Shinawar Waseem Ali

FIRST REPORT OF CURVULARIA LUNATA var. AERIA CAUSING LEAF BLIGHT ON TOMATO IN PAKISTAN

Tomato plants showing the symptoms of leaf blight were observed in March 2015 in the tunnels on the premises of the University of the Punjab, Lahore, Pakistan. Initial symptoms were water- soaked flecks of brown color, which coalesced later to form dark brown lesions. Diseased leaves were collected and a fungus was isolated on potato dextrose agar (PDA) plates incubated at 25 ± 2°C. Fungal colonies were dark brown, and usually zonate. Conidia were ellipsoidal, smooth, 3- septate, with middle cells broader and darker than two end cells and had a size of 18-32×8-16 μm. Conidiophores were septate, pale brown, smooth, and up to 800 μm long (Ellis, 1971). Total DNA was isolated from the mycelium and the internally transcribed spacer (ITS) region was amplified (White et al., 1990) and sequenced (GenBank accession No. LN879930). BLAST analysis of the fungal sequence showed 100% nucleotide similarity with Curvularia aeria accession Nos. KP340067.1, KP340066.1, KP131919.1, and EU680523.1. Based on its morphological and molecular features, the fungus was identified as Curvularia lunata var. aeria (Bat.) M.B. Ellis. C. lunata var. aeria is a taxon accepted as a variety of C. lunata, which is distinguished from C. lunata var. lunata because of the faster and floccose mycelial growth. Pathogenicity was assessed by reproduction of symptoms on inoculated healthy plants, which fulfilled Koch’s postulates. To our knowledge, this is the first report of the presence of C. aeria on tomato in Pakistasn.

Evidence of genetically diverse virulent mating types of Phytophthora capsici from Capsicum annum L.

Chili pepper (Capsicum annum L.) is an important economic crop that is severely destroyed by the filamentous oomycete Phytophthora capsici. Little is known about this pathogen in key chili pepper farms in Punjab province, Pakistan. We investigated the genetic diversity of P. capsici strains using standard taxonomic and molecular tools, and characterized their colony growth patterns as well as their disease severity on chili pepper plants under the greenhouse conditions. Phylogenetic analysis based on ribosomal DNA (rDNA), β-tubulin and translation elongation factor 1α loci revealed divergent evolution in the population structure of P. capsici isolates. The mean oospore diameter of mating type A1 isolates was greater than that of mating type A2 isolates. We provide first evidence of an uneven distribution of highly virulent mating type A1 and A2 of P. capsici that are insensitive to mefenoxam, pyrimorph, dimethomorph, and azoxystrobin fungicides, and represent a risk factor that could ease outpacing the current P. capsici management strategies.

Occurrence of Aflatoxin M1 in raw and processed milk and assessment of daily intake in Lahore, Multan cities of Pakistan

ABSTRACT In this survey aflatoxin, M1 was quantified in raw and processed milk from various areas of two big cities of Punjab province, i.e. Lahore and Multan. The results indicated that approximately 90% of the raw milk samples collected from Lahore city was contaminated with aflatoxin M1. Similarly, around 92% of the raw milk samples collected from Multan city was contaminated with aflatoxin M1. All samples of processed milk and tea whiteners were contaminated and 56% of the contaminated processed milk samples and 66% of the contaminated tea whitener samples were violating the maximum limits. The dietary exposure data of AFM1 among six different groups was calculated, which indicated that the male children population was the most vulnerable group to AFM1, up to 6.68 ng L−1 per day and the least affected one was the female group above 20 years of age with 1.13 ng L−1 per day.

Further characterization of o-nitrobenzaldehyde degrading bacterium Pseudomonas sp: ONBA-17 and deduction on its metabolic pathway

A previously reported o-nitrobenzaldehyde (ONBA) degrading bacterium Pseudomonas sp. ONBA-17 was further identified and characterized. Based on results of DNA base composition and DNA-DNA hybridization, the strain was identified as P. putida. Its degradation effect enhanced with increase of inoculum amount and no lag phase was observed. Higher removal rate was achieved under shaking conditions. All tested ONBA with different initial concentrations could be completely degraded within 5 d. In addition, degradative enzyme(s) involved was confirmed as intra-cellular distributed and constitutively expressed. Effects of different compounds on relative activity of degradative enzyme(s) within cell-free extract were also evaluated. Finally, 2-nitrobenzoic acid and 2, 3-dihydroxybenzoic acid were detected as metabolites of ONBA degradation by P. putida ONBA-17, and relevant metabolic pathway was preliminary proposed. This study might help with future research in better understanding of nitroaromatics biodegradation.