Cultural and biochemical properties of Ralstonia solanacearum causing bacterial wilt in potato (original) (raw)
Related papers
Journal of Agricultural Science, 2013
A survey was carried out in some selected potato growing districts of Bangladesh during December to February 2011 to know the status of bacterial wilt of potato caused by Ralstonia solanacearum in terms of its incidence and severity. The results showed that the highest wilt incidence was recorded in Munshigonj (22.65%), followed by Nilphamari (19.98%) and the lowest incidence was recorded in Jamalpur (9.07%). The highest bacterial wilt severity was recorded in Munshigonj (3.80), while the lowest wilt severity was recorded in Jamalpur (2.90). A total of 44 isolates (R. solanacearum) were obtained from the wilted potato plant samples i.e. 20 from Munshigonj, 17 from Nilphamari and 7 from Jamalpur and the isolates were divided into three groups. The production of pink or light red colour with whitish margin on TZC medium by the bacterial isolates indicated all groups of R. solanacearum isolates were virulent. The results of pathogenicity test revealed that all groups of R. solanacearum isolates were able to cause wilt symptoms in potato plants and brown rot symptoms in potato tuber. On the other hand, all biochemical tests were used for the identification of R. solanacearum isolates. The biovar test using the oxidization of disaccharides (sucrose, lactose, maltose) and sugar alcohols (manitol, sorbitol and dulcitol) by R. solanacearum isolates confirmed that all groups of R. solanacearum isolates belong to biovar III. The race identification of R. solanacearum isolates by pathogenicity test on brinjal, tomato, tobacco and chilli indicating a narrow host range (only in potato) and were categorized in race 3. Therefore, the R. solanacearum isolates causing bacterial wilt of potato in Bangladesh were belonging to Biovar III and Race 3.
2006
Ralstonia solanacearum is a very destructive pathogen that causes wilt in potato and many other solanacean crops in Ethiopia. In order to select effective antagonistic biocontrol agents for R. solanacearum strains, it is necessary to characterize the population of pathogenic strains. Therefore, 62 strains collected from wilted potato, tomato and pepper plants and potato tubers from the major potato producing regions of Ethiopia were characterized culturally and classified physiologically, based on their capacity to oxidize 3 disaccharides (lactose, maltose and cellobiose) and 3 hexose alcohols (mannitol, sorbitol and dulcitol). The results of this study indicated that all virulent strains from Ethiopia produce fluidal and irregular colonies with red centre and whitish periphery on triphenyl tetrazolium chloride (TZC) medium and irregular, fluidal, and creamy white colonies on casamino acids-pepton-glucose (CPG) medium. Physiologically, 19 strains were grouped to biovar I and 43 stra...
Bacterial wilt of sweet potato caused by Ralstonia solanacearum in Taiwan
Journal of General Plant Pathology, 2011
During the last decade, a new bacterial disease has impaired the yield of vegetable sweet potato (30-80%) in Taiwan. Infected plants developed stunting, root and stem rot, vascular discoloration and wilting. Ten bacterial isolates that caused the same symptoms in sweet potatoes after inoculation were reisolated and classified as Ralstonia solanacearum phylotype I biovar 4 based on physical and molecular analyses. Moreover, these isolates also caused wilting in convolvulaceous, solanaceaous and cruciferous plants. This report is the first of bacterial wilt of sweet potato caused by R. solanacearum in Taiwan.
