Morphological variation within and among six populations of Trillium erectum in southern Ontario

1987 ◽  
Vol 65 (11) ◽  
pp. 2450-2457 ◽  
Author(s):  
Gordon S. Ringius ◽  
Jerry G. Chmielewski
Keyword(s):  
Morphological Variation ◽  
Phenotypic Variation ◽  
Population Differentiation ◽  
Plant Size ◽  
Southern Ontario ◽  
General Symmetry ◽  
Precambrian Rocks ◽  
Aerial Shoot ◽  
Several Variables ◽  
Complex Relationships

Phenotypic variation within populations and among populations was examined in six populations of Trillium erectum from southern Ontario. The general symmetry of the flower was confirmed, although there was a tendency for the lower petals and sepals to be longer than the upper ones. Within populations, variation related to the overall expansion of the aerial shoot after emergence from the soil accounted for most of the variation. However, the expansion of the shoot was not uniform and independent growth components were found for the floral and vegetative variables. Only about one-third of the variation in floral variables was dependent on plant size. Also, within the flower, anthers, and filaments varied independently. Among-population differentiation was high and appeared to be determined by complex relationships among variables that are unique to each population. Several variables showed a correlation with underlying bedrock: populations located on Paleozoic limestone consist of plants that are smaller than those in populations located on Precambrian rocks. Whether the correlation between plant size and parental bedrock is causal is unknown.

scholarly journals Exposing Seeds of Sarcococca confusa to Increased Concentrations and Durations of Ethyl Methanesulfonate Reduced Seed Germination, Twinning, and Plant Size

HortScience ◽  
2019 ◽  
Vol 54 (11) ◽  
pp. 1902-1906 ◽  
Author(s):  
Tyler Hoskins ◽  
Ryan N. Contreras
Keyword(s):  
Seed Germination ◽  
Phenotypic Variation ◽  
Germination Rate ◽  
Plant Size ◽  
Mutation Breeding ◽  
Ethyl Methanesulfonate ◽  
Chemical Mutagenesis ◽  
Growing Seasons ◽  
Percent Germination ◽  
Future Evaluation

Sweetbox (Sarcococca confusa) is an evergreen shrub valued for attractive foliage, winter fragrance, black fruit, as well as shade and drought tolerance. The high degree of apomixis in Sarcococca limits the effectiveness of conventional breeding practices. However, mutation breeding may be a valuable tool to induce variation in seedling crops. As such, a study was conducted to expose seeds of S. confusa to ethyl methanesulfonate (EMS) at varying concentrations and exposure durations, and to evaluate the effects on seed germination, growth, and relative frequency of polyembryony. In 2010, seeds of S. confusa were treated with 0%, 0.2%, 0.4%, 0.8%, and 1.2% EMS for 24 and 48 hours. Seeds were sown and the relative germination and occurrence of polyembryony were recorded. Seedlings were later evaluated for size and phenotypic variation in the subsequent growing seasons. Percent germination was found to decrease with increasing EMS rates in the 24- and 48-hour treatments. The occurrence of polyembryony also decreased with increasing EMS rates in the 24-hour treatment but was observed to be greatest at 0.2% EMS. No significant differences in plant size index (SI) were found after four growing seasons. When mature, seeds were collected from any plants that bore fruit in each treatment and were then sown. The percentage of plants that bore fruit in each treatment decreased with increasing EMS rates, although the germination rate of these seeds did not differ. A chlorophyll mutant and several dwarf forms were identified in this population as well. They have been propagated asexually for future evaluation as new cultivars. This study demonstrates the utility of chemical mutagenesis to induce phenotypic variation in S. confusa while reducing the rate of polyembryony.

scholarly journals Morphological variation among populations of Hemigrammus coeruleus (Characiformes: Characidae) in a Negro River tributary, Brazilian Amazon

