Abstract Background: Parthenium weed (Parthenium hysterophorus L.) is an invasive weed that has invaded vast regions of Pakistan in a relatively very short period of a decade or two, threatening the crop fields of the agrarian fed country. Parthenium hysterophorus L. is native of central South America and Gulf of Mexico, has now turned out to be a weed of global significance due to its alarming invasions and profuse spread in approximately all parts of the world. Its invasion is probably due to the contamination of its seeds in the imported grains from other countries of the world. Objective: During comprehensive sampling from Pakistan and Australia, it was observed that parthenium weed accessions exhibited several distinct morphological features present at different geographical regions. Therefore this study focuses on the use of plastid DNA barcodes (psbA-trnH) to evaluate the extent of variations in nucleotide sequences between the parthenium weed sampled accessions. Methods: The variability or genetic diversity was evaluated through sequencing of the amplified products and data was subjected to phylogenetic analysis in Molecular Evolutionary Genetic Analysis (MEGA; version 6.06) software. Results: In Maximum Likelihood tree, mainly two clades with three subdivisions are evident which showed increased heterogenity. The results of sequence based markers showed 12 haplotypes of P.hysterophorus populations (having two parsimony informative sites) with 10 indels and a few SNPs (single nucleotide polymorphisms). Conclusions: The results advocate that there have been multiple introductions of parthenium weed into Pakistan.

This study was planned to determine the dynamics of total phenolic content, polyphenol oxidase and peroxidase activities in wheat (var. Inqlab-91) infected with Ustilago tritici with the objective to investigate the role of phenolics and related enzymes in host pathogen interaction. The biochemical analysis was carried out twice, once at grain filling stage when disease emerges and second at crop maturity. Roots were found most sensitive as considerable increase in both phenolic content and enzymes activity was recorded in early and later stage of disease development. Conversely in case of infected stem and leaves the enzyme activities were found lower at early disease stage in comparison to the control. However, the enzyme activities increased in both parts when checked again at crop maturity with an exception of no increment in peroxidase and cresolase activities in leaves.

Most of the studies regarding cyclosporin 'A' production through fungi concentrate around Tolypocladium inflatum. This is mainly due to lower reported production of this drug in other fungi. The present study was therefore conducted to explore indigenous isolates of Aspergillus terreus for synthesis of this drug and defining a production medium for obtaining high yield of cyclosporin 'A'. For this purpose carbon and nitrogen sources were optimized for the selected best strain of A. terreus. Overall results depicted that the best cyclosporin 'A' yield from selected Aspergillus terreus (FCBP58) could be obtained by using production medium containing glucose 10% as carbon source and peptone 0.5% as nitrogen source. This modification in production medium enhanced drug synthesis by selected fungi significantly. The production capabilities when compared with biomass of fungi there was found no relationship between the two confirming that the medium modification increased overall drug synthesis powers of the fungi.