Fungal endophyte diversity in coffee plants from Colombia, Hawai'i, Mexico and Puerto Rico

Coffee (Coffea arabica) plant tissues were surface-sterilized and fungal endophytes isolated using standard techniques, followed by DNA extraction and sequencing of the internal transcribed spacer region (ITS). A total of 843 fungal isolates were recovered and sequenced (Colombia, 267; Hawai'i, 393; Mexico, 109; Puerto Rico, 74) yielding 257 unique ITS genotypes (Colombia, 113; Hawai'i, 126; Mexico, 32; Puerto Rico, 40). The most abundant taxa were Colletotrichum, Fusarium, Penicillium, and Xylariaceae. Overall, 220 genotypes were detected in only one of the countries sampled; only two genotypes were found in all four countries. Endophytes were also isolated from Coffea canephora, Coffea congensis, Coffea liberica, Coffea macrocarpa, Coffea racemosa, and Coffea stenophylla in Hawai'i. The high biodiversity of fungal endophytes in coffee plants may indicate that most of these are " accidental tourists" with no role in the plant, in contrast to endophytes that could be defined as " influential passengers" and whose role in the plant has been elucidated. This study, the most comprehensive analysis of fungal endophytes associated with a single host species, demonstrates that coffee plants serve as a reservoir for a wide variety of fungal endophytes that can be isolated from various plant tissues, including the seed, and illustrates the different fungal communities encountered by C. arabica in different coffee-growing regions of the world.