2017 ◽  
Vol 15 (1) ◽  
Author(s):  
Henrique Lazzarotto ◽  
Thiago Barros ◽  
José Louvise ◽  
Érica Pellegrini Caramaschi
Keyword(s):  
Morphological Variation ◽  
Phenotypic Variation ◽  
Population Level ◽  
Brazilian Amazon ◽  
Additional Species ◽  
Geometric Morphometric ◽  
Blackwater River ◽  
Ecological Selection ◽  
Negro River ◽  
Morphological Differences

ABSTRACT We explored patterns of phenotypic variation in Hemigrammus coeruleus from the Unini River basin, a blackwater river in the Brazilian Amazon. Geometric morphometrics was used to evaluate variation in body shape among populations from four tributaries (UN2-UN5). We found no evidence for sexual dimorphism in body size and shape. However, morphological differences among populations were detected as the analyses recovered significant groups corresponding to each sub-basin, with some overlap among them. The populations from UN2, UN3 and UN5 had more elongate bodies than fish from UN4. The most morphologically divergent population belonged to UN4, the tributary with the most divergent environmental conditions and the only one with seasonally-muddy waters. The morphological variation found among these populations is likely due to phenotypic plasticity or local adaptation, arising as a product of divergent ecological selection pressures among sub-basins. This work constitutes one of the first to employ a population-level geometric morphometric approach to assess phenotypic variation in Amazonian fishes. This method was able to distinguish subtle differences in body morphology, and its use with additional species can bring novel perspectives on the evaluation of general patterns of phenotypic differentiation in the Amazon.

Ceratozamia sanchezae (Zamiaceae): a new cycad species from Chiapas Highlands (Mexico)

Phytotaxa ◽  
2021 ◽  
Vol 500 (3) ◽  
pp. 201-216
Author(s):  
JOSÉ SAID GUTIÉRREZ-ORTEGA ◽  
MIGUEL A. PÉREZ-FARRERA ◽  
ANDREW P. VOVIDES ◽  
ANGÉLICA CHÁVEZ-CORTÁZAR ◽  
SERGIO LÓPEZ ◽  
...  
Keyword(s):  
Morphological Variation ◽  
Population Differentiation ◽  
Species Delimitation ◽  
Species Complex ◽  
Herbarium Specimens ◽  
New Taxon ◽  
Linear Discriminant ◽  
Discriminant Analyses ◽  
Male Cones ◽  
Adult Plants

The taxonomic classification within the Neotropical cycad genus Ceratozamia (Zamiaceae) has been a challenging task because cohorts of morphological variation in association with conspicuous geographic discontinuities that delimit species are not always easy to observe. Ceratozamia robusta is one example. Although previous studies have suggested that C. robusta presents an unusually high morphological variation across populations, this variation remains unquantified. In particular, we noticed that herbarium specimens from populations in the region Los Altos de Chiapas (Chiapas Highlands) that have been considered as C. robusta notably differ from the rest of the typical C. robusta forms by having narrower leaflets and fewer prickles on the petioles. Thus, we asked whether the populations in the Chiapas Highlands correspond to C. robusta as currently circumscribed. We examined the variation of ten leaf and trunk traits of 97 adult plants from six populations of C. robusta. Variation among the ten traits was significantly differentiated across populations, and such variation is correlated with elevation. Pairwise population differentiation tests and linear discriminant analyses clearly separated three groups: 1) populations similar to the neotype of C. robusta occur at mid-elevations in Chiapas, 2) a large C. robusta form occurs at low elevations in Belize, and 3) populations in the Chiapas Highlands that differ from both. The latter have fewer leaves and leaflets, shorter rachis, arched leaves in mature plants, petioles sparsely armed with thin prickles, smaller male cones, and juvenile forms more similar to those of the C. miqueliana species complex. These results suggest that the populations from the Chiapas Highlands represent a new taxon, here described as Ceratozamia sanchezae. This study highlights the importance of quantifying morphological variation across cycad populations to identify the species delimitation in complex groups.

