scholarly journals Phenotypically Induced Intraspecific Variation in the Morphological Development of Wetland and Stream Galaxias gollumoides McDowall and Chadderton

Diversity ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 220
Author(s):  
Nicholas R. Dunn ◽  
Leanne K. O’Brien ◽  
Gerard P. Closs

The hypothesis that contrasting hydrology induces divergent intraspecific phenotypic plastic responses in non-migratory freshwater fish was investigated. Morphologies of wetland and stream Galaxias gollumoides from South Island, New Zealand, at different stages of ontogeny, were examined. Phenotypic responses were tested for in a 2 × 2 factorial laboratory based controlled reciprocal transplant experiment with flow (current or no current) and source habitat (wetland or stream), as treatments. There was a shift in the overall head morphology of wetland current treatment G. gollumoides away from the wetland no current treatment, and toward the stream current treatment, demonstrating convergence in head morphology in the presence of flow of wetland and stream sourced captive G. gollumoides. Morphologies of captive reared G. gollumoides were also compared to developmental trajectories of morphological characters during the ontogeny of field reared first year, and adult conspecifics. In combination, experimental and field results support the hypothesis, finding habitat hydrology to be the potential mechanism inducing and maintaining intraspecific morphological divergence in G. gollumoides. Recognition of this mechanism inducing morphological divergence between populations also aids the taxonomic description of long genetically recognised lineages of co-members of the Galaxias vulgaris species complex.

1970 ◽  
Vol 6 (6) ◽  
pp. 81-84 ◽  
Author(s):  
Ramesh Adhikari ◽  
Keshab Shrestha

Bambusa nutans Wallich ex Munro subspecies nutans is a valuable economic plant occurring especially on the Terai region and mid hills (Kathmandu valley) in Nepal from sea level to 1700 m. Variation plays major role to compare the populations and to select superior trees for breeding purpose. Infraspecific variation is the study of comparison between plants belonging to the same species but from different populations which could be distinguished in nature. Study on the infraspecific variation of this species has been carried out from six different stands (Kapan, Kirtipur, Sisneri, Naldum, Kafledi and Narayanghat) of Central Nepal ranging in altitude (from 256 m to 1850 m) and climatic conditions. Altogether 10 culms, from 3-4 clumps were selected and 6 morphological characters having utmost importance in bamboo growth has been studied. Those characters were culm height, culm diameter at breast height, culm wall thickness, internode length ,culm sheath length and culm sheath breadth. Statistical analysis was performed for the calculation of correlation coefficient using SPSS software program. Variation within and among population was analyzed using one way ANOVA. All the characters show significant differences with 5% level of significance and ratios of morphological characters also show the significant differences except CH/CD, which was not significant. From the present study it is concluded that significant differences were observed in phenotypic characters. Since genetic differences leads to the variation among the plants, these variations might be of genetic origin .Reciprocal transplant experiment and progeny testing should be conducted for further research. Provided information can be utilized to conserve the genetic resources and to exploit these resources scientifically and economically. Keywords: Bambusa nutans subspecies nutans; Infraspecific variation; Correlation; ANOVA; Genetic differences.   DOI: 10.3126/sw.v6i6.2639 Scientific World, Vol. 6, No. 6, July 2008 81-84


Climate ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 36
Author(s):  
Kelly L. Bennett ◽  
William Owen McMillan ◽  
Jose R. Loaiza

Ae. (Stegomyia) aegypti L. and Aedes (Stegomyia) albopictus Skuse mosquitoes are major arboviral disease vectors in human populations. Interspecific competition between these species shapes their distribution and hence the incidence of disease. While Ae. albopictus is considered a superior competitor for ecological resources and displaces its contender Ae. aegypti from most environments, the latter is able to persist with Ae. albopictus under particular environmental conditions, suggesting species occurrence cannot be explained by resource competition alone. The environment is an important determinant of species displacement or coexistence, although the factors underpinning its role remain little understood. In addition, it has been found that Ae. aegypti can be adapted to the environment across a local scale. Based on data from the Neotropical country of Panama, we present the hypothesis that local adaptation to the environment is critical in determining the persistence of Ae. aegypti in the face of its direct competitor Ae. albopictus. We show that although Ae. albopictus has displaced Ae. aegypti in some areas of Panama, both species coexist across many areas, including regions where Ae. aegypti appear to be locally adapted to dry climate conditions and less vegetated environments. Based on these findings, we describe a reciprocal transplant experiment to test our hypothesis, with findings expected to provide fundamental insights into the role of environmental variation in shaping the landscape of emerging arboviral disease.


2019 ◽  
Vol 35 (2) ◽  
pp. 74-82 ◽  
Author(s):  
Hamza Issifu ◽  
George K. D. Ametsitsi ◽  
Lana J. de Vries ◽  
Gloria Djaney Djagbletey ◽  
Stephen Adu-Bredu ◽  
...  

