Molecular characterization of <i>Pestalotiopsis</i> spp. associated with tea (<i>Camellia sinensis</i>) in southern India using RAPD and ISSR markers

377-383 The genus Pestalotiopsis is second most important fungal pathogen causing grey blight disease in tea plant (Camellia sinensis). Due to grey blight disease, total tea crop loss is estimated to be 17% in southern India. In the present study, 42 Pestalotiopsis isolates were collected from five different regions in southern India. Among them, 22 isolates showed diverse morphological characters like colour, size and length of conidia and virulence. Genetic diversity was studied for these 22 isolates using two molecular marker systems (RAPD and ISSR). In RAPD, a total of 255 loci were generated and all were polymorphic in nature and the band size ranged from 0.2 to 3.0 kb. In ISSR, 194 amplified loci were observed and all were polymorphic as like RAPD and the band size ranged from 0.25 to 3.2 kb. Using Jaccard’s similarity coefficient matrix, highest similarity of 95.9% and 92.6% was observed between AP-8 and AP-9 isolates in both RAPD and ISSR markers, respectively. Lowest similarity was observed between AP-14 and NP-5 (8.8%) in RAPD matrix but in ISSR matrix lowest similarity (18.5%) was between AP-14 and EN-5. The UPGMA clustering of both methods was comparable. The results indicate that, within southern India, the diversity of Pestalotiopsis was high both morphologically and genetically</smarttagtype

<i>Agrobacterium rhizogenes</i>-mediated hairy root production in tea leaves [<i>Camellia sinensis </i>(L.) O. Kuntze]

430-434Leaves of tea [Camellia sinensis (L.) O. Kuntze] plants were transformed with Agrobacterium rhizogenes strain (MTCC 532) and hairy roots were induced. Among the different concentrations of acetosyringeone tested, 300 M/L was found to enhance the transformation frequency upto 70%. Murashige and Skoog (MS) medium supplemented with 30 g/L maltose and indole-3-acetic acid (IAA) at 5 mg/L was found suitable for hairy-root culture and accumulation of phenolic compounds. Confirmatory studies were carried out by PCR analysis using rol C gene primer for transformation. Amplification of the specific gene was noted in the transformant at 540 bp. High performance liquid chromatography (HPLC) analysis confirmed the higher levels of catechins and their fractions in roots arising from the transformed tissues. Catechin fractions, viz., EC, ECG, EGC and EGCG were detected both in untransformed leaves and hairy roots produced by Agrobacterium infected cells

Facile Synthesis of Semiconducting Ultrathin Layer of Molybdenum Disulfide

In this paper, we have reported a simple and efficient method for the synthesis of uniform, highly conducting single or few layer molybdenum disulfide (MoS2) on large scale. Scanning Electron Microscopy (SEM) and High Resolution Transmission Electron Microscopy (HRTEM) have been used for the confirmation of mono or few layered nature of the as-synthesized MoS2 sheets. X-ray Photoelectron Spectroscopy (XPS), X-Ray Diffraction (XRD) and Raman Spectroscopy have also been used to study the elemental, phase, and molecular composition of the sample. Optical properties of as-synthesized sample have been probed by measuring absorption and photoluminescence spectra which also compliment the formation of mono and few layers MoS2 Current-voltage (I-V) characteristics of as-synthesized sample in the pellet form reveal that MoS2 sheets have an ohmic character and found to be highly conducting. Besides characterizing the as-synthesized sample, we have also proposed the mechanism and factors which play a decisive role in formation of high quality MoS2 sheets