scholarly journals Stressful Conditions Give Rise to a Novel and Cryptic Filamentous Form of Caulerpa cylindracea

2021 ◽  
Vol 8 ◽  
Author(s):  
Jorge Santamaría ◽  
Raül Golo ◽  
Emma Cebrian ◽  
María García ◽  
Alba Vergés
Keyword(s):  
Invasive Species ◽  
Extreme Temperature ◽  
Morphological Plasticity ◽  
Morphological Characterization ◽  
Ex Situ ◽  
High Plasticity ◽  
Filamentous Form ◽  
Colonization Process ◽  
Almost All ◽  
New Habitats

Morphological plasticity can enable algae to adapt to environmental change and increase their invasibility when introduced into new habitats. Nevertheless, there is still a lack of knowledge on how such plasticity can affect the invasion process of an invasive species. In this context, the high plasticity in the genus Caulerpa is well documented. However, after an extremely hot summer, a previously unreported filamentous morphology of Caulerpa cylindracea was detected; indeed, this morphology could only be confirmed taxonomically after in-depth morphological characterization and molecular analysis with the genetic marker tufA. We describe an ex situ culture experiment which showed that stressful conditions, such as high temperatures, can trigger this morphological change. Almost all of the thalli maintained at a constant extreme temperature of 29°C died, but after being returned to optimum temperature conditions, the filamentous morphology began to develop from the surviving microscopic tissue. In contrast, thalli at a control temperature of 21°C maintained the regular morphology throughout the experiment. When C. cylindracea develops this filamentous morphology, it may act as a cryptic invader because it is difficult to detect in the field. Furthermore, the filaments likely improve C. cylindracea’s invasive capabilities with regard to resistance, persistence and dispersion and may have an important role in the re-colonization process, after a population disappears following a period of stressful conditions. Possibly, C. cylindracea’s ability to respond plastically to stressful conditions might explain its remarkable success as an invasive species.

scholarly journals Morphological Characterization of Root System Architecture in Diverse Tomato Genotypes during Early Growth

2018 ◽  
Vol 19 (12) ◽  
pp. 3888 ◽  
Author(s):  
Aurora Alaguero-Cordovilla ◽  
Francisco Gran-Gómez ◽  
Sergio Tormos-Moltó ◽  
José Pérez-Pérez
Keyword(s):  
Root System ◽  
System Architecture ◽  
Lateral Root ◽  
Morphological Plasticity ◽  
Root System Architecture ◽  
Morphological Characterization ◽  
Early Growth ◽  
Soil Conditions ◽  
Wild Tomato Species ◽  
Local Soil

Plant roots exploit morphological plasticity to adapt and respond to different soil environments. We characterized the root system architecture of nine wild tomato species and four cultivated tomato (Solanum lycopersicum L.) varieties during early growth in a controlled environment. Additionally, the root system architecture of six near-isogenic lines from the tomato ‘Micro-Tom’ mutant collection was also studied. These lines were affected in key genes of ethylene, abscisic acid, and anthocyanin pathways. We found extensive differences between the studied lines for a number of meaningful morphological traits, such as lateral root distribution, lateral root length or adventitious root development, which might represent adaptations to local soil conditions during speciation and subsequent domestication. Taken together, our results provide a general quantitative framework for comparing root system architecture in tomato seedlings and other related species.

scholarly journals Demographics of Eucalyptus grandis and implications for invasion

Koedoe ◽  
2017 ◽  
Vol 59 (1) ◽  
Author(s):  
Kudakwashe Musengi ◽  
Sally Archibald
Keyword(s):  
Invasive Species ◽  
Eucalyptus Grandis ◽  
Reproductive Traits ◽  
Alien Invasive Species ◽  
Rate Of Spread ◽  
Invasion Stage ◽  
The Future ◽  
Plantation Species ◽  
Negative Impacts ◽  
Almost All

Alien invasive species can have negative impacts on the functioning of ecosystems. Plantation species such as pines have become serious invaders in many parts of the world, but eucalypts have not been nearly as successful invaders. This is surprising considering that in their native habitat they dominate almost all vegetation types. Available theory on the qualities that characterise invasive species was used to assess the invasive potential of Eucalyptus grandis – a common plantation species globally. To determine rates of establishment of E. grandis outside plantations, we compared population demographics and reproductive traits at two locations in Mpumalanga, South Africa: one at higher elevation with more frost. Eucalyptus grandis has a short generation time. We found no evidence that establishment of E. grandis was limiting its spread into native grassland vegetation, but it does appear that recruitment is limited by frost and fire over much of its range in Mpumalanga. Populations at both study locations displayed characteristics of good recruitment. Size class distributions showed definite bottlenecks to recruitment which were more severe when exposed to frost at higher elevations. Generally, the rate of spread is low suggesting that the populations are on the establishing populations’ invasion stage. This research gives no indication that there are any factors that would prevent eucalyptus from becoming invasive in the future, and the projected increase in winter temperatures should be a cause for concern as frost is currently probably slowing recruitment of E. grandis across much of its planted range.Conservation implications: Eucalyptus plantations occur within indigenous grasslands that are of high conservation value. Frost and fire can slow recruitment where they occur, but there are no obvious factors that would prevent E. grandis from becoming invasive in the future, and monitoring of its rates of spread is recommended.

