Molecular approach to determine taxonomic status of Septoria sp.causing leaf blotch of Castanea sativa in Hyrcanian forests

Castanea sativa is a valuable tree species in Hyrcanian forests, an evolutionary relict ecosystem whose communities suffer from overexploitation and fungal diseases. In the current study, three species delimitation methods were utilized with ITS regions sequencing to determine the taxonomic status of Septoria causing leaf blotch of C. sativa in Hyrcanian forests. The results indicated that the length of ITS region in the genus Septoria (extracted from GenBank) varied from 650 to 680 bp. There were almost three times more variable sites in ITS1 than in ITS2. The ITS2 secondary structure of Hyrcanian Septoria community had the highest similarity with Septoria castaneicola, except for some differences in helix II and III. Also, Hyrcanian samples had minimum genetic distances with S. castaneicola and maximum with Septoria quercicola. The maximum parsimony method divided the studied Septoria genus into three distinct clades, mostly located in clade I. Clade II consisted entirely of Septoria aciculosa, while clade III contained S. castaneicola as well as Hyrcanian samples.

The world’s ten most feared fungi

An account is provided of the world’s ten most feared fungi.Within areas of interest,we have organized the entries in the order of concern.We put four human pathogens first as this is of concern to most people.This is followed by fungi producing mycotoxins that are highly harmful for humans;Aspergillus flavus,the main producer of aflatoxins,was used as an example.Problems due to indoor air fungi may also directly affect our health and we use Stachybotrys chartarum as an example.Not everyone collects and eats edible mushrooms.However,fatalities caused by mushroom intoxications often make news headlines and therefore we include one of the most poisonous of all mushrooms,Amanita phalloides,as an example.We then move on to the fungi that damage our dwellings causing serious anxiety by rotting our timber structures and flooring.Serpula lacrymans,which causes dry rot is an excellent example.The next example serves to represent all plant and forest pathogens.Here we chose Austropuccinia psidii as it is causing devastating effects in Australia and will probably do likewise in New Zealand.Finally,we chose an important amphibian pathogen which is causing serious declines in the numbers of frogs and other amphibians worldwide.Although we target the top ten most feared fungi,numerous others are causing serious concern to human health,plant production,forestry,other animals and our factories and dwellings.By highlighting ten feared fungi as an example,we aim to promote public awareness of the cost and importance of fungi.

Quambalaria species associated with eucalypt diseases in southern China

The genus Quambalaria includes several important pathogens of species of Eucalyptus and Corymbia, mainly causing leaf and shoot blight. Recently,extensive shoot and leaf dieback and stem cankers suspected to be Quambalaria diseases have been found on young Eucalyptus urophylla ? E. grandis trees in Guangdong and Hainan Provinces. The occurrence of Quambalaria species and their association with eucalypt hosts within China needs to be investigated for tree diseases management. The isolates from the diseased samples were identified based on their morphological structures and phylogenetic analyses with DNA sequence data for the internal transcribed spacer region and large ribosome subunit RNA of the nuclear r DNA. This work revealed that three species of Quambalaria were present: Quambalaria pitereka from Corymbia citriodora,Q. eucalypti from E. urophylla ? E. grandis, both isolated from young eucalypt leaves and shoots in Guangdong Province, and Quambalaria simpsonii, which was isolated from stem cankers of E. urophylla ? E. grandis at four different sites across Guangdong and Hainan Provinces.These results confirmed that Quambalaria agents were associated with the diseases occurring on eucalypt hosts in South China. This is the first report of Q. eucalypti in Asia and the first report of Q. simpsonii in China on Eucalyptus trees.

Evidence for the polyphyly of Encoelia and Encoelioideae with reconsideration of respective families in Leotiomycetes

This study focuses on the genus Encoelia and the subfamily Encoelioideae in the morphologically and ecologically diverse Helotiales.The 28S and 18S rDNA as well as tef1,rpb1 and rpb2 were sequenced for 70 species.Phylogenetic analyses revealed Encoelia and Encoelioideae to be highly polyphyletic,with species distributed among eight major lineages.Encoelia fascicularis and E.pruinosa belonged to Sclerotiniaceae and were combined in a new genus,Sclerencoelia.Rutstroemiaceae comprised E.tiliacea and Dencoeliopsis johnstonii,both accepted in Rutstroemia.The type of Encoelia,E.furfuracea,was closely related to species of Velutarina,Cenangiopsis and Crumenulopsis.These species together with members of Hemiphacidiaceae formed a clade conforming to the emended concept of Cenangiaceae,introduced here.Another resurrected family,Cordieritidaceae,comprised E.fimbriata,E.heteromera and species of Ameghiniella,Cordierites,Diplocarpa and Ionomidotis,characterised by inamyloid asci and a positive ionomidotic reaction.Encoelia glauca showed closest affinities with Chlorociboria species in Chlorociboriaceae.A new genus,Xeropilidium,with sporodochial and pycnidial synanamorphs,was described for the distinct encoelioid member of the Chaetomellaceae,previously known as E.fuckelii.Morphological and ecological synapomorphies were distinguished from convergent characters to delimit monophyletic taxa including encoelioid fungi.Incorporation of public sequences from various biological samples in ITS rDNA analyses allowed identification of sequenced organisms at species,genus,or family level and added information on the ecology of seversal taxa.Members of Cenangiaceae appeared to be widespread as endophytes.Inclusion of encoelioid genera in Chaetomellaceae and Sclerotiniaceae added xylicolous saprotrophs to these families.

Bird-plant interactions and vulnerability to biological invasions

Aims Species interactions regulate the invasiveness of non-native species and as declines of native tree species escalate,exotic tree species that offer supplementary resources to animal seed-dispersers should expand their distributions as they fill ecological roles.Our primary objective was to forecast impacts from an imminent biological invasion(laurel wilt disease)by quantifying resources provided by native(threatened)and exotic fruits(disease-resistant)and associated bird foraging preferences.Methods In the southeastern USA,we tested for redundancy among the resources provided by native and exotic fruits to overwintering birds.Comparisons between abundant subcanopy species Persea borbonia(native)and Cinnamomum camphora(exotic)were paramount considering the widespread disease-induced decline of P.borbonia,and the biological and phylogenetic similarities between these species.Across two winter survey periods,we quantified fruit removal and documented bird species using motion-activated cameras in the field.Physical and chemical fruit characteristics were also quantified.Important Findings Foraging bouts on both P.borbonia and C.camphora fruits were documented for four native bird species.There was no difference in selectivity between fruit types during Year 1 of our survey,but there was a significant preference for C.camphora fruit in Year 2;the change in preference was correlated with significantly lower temperatures in Year 2.While the pulp/seed ratio and moisture content differed,the nutritional content of fruit pulp(g/100 g)was similar between fruit types.Given the apparent redundancy among these native and exotic fruit resources,we forecast increases in the consumption and dispersal of exotic propagules following the widespread laurel wilt disease-induced decline of P.borbonia and other native fruit bearing members of Lauraceae.This empirically based prediction is among the first to document exotic forest pathogens as indirect threats to native bird-plant interactions and potential facilitators of exotic plant invasion.