scholarly journals Performance of Solanum phureja-derived bacterial-wilt resistant potato clones in a field naturally infested with Ralstonia solanacearum in Central Brazil

2021 ◽  
Vol 39 (4) ◽  
pp. 411-416
Author(s):  
Carlos A Lopes ◽  
Agnaldo DF Carvalho ◽  
Arione S Pereira ◽  
Fernanda Q Azevedo ◽  
Caroline M Castro ◽  
...  

ABSTRACT Bacterial wilt (BW), or brown rot, caused by the soil and seed borne bacterium Ralstonia solanacearum, is one of the most devastating diseases of potatoes cultivated in warmer regions of the world. There are no potato cultivars with a desirable level of BW resistance, although it has been recognized that resistance can be an outstanding component for disease management. However, the sources of resistance available lack agronomic traits required by potato growers, therefore being of little interest to breeders. The objective of this work was to evaluate the performance of 11 clones selected for BW resistance and improved for tuber traits upon selection in the last two decades. The clones under test were compared with susceptible and resistant clones and cultivars, in a completely randomized blocks design with three replications of single lines of 10 plants, in a field naturally infested with race 1, biovar 1, phylotype II of R. solanacearum. BW incidence was assessed 60-70 days after planting and total tuber yield in each plot was recorded 110 days after planting. All the evaluated clones presented higher levels of resistance to BW compared with the commercial varieties, not differing from the resistant, not commercial, controls. In a next step, these clones will be characterized for other desirable traits and those which combine high level of resistance and commercial characteristics will be recommended for breeders for enriching the genotypic background in the search for commercial varieties. We also confirmed that the cultivar BRSIPR Bel displays an intermediate level of resistance, what makes it an interesting genitor for its good agronomic characteristics. The findings of this work demonstrate that the improved potato clones selected under tropical conditions in the Embrapa’s pre-breeding project possess high and stable levels of resistance to bacterial wilt, being a valuable resource for breeders.

Agriculture ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 157 ◽  
Author(s):  
Namisy ◽  
Chen ◽  
Prohens ◽  
Metwally ◽  
Elmahrouk ◽  
...  

Bacterial wilt, caused by Ralstonia solanacearum, is highly diverse and the identification of new sources of resistance for the incorporation of multiple and complementary resistance genes in the same cultivar is the best strategy for durable and stable resistance. The objective of this study was to screen seven accessions of cultivated eggplant (Solanum melongena L.) and 40 accessions from 12 wild relatives for resistance to two virulent R. solanacearum strains (Pss97 and Pss2016; phylotype I, race 1, biovar 3). The resistant or moderately resistant accessions were further evaluated with Pss97 in a second trial under high temperatures (and also with Pss2016 for S. anguivi accession VI050346). The resistant control EG203 was resistant to Pss97, but only moderately resistant to Pss2016. One accession of S. sisymbriifolium (SIS1) and two accessions of S. torvum (TOR2 and TOR3) were resistant or moderately resistant to Pss97 in both trials. Solanum anguivi VI050346, S. incanum accession MM577, and S. sisymbriifolium (SIS1 and SIS2) were resistant to Pss2016 in the first trial. However, S. anguivi VI050346 was susceptible in the second trial. These results are important for breeding resistant rootstocks and cultivars that can be used to manage this endemic disease.


Plant Disease ◽  
2007 ◽  
Vol 91 (9) ◽  
pp. 1200-1200 ◽  
Author(s):  
M. H. R. Khoodoo ◽  
E. S. Ganoo ◽  
S. Saumtally