A Good Land

2018 ◽  
pp. 69-98
Author(s):  
Wade Graham
Keyword(s):  
Invasive Species ◽  
Market Economy ◽  
New World ◽  
Traditional Farming ◽  
Seasonal Labor ◽  
Almost All

This chapter describes events from 1845 to 1869. By the time of the Mahele, much of Molokai was a shadow of its former self, its population having dropped steeply from a reported 6,000 in 1832 to about 3,400 in 1850; then, after recovering a few hundred by 1855, dropping further to 2,864 in 1860. The ruins of former hamlets, fishponds, and kalo loi were visible seemingly everywhere. Yet, because of its isolation, the island bore few marks of the new world outside: few haoles lived there, and almost all land was in Hawaiian hands; most residents subsisted on traditional farming and fishing, with some seasonal labor at Lahaina in the whaling economy; little shipping stopped there, and few of the biological intrusions such as invasive species and grazing animals had made an appearance. Nevertheless, a transition to the market economy was going on.

Distribution of Phytophthora cinnamomi in the northern jarrah (Eucalyptus marginata) forest of Western Australia in relation to dieback age and topography

2002 ◽  
Vol 50 (1) ◽  
pp. 107 ◽  
Author(s):  
K. L. McDougall ◽  
G. E. St J. Hardy ◽  
R. J. Hobbs
Keyword(s):  
Spatial Distribution ◽  
Western Australia ◽  
Aerial Photography ◽  
Phytophthora Cinnamomi ◽  
Ex Situ ◽  
Patchy Distribution ◽  
Jarrah Forest ◽  
Eucalyptus Marginata ◽  
Almost All

The spatial distribution of Phytophthora cinnamomi Rands at seven dieback sites in the jarrah (Eucalyptus marginata Donn. ex Smith) forest of Western Australia was determined by the following two baiting techniques: in situ baiting with live Banksia grandis Willd. seedlings and ex situ baiting of sampled soil and root material. Four areas within each site were sampled, reflecting dieback age and position in the landscape. Approximate dieback ages of 50, 20 and 5 years were determined by aerial photography. The 50-year-old age class was divided into wet valley floor and dry gravelly slope. Phytophthora cinnamomi was recovered most frequently from the 5-year-old (dieback fronts) and wet 50-year-old areas by both baiting techniques. It was recovered from more than twice as many areas and about five times as many samples when in situ B. grandis baits were used compared with ex situ soil and root baiting. Almost all recoveries from in situ baits were made between October and December. From both methods, it appears that P. cinnamomi has a patchy distribution within dieback sites in the northern jarrah forest. It is easily detected only on dieback fronts and wet valley floors. On dry gravelly sites affected 20 years or more ago, P. cinnamomi is rare and may even be absent at some sites. This makes confident detection of the pathogen difficult. In situ baiting at least allows a temporal component to the sampling and will be a useful method of detection in areas where P. cinnamomi is rare or transient.

Undrained shear strength properties of organic harbor mud at low consolidation stress levels

2011 ◽  
Vol 48 (3) ◽  
pp. 388-398 ◽  
Author(s):  
Benjamin Friedrich Schlue ◽  
Tobias Mörz ◽  
Stefan Kreiter
Keyword(s):  
Shear Strength ◽  
Large Scale ◽  
Strength Properties ◽  
Undrained Shear Strength ◽  
Ex Situ ◽  
High Plasticity ◽  
Compression Time ◽  
Stress Levels ◽  
Strong Surface ◽  
Undrained Shear

Dredging operations in European harbors for maintenance of navigable water depth produce vast amounts of harbor mud. Between 2005 and 2007, the second largest harbor construction project in Germany was designed as a pilot study, using dredged harbor mud as backfill material to avoid expensive deposition or ex situ treatment. During this project, strong surface deformations of the backfill highlighted the need for an improved assessment of undrained shear strength of naturally liquid harbor mud. The strength of harbor mud cannot be measured accurately under corresponding low in situ effective stress levels by standard laboratory tests. Therefore, a large-scale oedometer cell with a diameter of 22 cm was designed, providing the opportunity to perform vane shear measurements during consolidation. This study shows that East Harbor mud is a very sensitive, organogenic clay of extremely high plasticity, exhibiting very small undrained shear strength when compared with other cohesive soils. Both the peak and residual undrained shear strengths are shown to increase about 3%–4% per log-cycle increase in secondary compression time (days).

