Genotypic variation of bacterial wilt-causing pathogen, Ralstonia solanacearum (E.F. Smith) yabuuchi et al., isolated from L285, a resistant variety of tomato, Lycopersicon esculentum var. cerasiforme (Linn.)

Date

3-2000

Degree

Bachelor of Science in Biology

College

College of Arts and Sciences (CAS)

Adviser/Committee Chair

Merlyn S. Mendioro

Co-adviser

Jaw-fen Wang

Abstract

Genotypic variation of wilt-causing bacteria, Ralstonia solanacearum (E.F. Smith) Yabuuchi et al., in a single field was investigated by isolating and purifying strains from wilted plants of the L285, a resistant variety of tomato, from the Taichung Seed Service field. The strains isolated were first identified to be R. solanacearum by using the strain-specific primer-polymerase chain reaction method wherein a 281- basepair band was amplified. Using biochemical utilization of the six carbohydrates, the strains were identified to be biovar 3 and 4. A pairwise comparison was done to check the biovar in the rhizosphere and the stem. Nine out of the 12 strains yielded the same biovar. The REP-PCR and RAPD were used to investigate if the strains present in the rhizosphere and the stem are genetically similar. The strains from the same plant revealed bands different from each other, indicating genetic dissimilarity. A total of 58 banding patterns from the 63 strains were obtained. The Nei's value of haplotypic diversity (H) of the whole population is 0.997. This indicates that the strains are highly diverse. The strains collected from the stem are also diverse as well as in the rhizosphere. Values of 0.997 and 1 were obtained, respectively. There were no well-defined clusters when a UPGMA tree was done. Results reveal that indeed genotypic variation exists in R. solanacearum.

Language

English

Location

UPLB Main Library Special Collections Section (USCS)

Call Number

Thesis

Document Type

Thesis

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