Investigation of Phylogenetic Relationship among Three Species of Channa Based on ITS Sequence Analysis

[ Objective ] This study aimed to analyze genetic variation of ribosomal ITS region sequences in Channa argus, C moculata and C. asiatica, and to in- vestigate the phylogenetic relationship among Charma species based on ITS sequences. [ Method] ITS sequences of three Channa species were amplified by PCR, cloned and assembled to obtain the full length of ITS sequences. [ Result] The full length of ITS sequences of C. argus, C. maculata and C. asiatica was 902, 927, and 902/903 bp, respectively. ITS sequences of C. argus, C. maculata and C. asiatica exhibited higher G ＋ C （72%） than A ＋ T. Interspecific nucleotide differences were significantly greater than intraspecific differences of these three Channa species. Thus, these remarkably differential ITS fragments could be used to identify C. argus, C. maculata and C. asiatica. Phylogenetic tree constructed by Neighbor-joining and Maximum Likehood methods showed that C. argus shared the lowest genetic distance with C. maculata and the highest genetic distance with C. asiatica. [ Conclusion] This study provided reference for classification, i- dentification, phylogenetic analysis and interspecific hybridization of Channa species.

Diversity and composition of culturable fungi in Horqin Sandy Land

Soil fungi play a key role in soil functional performance and ecological restoration.To understand the diversity and composition of culturable fungi in soils of Horqin Sandy Land,China,mobile dune,semi-fixed dune,fixed dune and sandy grassland were selected to investigate the soil fungal diversity using a traditional culture-dependent approach.ITS sequencing was applied to identify the fungal strains.The counts of culturable fungi increased significantly from mobile dune to sandy grassland along the gradient of sandy land restoration.The Shannon-Wiener,Simpson and Evenness indices of culturable fungi ranged from 1.26-1.71,0.22-0.37 and 0.83-0.87,respectively.A total of 27 fungal strains were isolated using dilution plate cultural technique.The 27 fungal isolates were clustered into three groups:Ascomycota,Basidiomycota and Mucoromycota at phylum level,indicating that Ascomycota was the dominant fungal phylum(88.9%of the total).The isolated fungi were grouped into 3 phyla,5 classes,6 orders,11 families and 13 genera.The results show that culturable fungi were diverse in sandy land soils and fungal isolates have potential function in lipid turnover,cellulose degradation and ethanol,glucose and fatty acid production.Future studies should be carried out to explore their ecological and biological function for degraded sandy land restoration.