ABSTRACT
Aims: The tea industry is of great economic importance worldwide, owing to its possession of both food and medicinal values. Bangladesh is among the world-renowned tea exporting countries. However, the inadequate biochemical data for most cultivated Bangladeshi tea genotypes hinders its competitiveness on the world market. This is as a result of previous research mainly revolving around conventional breeding, mutagenesis, and polyploidization. This research aims to characterise the 12 Bangladeshi tea genotypes according to their biochemical content. Such information is inevitable in driving the demand and preference of these tea products on the world market. Study Design: The study was designed based on relevant research articles and standard laboratory procedures. Place and Duration of Study: This research was conducted at the Molecular Biology and Protein Science Laboratory, Department of Genetic Engineering and Biotechnology, University of Rajshahi, Rajshahi-6205, Bangladesh, from June 2015 to September 2016. Methodology: Reversed-Phase Liquid Chromatography was used to determine the composition of different tea genotypes. A mixture of 999 ml de-ionised water & 1 ml TFA was used as buffer A, and 80% acetonitrile was used as buffer B in RPLC system. Results: We found that all the 12 tea genotypes are rich in Theophylline, Theobromine, Gallic-Acid, and Caffeine content, but with varying quantities. Conclusion: These results indicate that some of these tea genotypes can be used to produce the decaffeinated tea, a newly introduced tea product on the market that is on high demand. To ascertain the diversity of chemical composition among the various tea genotypes, biochemical characterisation of other Bangladeshi tea genotypes should be performed. Such data will enhance the market value and demand for Bangladeshi tea on the world market.
ABSTRACT
Aims: To identify and characterize Citrus Huanglongbing disease causing pathogen Candidatus Liberibacter asiaticus and to evaluate its biological control using medicinal plant extracts. Study Design: The study was designed based on standard laboratory protocol. Place and Duration of Study: Professor Joarder DNA and Chromosome Research Lab, Department of Genetic Engineering and Biotechnology, University of Rajshahi, Rajshahi-6205, Bangladesh between June 2015 and September 2016. Methodology: Causal pathogen of Citrus Huanglongbing disease was isolated from infected leaves. Different types of biochemical and morphological characterizations of Candidatus Liberibacter asiaticus were done. 16S rDNA primers (27F and 1391R) were used to amplify genomic DNA of Candidatus Liberibacter asiaticus. Sequencing of 16S rDNA sequence of Candidatus Liberibacter asiaticus were performed. Sensitivity pattern of Candidatus Liberibacter asiaticus against several standard antibiotics were done. Antimicrobial activity test was observed using two solvents extracts of four medicinal plants by disc diffusion method in vitro condition. Results: Candidatus Liberibacter asiaticus showed positive and negative response to different biochemical test. Candidatus Liberibacter asiaticus showed gram negative in gram staining test. Candidatus Liberibacter asiaticus showed highest 35±0.5 mm and lowest 8±0.2 mm zone of inhibition against amoxycillin and kanamycin respectively. Approximately 1300bp band was found in PCR amplification and phylogenetic tree analysis of 16S rRNA gene sequence of Candidatus Liberibacter asiaticus showed 75% similarity with Candidatus Liberibacter asiaticus strain 374.15. Candidatus Liberibacter asiaticus showed highest 16±0.5 mm diameter of zone of inhibition at 60 µg/ml concentration for ethanol extract of Cuscuta reflexa. Conclusion: This study will be helpful for proper identification, characterization and control of Citrus Huanglongbing disease causing pathogen Candidatus Liberibacter asiaticus in an eco-friendly way.