs : Dans le cadre de la recherche de mesures de lutte efficace et durable contre le flétrissement bactérien causé par Ralstonia solanacearum (Rs), la présente étude s’est proposé d’évaluer les variétés de tomate pour leur résistance à la maladie. Méthodologie et Résultats : Six variétés de tomate cultivées aux Togo ont été inoculées par une suspension de la souche de Rs isolée du site de CECO de la prefecture de Sotouboua (Togo). Les résultats ont montré de fortes incidences et sévérités du flétrissement bactérien sur les variétés testées. Cependant, des différences de comportement vis-à-vis de cette maladie ont été observées entre les variétés. En considérant l’indice de maladie après inoculation et l’analyse des closters, deux groupes de variétés ont été identifiés parmi les six testées : un groupe “Résistant” constitué de la seule variété Cobra et un groupe “Sensible” constitué des variétés Petomech, Tropimech, Padma, Roma et Platinum. Conclusions et application des résultats : Cette étude a permis d’obtenir des données sur l’incidence et la sévérité du flétrissement bactérien cause par Rs et le comportement des variétés de tomate vis-à-vis de cette pathologie, et a permis aussi d’identifier les variétés Cobra, Roma et Platinum comme résistantes au flétrissement bactérien en conditions contrôlées. Ces résultats constituent une base de données importante pour des investigations futures en conditions de champs dans diverses zones agroécologiques du pays. Ces expérimentations permettront d’identifier des variétés résistantes pouvant être recommandées aux producteurs pour une gestion durable du flétrissement bactérien. Mots clés : R. solancearum, flétrissement bactérien de la tomate, criblage, résistance. Banito et al., J. Appl. Biosci. Vol : 166 2021 Criblage de variétés de tomate pour de la résistance au flétrissement bactérien causé par Ralstonia solanacearum au Togo 17213 ABSTRACT Objectives: In order to develop a control strategy against bacterial wilt caused by Ralstonia solanacearum (Rs), one of the most destructive diseases of tomato worldwide, the present study aimed to evaluate tomato varieties for resistance to Rs. Methodology and Results: Six tomato varieties cultivated in Togo were inoculated with Rs strain isolated from CECO site in the Prefecture of Sotouboua (Togo).The results revealed high incidence and severity occurring on these varieties. However, differences were observed among the tested varieties. The discrimination analysis based on the disease index after inoculation and the clusters analysis identified two groups of varieties: the resistant group composed of the varieties Cobra, Roma and Platinum and the susceptible group including the varieties Petomech, Tropimech, Padma. Conclusions and application of findings: The results provided useful information in terms of incidence and severity of Rs wilt on tomato and the behaviour of varieties against the disease. The results allowed identifying three tomato varieties, Cobra, Roma and Platinum as resistant to bacterial wilt under controlled conditions. These results are useful for further experiments under field conditions in different agroecological zones to find out resistant tomato varieties for sustainable management of bacterial wilt caused by Rs. Keywords: R. solancearum, bacterial wilt of tomato, screening, resistance.

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Reaction of Capsicum peppers commercialized in the Federal District to bacterial wilt

Horticultura Brasileira ◽

10.1590/s0102-053620180204 ◽

2018 ◽

Vol 36 (2) ◽

pp. 173-177 ◽

Cited By ~ 3

Author(s):

Maurício Rossato ◽

Thais R. Santiago ◽

Carlos Alberto Lopes

Keyword(s):

Bacterial Wilt ◽

Ralstonia Solanacearum ◽

Bacterial Pathogens ◽

Federal District ◽

Capsicum Frutescens ◽

Capsicum Baccatum ◽

Main Species ◽

Race 1 ◽

Resistant Group ◽

Phylotype I

ABSTRACT In Brazil, the bacterial pathogens Ralstonia solanacearum and R. pseudosolanacearum cause substantial losses by inducing bacterial wilt on several solanaceous crops; R. pseudosolanacearum is the main species associated with peppers (Capsicum sp.). To verify the bacterial wilt reaction on Capsicum peppers commercialized in the Federal District (DF), fruits of several genotypes within this genus were collected from six different fairs distributed in the satellite cities of Gama, Sobradinho and Guará. Seedlings with four true leaves derived from seeds extracted from such fruits were root inoculated with 108 CFU/mL with a representative isolate of R. pseudosolanacearum (race 1, biovar 3, phylotype I, sequevar 18). The evaluated species were: Capsicum frutescens (‘pimenta-malagueta’), Capsicum baccatum var. pendulum (‘pimenta-dedo-de-moça’) and C. chinense (‘pimenta-de-bode’ red and yellow, ‘pimenta-cumarí-do-Pará’, ‘pimenta-biquinho’, ‘pimenta-habanero’ and ‘pimenta-de-cheiro’). Not all species were found in all six fairs. The reaction to bacterial wilt was variable and species-dependent. From 26 evaluated genotypes, none presented an immune-like response, 10 were considered resistant and 16 susceptible based on wilt incidence (Scott-Knott, 5%). Four Capsicum baccatum accesses were positioned in the resistant group, whereas 14 out of 18 of C. chinense were susceptible. Capsicum frutescens showed variable reactions. These results contribute to indicate cultivation of specific groups of pepper according to the presence of the pathogen in the soil.

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Fabrication of pH-Sensitive Tetramycin Releasing Gel and Its Antibacterial Bioactivity against Ralstonia solanacearum

Molecules ◽

10.3390/molecules24193606 ◽

2019 ◽

Vol 24 (19) ◽

pp. 3606

Author(s):

Xiaozhou Ma ◽

Shunyu Xiang ◽

Huijun Xie ◽

Linhai He ◽

Xianchao Sun ◽

...

