The morphological characterization was carried out for 5 isolates of Trichoderma harzianum and 7 isolates of Trichoderma viride and tested for their biocontrol efficacy. The isolates belonging to T.harzianum were analogous in colony colour, culture smell, mycelial colour, conidiation, conidial shape, conidial wall and conidial colour. Correspondingly the isolates of T.viride showed certain similarity in colony colour, colony edge, culture smell, conidiophore branching, conidial wall, conidial colour and chlamydospores. Inter specific differences through cluster analysis based on morphological characters grouped the twelve isolates into three major clusters where all the isolates of T.harzianum formed a single cluster while the isolates of T.viride were bifurcated into two groups. The clustering was substantiated by similarity index which showed maximum similarity among T.harzianum isolates with only less than 20% variation among themselves. Similarly the clusters having isolates of T.viride also had less variation within them. The biocontrol efficacy of these twelve isolates of Trichoderma was experimented by dual culture test under laboratory condition and there existed some relation between the biocontrol efficacy of these isolates and morphology.
Mycoherbicides are special biotechnology products which contain fungi or fungal metabolites as nonchemical alternatives thereby reducing the input of harmful chemicals to control noxious weeds. The present communication emphasizes on the potential of an indigenous isolate of Alternaría alternata ITCC 4896 as a mycoherbicide for the global weed - Parthenium hysterophorus. Of the various spore concentrations tested by in vitro Detached Leaf Bioassay, 1x106 spores/ml was the most effective inducing 89.2% leaf area damage on the 7th day and was further tested by Whole Plant Bioassay. Both in vitro Detached Leaf Bioassay and Whole Plant Bioassay exhibited a similar trend in disease development showing 50% damage at 96 hours post treatment. However, 100% mortality was observed in the Whole Plant Bioassay on the 7th day. This is the very first report on the bioweedicidal potential of A. alternata ITCC 4896 (LC#508) for use as a mycoherbicide for P. hysterophorus.
Anthocyanins impart red, purple and violet colour to many flowers and fruits, mainly to attract pollinators and seed dispersers, but their function and biosynthetic regulation in foliages of several plants are less studied. The red and green forma of Ocimum tenuiflorum differ in anthocyanin accumulation in leaves and provide an excellent system for exploring the course of its regulation. It was observed that red forma gradually changed to green upon transfer to a particular greenhouse with limited transmission of ultraviolet light (both UV-B and UV-A). The sequential monitoring of anthocyanin content confirmed positive correlation between visible and ultraviolet light intensity with leaf colour and antioxidant activities. An ultra-performance liquid chromatography method of < 3.5 min was developed for rapid and precise quantification of anthocyanidins. Expressions of PAL, CHS and CHI were down-regulated by low light in both forma. The F3H and F3'H genes had reduced expression in both forma and were supported by reduced levels of cyanidin in red forma plants within greenhouse. The expression of late biosynthetic genes, DFR and LDOX, also plummeted within the greenhouse. The regulatory transcription factors bHLH and WD40 were severely down-regulated within the greenhouse suggesting that bHLH and WD40 control the expression of F3'H, DFR and LDOX to regulate the biosynthesis of anthocyanin pigments in leaves of O. tenuiflorum, whereas the expression of Myb remained almost unaffected.
Gladiolus flowers are ethylene insensitive and the signals that start catabolic changes during senescence of gladiolus flower are largely not known. Therefore, experiments were performed to understand the role of abscisic acid (ABA) in ethylene insensitive floral senescence in gladiolus (Gladiolus grandiflora Hort.). It was observed that ABA accumulation increased in attached petals of gladiolus flowers as they senesced. Exogenous application of ABA in vase solution accelerated senescence process in the flowers due to change in various senescence indicators such as enhanced membrane leakage, reduced water uptake, reduced fresh weight and ultimately vase life. Enhancement of in vivo ABA level in petals by creating osmotic stress also upregulates the same parameters of flower senescence as those occurring during natural senescence and also akin to exogenous application of ABA. Attempts to increase vase life of flowers by application of putative ABA biosynthesis inhibitor fluridone in vase solution to counteract ABA effect were unsuccessful. In contrast, ABA action was mitigated by application of GA₃ in holding solution along with ABA which is basically an antagonist of ABA action. The present study provides valuable insights into the role of ABA as a hormonal trigger in ethylene insensitive senescence process and therefore would be helpful for dissecting the complex mechanism underlying ABA-regulated senescence process in gladiolus.
In this study the biodegradation of oil by hydrocarbon degrading Pseudomonas putida in the presence of a biosurfactantproducing bacterium was investigated. The co-culture of test organisms exhibited improved degradation capacities, in a reproducible fashion, in aqueous and soil matrix in comparison to the individual bacterium culture. Results indicate that the in situ biosurfactant production not only resulted in increased emulsification of the oil but also change the adhesion of the hydrocarbon to cell surface of other bacterium. The understanding of interactions beetwen microbes may provide opportunities to further enhancement of contaminants biodegradation by making a suitable blend for bioaugmentation.
Background. COVID-19 pandemic has been a source of emerging public health problems for the past few years. Due to its contagious nature, health care professionals especially dentists, incorporated various modifications in their practices to prevent themselves and their patients from the risk of getting infected. Objective. The present study aims to assess whether dental professionals are still continuing with those modifications in practice in current times. Materials and Methods. The present study was conducted on 415 subjects after getting due approval from concerned authorities and consent from the subjects. Systematic random sampling methodology was employed for selection for study sample. The study employed a self-constructed questionnaire which was divided into 2 parts and information regarding demographic profile, practice modifications and safety protocols was gathered from subjects. Statistical analysis was conducted using Chi-square test and multiple regression analysis. Results. Only 8.6% of subjects were currently continuing with their all previous practice modifications. A vast majority of subjects (83.8%) were not deferring treatment of patients showing suspicious symptoms. Approximately 89% of subjects were not sanitizing the operating area at the end of the working day. More than two-thirds (76.4%) of the subjects stated that the pandemic was over. Female gender (OR:1.67) and high level of education (OR:2.45) had an important effect on the continuation of practice modifications. Conclusion. Very few subjects were adhering to all practice modifications previously incorporated. Dental professionals should not let their guard down even if COVID-19 cases have reduced considerably. The information collected will be useful for the dental community and further studies should be carried out.
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