scholarly journals Phenotypic variation in <i>Gyroidinoides altiformis</i> (Stewart & Stewart) and <i>Gyroidinoides subangulatus</i> (Plummer) (Foraminifera)

1991 ◽  
Vol 9 (2) ◽  
pp. 233-238 ◽  
Author(s):  
Roberto Barbieri
Keyword(s):  
Morphological Variation ◽  
Phenotypic Variation ◽  
Morphological Changes ◽  
Northern Italy ◽  
Foraminiferal Species ◽  
Late Neogene ◽  
Different Ages

Abstract. The morphological variation of two benthic foraminiferal species, Gyroidinoides altiformis (Stewart &amp; Stewart) and Gyroidinoides subangulatus (Plummer), are described from Late Neogene - Quaternary, and Palaeogene sequences from northern Italy and Greece. A number of morphotypes, two for each species, are thought to be ecophenotypes. The inferred ecological (bathymetric) conditioning derives from: 1) comparable shape variations occur in species of very different ages; 2) both species exhibit the same morphological changes as a result of a comparable environmental trend.

scholarly journals Stresses affect inbreeding depression in complex ways: disentangling stress-specific genetic effects from effects of initial size in plants

Heredity ◽  
2021 ◽  
Author(s):  
Tobias M. Sandner ◽  
Diethart Matthies ◽  
Donald M. Waller
Keyword(s):  
Gene Expression ◽  
Inbreeding Depression ◽  
Phenotypic Variation ◽  
Phenotypic Variability ◽  
Nutrient Deficiency ◽  
Plant Size ◽  
Genetic Effects ◽  
Initial Size ◽  
Copper Addition ◽  
Deleterious Alleles

AbstractThe magnitude of inbreeding depression (ID) varies unpredictably among environments. ID often increases in stressful environments suggesting that these expose more deleterious alleles to selection or increase their effects. More simply, ID could increase under conditions that amplify phenotypic variation (CV²), e.g., by accentuating size hierarchies among plants. These mechanisms are difficult to distinguish when stress increases both ID and phenotypic variation. We grew in- and outbred progeny of Mimulus guttatus under six abiotic stress treatments (control, waterlogging, drought, nutrient deficiency, copper addition, and clipping) with and without competition by the grass Poa palustris. ID differed greatly among stress treatments with δ varying from 7% (control) to 61% (waterlogging) but did not consistently increase with stress intensity. Poa competition increased ID under nutrient deficiency but not other stresses. Analyzing effects of initial size on performance of outbred plants suggests that under some conditions (low N, clipping) competition increased ID by amplifying initial size differences. In other cases (e.g., high ID under waterlogging), particular environments amplified the deleterious genetic effects of inbreeding suggesting differential gene expression. Interestingly, conditions that increased the phenotypic variability of inbred progeny regularly increased ID whereas variability among outbred progeny showed no relationship to ID. Our study reconciles the stress- and phenotypic variability hypotheses by demonstrating how specific conditions (rather than stress per se) act to increase ID. Analyzing CV² separately in inbred and outbred progeny while including effects of initial plant size improve our ability to predict how ID and gene expression vary across environments.

scholarly journals Morphological Variation of Limnonectes blythii in West Sumatera, Indonesia

2018 ◽  
Vol 6 (08) ◽  
Author(s):  
Wince Hendri Hendri ◽  
Djong Hon Tjong ◽  
Dahelmi . ◽  
Dewi Imelda Roesma
Keyword(s):  
Genetic Variation ◽  
Morphological Variation ◽  
Population Differentiation ◽  
Phylogenetic Relationships ◽  
Nature Reserve ◽  
Morphological Characters ◽  
Natural Sciences ◽  
Significant Differentiation ◽  
Morphological Variations ◽  
West Sumatra

