The active principle in a methanolic extract of the laboratory-grown cyanobacterium, Fischerella sp. isolated from Neem (Azadirachta indica) tree bark was active against Mycobacterium tuberculosis, Enterobacter aerogenes, Staphylococcus aureus, Pseudomonas aeruginosa, Salmonella typhi, Escherichia coli as well as three multi-drug resistant E. coli strains in in vitro assays. Based on MS, UV, IR 1 H NMR analyses the active principle is proposed to be Hapalindole T having the empirical formula C 21 H 23 N 2 ClSO and a molecular weight of 386 with the melting point range 179-182 • C. The estimated production of Hapalindole T from the cyanobacterium is 1.25 mg g −1 lyophilized biomass. It is suggested that cyanobacteria colonizing specialized niches such as tree bark could be an antibacterial drug resource.

The present study was aimed at the isolation, purification and structural elucidation of an antibacterial entity/lead molecule from the Antarctic cyanobacterium Nostoc CCC 537. A methanolic extract of the cyanobacterium was bioassayed with Enterobacter aerogenes as a target. The extract was purified by TLC, and the most active band was subjected to HPLC. The fraction (retention time 15.7 min) designated as the active principle was antibacterial towards Gram positive Mycobacterium tuberculosis H37Rv, Staphylococcus aureus ATCC 25923, Gram negative Salmonella typhi MTCC 3216, Pseudomonas aeruginosa ATCC 27853, Escherichia coli ATCC 25992, Enterobacter aerogenes MTCC 2822 and multi-drug resistant strains of Escherichia coli GS 2003/01, 02, 03.

A comprehensive germplasm evaluation study of wheat accessions conserved in the Indian National Genebank was conducted to identify sources of rust and spot blotch resistance. Genebank accessions comprising three species of wheat–Triticum aestivum, T. durum and T. dicoccum were screened sequentially at multiple disease hotspots, during the 2011–14 crop seasons, carrying only resistant accessions to the next step of evaluation. Wheat accessions which were found to be resistant in the field were then assayed for seedling resistance and profiled using molecular markers. In the primary evaluation, 19,460 accessions were screened at Wellington (Tamil Nadu), a hotspot for wheat rusts. We identified 4925 accessions to be resistant and these were further evaluated at Gurdaspur (Punjab), a hotspot for stripe rust and at Cooch Behar (West Bengal), a hotspot for spot blotch. The second round evaluation identified 498 accessions potentially resistant to multiple rusts and 868 accessions potentially resistant to spot blotch. Evaluation of rust resistant accessions for seedling resistance against seven virulent pathotypes of three rusts under artificial epiphytotic conditions identified 137 accessions potentially resistant to multiple rusts. Molecular analysis to identify different combinations of genetic loci imparting resistance to leaf rust, stem rust, stripe rust and spot blotch using linked molecular markers, identified 45 wheat accessions containing known resistance genes against all three rusts as well as a QTL for spot blotch resistance. The resistant germplasm accessions, particularly against stripe rust, identified in this study can be excellent potential candidates to be employed for breeding resistance into the background of high yielding wheat cultivars through conventional or molecular breeding approaches, and are expected to contribute toward food security at national and global levels.

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