Biotechnology Journal International

Biodegradation of indeno (1, 2, 3- c, d) pyrene and dibenzo (a, h) perylene; high molecular weight PAHs  by isolates of aerobic heterotrophic bacteria, cyanobacteria and its consortium from Boodo Creek characterized with brackish water was monitored for 56 days using GC- MS. The initial concentration of indeno (1, 2, 3- c, d) pyrene in treatment with aerobic heterotrophic bacteria (AHB) was 0.09 mg/l, cyanobacteria (CB) was 0.08 mg/l; AHB+CB was 0.3 mg/l and the control, C was 0.12. Dibenzo (a, h) perylene had AHB 0.10 mg/l; CB 0.07 mg/l; AHB + CB 0.21 mg/l and C 0.23 mg/l. The quantity of the PAH’s monitored reduced to 0 on day 56 in all the treatment options though fluctuation in the quantity of the HMW PAH’s was observed throughout the period monitored for biodegradation. Biodegradation of indeno (1, 2, 3- c, d) pyrene and dibenzo (a, h) perylene did not vary with time (p > 0.05).

Aim: To reveal differential expression of host- response genes activated after nuclear polyhedro virus infection in transgenic silkworm Bombyx mori larva and to show an influence of ‘BmNPV transgenes’ on expression pattern of host- response genes.

Study Design: Relative expression profile of immune genes was analysed after BmNPV infection in transgenic and non-transgenic larvae by real-time PCR.

Place and Duration of Study: Genomics Division, Seribiotech Research Laboratory, Bangalore, India; 2014 January – 2016 December.

Methodology: Expression of immune genes encoding components of Toll and melanisation pathways was analysed in third instar larvae of transgenic B. mori line mff118B by quantitative PCR at 0, 6, 9 and 24 h after BmNPV infection and compared with infected non-transgenic larvae. A significant difference in relative expression was analyzed by Students't – test or ANOVA and correlation in expression pattern, by linear regression in the probability distribution of Y as a function of X, at significance level P < 0.05.

Results: In transgenic larvae, survival rate after NPV infection was up to 70% compared to 30% in non-transgenic larvae. Immune genes encoding NF-kappa B inhibition factor, Cactus, NF kappa B transcription factors, Dorsal and Relish, Toll- activating cytokine Spätzle, melanization pathway components, prophenol oxidase activating enzyme and prophenol oxidase1 showed significantly lower expression in BmNPV infected- transgenic larva whereas enhanced expression in infected non-transgenic larvae. In infected transgenic larvae, selected gene pairs Cactus – Dorsal, Cactus – Relish, Spatzle - Dorsal, Spatzle - Cactus, Relish – Dorsal showed positively correlated expression whereas the correlation derailed in infected non-transgenic larvae.

Conclusion: RNA interference-mediated inhibition of BmNPV multiplication was engineered previously in B. mori. In infected transgenic silkworm, NPV multiplication rate is low and host-response genes showed low expression level. Under the influence of transgenes, host response genes showed correlated expression thus transgenes preserve specific host- gene interactions after NPV infection. Notably influence of ‘BmNPV transgenes' on expression of host response gene is a crucial revelation in the field of transgenesis to develop better antiviral resistance in silkworms.

The cultivar Nanjanagud Rasabale (Musa spp. AAB, Silk subgroup) geographical indication tagged and leading cultivar of Mysore district. It is known for unique taste, has a huge demand across the country. In vitro regeneration in banana is preferred for faster multiplication rate compared to sucker propagation. The present study was carried out with the objective to investigate the effect of different antioxidants, BAP and auxins on in vitro regeneration of banana cv. Nanjanagud Rasabale. Shoot tip explants cultured on MS liquid medium supplemented with ascorbic acid 50 mg/l was found effective in controlling browning. Enhanced shoot proliferation and shoot growth were observed with MS medium containing BAP 4.0 mg/l + NAA0.50 mg/l. In vitro rooting of microshoots was effective with half strength MS medium supplied with NAA 0.5 mg/l.

Infections caused by Aspergillus have grown in importance in the last decade. Outbreaks which are caused by Aspergillus flavus appeared to be related to the single or closely related fungal strains. The fungi produce a compound known as aflatoxin which is reputed to be the most toxic and powerful hepatocarcinogenic compound. Most of the recent studies are mainly based on, the most abundance species in the genus. However, A. flavus is the second major reason for invasive aspergillosis and direct infections in most part of the world especially tropical countries. This study is focused on the molecular identification of A. flavus. For this purpose, spores were collected from air sample. Molecular identification of the fungi was done by using universal primers ITS -1F and ITS-4R. Phylogenetic tree demonstrated that the fungal spores collected from the air lie in the clad with Aspergillus, indicating its close relationship with the group.

Background: In breeding programs, the selection of parental lines based on their phenotypic traits along with genetic variation at their DNA level is the better option in directional breeding as specific DNA profiles would be useful in producing reliable estimates of genetic identity and diversity at their genomic levels. In this context, Random amplified polymorphic DNA (RAPD) marker approach was used to ascertain genetic diversity and relationship among 12 bivoltine silkworms (Bombyx mori L.) genotypes for the identification of diverse genotypes to be used as parents for the improvement of quantitative traits in silkworms.

Results: RAPD analysis with 12 silkworm genotypes revealed high polymorphism of 88.88%. Ten RAPD primers utilized in this study generated PCR products in the range of 202-2876 bp across 12 silkworm genotypes. The Polymorphism information content (PIC) ranged from 0.295 to 0.493%. Based on Nei’s similarity coefficients, the genetic distance among the studied silkworm genotypes ranged from 0.93 to 0.99. Of the pairwise combinations, CSR₁₈ and SH₆, showed the highest similarity (0.99) whereas, SKAU-R-6 and DUN₆ showed the lowest similarity (0.93) among the genotypes. The dendrogram generated, using Unweighted pair group method using the arithmetic average (UPGMA) from this marker, grouped the 12 silkworm genotypes into five main clusters, which corroborates the differences in their phenotypic characters.

Conclusion: The study clearly indicated the potential use of RAPD markers in differentiating silkworm genotypes based on their characters. The information generated on genetically divergent genotypes identified in this study would be useful in future silkworm breeding programmes for modifying the yield potentials of silkworms so as to boost up bivoltine silk production in the interest of temperate sericulture industry.