Population structure of the banana black sigatoka pathogen [Pseudocercospora fijiensis (M. Morelet) deighton] in Luzon, Philippines
Abstract
© 2019, College of Agriculture and Food Science, University of the Philippines Los Banos. All rights reserved. Black Sigatoka has been considered as one of the important diseases of banana in the Philippines, however, no study has been done in the Philippines on the population structure of the pathogen— Pseudocercospora fijiensis. This research determines and analyzes the genetic diversity and genetic differentiation of the pathogen populations as well as phylogenetic relationships of the isolates in Luzon. Ten microsatellite markers were used for DNA fingerprinting of 164 P. fijiensis isolates obtained from 10 different banana-growing provinces in Luzon. Gene diversity estimate of 0.36 was obtained for the entire population. Subpopulations of P. fijiensis from Quezon and Batangas (FST: 0.02) were genetically similar, whereas the subpopulations from Laguna and Pangasinan (FST: 0.34) were genetically distinct. Analysis of genetic differentiation showed that genetic divergence or similarity of subpopulations had no correlation to the geographic distance nor the genome group of the banana cultivar of origin of the isolates. Moreover, determination of the phylogenetic relationships among the isolates showed no correlation between the groupings or clusters formed with either the geographical or cultivar origin of the isolates. AMOVA showed that the amount of variation was higher within subpopulations (85% within provinces and 96% within cultivars) than among subpopulations (15% and 4% among provinces and cultivars, respectively).