Rubber plantations have gained recognition not only for their economic value but also for their potential contribution to climate change mitigation through biomass accumulation and carbon sequestration. In Bangladesh, research on the carbon dynamics of rubber plantations remains limited, especially regarding large-scale spatial assessments integrating field and geospatial data. This study aimed to quantify above- and below-ground biomass and carbon sequestration potential in 17 rubber plantations across three major zones of Bangladesh, Chittagong, Sylhet, and Tangail-Sherpur, managed by the Bangladesh Forest Industries Development Corporation (BFIDC). Using a total of 340 sample plots (10 m × 10 m), tree measurements (height, DBH, age) were collected and used in allometric equations to estimate biomass and carbon stocks. Landsat-9 satellite imagery, chlorophyll index (red edge), and Normalized Difference Vegetation Index (NDVI) analysis were applied to delineate rubber plantations and assess vegetation coverage, with classification accuracy validated through ground truth data and Cohen’s Kappa coefficient. The results revealed a significant regional variation in biomass and carbon sequestration. Sylhet recorded the highest mean biomass (358 Mg/ha), followed by Tangail-Sherpur (356.10 Mg/ha) and Chittagong (148.32 Mg/ha). In contrast, Tangail-Sherpur recorded the highest carbon sequestration (23.15 Mg/ha/year), followed by Sylhet (14.49 Mg/ha/year) and Chittagong (7.79 Mg/ha/year). The highest NDVI value was observed in Kamalapur garden (0.7988 ± 0.00029), indicating higher tree coverage. Classification accuracy ranged from 75 to 94
Natural rubber produced by Hevea brasiliensis is a raw material for more than 40,000 products. 3-hydroxy-3-methylglutaryl-CoA reductase (HMGR) catalyses the rate-limiting step in the biosynthetic pathway of the rubber precursor and is encoded by a multigene family. Functional characterisation of individual HMGR genes is essential to understand their specific roles and to exploit them for the genetic improvement of rubber trees. Although the expression of HMGR genes has been studied across different tissues and clones, studies investigating their expression at different developmental stages or ages remain limited. In this study, five HMGR genes were identified by manually curating the sequences in public databases and designated as HbHMGR1-5. Two non-conserved transmembrane regions were identified in all HbHMGRs, whereas HbHMGR1 has an additional transmembrane region at the N-terminus. Besides, two conserved HMG-CoA binding regions and NADP(H) binding regions were identified in all HbHMGRs. Phylogenetic analysis clustered five HbHMGRs into 3 clades, with HbHMGR1 and HbHMGR5 forming a distinct Hevea cluster. HbHMGRs are distributed across different chromosomes, and syntenic relationships consistent with the phylogenetic clustering were observed. HbHMGR1, HbHMGR2, and HbHMGR5 were expressed in the latex, and their absolute quantification revealed distinct expression patterns in 1-, 5-, and 14-year-old trees. HbHMGR5 exhibited a progressive increase in expression with age, whereas HbHMGR2 showed relatively stable expression at 1 and 5 years, followed by a marked increase at 14 years. In contrast, HbHMGR1 displayed peak expression at 5 years. These distinct expression patterns suggest differential regulation of HbHMGR genes during plant development.
The origin of rubber has a significant impact on its properties. Indonesia is one of the traditional producing regions for smoked sheet rubber. This study compared the performance differences between Chinese Yun rubber (products from Jingyang and Jiangcheng companies) and Indonesian RSS No. 1 smoked sheet rubber to assess their potential suitability for use in high-end rubber products. The research shows that the nitrogen content (0.56