In October 2005 and September 2006, two outbreaks of bacterial wilt occurred in the south and north (90 and 95 m above sea level, respectively) of Mauritius, respectively, on different potato cultivars in seed potato fields. Symptoms were reported at harvest when profuse creamy exudates were observed oozing from the eyes of tubers. The brown appearance of the vascular rings, which was accompanied by extensive maceration, suggested potato brown rot. Severe symptoms with complete rotting of vascular tissues and oozing from heel ends of tubers were commonly observed. Ralstonia solanacearum has been regularly encountered for decades around the island, but before October 2005, all isolates belonged to Race 1 biovar 3. The pathogen was isolated from samples collected from the two outbreaks by plating on Kelman's medium amended with 100 ppm of polymixin B sulfate. Thirty-three isolates were obtained from stems and tubers of potato cvs. Spunta, Delaware, Atlantic, and Belle Isle, from soil samples, and weed hosts Solanum americanum, Lycopersicon pimpinellifolium, and Oxalis latifolia. These weeds, however, did not show symptoms of wilting or vascular browning, although oozing was observed when the stems were cut and placed in water. When reinoculated in tomato bioassays, 17 tested isolates caused wilting and were successfully reisolated, confirming Koch's postulates. All colonies were positive for Ralstonia by the Spot√Check LF test (Adgen, Ayr, UK) and by indirect plate-trapped antigen-ELISA (Agden) using monoclonal antibodies raised against Race 3 strains. Isolate biovar was determined by performing standard biochemical tests (1). All 33 isolates metabolized maltose, lactose, and cellobiose but not trehalose and the hexose alcohols dulcitol, mannitol, and sorbitol, thereby showing that they all belong to biovar 2 of Andean phenotype 2A. The final identification was performed by a PCR test using Race 1 specific primers PSIF and PSIR (4) and Race 3 specific primers 630 and 631 (3). The Race 3 specific band was amplified from all isolates while the Race 1 specific band was not. Assignment to biovar 2 was independently confirmed by CABI Identification Service, UK. R. solanacearum R3bv2 is distributed worldwide, occurring in temperate regions, subtropical areas, and at higher altitudes in the tropics, reportedly because of its lower temperature optimum. Brown rot is often disseminated by seed potato tubers that are latently infected by the pathogen (2). Seed potato fields typically undergo a 7-year crop rotation with sugar cane in Mauritius, so it is unlikely that the pathogen was present in these fields for a long time. The infection of weeds in these same fields was probably due to the movement of water contaminated by tuber exudates. Epidemiological results suggest that R. solanacearum R3bv 2A was recently introduced into Mauritius, although its origin is not known. Generally, R3bv2 strains around the world appear to be clonal and seem to be spreading rapidly into previously uninfested areas such as Mauritius. Stronger standards for seed potato testing may be needed to prevent a wide dissemination of R3bv2. References: (1) A. C. Hayward. J. Appl. Bacteriol. 27:265, 1964. (2) A. C. Hayward et al. Page 420 in: Bacterial Wilt Disease: Molecular and Ecological Aspects. P. Prior et al., eds. Springer, Berlin, 1998. (3) M. Fegan et al. Page 19 in: Bacterial Wilt Disease: Molecular and Ecological Aspects. P. Prior et al., eds. Springer, Berlin, 1998. (4) Y.-A. Lee et al. Appl. Environ. Microbiol. 67:3943, 2001.


2018 ◽  
Vol 36 (2) ◽  
pp. 173-177 ◽  
Author(s):  
Maurício Rossato ◽  
Thais R. Santiago ◽  
Carlos Alberto Lopes

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.


2020 ◽  
Vol 33 (7) ◽  
pp. 872-875 ◽  
Author(s):  
Nasim Sedighian ◽  
Marjon Krijger ◽  
Tanvi Taparia ◽  
S. Mohsen Taghavi ◽  
Emmanuel Wicker ◽  
...  

Ralstonia solanacearum, the causal agent of bacterial wilt and brown rot disease, is one of the major pathogens of solanaceous crops, including potato, around the globe. Biovar 2T (phylotype II/sequevar 25) of R. solanacearum is adapted to tropical lowlands and is only reported in South America and Iran. Thus far, no genome resource of the biovar 2T of the pathogen has been available. Here, we present the near-complete genome sequences of the biovar 2T strain CFBP 8697 as well as strain CFBP 8695 belonging to biovar 2 race 3, both isolated from potato in Iran. The genomic data of biovar 2T will extend our understanding of the virulence features of R. solanacearum and pave the way for research on biovar 2T functional and interaction genetics.


Plant Disease ◽  
2010 ◽  
Vol 94 (3) ◽  
pp. 372-372 ◽  
Author(s):  
A. T. Thera ◽  
B. J. Jacobsen ◽  
O. T. Neher

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.


2021 ◽  
Author(s):  
Ebrahim Osdaghi

Abstract Ralstonia solanacearum is included in the A2 (high risk) list of quarantine organisms by the European and Mediterranean Plant Protection Organization (EPPO). EPPO Code for R. solanacearum is RALSSO, while the phytosanitary categorization of the species in EPPO A2 list is no.58, EU: I/A2 (EPPO, 2018). Bacterial wilt disease was first reported in southern USA in the late nineteenth century on tomato plants (Smith, 1896). Infected plant materials (e.g. potato tubers) transmit the pathogen over long distances; hence, quarantine inspections and plant sanitary practices are the cornerstone of disease management (EPPO, 2018). R. solanacearum strains in the race 3 group are a select agent under the US Agricultural Bioterrorism Protection Act of 2002 (USDA, 2005). Peculiarly, the organism, if not yet already present in North America in pelargonium (Strider et al., 1981), was introduced with cuttings of this host by American companies producing these cuttings for their markets in countries like Kenya and Guatemala (Norman et al., 1999, 2009; Kim et al., 2002; Williamson et al., 2002; O'Hern, 2004). A similar situation led to introductions of the pathogen from Kenya into some northern European nurseries. Once the source (contaminated surface water) was recognized and proper control measures (use of deep soil water, disinfection of cutting producing premises and replacement of mother stock), the problem was solved and the disease in greenhouses eradicated (Janse et al., 2004). Similarly race 1 has been introduced into greenhouses with ornamental plants (rhizomes, cuttings or fully grown plants) such as Epipremnum, Anthurium, Curcuma spp. and Begonia eliator from tropical areas (Norman and Yuen, 1998, 1999; Janse et al., 2006; Janse, 2012). Introduction can and did occur from Costa Rica and the Caribbean, Indonesia, Thailand and South Africa. However, this idea of placing pathogens on bioterrorist list for unclear and perhaps industry-driven reasons and its effects, is strongly opposed in a recent publication from leading phytobacteriologists. This is because R. solanacearum is an endemic pathogen, causing endemic disease in most parts of its geographic occurrence, moreover normal quarantine regulations are already in place where the disease is not present or only sporadically and are thought to be more efficient and less damaging to trade and research than placing this pathogen on select agent lists and treating it as such (Young et al., 2008). Peculiarly, it has been used in the control of a real invasive species, the weed kahili ginger (Hedychium gardenarium) in tropical forests in Hawaii. This is not without risks because strains occurring on this weed host were thought to be non-virulent, but later appeared to be virulent on many edible and ornamental ginger species as well (Anderson and Gardner, 1999; Paret et al., 2008). Another threat for these countries could be strains belonging to race 1, biovar 1 (phylotype I) that have already been reported from field-grown potatoes in Portugal (Cruz et al., 2008).


