scholarly journals Identification of Ralstonia solanacearum resistant rootstocks for tomato grafting

2020 ◽  
Vol 43.3 ◽  
pp. 7452-7457
Author(s):  
Kanyua Stella ◽  
Mwangi Maina ◽  
Mbaka Jesca

Bacterial wilt, caused by Ralstonia solanacearum, causes severe losses to tomato (Solanum lycopersicum L). Current management measures are not fully effective. Grafting with resistant rootstocks may be an effective strategy for managing the disease. However, R. solanacearum populations maintain considerable diversity, and little information is known regarding the efficacy of available rootstocks for use in grafting to reduce bacterial wilt incidence and subsequent crop loss. Tomato belongs to family Solanaceae which includes other well-known species, such as eggplant (aubergine), peppers, tobacco and potato. The objective of this study was to identify bacterial wilt resistant germplasm that can be used as rootstocks in tomato grafting. The potential candidates for the study included species that belong to solanaceae family. Rootstocks included tomato cultivar Mt56, Eggplant (Solanum melongena), Capsicum and Sodom apple (Solanum incarnum). Tomato cultivars Anna F1 and Cal J were used as sources of scions. Diseased plants were collected from farmers’ fields and bacterial inoculum isolated using CPG Medium with TZC used to identify distinct colonies of R.solanacearum. The inoculum was applied on the test plants by injecting into the soil planted with tomatoes. Disease severity data was recorded using 0 to 5 scoring scale. Data was subjected to ANOVA using Genstat version 15 and significantly different treatment means separated using LSD at P < 0.05. Solanum melongena, Solanum incarnum and tomato cultivar (Mt56) did not develop infection while tomato cultivar Anna F1 and Cal J (used as positive controls) and Capsicum developed infection. It was concluded that resistant germplasm to bacterial wilt exists and can be utilized to graft susceptible tomato cultivars and contribute to management of bacterial wilt.

2020 ◽  
Vol 147 ◽  
pp. 15100-15107
Author(s):  
Kanyua Stella ◽  
Mwangi Maina ◽  
Mbaka Jesca

Objective: Tomato (Solanum lycopersicum L.) belongs to the Solanaceae family and currently is one of the most important vegetable crops. Bacterial wilt, caused by Ralstonia solanacearum is a soil borne disease of tomato causing significant economic damage on tomatoes, tobacco and potatoes. Bacterial wilt is difficult to manage because the pathogen can survive in soil for long periods in association with a wide range of crops such as pepper, potato, capsicum, eggplants and weeds such as Jimson weed and nightshade. The objective of this study was to determine compatibility and performance of susceptible tomato cultivars grafted onto bacterial wilt resistant rootstocks. Methodology: Scions from susceptible tomato commercial cultivars (Anna F1 and Cal J) were grafted onto rootstocks of Eggplant, Sodom apple and tomato cultivar Mt56 that were determined to be resistant to bacterial wilt in a previous study. Cleft grafting technique was used in the experiment. Data on compatibility was assessed daily to check on the healing of the graft union and number of established plants. The grafted plants were considered compatible if 67% of the grafted plants had healed and growth established fourteen days after grafting. Data were subjected to ANOVA using GenStat version 15 and significantly different treatment means separated using LSD at P < 0.05. Results and application: The grafted plants were compatible at varying rates, that is Mt56 + Anna F1 (93.30%), Mt56 + Cal J (76.7%), S. melongena + Anna F1 (96.7%), S. melongena + Cal J (83.3%), S. incarnum + Anna F1 (73.3% ), and S. incarnum + Cal J (100%). It was concluded that tomato scions and the botanically related wilt resistant rootstocks are compatible. All the grafted plants performed well except those on Sodom apple rootstock whose stem did not expand at the rate as the scion stem. It is recommended that the proven resistant rootstocks be deployed to tomato farmers for use in tomato grafting and subsequent increase in their production. Key words: Grafting, Compatibility, Performance, Bacterial wilt


2016 ◽  
Vol 2 ◽  
pp. 22-26 ◽  
Author(s):  
Ram Devi Timila ◽  
Shrinkhala Manandhar

Bacterial wilt caused by Ralstonia solanacearum E.F. Smith is one of the destructive diseases of solanaceous vegetables specially tomato (Lycopersicon esculentum L.) and eggplant (Solanum melongena L.). Experiments were conducted to determine biovar types existing among the strains or isolates of Nepal and variation in virulence in some vegetables belonging to solanaceae family. A total of 39 isolates infecting tomato, eggplant, chilli and potato collected from different parts of Nepal were analyzed for biovar types on the basis of 3 disaccharides and 3 hexose alcohols oxidation test.  Experiments were conducted to determine variation in virulence or aggressiveness of some of the  isolates under  screen house conditions using three host differentials such as Pusa Ruby (susceptible), Bishesh (moderately resistant) and Srijana (resistant) tomato cultivars. Of the 39 isolates, 23 were biovar III, three biovar II, three biovar IV, and one was biovar I. Nine isolates could not be differentiated into any of the five biovars. For breeding and epidemiological purposes it is very important to analyze the variability of aggressiveness. A total of 5 isolates collected from different places were included in the test. Isolates from Bhaktapur was found the most virulent causing wilt in the variety Bishesh (moderately resistant). Other isolates had the negative impact with zero wilt on the differentials used. Isolates from Jungekhola of Dhading district did not induce wilt even on susceptible variety (Pusa Ruby), but exhibited only senescence reaction. The result indicated that there is some slight variation among the isolates tested. Some effective management tactics might be needed in those locations where highly aggressive or virulent strain of bacterial wilt is prevalent, because resistant variety may not be stable in such locations.


