, San Leandro, CA). The zero–one matrices were prepared on the basis of RFLP pattern and operational taxonomic units (OTUs) grouped through CLUSTAL W program using the
NTSYS version 2.1 software for each soil sample, and more than one representative of each group was sequenced. The sequencing of the actinomycetal specific 16S rRNA clones as performed on both the strands in ABI PRISM® 3100 Genetic EVP4593 nmr Analyzer (ABI, USA) using the Big Dye Terminator Kit (Version 3.1). Electropherograms were generated using the Chromas freeware (Version 2.01; Chromas lite Technelysium Pvt Ltd, Australia). Clones were finally checked for chimeric artifacts using CHECK-CHIMERA of the Ribosomal Database Project, and the chimeric sequences were discarded. The 16S rRNA sequences obtained, were initially recognized and aligned against the known sequences in the GenBank database using the BLAST program of the National Centre for Biotechnology Information (NCBI, http://www.ncbi.nlm.nih.gov/). The 16S rRNA clones obtained from
the non-Bt and Bt planted rhizospheric soils with > 90% similarity with the NCBI data base, were used for phylogenetic analysis using MEGA software version. Further details related to sequencing analysis are given elsewhere . Statistical analysis The complete randomized Ruboxistaurin cost design (CRD) with three replicates was used. Multivariate analysis of variance (MANOVA) was performed to determine the effect of treatments (non-Bt and Bt) at different growth stages. Multiple comparisons for difference in the means were Silibinin made using Tukey’s Highest Significant Difference (HSD) test (P < 0.05), SPSS 16.0. The correlation coefficient was calculated between different parameters using the method given by Senedecor and Cochran . The levels of significance (P < 0.01) and P < 0.05) are based on Pearson’s coefficients. Nucleotide sequence accession numbers The sequences of the 16S rRNA gene reported in this study,
have been deposited with the NCBI database under accession numbers: JQ285871- JQ285932. Results and discussion It is well proven that plants affect the population and diversity of soil microbial communities, but the reports on the impact of transgenic crops on soil microbial communities, are contrasting. From (Additional file 1: Table S1 ), it is clear that transgenic crops affect the actinomycetes population. However, a few studies have focussed on the actinomycetes community structure [35–37]. Wei et al.  reported on the impact of transgenic papaya on soil macro- and micronutrients only selleck screening library during pre- and post-cultivations. The available information on the impact of transgenic crops during different crop growth stages is scanty.