Showing papers on "Excoecaria agallocha published in 2019"

Effects of nutrient limitation, salinity increase, and associated stressors on mangrove forest cover, structure, and zonation across Indian Sundarbans

Abstract: Anthropogenic coastal activities and natural stressors aggravate degradation of small coastal patches of mangroves, which in turn destroy local resilience of mangrove forests in the Indian Sundarbans, the continuous mangrove habitat that spans between India and Bangladesh. We conducted an analytical survey across 19 shoreline mangrove fringes spanning the Sundarbans, including both healthy and disturbed forests, and evaluated ninety-five 60-cm composite sediment cores across a degradation and salinity gradient from ~ 4 to ~ 12 ppt. Increased salinity and anoxicity greatly inhibited nutrient cycling and release by microbial decomposers, subsequently resulting in nutrient-poor soil as a condition of degradation. Nutrient limitation, salinity rise, anoxicity increase, and sulfide build-up negatively controlled forest structure causing declines of forest coverage from ~ 98 to ~ 11%. In addition, the tide-dominated salinity gradient controlling species zonation was disrupted in disturbed forests with salinity-sensitive species gradually disappearing. An obvious change in species distribution is anticipated while salt-sensitive Heritiera fomes, Xylocarpus spp., and Phoenix paludosa failed to cope with increased salinity, evident by their absence from many forests. Excoecaria agallocha and Avicennia spp. acclimated well and expanded freely into degraded forests across the Sundarbans. Overall, our study strongly establishes salinity intrusion as primary mechanism for mangrove degradation.

Structure and regeneration status of mangrove patches along the estuarine and coastal stretches of Kerala, India

Abstract: This study presents the structural characteristics and regeneration potential of mangrove patches in the estuarine and coastal areas of Kerala, a tropical maritime state in India. Field surveys were carried out at 46 selected sites during August 2015 to May 2016. In each site, the vegetative structure and regeneration status were assessed using the quadrat method. Altogether 219 quadrates were laid out and a total of 13 true mangrove species, belonging to 5 families and 8 genera, were recorded. The total tree density and stand basal area of the study region was 1678.08/ha and 20.33 m2/ha respectively. The low basal areas indicate the reduced structural development in mangroves. Of the 13 tree species, Avicennia constitutes 56% of the total Important Value Index (IVI) and Avicennia officinalis represents 41% of the IVI in Kerala, followed by Avicennia marina (15%), Rhizophora mucronata (15%), Sonneratia alba (8%) Rhizophora apiculata (7%) and Excoecaria agallocha (7%). The diameter at breast height (DBH) in the study area revealed that 47% of the tree species came under the 1–10 cm DBH class. Total sapling and seedling density in Kerala was 2238.35 and 3232.42 individuals/ha respectively. Density of young plants (seedlings + saplings) was only 31% greater of tree density and varied from 3–63%, which indicates poor regeneration potential. The Maturity index value (MIV) and complexity index (Ic) value of mangroves were 18.30 and 109.81 respectively. However, the low Ic value (< 10) observed in seven out of ten coastal districts indicated poor structural development of mangroves in Kerala. Therefore, location-specific conservation and management measures, guided by the knowledge on spatial distribution and habitat requirements of mangrove varieties should be taken to preserve the mangrove diversity of Kerala.

Comparison of calorific values and ash content for different woody biomass components of six mangrove species of Bangladesh Sundarbans

Abstract: The study of calorific values of mangrove plants is valuable indices for reflecting the energy conversion and material flow of the forest ecosystem. In this study, the calorific value and ash content of different biomass components, i.e. leaf, bark, sapwood and heartwood of six important mangrove species, namely goran (Ceriops decandra Griff. W. Theob.), keora (Sonneratia apetala Buch.-Ham.), passur (Xylocarpus mekongensis Pierre), sundri (Heritiera fomes Buch.-Ham.), gewa (Excoecaria agallocha L.) and jhana garjan (Rhizophora mucronata Lam.) of Bangladesh were evaluated. The gross calorific values (GCVs) and ash-free calorific values (AFCVs) of different biomass components of six species were in the range of 14.15–19.18 MJ/kg and 14.90–19.37 MJ/kg, respectively. Heartwood of H. fomes showed the highest GCV and AFCV among all of the mangrove species. The highest ash content (AC) was found for the bark of X. mekongensis (6.7%), while S. apetala sapwood and H. fomes bark showed the lowest AC (0.5%). The GCVs, AFCVs and ACs of different woody biomass components of six mangrove species were significantly different. The fuel value index (FVI) of heartwood and sapwood of six mangrove species was ranged between 1.34 for E. agallocha heartwood and 7.15 for H. fomes heartwood. The findings of this study are important for selecting the suitable fuelwood species for higher fuel value from and around the biggest single tract mangrove forest, the Sundarbans.