2014 ◽  
Vol 32 (4) ◽  
pp. 453-457 ◽  
Author(s):  
Ivani T Oliveira ◽  
Carlos A Lopes ◽  
Andrea B Moura

Fruit yield and bacterial wilt symptoms of eggplant genotypes CNPH006, CNPH171, CNPH658, CNPH778, CNPH783, and CNPH785 were quantified in soil naturally infested with Ralstonia solanacearum(race 1, biovar 3) in Brasília, Brazil.Exceptfor CNPH778, all genotypes developed at least one typical wiltedplant. Besides wilt,other symptoms considered for assessing levels of tolerance/resistance among genotypes wereplant death (CNPH006, CNPH171, CNPH658 and CNPH783), leaf chlorosis(CNPH785) and plant dwarfing (all genotypes). The occurrence of bacterial ooze on cut stems was observed in all plants grown in infested beds, including those that did not exhibit wilt symptoms. Plants grown simultaneouslyin noninfested beds of the same dimensions and soil characteristics allowed the comparison ofyield losses due to the pathogen. The genotypes were grouped according to their ability to maintain fruit production in the infested area. CNPH785 was the most tolerant genotype, with no significant loss due to the disease,followed by CNPH783, CNPH778 and CNPH171, with mean losses of 19.3%, 11.4%, and 10.1%, respectively. The genotypes CNPH658 and CNPH006 were the most susceptible, with average losses of 99.53 and 99.32%, respectively.


Plant Disease ◽  
2006 ◽  
Vol 90 (6) ◽  
pp. 798-802 ◽  
Author(s):  
D. J. Norman ◽  
J. Chen ◽  
J. M. F. Yuen ◽  
A. Mangravita-Novo ◽  
D. Byrne ◽  
...  

Various bactericides were screened for efficacy in protecting geranium plants (Pelargonium hortorum) from Ralstonia solanacearum infection. Many of these bactericides were found to slow the disease progress; however, they were not able to protect the plants from infection and subsequent death. Potassium salts of phosphorous acid were found to be effective in protecting plants from infection when applied as a drench. The active portion of the potassium salts was found to be phosphorous acid (H3PO3). Phosphorous acid was found to inhibit in vitro growth of R. solanacearum. It is thought to be protecting plants from infection by acting as a bacteriostatic compound in the soil. The plants, however, are not protected from aboveground infection on wounded surfaces. Phosphorous acid drenches were shown to protect geranium plants from infection by either race 1 or 3 of R. solanacearum. Other phosphorous-containing products commonly used in the industry, such as phosphorus pentoxide (P2O5) and phosphoric acid (H3PO4), were not able to protect plants from bacterial wilt infection.


Agronomy ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1513
Author(s):  
Herbaud Zohoungbogbo ◽  
Adonis Quenum ◽  
Judith Honfoga ◽  
Jaw-Rong Chen ◽  
Enoch Achigan-Dako ◽  
...  

Finding sources of resistance to bacterial wilt (BW) caused by Ralstonia solanacearum species complex is a crucial step toward the development of improved bacterial wilt-resistant tomato varieties. Here, we evaluated new sources of bacterial wilt-tolerant/resistant tomato lines and identified associated phylotype/sequevar of R. solanacearum strains in Benin. Eighteen F5 lines and five checks were evaluated in two hotspots: the experimental site of the World Vegetable Center, Cotonou Benin, and the Laboratory of Genetics, Biotechnology and Seed Science of the University of Abomey-Calavi. Experiments were laid out in a randomized complete block design with four replicates. Data were collected on bacterial wilt incidence, horticultural and fruit traits and yield components. Across the two experiments, the F5 lines showed no wilting, while the local variety ‘Tounvi’ used as susceptible check showed 57.64% wilting. The wilting was due to BW and was associated with sequevars I-14, I-18 and I-31 of phylotype I. AVTO1803, AVTO1955-6 and H7996 were the highest yielding lines with 20.29 t·ha−1, 17.66 t·ha−1 and 17.07 t/ha, respectively. The sources of resistance to BW can be recommended to national agricultural system for dissemination or used in tomato breeding programs.


Sign in / Sign up

Export Citation Format

Share Document