AbstractDifferential tree seedling recruitment across forest-savanna ecotones is poorly understood, but hypothesized to be influenced by vegetation cover and associated factors. In a 3-y-long field transplant experiment in the forest-savanna ecotone of Ghana, we assessed performance and root allocation of 864 seedlings for two forest (Khaya ivorensis and Terminalia superba) and two savanna (Khaya senegalensis and Terminalia macroptera) species in savanna woodland, closed-woodland and forest. Herbaceous vegetation biomass was significantly higher in savanna woodland (1.0 ± 0.4 kg m−2 vs 0.2 ± 0.1 kg m−2 in forest) and hence expected fire intensities, while some soil properties were improved in forest. Regardless, seedling survival declined significantly in the first-year dry-season for all species with huge declines for the forest species (50% vs 6% for Khaya and 16% vs 2% for Terminalia) by year 2. After 3 y, only savanna species survived in savanna woodland. However, best performance for savanna Khaya was in forest, but in savanna woodland for savanna Terminalia which also had the highest biomass fraction (0.8 ± 0.1 g g−1 vs 0.6 ± 0.1 g g−1 and 0.4 ± 0.1 g g−1) and starch concentration (27% ± 10% vs 15% ± 7% and 10% ± 4%) in roots relative to savanna and forest Khaya respectively. Our results demonstrate that tree cover variation has species-specific effects on tree seedling recruitment which is related to root storage functions.


Author(s):  
Şemsettin Kulaç ◽  
Özge Yıldız

In this study, in order to help the mass production of seedlings, the effect of fertilization on the morphological development of hornbeam leafy European hophornbeam (Ostry carpinifolia Scop) seedlings were investigated. For this, seedlings, which were obtained from the seeds coming from different European hophornbeam populations (Düzce-Yığılca, Antalya-Finike, Antalya-Akseki, Kastamonu-Şehdağ ve Adana-Saimbeyli) from various parts of Turkey, were used. European hophornbeam seedlings were treated with different fertilizers, including urea, ammonium sulphate, compound fertilizer 15-15-15 and 20-20-0, and 6-9 months Osmocote release fertilizer, and effects of these fertilizers on the morphological characters were investigated. Fertilization contained the same amount of nitrogen, and was made in three different ways; (1) mixing with habitat, (2) topical application and (3) liquid application. The development of germinated European hophornbeam seeds, which were spring-sowed in the same medium were monitored during the vegetation period. At the end of vegetation period, seedlings were removed from the soil and morphological characteristics of root (seedling length, root collar diameter, root length, fresh root and stem weight of the seedlings, dried root and stem weight of the seedlings and bud number) were measured. As a result, it was observed that fertilization positively affects the development of seedlings and depending on the fertilization type the seedlings of European hophornbeam populations were found to exhibit different improvements/growing. In addition, 6-9 months Osmocote release fertilizers were determined to be the best fertilizers affecting the morphological (diameter and height) development of European hophornbeam populations effectively, and among the populations, Düzce and Kastamonu populations showed the best improvement/growing.


2020 ◽  
Vol 14 (2) ◽  
pp. 167-185
Author(s):  
Brian A. Perry ◽  
Harold W. Keller ◽  
Edward D. Forrester ◽  
Billy G. Stone

A  Mycena species new to science was obtained from moist chamber cultures of trunk bark of a living American elm tree (Ulmus americana) located in the Fort Worth Botanic Garden, Tarrant County, Texas. This discovery was part of an ongoing study of corticolous myxomycetes on larger American elm trees occurring in Fort Worth nature parks. More than 15 American elm trees were sampled for trunk bark but only a single tree yielded  Mycena basidiomes. Collections of bark began in the summer of 2017 and continued until the beginning of 2020. Bark samples from the north, south and west side of the tree yielded fruit bodies of the mushroom in moist chamber culture. No fruit bodies were observed in nature nor were early formation stages on the underside of the bark. Crystals previously described in another study were present on the bark surfaces, edges, and undersides. Habit and morphological development were photographed using light microscopy applying multifocal imaging and computer stacking to increase depth of field. Basidiome development was observed and photographed from the earliest primordial beginning stage, the button stage, intermediate stage and the final emerging stalk elongation and mature cap formation stage. Mature mushroom development took from 9 to 21 days after wetting the bark in moist chamber cultures. Scanning electron microscopy was used to illustrate development of the button stage, emerging stalk and pileus stage, and the fully mature pileus, lamellae, and pseudocollarium. Morphological features and DNA sequence data confirmed that this  Mycena species was undescribed and distinct from other  Mycena taxa. Morphological features suggest placement of the novel taxon in  Mycena sect. Viscipelles, distinct from other members based on morphological characters and phylogenetic analysis.


2019 ◽  
Vol 6 (1) ◽  
pp. 54-62
Author(s):  
Ronak N Kachhiyapatel ◽  
Sachin M Patil ◽  
Vinay M Raole ◽  
Kishore S Rajput

Present study deals with the diversity, distribution and conservation status of the genus Athyrium Roth in different climatic regimes of Gujarat state. Five species of Athyrium viz., A. hohenackerianum T. Moore, A. falcatum Bedd., A. micropterum Fraser-Jenk., A. parasnathense (C.B.Clarke) Ching ex Mehra & Bir and A. schimperi subsp. biserrulatum (Christ) Fraser-Jenk., were collected form the Gujarat state, of which A. hohenackerianum T. Moore is documented earlier. Therefore, occurrence of A. falcatum, A. micropterum, A. parasnathense, and A. schimperi subsp. biserrulatum, stands as a new distribution records and reported for the first time from Gujarat state. A detailed taxonomic description, photo plates, morphological characters, distribution and comparison of species is provided here for their identification.