Therapeutic potentials of Excoecaria agallocha against gram-positive and gram-negative fish bacterial pathogens

Abstract: Background: The present investigation of a mangrove plant, Excoecaria agallocha, which is a popular medicinal substitute for the treatment of microbial ailments, were evaluated for potential antimicrobial activity against pathogenic bacteria Escherichia coli and Streptococcus agalactiae in tilapia, Oreochromis niloticus. Methods: Antibacterial activity was performed using agar diffusion method, disc diffusion method, minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and antibiotic susceptibility assays. Experimental fish fed diet containing 0 (control), 5, 25, and 50 mg kg-1 E. agallocha leaf methanol extract for 28 days then challenged individually with E. coli or S. agalactiae and mortalities were recorded over a ten-day post-infection period. Results: Results indicated that both bacterial species are sensitive to tetracycline, ampicillin, and amoxicillin. E. coli was found to be resistant to neomycin. E. agallocha extract concentration of 50 mg/ml produced a zone of inhibition of 18 mm against E. coli, in contrast to 13 mm against S. agalactiae. E. agallocha showed bactericidal activity against E. coli and bacteriostatic activity against S. agalactiae. The highest E. agallocha LC50 activity was 83 mg/ml. The highest cumulative mortality was 90.0 ± 10.0% in control as compared to 26.7 ± 11.5% in the group fed with 50 mg kg-1 E. agallocha extract, significant differences (P < 0.05). Conclusion: Hence, E. agallocha showed antibacterial activity against fish pathogens Escherichia coli and Streptococcus agalactiae in tilapia, Oreochromis niloticus; therefore, E. agallocha may be used as an alternative therapeutic agent against fish pathogenic bacteria as an additive to feed at a concentration depend, safe, non-cytotoxic doses.

Effect of NPK fertilizers on seedling growth of mangrove species

Abstract: An experiment was conducted to assess the effect of NPK fertilizers on seedling growth and survival of five important mangrove species of Bangladesh for nine months. Seedlings were raised in the nursery using plastic pots. NPK fertilizers with three treatments (control, 4 gm and 8 gm doses) were used two times when seedlings age was 3 and 6 months. The result showed that seedlings height growth of Excoecaria agallocha was enhanced significantly with the application of NPK fertilizers but it was shown negatively significant effect on height growth of Xylocarpus mekongensis after second time fertilizer application. Moreover, NPK application enhanced mortality of Avicennia officinalis and Ceriops decandra seedlings in both times of fertilizer application. But no effect of NPK fertilizers on seedlings growth and survival of Heritiera fomes were observed.

Effect of ethanolic extract of Excoecaria agallocha leaves on the cytotoxic activity and cell cycle arrest of human breast cancer cell lines – MCF-7

Abstract: Background: At present, Mangrove plants have gained importance in drug discovery due to the presence of many phytomolecules of medicinal importance. Excoecaria agallocha is widely distributed medicinal mangrove which has been traditionally used to treat sores, ulcers, and leprosy. Objective: The aim of the present study is to analyze the cytotoxic potential of Exoecaria agallocha leaves in terms of its antiproliferative activity, apoptosis induction, and cell cycle arrest in the breast cancer MCF-7 cell lines. Materials and Methods: The ant proliferative nature of the EEEA extract was determined by direct microscopic observation as well as 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-tetrazolium bromide (MTT) assay by employing the different concentrations of the plant extract, and the IC50 values were calculated. Apoptosis-inducing potential was determined by double staining with acridine orange/ethidium bromide staining method and further confirmed by annexin V staining. Flow cytometry was performed with IC50 concentration of EEEA drug treated MCF-7 cells to determine arresting stage in the cell cycle progression. Results: There was a significant cytotoxic activity exhibited by the ethanolic extract of E. agallocha leaves (EEEA) in the direct microscopic as well as MTT assay with IC50 value of 56.5 μg/ml. Well prominent fluorescent microscopic images of morphological changes in the double staining method indicate the apoptotic potential of the extract which was further confirmed by annexin V staining. Suppression of cell cycle progression at subG1 and G1/G2 phases were also evidenced in the flow cytometry analysis. Conclusion: From the above results, it may be concluded that the ethanolic leaf extract of E. agallocha (EEEA)-induced apoptosis mediated cytotoxic and antiproliferative activity in the breast cancer MCF-7 cell lines which can be developed into a new drug for treating breast cancer.

