Studies On The Taxonomy And Molecular Phylogeny Of Mortierella And Allied Genera In China

The genus Mortierella(Mortierellaceae,Mortierelales,Mortierellomycetes,Zygomycota,Fungi)is diverse and distributed worldwide.It is important in biotechnology and biotransformation,though it causes serious animal and plant diseases.The classification of Mortierella currently adopted in China is only based on morphological characteristics.Nowadays,systematic has entered the age when morphology must be combined with molecules.Although ITS r DNA,the preferred molecular barcode of fungi,has been widely used,it cannot resolve all problems yet.With the globalization of biological resources,the screening of fungal auxiliary DNA barcodes is necessary.In order to provide support for industrial and agricultural production,this study focused on the morphological classification and multi-locus phylogeny of Mortierella in China,and consequently screened out its auxiliary barcodes.Morphologically,a new section,Indohii,was established herein for Mortierella in addition to the existing six sections.A total of 376 Mortierella strains isolated and collected in this study were identified into 43 taxa,including eight new Chinese records and eight possible new species.The new Chinese records are M.amoeboidea,M.antarctica,M.bainieri,M.beljakovae,M.cystojenkinii,M.fimbricystis,M.macrocystis and M.pulchella.The macro-and micro-scopic morphology of eight possible new species was described and illustrated in detial,with a discussion with allied species.In addition,the key to the sections and species of the Mortierella in China was updated.Multi-locus molecular phylogeny analysis showed that Mortierella is not monophyletic but paraphyletic with three genera Dissophora,Gamsiella and Lobosporangium.Therefore,this paper suggested that these genera should be treated as synonym of Mortierella,and consequently some new combinations were made.According to phylogenetic relationship among species,this study noted that the shape of sporangiospores were not phylogenetically informative,and should be regarded as a minor morphological feature in the classification,while the branching of sporangiophores with phylogenetic information should be treated as a major morphological characteristics.Based on a comprehensive assessment of success rates of PCR and sequencing,phylogenetic information,and average intra-and inter-specific similarities,LSU r DNA was screened out as an auxiliary barcode for Mortierella.This study updated and revised the classification of Mortierella,along with new section,new Chinese records,and possible new species.Its molecular phylogeny was reconstructed,its morphological characteristics were re-evaluated,and its auxiliary molecular barcode was preliminarily screened out.The present study enriched the fungal resources of Mortierella,and the result laid a foundation for the exploitation of beneficial Mortierella and for the prevention of harmful ones in China.