Scaevola Taccada Research Articles

Chromolaena odorata affects soil nitrogen transformations and competition in tropical coral islands by altering soil ammonia oxidizing microbes

Invasive plants can change the community structure of soil ammonia-oxidizing microbes, affect the process of soil nitrogen (N) transformation, and gain a competitive advantage. However, the current researches on competition mechanism of Chromolaena odorata have not involved soil nitrogen transformation. In this study, we compared the microbially mediated soil transformations of invasive C. odorata and natives (Pisonia grandis and Scaevola taccada) of tropical coral islands. We assessed how differences in plant biomass and tissue N contents, soil nutrients, N transformation rates, microbial biomass and activity, and diversity and abundance of ammonia oxidizing microbes associated with these species impact their competitiveness. The results showed that C. odorata outcompeted both native species by allocating more proportionally biomass to aboveground parts in response to interspecific competition (12.92 % and 22.72 % more than P. grandis and S. taccada, respectively). Additionally, when C. odorata was planted with native plants, the available N and net mineralization rates in C. odorata rhizosphere soil were higher than in native plants rhizosphere soils. Higher abundance of ammonia-oxidizing bacteria in C. odorata rhizosphere soil confirmed this, being positively correlated with soil N mineralization rates and available N. Our findings help to understand the soil N acquisition and competition strategies of C. odorata, and contribute to improving evaluations and predictions of invasive plant dynamics and their ecological effects in tropical coral islands.

On the Fore-Shore Vegetation of Malacca Coast of the Car-Nicobar Island

In this paper, an account is given of the Fore-shore Vegetation of a part of E. Coast of Car-Nicobar along the Malacca Coast. The various types of plant species found on the shore above upper tidal limits are described, and the characteristic ones being Ipomoea pes-caprae (Linn.) Sweet., Panicum repens Linn., Vigna marina Mers., Ischaemum muticum Linn., Blainvillea acmella (Linn, f.) Philipson., Pandanus furcatus Roxb., Scaevola frutescens (Mill.) Krausse., Tournefortia argentea Linn., with Cocos nucifera Linn, occur behind, followed by Hibiscus tiliaceus Linn., Erythrina variegata Linn. var. orientalis (Linn.) Merr., Calophyllum inophyllum Linn., Thespesia populnea Corr., Guettarda speciosa Linn., Syzygium aqueum (Burm f.) Alston, and other trees in jungles. The various species met with are enumerated, in which 13 species and one variety would appear to be new records for the Andamans and Nicobars.

Biophysical characteristics of coastal habitat at Geleang island Karimunjawa National Park as a nesting area hawksbill turtle (Eretmochelys imbricata, Linnaeus 1766)

The hawksbill turtle (E. imbricata) are internationally Critically Endangered as determined by the IUCN. For this reason, action is needed to preserve the sea turtle in the future. The purpose of this study was to determine the bio-physical characteristics of the beach (beach width and slope; pH, temperature, grain size and sand moisture; nest size; nest distance from high tide; beach vegetation and predators) where hawksbill turtles (E. imbricata) lay their eggs on Geleang Island, Karimunjawa National Park. Concerning conservation, the number, condition, egg removal techniques and egg maintenance found on Geleang Island from January to February 2022 were also described. The research was conducted from January to April 2022 using the observation method which includes field observation and primary data collection. The results showed that Geleang Island has a narrow beach width with a gentle slope. The pH of the sand ranges from 6.5 - 7, the average sand temperature variable is around 28˚C. Sand humidity has a value range of 82% - 90%. Sand grain analysis on Geleang Island, the results of the most retained sediment were found to be on test sieves with a diameter of 250 µm so that it was classified as a type of medium sand. The dominant vegetations are sea pine (Casuarina equisetifolia) and gabusan (Scaevola taccada). No predators of hatchlings were found on Geleang Island. The amount of hawksbill turtle eggs found on Geleang Island from January to February 2022 amounted to 1.981 eggs.Keywords: Characteristic of coastal habitat; hawksbill hatchlings

First Report ofLasiodiplodia hormozganensisCausing Leaf Spot Disease onAreca catechuin China.

