Botryosphaeriaceae Theiss. & H.Syd.

Review of Botryosphaeriaceae species reported from Arecaceae

Twenty-two genera are currently included in Botryosphaeriaceae, viz. Alanphillipsia, Barriopsis, Botryobambusa, Botryosphaeria, Cophinforma, Diplodia, Dothiorella, Endomelanconiopsis, Eutiarosporella, Lasiodiplodia, Macrophomina, Marasasiomyces, Mucoharknessia, Neodeightonia, Neofusicoccum, Neoscytalidium, Oblongocollomyces, Phaeobotryon, Sakireeta, Sardiniella, Sphaeropsis and Tiarosporella (Yang et al. 2017, Wijayawardene et al. 2022). A search of the US National Fungus Collections Fungus-Host Database (Farr & Rossman 2023) was conducted to reveal the reported associations between each Botryosphaeriaceae genus and members of the family Arecaceae. These were supplemented with additional reports from available literature on Botryosphaeriaceae species reported from palms not covered by Farr & Rossman (2023). About 60 species of Botryosphaeriaceae were found to be associated with hosts in the family Arecaceae. These species names were verified against MycoBank and Index Fungorum databases (Crous et al. 2004, Index Fungorum Partnership 2023) as well as the available literature, including the most recent overviews of the taxonomy of the family Botryosphaeriaceae (e.g., Slippers et al. 2017, Yang et al. 2017, Phillips et al. 2019, Zhang et al. 2021a). Taking into account that some species are regarded as synonyms, including the data from this study, we can accept that 31 valid species are associated with Arecaceae worldwide.

Reports of Botryosphaeriaceae taxa collected from Arecaceae hosts prior to the early 2000 should be considered unreliable, since the taxonomic concept of the family and respective genera was not clear until the first phylogenetic treatments of Botryosphaeriaceae (e.g., Crous et al. 2006, Schoch et al. 2006) and subsequent revision and update studies (e.g., Phillips et al. 2013, 2019, Slippers et al. 2013, 2017, Yang et al. 2017, Zhang et al. 2021a). Thus, many of the early reports and respective host associations with Arecaceae members could be misidentifications. Morphological characters have long been considered inadequate to define genera or identify species in Botryosphaeriaceae, particularly given the confusion that they have repeatedly introduced in several lineages over the years (Phillips et al. 2013, Slippers et al. 2013, 2014, 2017). In this sense, currently valid Botryosphaeriaceae species that were described on palms based solely on morphological data were disregarded, and comments on their exclusion from the present review are noted below. Table 5 lists all current accepted names of Botryosphaeriaceae species associated with Arecaceae, their respective hosts and countries from which they were recorded.

The following genera have not previously been reported from palm hosts: Alanphillipsia, Botryobambusa, Cophinforma, Dothiorella, Eutiarosporella, Marasasiomyces, Mucoharknessia, Neoscytalidium, Oblongocollomyces, Phaeobotryon, Sakireeta, Sardiniella and Tiarosporella. Nevertheless, in the present study D. viticola is reported from four palm species (Chamaerops humilis, Trachycarpus fortunei, Phoenix roebelenii and Washingtonia filifera) and S. urbana is reported from P. reclinata. Thus, currently only one species in each of the genera Dothiorella, Sardiniella, as well as Barriopsis and Endomelanconiopsis, have been reported from palm hosts (Table 5). Two species of Macrophomina and Sphaeropsis have been reported from palm hosts, but their identification was based solely on morphology. Thus, for the reasons detailed above, the valid name for these taxa cannot be confirmed and the reports were excluded from the list of Botryosphaeriaceae species recorded on Arecaceae.

Most Botryosphaeriaceae species reported from palm hosts reside in the genera Botryosphaeria, Diplodia, Lasiodiplodia, Neodeightonia and Neofusicoccum. Nonetheless, most of these species were identified based on morphological data and, for the reasons detailed above, they were disregarded in this analysis. Ten Botryosphaeria species have been reported from palms, besides some unnamed reports, but only two (B. dothidea and B. fabicerciana) were based on both morphological and molecular data and are here considered. In the present study, B. dothidea was recorded from C. humilis, representing a new host record (Table 5). Concerning Diplodia, 25 species have been reported from palms, besides some unnamed reports, but only three (D. arengae, D. laelio-cattleyae and D. mutila) were based on both morphological and molecular data and are here considered. In the present study, D. mutila has also been recorded from P. dactylifera (Table 5). A total of nine Lasiodiplodia species, besides some unnamed reports, have been reported from palms, and all of them have been reported based on both morphological and molecular data. For that reason, the nine species (L. brasiliensis, L. euphorbiaceicola, L. hormozganensis, L. iranensis, L. lodoiceae, L. mexicanensis, L. pseudotheobromae, L. subglobosa and L. theobromae) are here considered (Table 5). Six Neodeightonia species have been reported from palms based on morphological and phylogenetic data and are here considered (N. licuriensis, N. palmicola, N. phoenicum, N. rattanica, N. rattanicola and N. septata). In the present study, the new species N. chamaeropicola collected from foliar lesions of C. humilis is introduced and represent a new Neodeightonia taxa from palms (Table 5). During a study aimed to identify the Botryosphaeriaceae species associated with diseased symptomatic palms in Florida, a new species of Neodeightonia has been noted by Elliot et al. (2018) based on phylogenetic analyses. Although this report was supported with molecular data, no morphological information was included, and the species remained unnamed and was simply regarded as Neodeightonia sp. (Figure 4). Thus, this species was disregarded from the present listing of Botryosphaeriaceae species reported from Arecaceae. Three Neofusicoccum species, supported with morpho-molecular data have been reported from palm hosts and are here considered (N. brasiliense, N. cryptoaustrale and N. ribis). In this study, besides the report of N. Cryptoaustrale from C. humilis, three additional Neofusicoccum species were isolated from foliar lesions of different palm hosts, representing new host records, namely N. australe (from P. canariensis), N. luteum (from C. humilis, P. canariensis and W. filifera) and N. parvum (from P. dactylifera and P. roebelenii) (Table 5). Elliot et al. (2018) also reported an unidentified Neofusicoccum species from P. dactylifera in Florida based on phylogenetic analyses, but due to insufficient resolution of the combined ITS- tef1 dataset, the isolate was only regarded as Neofusicoccum sp. Thus, this record was disregarded from the present listing of Botryosphaeriaceae species reported from Arecaceae.