Characteristics of Ralstonia Solanacearum Strains of Potato Wilt Disease from Nepal and Thailand1
2000
Characterization of strains of Ralstonia solanacearum, the causal agent of potato bacterial wilt disease from Nepal and Thailand was performed based on pathogenicity, biochemical/physiological and serological tests. Fifteen R. solanacearum strains isolated from wilt infected potato plants and tubers grown in Nepal were characterized as race 3, biovar II based on the pathogenicity on different host plants, hypersensitive re action
Isolation and Characterization of Ralstonia solanacearum Causing Bacterial Wilt of Tomato in Nigeria
2015
Bacterial wilt of tomato, caused by Ralstonia solanacearum (Rs), is endemic in most tomato-growing areas of Nigeria, causing 60 to 100% loss in yield. Control measure requires definite information on race and biovar characteristics of the pathogen in those endemic areas. Soil samples were collected from seven states in Nigeria known for high incidence of tomato bacterial wilt. Isolations were performed on triphenyl tetrazolium chloride (TZC) and casamino peptone glucose (CPG) media. Morphological characterization of the pathogen was through simple staining, streaming and KOH solubility test. Molecular confirmation of pathogen’s identity was through PCR amplification of genomic DNA using Rs-specific 759/760 primers (f:5'GTCGCCGTCAACTCACTTTCC-3’; r:5'-GTCGCCGTAGCAATGCGGAATCG-3’). Race was determined through hypersensitive reaction on tobacco leaves and biovar characterization was through carbohydrate utilization test. Thirty-four bacterial isolates showed the characteristic cr...
The most devastating disease of tomato is bacterial wilt (BW) caused by Ralstonia solanacearum which occur in hot and humid areas of Pakistan. Control of bacterial wilt is difficult, because the pathogen is soil-borne and has a wide host range. There is a need to establish resistance against this pathogen through biotechnological approaches. As a first step, infected tomato leaf samples were collected from various parts of soan skesar valley of Punjab, Pakistan. Isolations were performed on triphenyl tetrazolium salt (TTC) medium. Five samples, each of ten plants, from seven fields were used for isolation. Bacteria with similar characteristics were isolated from all positive samples which produced fluidal colonies that were either entirely white or white with red centre after incubation for 48 hours at 28 o C on TTC medium. They were found positive for gram staining, KOH test, Kovacs oxidase test, Catalase test, Oxidation/fermentation of glucose, Hydrolysis of tween 80 and negative for Arginine dihydrolase, Levan production, Salt tolerance, Lecithinase detection, Gelatin hydrolysis and production of Fluorescent pigment. Wilting and necrosis were observed for pathogenicity test and chlorosis/necrosis was observed for hypersensitivity. Isolates were identified as Ralstonia Solanacearum.. Out of 10 diseased plants, 7 were found positive and 3 were negative.
Phytopathology
Bacterial wilt (BW) caused by the Ralstonia solanacearum species complex (RSSC) is a serious threat to potato production in Uganda. However, little is known about the extent of the disease and the type of the pathogen strains involved. A nationwide survey was conducted to study BW prevalence and incidence in potato, and potato tuber and stem samples of potential alternative hosts were collected for pathogen isolation. DNA was extracted from pure cultures for genetic diversity studies. The pathogen was phylotyped by multiplex PCR; then, a subset of isolates was typed at sequevar level. Isolates of the same sequevar were then haplotyped using multilocus tandem repeat sequence typing (TRST) schemes. BW prevalence and incidence in potato farms were 81.4 and 1.7%, respectively. Three RSSC phylotypes were identified, with the majority of the strains belonging to Phylotype II (80%) followed by Phylotype I (18.5%) and III (1.5%). Phylotype I strains belonged to Sequevar 31, and Phylotype II...
Identification and Prevalence of Ralstonia Solanacearum from Potato Fields of Kyrgyzstan
2014
For the first time in Kyrgyzstan Raltsonia solanacearum bacterium as a pathogen of bacterial wilt (quarantine for the country object) was obtained and identified by enzyme-linked immunosorbent assay (ELISA) and biochemical methods. Three potato (Solanum tuberosum) cultivars: Picasso, Sante and Nevskiy were used for isolation of pathogen, which were collected from different regions of Kyrgyzstan. Detection and identification of the pathogen by ELISA performed directly from diseased potato shoots and leaves, and from pure culture of Ralstonia solanacearum isolated from tubers of potato seed during storage. For ELISA was used Ralstonia solanacerium PathoScreen R Kit DAS ELISA (Agdia product, USA).Isolated races of Ralstonia solanacearum by biochemical characteristics were classified as a 3-biotype.