Population Characterization of Brazilian Isolates of Ceratocystis spp Using Microsatellites

The genus Ceratocystis includes several species of economically important plant pathogens and has a global distribution. In Brazil, species in the genus cause disease and death of hosts such as cacao, eucalypts and mango. This study aimed to characterize the population structure and diversity of isolates of Ceratocystis fimbriata sensu lato collected from diseased Eucalyptus species and to compare these to isolates from cacao, mango, teak, fig, rubber and atemoya. Ten SSR markers developed previously were used and were polymorphis. These markers produced a total of 76 alleles for the 49 C. fimbriata isolates used in this study. Three distinct populations were identified using STRUCTURE and LNK analyses. Analysis of population differentiation show a Ө = 0.27 and p ≤ 0.04. High values of genotypic diversity were obtained for the combined (68.25%) and separate populations (77.77%, 52.08% and 100%). For the combined population, the Association Index (Ia) and baD values (Rd) were 1.91 and 0.22, respectively, indicating a high rate of recombination among the isolates.