Submitted to: Fungal Diversity
Publication Type: Peer reviewed journal
Publication Acceptance Date: 2/24/2012
Publication Date: 3/24/2012
Citation: Tadych, M., Bergen, M., Cicalese, J., Polashock, J.J., Vorsa, N., White, J.F. 2012. Endophytic and pathogenic fungi of developing cranberry ovaries from flower to mature fruit: diversity and succession. Fungal Diversity. 54:101-116. Interpretive Summary: Relatively little is known about the diversity of fungal pathogens that infect developing cranberry fruit. We isolated fungi present in cranberry from the flower through the mature fruit stage and compared the results between fruit rot-resistant and fruit rot-susceptible accessions. A total of 2255 fungal isolates were cultured, representing 42 species of fungi. We found that the number of fungal species isolated increased throughout the season. Many of the fungi isolated did not cause fruit rot. There were no real differences between the species collected from rot-resistant accessions as compared to those that were rot-susceptible. These results suggest that the mechanism of fruit rot resistance in cranberry is expressed post-infection. These data will be useful to other research scientists as well as extension personnel working to improve cranberry fruit rot resistance.
Technical Abstract: Culturable fungal population diversity and succession were investigated in developing cranberry ovaries of fruit rot-resistant and rot-susceptible cranberry selections, from flower through mature fruit. Fungi were recovered in culture from 1185 of 1338 ovary tissues collected from June to September, yielding 2255 isolates that represented 42 morphotaxa. During the season, species richness varied from 2 to 17 and 2 to 18 in rot-resistant and rot-susceptible selections, respectively, increasing from wk1 to wk10 and then gradually declining to wk14. Shannon-Wiener diversity index varied from 0.27 to 2.32 in rot-resistant and 0.18 to 2.38 in rot susceptible, and Pielou’s evenness index varied from 0.11 to 0.63 and 0.06 to 0.64 in rot-resistant and rot-susceptible selections, respectively, confirming that diversity of fungi in developing ovaries was similar among rot-resistant and rot-susceptible selections, but varied among sampling time points. Principal component analysis grouped samples collected at the same sampling time point together regardless of rot susceptibility of the selections, and detected the predominant fungal species associated with each stage of development. Successional changes were observed in populations of endophytic, pathogenic and saprophytic fungi throughout the season as ovaries matured.