Isolation and Characterisation of Ralstonia Solanacearum Strains of Tomato Wilt Disease from Maseno, Kenya

Abstract

Article HistoryRalstonia solanacearum (E.F. Smith) Yabuuchi, is the cause of bacterial wilt of tomato and one of the most severe pathogens of solanaceous crops with a very wide host range. There is little information on R. solanacearum strains in Maseno region in Kenya despite the fact that bacterial wilt of tomato is of economic importance. The objective of this study was to isolate the strains of R. solanacearum of tomato and characterize morphologically and biochemically Ralstonia solanacearum races and biovars from infected tomato plants in Maseno region. This study was conducted at Maseno University in the Department of Botany at Microbiology Laboratory. Ten diseased tomato plants from Maseno, Mariwa, Seme and Hollo were collected and cut into small sections (0.5-1cm). The plant sections were then plated onto Triphenyl tetrazolium chloride (TZC) media. Profiling of the pathogen was done morphologicaly using culture techniques; biochemical tests included Gram staining test, Potassium hydroxide test, Catalase oxidase test, Gas production test, Starch hydrolysis test and sugar utilization test. The races were then identified by pathogenicity test on wide host range. All the isolates had fluidal pinkish red centered colonies on TZC media, they were Gram negative, potassium hydroxide solubility positive, produced gas from glucose, ooze test positive and did not hydrolyse starch which is typical of R. solanacerum. R. solanacearum strains from infected tomato plants in Maseno region were race 3 biovar 1 and race 3 biovar 3. All isolates were pathogenic on tomato plants.

Antibacterial activity of guava, moringa, camphor bush and pelargonium extracts against bacterial wilt (Ralstonia pseudosolanacearum sp. nov.) of potato

“…Similarly, morphological characteristics of the re-isolated bacterium from these test plants were identical to those of the original pathogen on TZC media. Similar results were reported in other studies ( Rahman et al, 2010 , Popoola et al, 2015 , Khasabulli et al, 2017 , She et al, 2017 ).…”

“…nov. characteristics on this medium as described by Kelman (1954) . Both the Gram stain and KOH solubility tests confirmed that the isolated bacterium was gram negative and this was in agreement with the research findings by Rahman et al, 2010 , Khasabulli et al, 2017 , She et al, 2017 . The isolated bacterium oxidized all the disaccharide sugars and hexose alcohols.…”

“…Similar results were reported by various scientists who classified the isolated R. pseudosolanacearum sp. nov. with similar characteristics as biovar III race 1 (Ralstonia solanacearum (phylotype I)) ( Rahman et al, 2010 , Popoola et al, 2015 , Boschi et al, 2017 , Khasabulli et al, 2017 ). Pathogenicity test of the isolated R. pseudosolanacearum sp.…”

Identification and Prevention of Microbial Contaminants in Musa paradisiaca Tissue Culture

“…The H 2 O 2 is a reactive oxygen species (ROS) that can cause plant cell death because of the carcinogenic effects at the high cellular level of H 2 O 2 (Khandaker et al, 2020). The catalase test suggested that these bacteria contain catalase that could neutralize hazardous forms of oxygen metabolites, such as H 2 O 2 into oxygen and water (Khasabulli et al, 2017). However, excessive accumulation of water in the vessels will cause hyperhydricity of the plant tissue, causing oxidative stress and oxygen depletion in the cells (Ziv, 2005).…”

EFFECT OF INOCULATING Bradyrhizobium liaoningense ON GROWTH, CHLOROPHYLL CONCENTRATION, NODULATION AND YIELD OF SOYA BEANS

“…Plant height was measured as described by Khasabulli et al (2017), from soil level to the upper point of the terminal bud of the seedling using a meter rule every fourteen days up to the end of the experiment. Two randomly selected plants in each pot were tagged and measured.…”