The areca palm (Areca catechu L.) is one of the significant cash crops in Hainan Province (China), and a valuable tropical medicinal plant (Cao et al. 2020). In September 2020, spots were found on about 80% of the area of the leaves in a 1,000-acre plantation of areca palms in Haikou City, Hainan Province, and the average incidence was 25%. Initially, Elliptical or irregular dark brown spots appeared on the leaves, with an average size of about 1.5 cm2. With the further expansion of the disease, the spot turned light brown in the center with dark brown edges and a prominent yellow halo. Later stage of the disease, the spots became grayish-white in the center, with obvious whorls, on which many small black spots (pycnidia) were scattered. Eventually the leaves dried out. Ten leaves with typical symptoms were collected from the field. Lesion marginal tissues (5×5 mm2) were surfaced sterilized in 75% ethanol for 20 s, followed by 4 min in 1% NaClO, rinsed 3 times with sterile water, plated on PDA and incubated at 28 ℃. A fungus was isolated with a 98% isolation rate. This strain was named HNAC-5. Subcultures were 80 mm in diameter, white, villous, and neatly edged, after two days of incubation at 28 ℃ in dark. Pycnidia were solitary or clustered in stromata, with orifices that oozed black liquid. Conidiogenous cells were colorless and short cylindrical. Conidia unicellular, initially hyaline, aseptate, ellipsoid to ovoid with granular content, becoming pigmented, 1-septate with longitudinal striations, and measuring 20-31×10-13 μm (n=100). These morphological characteristics were similar to Lasiodiplodia spp. (Abdollahzadeh et al. 2010). The internal transcribed spacer region of rDNA, β-tubulin gene, and translation elongation gene were amplified using ITS1/ITS4, Bt2a/Bt2b, and EF1-728F/EF1-986R primers, respectively (Alves et al. 2008; Glass and Donaldson 1995; White et al. 1990). The resulting sequences were deposited in GenBank under accession numbers OR272043, OR282568, and OR282567. BLAST analysis showed that the three sequences of HNAC-5 were more than 99% similar to strain CBS 124709 of L. hormozganensis. Phylogenetic analysis was performed using the maximum likelihood method based on the three-gene combined dataset with MEGA 7.0 software. The results indicated that HNAC-5 was grouped in the same clade as otherL. hormozganensis Abdollahzadeh, Zare & A.J.L. Phillips. Pathogenicity test was carried out on 15 healthy leaves by in vivo inoculation. Ten leaves were pricked with a sterile needle and divided into group 1 and 2. The remaining five uninjured leaves were group 3. Group 1 and 3 were inoculated with 5-mm-diameter mycelial plugs obtained from 3-day cultures, and group 2 treated with PDA plugs served as controls. Fifteen leaves were cultured at 28°C and 100% relative humidity. After 5 days, leaves of group 1 showed symptoms of the disease and on the tenth day showed the same symptoms as the initial onset of the disease in the field, while leaves of Group 2 and 3 showed no symptoms. Pathogenicity tests were conducted three times with the same results. L. hormozganensiswas re-isolated from the inoculated symptomatic leaves, thus, Koch's postulates were confirmed. In China, L. hormozganensis has been reported to cause Bougainvillea spectabilis Willd. branch blight disease (Li et al. 2015), and Scaevola taccada (Gaertn.) Roxb. leaf spot disease (Zhang et al. 2020). To our knowledge, this is the first report of L. hormozganensiscausing leaf spot disease onA. catechuin China.

Molecular Characterization of Endophytic Fungi from the Leaves of Beruwas Laut (Scaevola taccada (Gaertn.) Roxb.) as Antibacterial Producer

Molecular Characterization of Endophytic Fungi from the Leaves of Beruwas Laut (Scaevola taccada (Gaertn.) Roxb.) as Antibacterial Producer

Minimal impacts of invasive Scaevola taccada on Scaevola plumieri via pollinator competition in Puerto Rico

