| Junggar Basin,located in the north of Xinjiang,is the second largest inland basin of China.The special geographic location,unique climatic condition and diverse ecological environment in the Basin bred and formed a unique and diverse group of desert vegetation.But the abnormal growth and development of these desert plants owing to the infection and damage of pathogenic fungi,had an adverse effect to the fragile ecosystem.As a diverse and indistinguishable taxa,studies on Septoria and Septoria-like genera in Xinjiang had focused on morphology,and few on molecular systematic have been conducted.With the Septoria and septoria-like genera on desert plant as the object,a wide range of specimen collection and isolation were conducted in the Junggar Basin of Xinjiang in this study.A total of 93 disease samples were collected and 93 strains were isolated.Combined with the 17 strains stored in the HMUT at Tarim University,110 strains were studied in this research.Based on the concatenated alignments of LSU,ITS and RPB2,the phylogenetic trees on the the genera of the tested isolations and the related genera in Gen Bank were generated with Bayesian Inference and Maximum Likelihood,to clarify the position of genera that the strains from Junggar Basin belonged to.And based on a concatenated alignments of seven loci including LSU,ITS,RPB2,EF,Tub,ACT and CAL,the phylogenetic trees were generated with Bayesian Inference and Maximum Likelihood to resolve the phylogenetic positions of the strains in Septoria and Sphaerulina in the region,to provide the molecular foundation for phylogeny and evolution analysis of Septoria.The main results in this study are as follows.Based on the morphology study of the 110 sequenced strains in vitro and the phylogenetic analysis of the concatenated alignment of the three loci,it was clarified that the 110 strains in the region belong to 3 families: Saccotheciaceae,Dothideaceae and Mycosphaerellaceae.Of the 110 strains,Only Pseudoseptoria was found in Saccotheciaceae;Dothiora was found in Dothideaceae;But in Mycosphaerellaceae,there are eleven recorded genera: Ramularia,Leptothyrium,Parasphaerulina,Pseudocercospora,Sphaerulina,Neoseptoria,Caryophylloseptoria,Cercospora,Septoria,Apseudocercosporella and Neopseudocercosporella,and six potential genera: Clade 11,Clade 14,Clade 44,Clade 48,Clade 51 and Clade 60.A new genus Parasphaerulina B.Xu,S.H.Zhang & Z.D.Jiang;two new species Neoseptoria tienshanensis B.Xu & Z.D.Jiang,Parasphaerulina alhagicola B.Xu,S.H.Zhang & Z.D.Jiang and two new combinations Parasph.caraganae(Hennings)B.Xu,S.H.Zhang & Z.D.Jiang,Parasph.thermopsidis(Murashk)B.Xu,S.H.Zhang & Z.D.Jiang were confirmed.With the phylogenetic analysis of the combined seven loci sequence alignment,the systematic positions of 16 species in Septoria and 4 species in Sphaerulina on desert plants in Junggar Basin were clarified. |
