Segregation by morphological analyses of trisomy types in Lotus tenuis (Fabaceae)

1997 ◽  
Vol 75 (8) ◽  
pp. 1209-1214 ◽  
Author(s):  
Pierre St.-Marseille ◽  
William F. Grant
Keyword(s):  
Key Words ◽  
Morphological Traits ◽  
Colchicine Treatment ◽  
Phenotypic Traits ◽  
Morphological Comparison ◽  
Primary Trisomics ◽  
Lotus Tenuis

Two autotetraploids (2n = 4x = 24) were produced by colchicine treatment of dry seeds of Lotus tenuis Waldst. et Kit. Triploids (2n = 3x = 18) were obtained by backcrossing the tetraploids to normal diploid plants. Primary trisomies (2n = 12 + 1) were obtained by selfing the triploids. A morphological comparison was made between a randomly selected diploid, a tetraploid, and five trisomic plants. The trisomics could be distinguished distinctly from the diploid and tetraploid using 12 quantitative phenotypic traits. Two traits, bract index and number of flowers per umbel, were not significantly different between all three cytotypes (2x, 2x + 1, 4x). By means of morphological analyses it was possible to select trisomic plants for presumably different trisomes prior to detailed cytological analyses of individual chromosomes. Key words: aneuploidy, tetraploids, Fabaceae, Lotus tenuis, morphological traits, triploids, primary trisomics.

Comparing Mutational Variabilities

Genetics ◽  
1996 ◽  
Vol 143 (3) ◽  
pp. 1467-1483 ◽  
Author(s):  
David Houle ◽  
Bob Morikawa ◽  
Michael Lynch
Keyword(s):  
Life History ◽  
Morphological Traits ◽  
Life History Traits ◽  
Genetic Variance ◽  
Balance Model ◽  
Phenotypic Traits ◽  
Infinite Population ◽  
Persistence Time ◽  
Coefficients Of Variation ◽  
Balance Hypothesis

Abstract We have reviewed the available data on VM, the amount of genetic variation in phenotypic traits produced each generation by mutation. We use these data to make several qualitative tests of the mutation-selection balance hypothesis for the maintenance of genetic variance (MSB). To compare VM values, we use three dimensionless quantities: mutational heritability, the mutational coefficient of variation, CVM; and the ratio of the standing genetic variance to VM, VG/VM. Since genetic coefficients of variation for life history traits are larger than those for morphological traits, we predict that under MSB, life history traits should also have larger CVM. This is confirmed; life history traits have a median CVM value more than six times higher than that for morphological traits. VG/VM approximates the persistence time of mutations under MSB in an infinite population. In order for MSB to hold, VG/VM must be small, substantially less than 1000, and life history traits should have smaller values than morphological traits. VG/VM averages about 50 generations for life history traits and 100 generations for morphological traits. These observations are all consistent with the predictions of a mutation-selection balance model.

scholarly journals Delimitation, new species and teleomorph-anamorph relationships in Codinaea, Dendrophoma, Paragaeumannomyces and Striatosphaeria (Chaetosphaeriaceae)

MycoKeys ◽  
2020 ◽  
Vol 74 ◽  
pp. 17-74
Author(s):  
Martina Réblová ◽  
Jana Nekvindová ◽  
Jacques Fournier ◽  
Andrew N. Miller
Keyword(s):  
New Species ◽  
Type Species ◽  
Morphological Traits ◽  
Phylogenetic Analyses ◽  
Axenic Culture ◽  
Monophyletic Clade ◽  
Morphological Comparison ◽  
The Family ◽  
Terrestrial Habitats ◽  
First Time

The Chaetosphaeriaceae are a diverse group of pigmented, predominantly phialidic hyphomycetes comprised of several holomorphic genera including Chaetosphaeria, the most prominent genus of the family. Although the morphology of the teleomorphs of the majority of Chaetosphaeria is rather uniform, their associated anamorphs primarily exhibit the variability and evolutionary change observed in the genus. An exception from the morphological monotony among Chaetosphaeria species is a group characterised by scolecosporous, hyaline to light pink, multiseptate, asymmetrical ascospores and a unique three-layered ascomatal wall. Paragaeumannomyces sphaerocellularis, the type species of the genus, exhibits these morphological traits and is compared with similar Chaetosphaeria with craspedodidymum- and chloridium-like synanamorphs. Morphological comparison and phylogenetic analyses of the combined ITS-28S sequences of 35 isolates and vouchers with these characteristics revealed a strongly-supported, morphologically well-delimited clade in the Chaetosphaeriaceae containing 16 species. The generic name Paragaeumannomyces is applied to this monophyletic clade; eight new combinations and five new species, i.e. P. abietinussp. nov., P. eleganssp. nov., P. granulatussp. nov., P. sabinianussp. nov. and P. smokiensissp. nov., are proposed. A key to Paragaeumannomyces is provided. Using morphology, cultivation studies and phylogenetic analyses of ITS and 28S rDNA, two additional new species from freshwater and terrestrial habitats, Codinaea paniculatasp. nov. and Striatosphaeria castaneasp. nov., are described in the family. A codinaea-like anamorph of S. castanea forms conidia with setulae at each end in axenic culture; this feature expands the known morphology of Striatosphaeria. A chaetosphaeria-like teleomorph is experimentally linked to Dendrophoma cytisporoides, a sporodochial hyphomycete and type species of Dendrophoma, for the first time.