IntroductionScaevola taccada and Scaevola plumieri co-occur on shorelines of the Caribbean. Scaevola taccada is introduced in this habitat and directly competes with native dune vegetation, including S. plumieri, a species listed as locally endangered and threatened in Caribbean locations. This study addresses whether the invasive S. taccada also impacts the native S. plumieri indirectly by competing for pollinators and represents the first comparative study of insect visitation between these species.MethodsInsect visitation rates were measured at sites where species co-occur and where only the native occurs. Where species cooccur, insect visitors were captured, identified and analyzed for the pollen they carry. Pollen found on open-pollinated flowers was analyzed to assess pollen movement between the two species. We also compared floral nectar from each species by measuring volume, sugar content, and presence and proportions of amine group containing constituents (AGCCs).ResultsOur results demonstrate that both species share insect visitors providing the context for possible pollinator competition, yet significant differences in visitation frequency were not found. We found evidence of asymmetrical heterospecific pollen deposition in the native species, suggesting a possible reproductive impact. Insect visitation rates for the native were not significantly different between invaded and uninvaded sites, suggesting that the invasive S. taccada does not limit pollinator visits to S. plumieri. Comparisons of nectar rewards from the invasive and the native reveal similar volumes and sugar concentrations, but significant differences in some amine group containing constituents that may enhance pollinator attraction.ConclusionOur analysis finds no evidence for pollination competition and therefore S. taccada’s main impacts on S. plumieri are through competitive displacement and possibly through reproductive impacts as a consequence of heterospecific pollen deposition.

Assessment of the role of ACC deaminase, IAA, and siderophore-producing bacteria isolated from Spratly Islands on the growth of Brassica juncea on the coral sand

Root endophytic and rhizosphere bacteria play a significant role in enhancing plant tolerance and promoting growth by producing 1-aminocyclopropane-1-carboxylate (ACC) deaminase, indole-3-acetic acid (IAA), and siderophore. These bacteria have been isolated and screened from 45 plants’ roots and rhizosphere soil samples of 19 types of plants which are growing on 8 floating islands in Spratley Islands, Viet Nam. In which, 3 root endophytic bacteria strains were selected and identified to be Agrobacterium tumefaciens, Pseudomonas plecoglossicida, and Klebsiella aerogenes from roots of Scaevola taccada, Barringtonia asiatica (L.) Kurz, and Carica papaya, respectively. Correspondingly, 3 rhizosphere bacteria strains were selected and identified to be Bacillus velezensis, Bacillus aryabhattai, and Bacillus velezensis from rhizosphere soils of Canavalia maritima (Aubt) Thouars (C. obtusifolia DC.), Cucumis sativus, Heliotropium foertherianum, respectively. These strains were found could increase the germination rate of Brassica juncea’s seeds and 20-day-old fresh biomass, compared to the control treatment in the same condition of 10‰ saline watering. When these bacterial strains were combined as an inoculant, they indicated the same result on coral sand. Thus, the addition of selected endophytic and rhizosphere bacteria is efficient in improving the coral sand environment to enhance food crops’ development in the Spratly Islands.

Comparative genomics reveals a unique nitrogen-carbon balance system in Asteraceae

The Asteraceae (daisy family) is one of the largest families of plants. The genetic basis for its high biodiversity and excellent adaptability has not been elucidated. Here, we compare the genomes of 29 terrestrial plant species, including two de novo chromosome-scale genome assemblies for stem lettuce, a member of Asteraceae, and Scaevola taccada, a member of Goodeniaceae that is one of the closest outgroups of Asteraceae. We show that Asteraceae originated ~80 million years ago and experienced repeated paleopolyploidization. PII, the universal regulator of nitrogen-carbon (N-C) assimilation present in almost all domains of life, has conspicuously lost across Asteraceae. Meanwhile, Asteraceae has stepwise upgraded the N-C balance system via paleopolyploidization and tandem duplications of key metabolic genes, resulting in enhanced nitrogen uptake and fatty acid biosynthesis. In addition to suggesting a molecular basis for their ecological success, the unique N-C balance system reported for Asteraceae offers a potential crop improvement strategy.

Flora of Singapore precursors, 37: Notes on Goodeniaceae in Singapore

The nomenclature and typification of Scaevola taccada (Gaertn.) Roxb. and its synonyms are reviewed. In total, nine new lectotypifications are presented.

Chromosomal-Scale Genome Assemblies of Two Coastal Plant Species, Scaevola taccada and S. hainanensis-Insight into Adaptation Outside of the Common Range.

