Genetic diversity of bacterial wilt pathogen, Ralstonia solanacearum (E.F. Smith) Yabuuchi et. al., isolated from stem and rhizosphere of farmer 301, a susceptible cultivar of tomato (Lycospercon esculentum Linn.)

Date

4-2000

Degree

Bachelor of Science in Biology

College

College of Arts and Sciences (CAS)

Adviser/Committee Chair

Celia B. Dela Viña

Co-adviser

Jaw-Fen Wang

Abstract

A total of thirty-six strains from the stem and rhizosphere of Farmer 301, a susceptible tomato cultivar, were used to assess the genetic diversity of Ralstonia solanacearum population. All the strains were identified as R. solanacearum using R. solanacearum-strain-specific primer (AL1759/760). Results showed a specific 281-bp band amplified by the 759/760 primer. Strains were characterized as biovar 3 and biovar 4 according to Hayward's classification scheme. Biovar 3 oxidized both the disaccharides, lactose, maltose and celliobiose, and alcohols ,mannitol, sorbitol and dulcitol, whereas, biovar 4 oxidized the alcohols but not the dissacharides. Both biovars are known to infect tomato. Comparison of the isolated biovars showed that 89,0% of the tomato plants contain strains with the same biovar whereas 11.0% of the tomato plants have different biovars. Repetitive Extragenic Palindromic Polymerase Chain Reaction (REP-PCR) generated large genetic variation among the 36 isolates A total of 22 band positions, ranging from 250 to 5,000 by were observed, resulting to 35 haplotypes. Bands 250 and 3000 were present in all the strains. The calculated genetic diversity (H) revealed a high genetic variation in all the isolates. A tree was generated using unweighted pair-group method with arithmetic mean method (UPGMA). Based on cluster analysis, the 36 strains can be grouped into 7 clusters. No association exists among biovar, genotype and location

Language

English

Location

UPLB Main Library Special Collections Section (USCS)

Call Number

Thesis

Document Type

Thesis

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