Complete chloroplast genomes of 14 mangroves: phylogenetic and genomic comparative analyses

Abstract: Mangroves are main components of an ecosystem which connect land and ocean and is of significant ecological importance. They are found around the world and taxonomically distributed in 17 families. Until now there has been no evolutionary phylogenetic analyses on mangroves based on complete plastome sequences. In order to infer the relationship between mangroves and terrestrial plants at the molecular level, we generated chloroplast genomes of 14 mangrove species from eight families, spanning six orders: Fabales (Pongamia pinnata), Lamiales (Avicennia marina), Malpighiales (Excoecaria agallocha, Bruguiera sexangula, Kandelia obovata, Rhizophora stylosa, Ceriops tagal), Malvales (Hibiscus tiliaceus, Heritiera littoralis, Thespesia populnea), Myrtales (Laguncularia racemose, Sonneratia ovata, Pemphis acidula), and Sapindales (Xylocarpus moluccensis). The whole-genome length of these chloroplasts is from 149kb to 168kb. They have a conserved structure, with two Inverted Repeat (IRa and IRb, ~25.8kb), a large single-copy region (LSC, ~89.0kb), a short single-copy (SSC, ~18.9kb) region, as well as ~130 genes (85 protein-coding, 37 tRNA, and 8 rRNA). The number of simple sequence repeats (SSRs) varied between mangrove species. Phylogenetic analysis using complete chloroplast genomes of 71 mangrove and land plants, confirmed the previously reported phylogeny within rosids, including the positioning of obscure families such as Linaceae within Malpighiales. Most mangrove chloroplast genes are conserved and we found six genes subjected to positive or neutral selection. Genomic comparison showed IR regions have lower divergence than other regions. Our study firstly reported several plastid genetic resource for mangroves, and the determined evolutionary locations as well as comparative analyses of these species provid insights into the mangrove genetic and phylogenetic research.

Strategy of the Mangrove ecosystem management in efforts to combat abrasion in the Bantan District case of the Mangrove ecosystem in Teluk Papal Village, Bantan District, Bengkalis Regency, Indonesia

Abstract: Mangroves in the Teluk Papal Village are in a community that grow naturally. Mangrove conditions in the Teluk Papal Village in some areas have been damaged as a result of beach abrasion, land conversion into plantations, and community logging. Damage to the mangrove area is expected to increase in the future. Therefore, it is necessary to research about the mangrove damage by monitoring the change of the mangrove area and to analyze the leading factors as to why this damage is occuring. The purpose of this study is to assess the level of damage and factors which cause mangrove damage, to calculate the total economic value and formulate a mangrove management strategy for the Teluk Papal Village, in the Bantan District. The results show that mangrove vegetation in the Teluk Papal Village consists of 10 species, namely Avicennia alba, Rhyzophora mucronata, Thespesia populnea, Sonneratia alba, Excoecaria agallocha, Sonneratia caseolaris, Bruguiera gymnorhyza, Xylocarpus granatum, Rhyzophora apiculata, Nypa fruticans. Based on the results of standardized criteria and guidelines for damage to mangroves KEPMENLH 201 in 2004, mangroves in the Teluk Papal Village are in good condition ( they are very solid and medium). This is based on the amount of tree density per hectare. The leading factor is coastal abrasion due to reduced mangrove vegetation in the front row, land conversion to plantation land and brick production. The estimated economic value of the mangroves is calculated by direct benefits, indirect benefits, benefits of choice and benefits of existence with a financial result of Rp 42.567.271.593.04. Based on the results of economic analysis it shows that the mangrove ecosystem in the Teluk Papal Village has a large economic value which means if there is a change in the mangrove area and its positive (increasing), then the value of the mangrove economy is positive (increased) and vice versa. This condition indicates that the mangrove ecosystem must be maintained so that its ecological, economic, social and environmental functions can be utilized sustainably.