While most of the species in Goodeniaceae family, excluding the Scaevola genus, are endemic to Australasia, S. taccada and S. hainanensis have expanded their distribution range to the tropical coastlines of the Atlantic and Indian Oceans. S. taccada appears to be highly adapted to coastal sandy lands and cliffs, and it has become invasive in places. S. hainanensis is found mainly in salt marshes near mangrove forests, and is at risk of extinction. These two species provide a good system to investigate adaptive evolution outside the common distribution range of this taxonomic group. Here, we report their chromosomal-scale genome assemblies with the objective of probing their genomic mechanisms related to divergent adaptation after leaving Australasia. The scaffolds were assembled into eight chromosome-scale pseudomolecules, which covered 90.12% and 89.46% of the whole genome assembly for S. taccada and S. hainanensis, respectively. Interestingly, unlike many mangroves, neither species has undergone whole-genome duplication. We show that private genes, specifically copy-number expanded genes are essential for stress response, photosynthesis, and carbon fixation. The gene families that are expanded in S. hainanensis and contracted in S. taccada might have facilitated adaptation to high salinity in S. hainanensis. Moreover, the genes under positive selection in S. hainanensis have contributed to its response to stress and its tolerance of flooding and anoxic environments. In contrast, compared with S. hainanensis, the more drastic copy number expansion of FAR1 genes in S. taccada might have facilitated its adaptation to the stronger light radiation present in sandy coastal lands. In conclusion, our study of the chromosomal-scale genomes of S. taccada and S. hainanensis provides novel insights into their genomic evolution after leaving Australasia.

Antibacterial Activity of Sea Leaf Extracts (Scaevola Taccada) Against Staphylococcus Aureus and Escherichia Coli

Scaevola taccada is one of coastal plants founded at Riau Island.. This research aims to determine the antibacterial activity of the crude extracts leaves of Scaevola taccada. this research was conducted in several stages including, sample preparation, extraction of leaves with maseration method, photochemical analysis and antibacterial activity test using the agar disc diffusion technique. The phytochemical results, crude leaves extract contained flavonoid, tannins, steroids, and saponins. The results of the antibacterial activity test showed that there was an inhibition of antibacterial activity on Staphylococcus aureus and Escherichia coli as indicated by the presence of a clear zone. Based on the results of the research, it was concluded that both ectract had antibacterial activity.

Effects of fruit dimorphism on genetic structure and gene flow in the coastal shrub Scaevola taccada.

Plant propagules often possess specialized morphologies that facilitate dispersal across specific landscapes. In the fruit dimorphism of a coastal shrub, Scaevola taccada, individual plants produce either cork-morph or pulp-morph fruits. The former is buoyant and common on sandy beaches, whereas the latter does not float, is bird-dispersed, and is common on elevated sites such as slopes on sea cliffs and behind rocky shores. We hypothesized that beach populations bridge the heterogeneous landscapes by serving as a source of both fruit types, while dispersal is biased for the pulp morph on elevated sites within the islands and for the cork morph between beaches of different islands. Based on this hypothesis, we predicted that populations in elevated sites would diverge genetically over time due to isolation by distance, whereas beach populations would maintain high genetic similarity via current gene flow. The genetic structure and gene flow in S. taccada were evaluated by investigating genome-wide single nucleotide polymorphisms in plants from 17 sampling sites on six islands (belonging to the Ryukyu, Daito and Ogasawara Islands) in Japan. Geographical isolation was detected among the three distant island groups. Analyses within the Ryukyu Islands suggested that sandy beach populations were characterized by genetic admixture, whereas populations in elevated sites were relatively isolated between the islands. Pairwise FST values between islands were lowest between sandy beaches, intermediate between sandy beaches and elevated sites, and highest between elevated sites. Dispersal across the ocean by cork morphs is sufficiently frequent to prevent genetic divergence between beaches of different islands. Stronger genetic isolation of elevated sites between islands suggests that bird dispersal by pulp morphs is restricted mainly within islands. These contrasting patterns of gene flow realized by fruit dimorphism provide evidence that fruit characteristics can strongly mediate genetic structure.