2019 ◽  
Vol 32 (Supplement_1) ◽  
Author(s):  
F Bevilacqua ◽  
B Ragni ◽  
L Valfrè ◽  
A Conforti ◽  
A Braguglia ◽  
...  

Abstract Background Esophageal atresia (EA) prognosis have improved significantly over the past three decades. Research and clinical attention has shifted to neurodevelopmental outcomes and quality of life. Aim The aim of this study wasto examine neurodevelopmental outcomes and to identify clinical and sociodemographic risk factors in a cohort of infants with EA. Methods An observational prospective longitudinal study was conducted between 2009 and 2017. Neurodevelopment was assessed at 6 and 12 months by Bayley Scales of Infants and Toddler Development—3rd Edition. Clinical and sociodemographic variables included were gender, birthweight, gestational age, associated malformations, number of hospitalizations, surgeries and dilatations at 12 months, days of mechanical ventilation, parental age, education level, and socioeconomic status. Results Ninety-six infants were enrolled in the study at 6 months and 73 of them were evaluated also at 12 months. Analysis showed significant differences between motor development at 6 and 12 months (M6 = 95.39, SD = 15.71; M12 = 91.83, SD = 12.87; t = 0.245, P = 0.017); significant differences emerged also between cognitive development at 6 and 12 months (M6 = 91.80, SD = 11.70; M12 = 100.92, SD = 15.39; t = −5.10, p = .000). Infants with long-gap AE achieved the worst scores in cognitive (r = -.28, P < .01) and motor scales (r = -.36, P < .01) at 6 months and in motor scale at 12 months (r = −0.30, P < 0.05). More days of mechanical ventilation were related to a lower score in both the cognitive (6 months r = −0.26, P < 0.05; 12 months r = −0.26, P < 0.05) and motor scale (6 months: r = −0.38, P < 0.01; 12 months r = −0.42, P < 0.01). A major number of interventions in the first year of life were related to lower scores in the motor scale at 12 months (r = −0.43, P < 0.01). Conclusions Infants operated on for AE are at risk of neurodevelopmental impairment in the first year of life. Findings support the association between neurodevelopmental outcomes and clinical risk factors. Careful interdisciplinary follow-up is essential for early detection of neurodevelopmental delay.


Botany ◽  
2010 ◽  
Vol 88 (10) ◽  
pp. 930-936 ◽  
Author(s):  
Laura L. Beaton ◽  
Susan A. Dudley

Previous studies have demonstrated that plants collected as seeds from roadside populations of Dipsacus fullonum L. subsp sylvestris (Huds.) Claphamare more tolerant of high salinity, low osmotic potentials, and hypoxia during juvenile growth stages than those from oldfield populations. However, it is unclear how tolerance to these abiotic stressors translates into performance in the roadside environment. Here, we conducted a reciprocal transplant experiment between oldfield and roadside environments. Seeds from three roadside and three oldfield populations were planted into oldfield and roadside sites in late fall. Throughout the spring and summer, the survivorship and size of the seedlings were monitored to examine differences in performance in the two habitats. We also assessed the relation between performance in the field and previous in vitro measures of salt and drought tolerance of each population. A drought caused high mortality levels in the oldfield and roadside. Individuals from roadside populations did not exhibit increased growth or survivorship in the roadside environment. In the early months of seedling growth, neither salt nor drought tolerance were significantly correlated with performance in the roadside during seedling establishment. Rather, during these early months, the average size of individuals in each population in the field was positively correlated with the population’s average seed mass, indicating that maternal provisioning had a greater impact than tolerance to particular environmental stresses during the juvenile stages of development. However, later in the summer, after the drought began, the average size of individuals from each population in the field was positively correlated with that population’s average drought tolerance.


Phytotaxa ◽  
2020 ◽  
Vol 477 (2) ◽  
pp. 253-260
Author(s):  
ZEKI AYTAC ◽  
PHILIPPE RABAUTE ◽  
PIERRE COULOT

Onobrychis silvanensis sp. nov., is described from Silvan, Diyarbakır province, in southeastern Anatolia, Turkey. The new species is closely related to O. galegifolia and O. radiata. The white corolla feature of O. silvanensis is uncommon in Turkish Onobrychis species and is otherwise known only in O. haussknecthii and O. hypargyrea. In addition to the diagnosis and taxonomic description, morphological characters of both flowering and fruiting O. silvanensis plants are presented. Distribution maps for O. silvanensis, O. galegifolia and O. radiata in Turkey are also provided. Although currently Data Deficient by IUCN status criteria, we anticipate O. silvanensis constitutes a candidate for Endangered status.


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