Abstract: This study aimed to analyze the morphological variations of Limnonectes blythii in West Sumatra by using morphometric in Genetics and Cytology Laboratory, Department of Biology, Faculty of Mathematics and Natural Sciences, Andalas University, Padang. The sample of this research was collected directly in West Pasaman (Nature Reserves Malampah), Sijunjung (Nature Reserve Pangean) and Payakumbuh (Harau Nature Reserve) in February until Mai 2015. The results showed that there is genetic variation in morphology of the population L. blythii in Malampah and Pangean as the first cluster with a population in Harau. The kinship between populations in Pangean and Malampah as the second cluster is closer to the population at second subcluster with Harau population and have the more distant kinship of the population L. blythii in Pangean. It was concluded that 12 morphological characters show differentiation significant (p≥ 0005) of the population, while the population of Harau and Sijunjung showed significant differentiation as many as 10 characters (32.2%), Between population differentiation Harau with Malampah show as much as 8 characters (25.8% ), and between population Malampah with Sijunjung show 7 (22:58%) differentiated character. This study requires molecular analysis to clarify the phylogenetic relationships among L. blythii to preserve the information of this frog as an export commodity.

scholarly journals Morphological Variation in Arabica Coffee (Coffea arabica L.) Growing in North Sumatra Indonesia

2018 ◽  
Vol 46 (3) ◽  
pp. 314-321
Author(s):  
Sabam Malau ◽  
And Samse Pandiangan
Keyword(s):  
Genetic Correlation ◽  
Morphological Variation ◽  
Phenotypic Variation ◽  
Yield Components ◽  
Genotypic Variation ◽  
Phenotypic Correlation ◽  
Genetic Advance ◽  
Arabica Coffee ◽  
Leaf Weight ◽  
North Sumatra

Genetic variation is important in plant breeding. However, information on the genetic variability of Arabica coffee especially in coffee field of North Sumatra was not yet available.  Magnitude of morphological variation, genotypic variation, phenotypic variation, heritability, genetic advance, genetic correlation, and phenotypic correlation of plant vigors and yield components of 28 genotypes were evaluated using nested design.  This research showed morphological and genetic variations of the genotypes in the field. Based on the research locations as operational taxonomic unit, the genotypes were separated into three clusters. Most of the parameters had low to moderate genotypic variation, while phenotypic variation was moderate to high. Heritability and genetic advance were low, moderate, and high. Several plant vigors and yield components had a positive significant genetic and phenotypic correlation one another, and several had negative ones. Coffee berry borer infestation (CBBI) had a highly significant negative genetic correlation with leaf width (rG = -0.309**), leaf weight (rG = -0.671**), fruit diameter (rG = -0.320**), and bean length (rG = -0.175**). CBBI showed a significant positive genetic correlation with mesocarp pH (rG = 0.134*).  To reduce CBBI, selection for higher leaf weight is better. Selection on lower pH of mesocarp could be considered to decrease CBBI.Keywords: cluster analysis, genetic correlation, genetic heritability, variability

Phenotypic variation in Heremites vittatus (Olivier, 1804) (Sauria: Scincidae) from Iran and Turkey

Zootaxa ◽  
2021 ◽  
Vol 5004 (1) ◽  
pp. 181-192
Author(s):  
NASRULLAH RASTEGAR-POUYANI ◽  
YUSUF KUMLUTAŞ ◽  
AZIZ AVCI ◽  
KAMIL CANDAN ◽  
CETIN ILGAZ ◽  
...  
Keyword(s):  
Morphological Variation ◽  
Phenotypic Variation ◽  
Taxonomic Status ◽  
Morphological Characters ◽  
Zagros Mountains ◽  
Iranian Populations

According to a large morphological dataset of specimens from Turkey to Iran and based on several morphological analyses, the Iranian populations of the skink Heremites vittatus are separated from other populations of this taxon in Turkey. The values of most of morphological characters were higher in the Turkish populations. Morphological variation among populations of H. vittatus (Olivier, 1804) from Turkey and the western slopes of the Zagros Mountains in Kermanshah province in Iran may be the result of different dispersal and vicariance events. Comparison the current study dataset with specimens from Egypt can definite the taxonomic status of Iranian and Turkish populations.

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