Analysis of wild Lactuca accessions: conservation and identification of redundancy

2008 ◽  
Vol 6 (02) ◽  
pp. 153-163 ◽  
Author(s):  
Tatjana Sretenović Rajičić ◽  
Theo van Hintum ◽  
Aleš Lebeda ◽  
Klaus J. Dehmer
Keyword(s):  
Disease Resistance ◽  
Length Polymorphism ◽  
Fragment Length Polymorphism ◽  
Morphological Characterization ◽  
Ex Situ ◽  
Population Parameters ◽  
Lactuca Saligna ◽  
High Level ◽  
Germplasm Accessions ◽  
Morphological Assessment

Germplasm accessions of wildLactucaspecies are maintained worldwide inex situcollections as gene reservoirs for quality and disease resistance traits for cultivated lettuce. Accessions of 12Lactucaspecies from 6 genebanks were compared via morphological characterization and AFLP (Amplified Fragment Length Polymorphism)-based profiling to estimate the extent of duplication. A method of assessing redundancy within very similar, but not identical accessions, is proposed, based on 352 polymorphic AFLP products. Seven duplication groups showed a high level of AFLP similarity, and one pair ofLactuca salignaaccessions displayed identical AFLP profiles. In several cases, the morphological assessment indicated that a taxonomic reclassification of accessions was necessary. Candidate duplicates were identified using population parameters and inter- and intra-accession variability. The implications of these findings on the conservation of wild species are discussed.

scholarly journals JENIS AVES DAN MAMALIA DIURNAL YANG MEMANFAATKAN JAMBU TANGKALAK (Bellucia pentamera) SEBAGAI SUMBER PAKAN DI KEBUN RAYA SAMBAS

2019 ◽  
Vol 7 (2) ◽  
Author(s):  
Aldi Haryono ◽  
Hari Prayogo ◽  
. Erianto
Keyword(s):  
Macaca Fascicularis ◽  
Ex Situ Conservation ◽  
Secondary Forest ◽  
Botanical Garden ◽  
Ex Situ ◽  
Survey Method ◽  
Wild Animals ◽  
Conservation Area ◽  
Management Area ◽  
Almost All

Sambas Botanical Garden is an ex-situ conservation area, in its management there is the term Vak, which is a small management area with care and supervision that is more focused on the inside plants, Bellucia pentamera in the management of Vak is very limited and cut down, but actually Bellucia pentamera is forest plant which has the criteria of providing fruit almost all year long and is widely used by most wildlife. The study aims to record species of aves and diurnal mammals that use Bellucia pentamera as a source of feed for wild animals in the Sambas Botanical Gardens. The research was carried out in the management area and secondary forest, each represented by three growing places, namely hills, foothills and riparians. The study was conducted in July-August with a survey method by observing direct observation at the point of tangkalak guava stands with repetitions three times. The results showed that seven types of aves were found, namely Chloropsis sonnerati, Dicaeum trigonostigma, Dicaeum trochileum, Pycnonotus goiavie, Chloropsis cochinchinensis, Zosterops palpebrosus, and Arachnothera crassirostris, There are four types of mammals found, namely Macaca fascicularis, Sundasciurus lowii, Callosciurus prevostii, and Callosciurus orestes.Keywords: Aves, Bellucia pentamera, Feed, Mammals

scholarly journals Morphological Characterization and Genetic Diversity Analysis of a Tunisian Durum Wheat (Triticum Turgidum Var. Durum) Collection

2020 ◽  
Author(s):  
Maroua Ouaja ◽  
Bochra Amina Bahri ◽  
Lamia Aouini ◽  
Sahbi Ferjaoui ◽  
Maher Medini ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Durum Wheat ◽  
Gene Diversity ◽  
Polymorphic Information Content ◽  
Morphological Characterization ◽  
Genetic Variations ◽  
Mantel Test ◽  
Ex Situ ◽  
The South ◽  
Population Structure Analysis