STRUCTURE AND COMPOSITION OF FLORAL AT MANGROVE FOREST IN PITAS SABAH MALAYSIA

The aim of the study was to determined and record mangrove species composition anddiversity at Pitas mangrove forest, Sabah. Mangroves forest occurs in waterlogged, saltysoils of sheltered tropical and subtropical shores. It usually found along the coastlinesthroughout the world, usually between 25º N longitude and 25º S latitude. This study wasconducted in Pitas district (N 06?43’, E 117?4’) which is located at the northern tip ofSabah, Malaysia. Whereas, Pitas district has an approximately 38,564 ha of the mangrovearea. In this study, the mangrove location covered an area ranges from Malawali island(N 07?2.023', E 117?16.883'), Tobo island (N 07?01.070', E 117?19.008'), Layak-layakisland (N 06?56.587', E 117?14.323'), Mapan-mapan (N 06?51.608', E 117?14.861'), andJambongan island (N 06?45.016', E 117?25.816'). The random sampling method wasdone with simple plots sizes of 20m x 20m to determine the species’ biodiversity,composition and structure. As a result, 13 mangrove species have been identified in allstudy locations namely known as Sonneratia caseolaris, Ceriops tagal, Bruguieragymnorhiza, Rhizophora mucronata, Aegiceras corniculatum, Avicennia marina,Rhizophora apiculata, Sonneratia alba, Bruguiera cylindrica, Lumnitzera littorea,Pemphis acidula, Scyphiphora hydrophyllacea, and Scaevola taccada. The result showsthat the Shannon –Wiener biodiversity index (H’) at the island and disturbed mangroveareas is less diverse (H’ below than 1.5) compared to the undisturbed mainland areaswith (H’=1.95). Sonneratia caseolaris is the dominant mangrove species in the islandwith the highest value of Important Value Index (IVI) with 144.77% compared to allspecies in the study location. These areas show the importance of ecological aspectswithin the forest ecosystem. Therefore, the protection and conservation of this mangrovein this area is a necessity.Keywords: Mangrove, species composition, diversity, Important Value Index (IVI),island, mainland, disturbed, Pitas Sabah

SUBACUTE TOXICITY TEST OF BEACH CABBAGE [Scaevola taccada (Gaertn.) Roxb.] LEAF EXTRACT ON HISTOPATHOLOGICAL CHANGES IN THE LIVER AND KIDNEYS OF WHITE RATS

The purpose of this study was to evaluate the toxic effects of beach cabbage leaves [Scaevola taccada (Gaertn.) Roxb.]by observing the histopathological changes in the livers and kidneys of male white rats. This study used 20 white rats which were divided into 4 groups: 1 control group and 3 groups receiving treatments in the form of Scaevola taccada leaf ethanolic extract (STLEE) in graded doses (200 mg/kg BW, 400 mg/kg BW, and 600 mg/kg BW). Toxicity test was performed by administering STLEE for 14 days. The results of daily observations showed that the experimental animals experienced diarrhea. Meanwhile, histopathological observations showed the occurrences of hydropic degeneration, fat degeneration, necrotic liver cells, and dilatation of Bowman's capsule in the animals’ kidney cells. It was concluded that STLEE at a dose of 200 mg/kg BW is safe to use, but is toxic at a dose of 600 mg/kg BW, both to the livers and kidneys.

The diet of Florida Box Turtles (Terrapene bauri) in a coastal ecosystem in southwestern Florida

North American Box Turtles are opportunistic generalists with omnivorous tendencies, but diets of box turtles are known to vary by population, region, and season. Relatively few studies have examined the diet of Florida Box Turtles (Terrapene bauri). By analyzing fecal samples and direct observations of feeding, we describe the diet of Florida Box Turtles in a coastal area in southern Florida. Fecal samples of turtles in this population contained four functional groups of plants and algae, 11 categories of animals, plus miscellaneous unidentifiable and mineral matter. Frequencies of occurrence differed significantly between wet and dry seasons but not between sexes. Seeds of the invasive Beach Cabbage (Scaevola taccada) were among the most frequently detected plant items, whereas Coffee Bean Snails (Melampus coffea) and ocypodid crabs were the most frequently encountered animal items.

