Molecular detection and analysis of population structure of Mycosphaerella fijiensis deighton in Luzon

Date

12-2015

Abstract

The negative result obtained from the detection of the pathogen from planting materials indicates the absence of the pathogen since the plants tested were tissue cultured, and later grown in the greenhouse and showing no symptom. Negative results were also obtained from fruits from heavily infected banana plant and from fruits previously exposed to ascospores of the pathogen. These results confirm the reports that the pathogen does not infect the fruit. For the analysis of population structure of the M. fijiensis isolates from Luzon, ten microsatellite markers were used for DNA fingerprinting of 168 M. fijiensis isolates obtained from different banana growing regions in Luzon. Gene diversity estimate of 0.42 as determined by PowerMarker v3.25 was obtained for the entire population. From the 168 isolates, 129 multilocus haplotypes were generated,of which 113 and 16 were unique and common haplotypes, respectively, resulting to high haplotypic diversity of 0.9875 for the entire population. Analysis of genetic differentiation showed that subpopulations of M. fijiensis from Quezon and Batangas (F sub ST: 0.0148) were genetically similar whereas subpopulations from Laguna and Pangasinan (Fst: 0.3090) were genetically distinct. Subpopulation from Mindoro was genetically distinct from the subpopulations from seven provinces (Pangasinan, Cagayan, Isabela, Cavite, Laguna, Quezon, and Batangas). Determination of the phylogenetic relationships among the isolates showed no correlation between the groupings or cluster formed with either geographical or varietal origin of the isolates. However, isolates from a particular province or cultivar were found to be predominant in particular cluster. Analysis of Molecular Variance (AMOVA) showed that the amount of variation within subpopulations (85% within province and 96% within variety) was higher than among subpopulations (15% and 4% among province and varieties, respectively).

Document Type

Master Thesis

Degree

Doctor of Philosophy in Plant Pathology

College

Graduate School (GS)

Adviser/Committee Chair

Ardales, Edna Y.

Language

English

En – AGROVOC descriptors

MUSA (BANANAS); MYCOSPHAERELLA FIJIENSIS; PCR; DNA; DISEASE CONTROL; PLANT DISEASES; PHILIPPINES

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