Abstract Background: Tunisia is a center of genetic diversity of durum wheat and has a large number of abandoned old local landraces. An accurate investigation and characterization of the morphological and genetic features of these landraces would allow their rehabilitation and use for practical and beneficial purposes. In this context, a collection of 304 local accessions of durum wheat, collected from five regions and three climatic zones of central and southern Tunisia, was studied. Results: Morphological characterization was carried out using 12 spike-related traits and rendered a mean Shannon-Weaver Index (H') of 0.80 indicating the presence of a high level of polymorphism among accessions. Based on these traits 11 local landraces, namely Mahmoudi, Azizi, Jneh Khotifa, Mekki, Biskri, Taganrog, Biada, Badri, Richi, Roussia and Souri were identified. Spike length (H’=0.98) and shape (H’=0.86) with grains size (H’=0.94), form (H’=0.87) and color (H’=0.86) were the most polymorphic morphological traits. The genetic diversity was assessed using 10 SSR markers, with a polymorphic information content (PIC) of 0.69. Levels of genetic diversity were generally high, with a Shannon's Information Index (I) of 0.62 and a gene diversity (He) of 0.35. In addition, population structure analysis distinguished 11 genetic groups resulted from STRUCTURE and Mantel test showed a significant correlation between genetic and morphological distances. Analysis of molecular variance (AMOVA) showed high genetic variations within regions (81%) and wheat subpopulations (41%) showing a considerable amount of admixture between landraces realized by farmers; as well as a moderate (19%) and high (59%) genetic variations among regions and wheat subpopulations, indicating practices of selection pressure conducted by farmers. The Mahmoudi landrace showed spike densities significantly different between the center to the south of Tunisia; notably loose spikes with open glumes in the south and compact ones in the center, which may represent an adaptation form for tolerance to high temperature. Conclusion: Overall, this study highlights the genetic richness of local resources for better in situ or ex situ conservation and for their subsequent use in plant breeding programs.

scholarly journals Translocation and new geographical distribution of the invasive Redbelly Tilapia, Coptodon zillii (Gervais, 1848) (Teleostei: Cichlidae) in southern Iran

Check List ◽  
2017 ◽  
Vol 13 (1) ◽  
pp. 2051 ◽  
Author(s):  
Azad Teimori ◽  
Mina Motamedi ◽  
Majid Askari Hesni
Keyword(s):  
Invasive Species ◽  
Geographical Distribution ◽  
New Record ◽  
Ecological Monitoring ◽  
Exotic Fish ◽  
Southern Iran ◽  
Native Fishes ◽  
Distribution Record ◽  
Exotic Fish Species ◽  
New Habitats

A new geographical distribution record of the invasive species of Redbelly Tilapia, Coptodon zillii, is reported here from a drainage in southern Iran, based on the discovery of a population at Howba spring. The locality of the new record is now completely dominated by this exotic fish; this location was previously inhabited by native fishes. As tilapia species have a high resilience to harsh environmental conditions, they can easily be translocated to, and establish in, new habitats. Thus, ecological monitoring of this exotic fish species is highly recommended.

scholarly journals Characterization of Selected Polymeric Membranes Used in the Separation and Recovery of Palladium-Based Catalyst Systems

Membranes ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 166
Author(s):  
Bongani Michael Xaba ◽  
Sekomeng Johannes Modise ◽  
Bamidele Joseph Okoli ◽  
Mzimkhulu Ephraim Monapathi ◽  
Simphiwe Nelana
Keyword(s):  
Organic Solvent ◽  
Membrane Separation ◽  
Pure Water ◽  
Morphological Characterization ◽  
Polymeric Membrane ◽  
Separation Processes ◽  
Solute Permeability ◽  
Catalyst Systems ◽  
Almost All ◽  
Microscopy Characterization

Membrane separation processes tender a capable option for energy-demanding separation processes. Nanofiltration (NF) and reverse osmosis (RO) membranes are among the most explored, with a latent use in the chemical industry. In this study, four commercial membranes (NF90, NF270, BW30, and XLE) were investigated for their applicability based on the key structural performance characteristics in the recycling of Pd-based catalysts from Heck coupling post-reaction mixture. Pure water and organic solvent permeabilities, uncharged solute permeability, swelling, and catalyst rejection studies of the membranes were conducted as well as the morphological characterization using Fourier transform infrared, field emission gun scanning electron microscopy, and atomic force microscopy. Characterization results showed trends consistent with the manufactures’ specifications. Pure water and organic solvent fluxes generally followed the trend NF270 > NF90 > BW30 > XLE, with the solvent choice playing a major role in the separation process. Pd(PPh3)2Cl2 was well rejected by almost all membranes in 2-propanol; however, XLE rejects Pd(OAc)2 better at high pressure in acetonitrile. Our study, therefore, revealed that the separation and reuse of the two catalysts by NF90 at 10 bar resulted in 97% and 49% product yields with 52% and 10% catalyst retention for Pd(OAc)2 while Pd(PPh3)2Cl2. gave 87% and 6% yields with 58% and 36% catalyst retention in the first and second cycles, respectively. Considering, the influence of membrane–solute interactions in Pd-catalyst rejection, a careful selection of the polymeric membrane and solvent, a satisfactory separation, and recovery can be achieved.

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