Organic Carbon Concentration in the Soils of Coastal Afforestation Sites in Bogachattor, Chittagong

not available The Chittagong Univ. J. Sci. 42(1): 84-98, 2020

Chemical and morphological characterization and pulping of Casuarina equisetifolia

Bangladesh is very much successful in coastal afforestation programmes, which protects from frequent cyclones. Casuarina equisetifolia has showed a climate resilient and promising species. No study has been done on industrial application of C. equisetifolia in Bangladesh. In this study, C. equisetifolia was characterized in terms of chemical, morphological and anatomical properties. It is characterized with higher α-cellulose, similar hemicelluloses and lignin as compared to other hardwood species grown in Bangladesh. The C. equisetifolia lignin contained mainly of syringyl unit followed by guaiacyl unit. The fiber of C. equisetifolia was shorter in length with very thick cell wall and narrow lumen, consequently the wood density and runkel ratio were very high (2.89). The C. equisetifolia was also fractionated by formic acid (FA) at atmospheric pressure to pulp, dissolved lignin and hemicelluloses. Pulp yield was 50 % with kappa number of 40 at the conditions of 3 h treatment with 90 % FA followed by 2 h peroxyformic acid treatment. But in the kraft process, C. equisetifolia produced pulp yield of 44 % with kappa number 17. Both pulps showed good bleachability. The papermaking properties were in acceptable range. Finally, it can be said that C. equisetifolia is promising species for pulping.

Efficient virus-induced gene silencing in Hibiscus hamabo Sieb. et Zucc. using tobacco rattle virus

Background Hibiscus hamabo Sieb. et Zucc. is a semi-mangrove plant used for the ecological restoration of saline-alkali land, coastal afforestation and urban landscaping. The genetic transformation H. hamabo is currently inefficient and laborious, restricting gene functional studies on this species. In plants, virus-induced gene silencing provides a pathway to rapidly and effectively create targeted gene knockouts for gene functional studies. Methods In this study, we tested the efficiency of a tobacco rattle virus vector in silencing the cloroplastos alterados 1 (CLA1) gene through agroinfiltration. Results The leaves of H. hamabo showed white streaks typical of CLA1 gene silencing three weeks after agroinfiltration. In agroinfiltrated H. hamabo plants, the CLA1 expression levels in leaves with white streaks were all significantly lower than those in leaves from mock-infected and control plants. Conclusions The system presented here can efficiently silence genes in H. hamabo and may be a powerful tool for large-scale reverse-genetic analyses of gene functions in H. hamabo.

Climate change adaptation and disaster risk reduction (DRR) through coastal afforestation in South-Central Coast of Bangladesh

Purpose The purpose of this paper is to focus on the local-level initiatives through coastal afforestation, the natural and socio-economic context of the study area (Hatiya Upazila of Noakhali District, Bangladesh) and the adaptation and DRR strategies generated through coastal afforestation in coastal Bangladesh. Design/methodology/approach Field observations, focus group discussions (FGDs), semi-structured interviews, and transects were accomplished in both the dry and wet season. Spatial database generated and land use mapping integrated social and technical investigation. Five FDG sessions with participants from different livelihood options (fishermen, farmers and social representatives) were organised and, on average, 15~18 participants participated in each participatory session. Findings Mangrove plantation can be used to access new land and create alternative livelihoods, which are important for local community adaptation and to reduce disaster risks. Mangrove plantations provide chances for new land management options to be developed for use in Bangladesh. Research limitations/implications This study was conducted only at the south-central coastal district of Bangladesh. Data collection to summarise all the socio-economic issues is limited. Practical implications This paper can be used for the integration of geospatial and social research techniques to understand the community approach to fight against climate change-induced impacts. Originality/value The research is solely conducted by the authors. The conducted approach is a blend of social and technical knowledge and techniques in generating community resilience at the south-central coast of Bangladesh.

Efficient virus-induced gene silencing in Hibiscus hamabo Sieb. et Zucc. using Tobacco rattle virus

Background. Hibiscus hamabo Sieb. et Zucc. is a semi-mangrove plant used for the ecological restoration of saline-alkali land, coastal afforestation and urban landscaping. Because the genetic transformation of H. hamabo is difficult, molecular breeding and gene functional studies have been severely restricted. In plants, virus-induced gene silencing provides a pathway to rapidly and effectively create targeted gene knockouts for gene functional studies. Methods. In this study, we tested the efficiency of a Tobacco rattle virus vector in silencing the cloroplastos alterados 1 (CLA1) gene through agroinfiltration. Results. The leaves of H. hamabo showed white streaks typical of CLA1 gene silencing three weeks after agroinfiltration. In agroinfiltrated H. hamabo plants, the CLA1 expression levels in leaves with white streaks were all significantly lower than in those of mock-infected and control plants. Conclusions. Thus, this virus-induced gene silencing system was efficient in H. hamabo and may be a powerful tool for large-scale reverse-genetic analyses of gene functions in H. hamabo.

Efficient virus-induced gene silencing in Hibiscus hamabo Sieb. et Zucc. using Tobacco rattle virus

Background. Hibiscus hamabo Sieb. et Zucc. is a semi-mangrove plant used for the ecological restoration of saline-alkali land, coastal afforestation and urban landscaping. Because the genetic transformation of H. hamabo is difficult, molecular breeding and gene functional studies have been severely restricted. In plants, virus-induced gene silencing provides a pathway to rapidly and effectively create targeted gene knockouts for gene functional studies. Methods. In this study, we tested the efficiency of a Tobacco rattle virus vector in silencing the cloroplastos alterados 1 (CLA1) gene through agroinfiltration. Results. The leaves of H. hamabo showed white streaks typical of CLA1 gene silencing three weeks after agroinfiltration. In agroinfiltrated H. hamabo plants, the CLA1 expression levels in leaves with white streaks were all significantly lower than in those of mock-infected and control plants. Conclusions. Thus, this virus-induced gene silencing system was efficient in H. hamabo and may be a powerful tool for large-scale reverse-genetic analyses of gene functions in H. hamabo.