Keyword(s):

Bacterial Wilt ◽

Ralstonia Solanacearum ◽

Onset Time ◽

Ph Sensitive ◽

Ph Change ◽

Great Loss ◽

Management Efficiency ◽

High Incidence ◽

Application Potential ◽

Base Structure

Ralstonia solanacearum (R. solanacearum)-induced bacterial wilt of the nightshade family causes a great loss in agricultural production annually. Although there has been some efficient pesticides against R. solanacearum, inaccurate pesticide releasing according to the onset time of bacterial wilt during the use of pesticides still hinders the disease management efficiency. Herein, on the basis of the soil pH change during R. solanacearum growth, and pH sensitivity of the Schiff base structure, a pH-sensitive oxidized alginate-based double-crosslinked gel was fabricated as a pesticide carrier. The gel was prepared by crosslinking oxidized sodium alginate (OSA) via adipic dihydrazide (ADH) and Ca2+. After loading tetramycin into the gel, it showed a pH-dependent pesticide releasing behavior and anti-bacterial activity against R. solanacearum. Further study also showed that the inhibition rate of the tetramycin-loaded gel was higher than that of industrial pesticide difenoconazole. This work aimed to reduce the difficulty of pesticide administration in the high incidence period of bacterial wilt and we believe it has a great application potential in nightshade production.

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First phylotype analysis of Ralstonia solanacearum causing Eggplant bacterial wilt in the Republic of Guinea

Journal of Animal & Plant Sciences ◽

10.35759/janmplsci.v46-2.3 ◽

2020 ◽

Vol 46 (2) ◽

pp. 8187-8196

Keyword(s):

Bacterial Wilt ◽

Ralstonia Solanacearum ◽

Management Strategies ◽

Pcr Amplification ◽

Universal Primer ◽

Fta Cards ◽

Agroecological Zones ◽

The Republic ◽

Production Areas ◽

Phylotype I

Eggplant is one of the important cash crops in Guinea and it is cultivated in all the agroecological zones of the country with the areas and production are constantly growing. However, this crop is affected by bacterial wilt disease caused by bacteria of the Ralstonia solanacearum species complex (RSSC). in these production areas. In August 2018, a total of 81 strains were collected from stems of withered eggplant plant in the nine prefectures of the three administrative regions of Guinea. These strains were extracted and put on FTATM cards at the Foulayah laboratory in Guinea. for their molecular characterization the FTA cards were transported to the World vegetable center laboratory in Taiwan where all the 81 strains were confirmed as R. solanacearum . single 280 bp fragment resulted in all the isolates following polymerase chain reaction (PCR) amplification using the R. solanacearum specific universal primer pair 759/760. A phylotype specific multiplex PCR revealed that 55 of the 81 strains could be assigned to phylotypes. 85, 5% of this batch consisted of phylotype I; 3, 6% of phylotype II; 10, 9% of phylotype III. The objective of this study is to open the way to developing better eggplant BW management strategies for Guinea, including screening for eggplant lines resistant to phylotype I and phylotype III either together or separately for subsequent hybridization.

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Temporal Trend of ST131 Clone among Urinary Escherichia coli Isolates in the Community: A Taiwan National Surveillance from 2002 to 2016

Microorganisms ◽

10.3390/microorganisms9050963 ◽

2021 ◽

Vol 9 (5) ◽

pp. 963

Author(s):

Jiun-Ling Wang ◽

Wen-Chien Ko ◽

Chih-Hsin Hung ◽

Ming-Fang Cheng ◽

Hui-Ying Wang ◽

...

Keyword(s):

Temporal Trend ◽

Multidrug Resistant ◽

Population Based ◽

Pulsed Field Gel Electrophoresis ◽

Sequence Type ◽

E Coli ◽

Factors Associated ◽

Resistant Group ◽

Ciprofloxacin Resistance ◽

Susceptible Group

Sequence type (ST) 131 is a multidrug-resistant pandemic lineage of E. coli responsible for extraintestinal infections. Few surveillance data of ST131 included all antimicrobial-susceptible and -resistant isolates or focused on community-acquired urinary tract infection (UTI). From a population-based surveillance pool of 2997 outpatient urine E. coli isolates, 542 were selected for detection of ST131 based on ciprofloxacin and/or cefotaxime resistance. Pulsed-field gel electrophoresis (PFGE) was performed on all ST131 isolates to further determine their relatedness. The estimated overall ST131 prevalence in this community UTI cohort increased from 11.2% (in 2002–2004), 12.2% (in 2006–2008), 13.6% (in 2010–2012), to 17.4% in 2014–2016 (p < 0.01). In the ciprofloxacin-resistant/cefotaxime-resistant group, ST131 increased from 33.3% in 2002–2004 to 72.1% in 2014–2016 (p < 0.01). In the ciprofloxacin-resistant/cefotaxime-susceptible group, ST131 was found in 24.3% overall without significant increase in its prevalence over time. PFGE showed emergence of a cluster of ciprofloxacin-resistant/cefotaxime-resistant ST131 carrying Gr. 1 CTX-M ESBL in 2014–2016, especially 2016. Multivariate analysis revealed that age (≥65 y.o) and ciprofloxacin resistance were independent factors associated with ST131. This longitudinal surveillance showed that ciprofloxacin-resistant/cefotaxime-susceptible ST131 has been circulating in the community since 2002 but ciprofloxacin-resistant/cefotaxime-resistant ST131 increased rapidly in the later years.

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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.

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