ena-STUDY-Integrative Pilzforschung-20-02-2018-22:08:31:534-554
Broad host range species in specialised pathogens should be treated with suspicion – A case study in Entyloma reveals high, host-correlated diversity in pathogens infecting Ranunculus
Plantpathogenic smut fungi in the broader sense can be divided into the Ustilaginomycetes, which cause classical smut symptoms with masses of blackish spores being produced in a variety of angiosperms, and the Exobasidiomycetes,which are often less conspicuous, as many do not shed large amounts of blackish spores. The leaf-spot causing members of the genus Entyloma belong to the latter group. Currently, 172 species, all dicot-affecting, are included in the genus. Vánky (2012) recognised five Entyloma species on host plants belonging to the genus Ranunculus sensulato. Two of them have been reported only from Ficaria verna s. lat., while three of them, E. verruculosum, E.microsporum, and E.ranunculi-repentis, have been reported to have a broad host spectrum,encompassing 5, 30, and 26 Ranunculusspecies, respectively. This is in contrast to the generally high host specificity assumed for species of Entyloma,suggesting that they might represent a complex of specialized species. Thus, it was the aim of this study to investigate Entyloma on Ranunculus s. lat. using multi gene phylogenies and morphological comparisons, focusing on the two species reportedly occurring on the largest amount of different host species. Phylogenetic analysis using up to four loci (ITS, atp2, ssc1 and map) showed a clustering of Entyloma specimens according to host species. For some of the resultant Entyloma lineages, names not in use are available and were, thus, reinstated. In addition, Entyloma microsporum s. str. is fixed in its application by neotypification. Six species, for which no nameshad previously been published, are described in this study: Entyloma jolantae on Ranunculus oreophilus, E. klenkei on R. marginatus, E. kochmaniion R. lanuginosus, E. piepenbringiaeon R. polyanthemos subsp. nemorosus (type host) and R. repens, E. savchenkoi on R. paludosus,and E. thielii on R. montanus. For all species diagnostic bases and morphological characteristics are provided. The results in this study once more highlight the importance of detailed re-investigation of broad-range pathogens of otherwise specialised plant pathogen groups.
Plantpathogenic smut fungi in the broader sense can be divided into the Ustilaginomycetes, which cause classical smut symptoms with masses of blackish spores being produced in a variety of angiosperms, and the Exobasidiomycetes,which are often less conspicuous, as many do not shed large amounts of blackish spores. The leaf-spot causing members of the genus Entyloma belong to the latter group. Currently, 172 species, all dicot-affecting, are included in the genus. Vánky (2012) recognised five Entyloma species on host plants belonging to the genus Ranunculus sensulato. Two of them have been reported only from Ficaria verna s. lat., while three of them, E. verruculosum, E.microsporum, and E.ranunculi-repentis, have been reported to have a broad host spectrum,encompassing 5, 30, and 26 Ranunculusspecies, respectively. This is in contrast to the generally high host specificity assumed for species of Entyloma,suggesting that they might represent a complex of specialized species. Thus, it was the aim of this study to investigate Entyloma on Ranunculus s. lat. using multi gene phylogenies and morphological comparisons, focusing on the two species reportedly occurring on the largest amount of different host species. Phylogenetic analysis using up to four loci (ITS, atp2, ssc1 and map) showed a clustering of Entyloma specimens according to host species. For some of the resultant Entyloma lineages, names not in use are available and were, thus, reinstated. In addition, Entyloma microsporum s. str. is fixed in its application by neotypification. Six species, for which no nameshad previously been published, are described in this study: Entyloma jolantae on Ranunculus oreophilus, E. klenkei on R. marginatus, E. kochmaniion R. lanuginosus, E. piepenbringiaeon R. polyanthemos subsp. nemorosus (type host) and R. repens, E. savchenkoi on R. paludosus,and E. thielii on R. montanus. For all species diagnostic bases and morphological characteristics are provided. The results in this study once more highlight the importance of detailed re-investigation of broad-range pathogens of otherwise specialised plant pathogen groups.