2018 ◽  
Vol 31 (4) ◽  
pp. 432-444 ◽  
Author(s):  
Elizabeth French ◽  
Bong-Suk Kim ◽  
Katherine Rivera-Zuluaga ◽  
Anjali S. Iyer-Pascuzzi

The soilborne pathogen Ralstonia solanacearum is the causal agent of bacterial wilt and causes significant crop loss in the Solanaceae family. The pathogen first infects roots, which are a critical source of resistance in tomato (Solanum lycopersicum L.). Roots of both resistant and susceptible plants are colonized by the pathogen, yet rootstocks can provide significant levels of resistance. Currently, mechanisms of this ‘root-mediated resistance’ remain largely unknown. To identify the molecular basis of this resistance, we analyzed the genome-wide transcriptional response of roots of resistant ‘Hawaii 7996’ and susceptible ‘West Virginia 700’ (WV) tomatoes at multiple timepoints after inoculation with R. solanacearum. We found that defense pathways in roots of the resistant Hawaii 7996 are activated earlier and more strongly than roots of susceptible WV. Further, auxin signaling and transport pathways are suppressed in roots of the resistant variety. Functional analysis of an auxin transport mutant in tomato revealed a role for auxin pathways in bacterial wilt. Together, our results suggest that roots mediate resistance to R. solanacearum through genome-wide transcriptomic changes that result in strong activation of defense genes and alteration of auxin pathways.


2017 ◽  
Vol 16 (1) ◽  
pp. 96-104
Author(s):  
A S. GANIYU, ◽  
R A. POPOOLA, ◽  
A O. ENIKUOMEHIN, ◽  
G J. BODUNDE,

Bacterial wilt, Ralstonia solanacearum, causes severe loss of tomato (Solanum lycopersicum L.) pro-duction in Nigeria. Tube grafting of two tomato cultivars (Beske and UC82-B) on bacterial wilt-resistant tomato landrace rootstock (Tomachiva) was conducted to reduce incidence of bacterial wilt and in-crease the yield in the two cultivars. The experiments were laid in Randomized Complete Block De-sign (RCBD). Percentage incidence and Percentage Severity Index (PSI) of grafted tomato were 0.00% each in the early planting season. Incidence (1.70%) and PSI (1.50%) of grafted tomato were observed in late planting season. Non-grafted tomato had higher significant values of 42.50% and 38.80% in incidence and percentage severity index in late planting season. Grafting on Tomachiva effectively reduced the incidence and severity of bacterial wilt in two cultivars of tomato in southwest Nigeria


Author(s):  
Bitang Bamazi ◽  
Agnassim Banito ◽  
K. D. Ayisah ◽  
Rachidatou Sikirou ◽  
Mathews Paret ◽  
...  

Tomato (Solanum lycopersicum L.) is one of the most important vegetables in Togo. Unfortunately, tomatoes are susceptible to many diseases, among which bacterial wilt caused by Ralstonia solanacearum causes major yield losses. In this study, incidence of bacterial wilt and its distribution was evaluated in the central region of Togo, the major tomato producing area in the country. Overall, 16 localities were surveyed in four prefectures. In each locality, three fields were visited, and the incidence of the disease was recorded, and diseased samples were collected for laboratory investigation. The results showed that bacterial wilt occurred in all the fields visited, indicating a field incidence of 100%, whereas the plant incidence ranged from 10.00±00% to 43.33±3.33%, with an average of 20.94±1.77%. The antibody based Immunostrip test was positive for R. solanacearum in 100% of the visited fields. From 144 samples collected from fields, 45 R. solanacearum isolates were isolated on Modified SMSA media. This survey results show that tomato bacterial wilt is a real threat to tomato production in the central region of Togo.


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 ◽  
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):  
Anurag Kashyap ◽  
Montserrat Capellades ◽  
Weiqi Zhang ◽  
Sumithra Srinivasan ◽  
Anna Laromaine ◽  
...  

The soil borne pathogen Ralstonia solanacearum is the causing agent of bacterial wilt, a devastating disease affecting major agricultural crops. R. solanacearum enters plants through the roots and reaches the vasculature, causing rapid wilting. We recently showed that tomato varieties resistant to bacterial wilt restrict bacterial movement in the plant. In the present work we go a step forward by identifying the physico-chemical nature of the barriers induced in resistant tomato roots in response to R. solanacearum. We describe that resistant tomato specifically responds to infection by assembling de novo a structural barrier at the vasculature formed by a ligno-suberin coating and tyramine-derived hydroxycinnamic acid amides (HCAAs). On the contrary, susceptible tomato does not form these reinforcements in response to the pathogen but instead displays lignin structural changes compatible with its degradation. Further, we show that overexpressing genes of the ligno-suberin pathway in a commercial susceptible variety of tomato restricts R. solanacearum movement inside the plant and slows disease progression, enhancing resistance to the pathogen. We thus propose that the induced barrier in resistant plants does not only restrict the movement of the pathogen, but may also prevent cell wall degradation by the pathogen and confer anti-microbial properties.


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