The purified re-amplified PCR
products were ligated into the pEASY-T3Cloning Vector (TransGene
Biotech, Beijing, China) and the resultant ligation mix was
transformed into Trans1-T1 Phage Resistant Chemically Competent
Cells as per the manufacturer's instructions. The positive clones
were amplified using the above primers with GC clamp and
checked by DGGE. The correct clones were selected for sequencing
(Invitrogen). The sequences were aligned according to BLAST
similarity in order to find the most similar sequences from the
GenBank database. Similarity analyses were performed with
DNAStar and DNAMAN version 4.0; sequences with >97% similarity
were considered as the same phylotype. Phylogenetic analyses
were conducted using MEGA version 4.0 and
the neighbour-joining tree was constructed using Kimura
2-parameter distance with 1000 replicates to produce Bootstrap
values. The sequence types were named according to their genera
(Glo for Glomus and Arc for Archaeospora, etc.). The AMF sequences
that could not be aligned to sequences in the database were
indicated by “Unknown-AMF”.