Updates and new reports for the Flora of southern Somalia and north‐eastern Kenya (with a note on Blepharis kenyensis)

Based on the collections held at herbarium FT, new and noteworthy records of vascular plants are provided for the flora of southern Somalia and north‐eastern Kenya. One taxon, Polycarpaea somalensis is recorded as new for the flora of Kenya. Nine taxa, Cyanotis aff. foecunda, Blepharis kenyensis, Launaea sarmentosa, Jatropha hildebrandtii var. hildebrandtii, Scaevola taccada, Polygala aff. muratii, Portulaca coralloides, Portulaca oblonga, Grewia glandulosa are recorded as new for the flora of Somalia and the presence of four taxa, Aneilema lamuense, Ehretia bakeri, Ipomoea aitonii, Strychnos decussata, previously known from single collections, is confirmed. New distributional or noteworthy records are reported for 16 species (Dyschoriste bayensis, Kleinia grantii, Pluchea sarcophylla, Vernonia bayensis, Maerua angolensis subsp. angolensis, Polycarpaea somalensis, Ipomoea kotschyana, Euphorbia hirta, Jatropha stuhlmannii, Lobelia fervens subsp. fervens, Flueggea leucopyrus, Digitaria macroblephara, Portulaca commutata, Talinum portulacifolium, Melhania kelleri, Corchorus aestuans) and for the recently described Emilia corallina one additional record is provided. A note on capsule and seed morphology of Blepharis kenyensis is included.

Scaevola taccada (beach naupaka)

This datasheet on Scaevola taccada covers Identity, Overview, Distribution, Dispersal, Diagnosis, Biology & Ecology, Environmental Requirements, Natural Enemies, Impacts, Uses, Prevention/Control, Further Information.

Subacute Toxicity Test of (Scaevola taccada Gaertn.) Roxb Leaf Extract on Kidney and Liver Function in Rats (Rattus norvegicus)

Beruwas laut leaf (Scaevola taccada (Gaertn.) Roxb has pharmacological effects such as anti-inflammatory, analgesic, antioxidant, antidiabetic and anticancer. Although beruwas laut leaf have many advantages, safety is the main requirement that herbal medicine must have. This research was aimed to prove sebacute of beruwas laut leaf (Scaevola taccada (Gaertn.) Roxb.) about the function of kidney and liver. This research used 20 rats were devided into 4 groups. Group 1 as a control group and groups 2,3, and 4 as an experimental group by administration of beruwas laut leaf extract with dose 200 mg/kgBB, 400 mg/kgBB, and 600 mg/kgBB. The extract was made using maceration and sebacute toxicity testing was carried out for 14 days. After giving the extract, some of rats had diarrhea. The results showed significant effect to increase levels of ureum and CGT after administration of dose 400mg/kgBB. Moreover, administration of dose 600 mg/kgBB caused significant effect in liver biomarkers and kidney (GGT and ureum). It was concluded that ethanol extract of beruwas laut leaf (Scaevola taccada (Gaertn.) Roxb.) with dose 200mg/kgBB showed safe but toxic to kidney and liver with dose 600mg/kgBB.

First report of Pseudocercospora coprosmae causing leaf spot on Scaevola taccada in China

First report of Pseudocercospora coprosmae causing leaf spot on Scaevola taccada in China

Review: Antioxidant Activity Test of Various Types of Mangroves

Free radicals are reactive oxygen that have unpaired electrons looking for partners by binding to electron molecules in the vicinity. Free radicals can cause several degenerative diseases such as diabetes, atherosclerosis, Parkinson's disease, Alzheimer's disease. The content of secondary metabolites in mangroves has the potential to prevent various diseases. Several methods commonly used to estimate the presence of antioxidants in plants include DPPH (2,2-diphenyl-1-picrylhydrazyl), FRAP (ferrous reducing antioxidant power), and ABTS (2,2-azinobis-3-ethylbenzothiazole-6-sulfonic acid). The results of recent studies showed that some mangrove plants have antioxidant activity including: Rhyzophora mucronata, Nypa fruticans, Avicennia marina, Sonneratia alba, Acanthus ilicifolius L, Acrostichum aureum dan Scaevola taccada. Mangrove plants that have the highest IC50 value were found in leaves (methanol extract). The antioxidant activity of mangrove plants is caused by the presence of secondary metabolites contained in the extract such as flavonoids, phenolics, saponins, and tannins.