scholarly journals Evolvability meets biogeography: evolutionary potential decreases at high and low environmental favourability

2017 ◽  
Vol 284 (1856) ◽  
pp. 20170516 ◽  
Author(s):  
J. Martínez-Padilla ◽  
A. Estrada ◽  
R. Early ◽  
F. Garcia-Gonzalez
Keyword(s):  
Environmental Change ◽  
Morphological Traits ◽  
Evolutionary Dynamics ◽  
Environmental Variation ◽  
Phenotypic Traits ◽  
Published Data ◽  
Evolutionary Potential ◽  
Critical Question ◽  
Climate Conditions ◽  
Environmental Selection

Understanding and forecasting the effects of environmental change on wild populations requires knowledge on a critical question: do populations have the ability to evolve in response to that change? However, our knowledge on how evolution works in wild conditions under different environmental circumstances is extremely limited. We investigated how environmental variation influences the evolutionary potential of phenotypic traits. We used published data to collect or calculate 135 estimates of evolvability of morphological traits of European wild bird populations. We characterized the environmental favourability of each population throughout the species' breeding distribution. Our results suggest that the evolutionary potential of morphological traits decreases as environmental favourability becomes high or low. Strong environmental selection pressures and high intra-specific competition may reduce species' evolutionary potential in low- and high- favourability areas, respectively. This suggests that species may be least able to adapt to new climate conditions at their range margins and at the centre. Our results underscore the need to consider the evolutionary potential of populations when studying the drivers of species distributions, particularly when predicting the effects of environmental change. We discuss the utility of integrating evolutionary dynamics into a biogeographical perspective to understand how environmental variation shapes evolutionary patterns. This approach would also produce more reliable predictions about the effect of environmental change on population persistence and therefore on biodiversity.

Nucleotypic influences on chromosome-specific chiasma variation in Crepis capillaris. I. Responses to early colchicine treatment and chromosome doubling

Genome ◽  
1996 ◽  
Vol 39 (6) ◽  
pp. 1078-1085 ◽  
Author(s):  
M. T. Abberton ◽  
R. S. Callow
Keyword(s):  
Key Words ◽  
Chiasma Frequency ◽  
Chromosome Doubling ◽  
Colchicine Treatment ◽  
Seedling Stage ◽  
Published Data ◽  
Crepis Capillaris ◽  
The Mean ◽  
Diploid Level ◽  
Multiplicative Effects

Additive and multiplicative effects of colchicine treatment at the seedling stage and of chromosome doubling on chromosome-specific chiasma frequency at metaphase I have been measured in comparisons between C0 and untreated diploids and between C0 autotetraploids and C0 diploids. Early colchicine treatment increases the frequency of chromosome C univalents to 1.8% but has no similar effect on chromosomes A and D. Colchicine treatment has little net effect on mean chiasma frequency, deducting an average of 0.204 chiasmata per set but otherwise multiplying the mean by a factor of 1.182. These additive and multiplicative effects represent averages of six phenotypes. Chromosome doubling in a tetraploid–diploid chimaera subtracts an average of 0.265 chiasmata per set but otherwise doubles the numbers of chiasmata at the diploid level (× 2.134). Comparison of six diploids and tetraploids reveals modest average additive (+ 1.103) and multiplicative effects (× 1.190). The implications of these findings are discussed in the light of new analyses of previously published data. Key words : chiasmata, Crepis, colchicine, meiosis, polyploidy.

scholarly journals A complex performance landscape for suction-feeding reveals constraints and adaptations in a population of reef damselfish

2017 ◽  
Author(s):  
Tal Keren ◽  
Moshe Kiflawi ◽  
Christopher H Martin ◽  
Victor China ◽  
Ofri Mann ◽  
...  
Keyword(s):  
Morphological Traits ◽  
Prey Capture ◽  
Mechanistic Model ◽  
Adaptive Landscape ◽  
Phenotypic Traits ◽  
Stabilizing Selection ◽  
Suction Feeding ◽  
Feeding Performance ◽  
Genetic Constraints ◽  
A Performance

AbstractThe ability to predict how multiple traits interact in determining performance is key to understanding the evolution of complex functional systems. Similar to Simpson’s adaptive landscape, which describes the fitness consequences of varying morphological traits, performance landscapes depict the performance consequences of varying morphological traits. