DNA barcoding and scanning electron microscopy reveals Erysiphe ahmadii sp. nov. and a new record Erysiphe populicola (Erysiphaceae, Helotiales) on salicaceous hosts from Pakistan.

A new species of powdery mildew fungus Erysiphe ahmadii and a new record, Erysiphe populicola, on Salicaceae are described from Pakistan. In addition to light microscopy, scanning electron microscopy is also done to clearly demonstrate the surface characters of chasmothecia. E. ahmadii sp. nov. is characterized by large conidia ((-26)29-35(-37) × (-16)17-21(-23) µm), long chasmothecial appendages (198-286 µm) and small conidiophores. The novelty is confirmed by analyzing the genetic variation of internal transcribed spacer region (ITS1-5.8S-ITS2) of the ribosomal DNA gene, a universal fungal marker. E. populicola is characterized for the first time using molecular phylogenetic markers. Detailed descriptions along with scanning electron microscopy (SEM) photographs are provided in this paper. RESEARCH HIGHLIGHTS: Powdery mildews are obligate biotrophic pathogens of plants. Erysiphe ahmadii, a new powdery mildew fungus on willow trees, is described. First reference sequence of Erysiphe populicola is also generated. Both taxa are discussed in detail using macro- and micro-morphological and DNA barcoding techniques.

Mathematical modeling and experimental study of mechanical properties of chitosan based polyurethanes: Effect of diisocyanate nature by mixture design approach.

This research work has been done to investigate the influence of the geometry of aliphatic diisocyanate (hexamethylene diisocyanate, HDI), cycloaliphatic diisocyanate (isophorone diisocyanate, IPDI) and aromatic diisocyanate (2,4-toluene diisocyanate, TDI) on the tensile strength and hardness of chitosan based polyurethane biomaterials. For this purpose, chitosan (CS) and polycaprolactone diol (PCL) based polyurethanes have been synthesized with above mentioned diisocyanates following statistical design (mixture design). Simplex mixture design was used for analysis and totally 10 experiments were generated by the software. Samples were tested based on the portions of mixture components. Fourier transform Infrared attenuated total reflection (FTIR-ATR) and nuclear magnetic resonance (NMR) spectroscopic techniques confirmed the synthesis of chitosan based polyurethanes. This biomaterial has been established as an innovative and promising strategy to improve the mechanical strength of chitosan-based polyurethanes.