Pengaruh metode perebusan terhadap uji fitokimia daun mangrove Excoecaria agallocha

Abstract: Abstrak Following a rigorous and careful concerns and consideration in the review of the article published in JActa Aquatica entitled “Pengaruh metode perebusan terhadap uji fitokimia daun mangrove Excoecaria agallocha” Vol 6, No 1, pp. 28-31, April 2019, DOI: https://doi.org/10.29103/aa.v6i1.1046 This paper has been found to violate the principles of Acta Aquatica: Aquatic Sciences Journal publication and has been retracted. The article has been drawn by the Author. The document and its content have been removed from Acta Aquatica: Aquatic Sciences Journal, and reasonable effort should be made to remove all references to this article.

Distribution of Mangrove Species in the Jaffna District, Sri Lanka

Abstract: Mangroves are woody, seed-bearing, and highly specialised trees and shrubs that grow in the intertidal zone. They provide suitable habitats for a large number of migratory and resident bird species and other aquatic organisms and possess a high ecotouristic value. Jaffna district harbors some of the major mangrove sites in Sri Lanka, with large extents of undisturbed mangroves. Mangrove diversity and distribution has never been studied in Jaffna district since 1969 due to three-decade long armed conflict that prevailed in the entire northern part of Sri Lanka. The objective of the present study was to identify the mangrove species and their distribution in the Jaffna District. The study was conducted in the Jaffna district from 2014 to 2018. Line transects and spot-check methods were used to determine the distribution and abundance of mangrove species. Distribution of mangroves in the entire district was surveyed using GPS and the distribution maps were prepared using Q-GIS and ArcView. Then the distribution maps were intersected with Grama Niladhari Division maps and mangrove species distribution was evaluated Grama Niladhari Division wise. The current distribution map was compared with the distribution map of 1969. The mangrove species recorded in the present study are Excoecaria agallocha, Lumnitzera racemosa, Rhizophora mucronata, Aegiceras corniculatum, Avicenna marina, A. officinalis, Ceriops tagal, B. cylindrica and Pemphis acidula. Of these, Bruguiera cylindrica on the Island of Sirudivu, C. tagal on Mandaitivu Island and A. corniculatum from Sarasalai to Chempiyanpattu were first records of these species in Jaffna district. Avicenna marina is the dominant species which was recorded in high salinity areas especially in southern and western parts of Jaffna and the Islands. These areas are associated with the Jaffna Lagoon. E. agallocha, L. racemosa and R. mucronata are the most common species in other parts of the district. They are commonly found in the northern and eastern parts of the district and these areas are connected to Thondamanaru and Upparu lagoons. A. officinalis, C. tagal, B. cylindrica and A. corniculatum are restricted to mainland Jaffna District. Mangroves are distributed in 60 Grama Niladhari Divisions (totaling 3,680.83 ha) where large extents (over 100 ha) of mangroves are found in 15 divisions (totaling 3,099.58 ha). Thirty five divisions support smaller extents of mangroves. High density of tall trees of Rhizophora mucronata were found from Sarasalai to Chempiyanpattu in the middle part of the Thondamanaru lagoon. New mangrove stands are establishing in some parts of islands such as Kerativu and Thanankilappu areas and they are absent in some parts of the southern part of Jaffna District compared to the distribution map of 1969. This may be due to clearing of mangroves in these areas. The study revealed that nine true mangrove species, belonging to five families occur in the Jaffna District, distributed over a large number of Grama Niladhari divisions. At present, improper road constructions, hotel development, construction of a sea water exclusion barrage at Thondamanaru, and lack of awareness on mangrove ecosystems have negatively impacted on these ecosystems. Hence, more attention should be given to protect the mangrove ecosystem and environmentally friendly development activities should be promoted to conserve them. Keywords: Mangroves, Thondamanaru lagoon, Distribution, Species, Jaffna district