Genetic variation in populations of the cacao wilt pathogen, Ceratocystis cacaofunesta

• Published in: Plant pathology Vol. 56; no. 6; pp. 923 - 933
• Main Authors: Engelbrecht, C.J.B, Harrington, T.C, Alfenas, A.C, Suarez, C
• Format: Journal Article
• Language: English
• Published: Oxford, UK Oxford, UK : Blackwell Publishing Ltd 01-12-2007; Blackwell Publishing Ltd; Blackwell
• Subjects: Biological and medical sciences; Ceratocystis; Ceratocystis fimbriata; Ceratocystis fimbriata complex; Fundamental and applied biological sciences. Psychology; Fungal plant pathogens; fungal population genetics; genetic diversity; genetic variation; Herrania; Herrania spp; Phytopathology. Animal pests. Plant and forest protection; Theobroma; Theobroma cacao; Ascomycota; Plant pathology; Genetic variability; Plant pathogen; Ceratocystis fimbriata complex; fungal population genetics; Herrania spp; Tropical crop; Stimulant plant; Population structure; Genetic diversity; Biodiversity; Population genetics; Fungi; Dicotyledones; Sterculiaceae; Ceratocystis fimbriata; Pathogenic; Angiospermae; Spermatophyta; Theobroma cacao
• ISSN: 0032-0862; 1365-3059
• DOI: 10.1111/j.1365-3059.2007.01735.x

Ceratocystis cacaofunesta (= Ceratocystis fimbriata) causes a lethal wilt disease of cacao (Theobroma cacao) in Latin America. Polymorphic microsatellite markers, (CAT)₅ nuclear DNA fingerprints and Hae III mitochondrial DNA fingerprints were used to compare genetic diversity among isolates of C. cacaofunesta collected from populations in western Ecuador, Costa Rica, Colombia, and Rondônia and Bahia in Brazil. Microsatellite markers and nuclear DNA fingerprints separated Ecuadorian isolates from isolates of the other four populations, and these two major groups correspond to genetic lineages already identified from ITS-rDNA sequences and intersterility groupings. Mitochondrial DNA fingerprints also demonstrated substantial diversity and split the Ecuadorian isolates into two groups. All marker types showed limited variation in the Colombian, Costa Rican and Bahian populations, as might be expected for introduced populations that have gone through recent genetic bottlenecks. In contrast, the Rondonian and western Ecuadorian populations showed gene diversity values similar to natural populations of other Ceratocystis species. The Rondonian population was the only sampled population in the native range of T. cacao (the Upper Amazon), and the putatively introduced populations were more closely related to the Rondonian population than to the western Ecuadorian population. The Ecuadorian population is in an area with other native Theobroma species, which may serve as natural hosts.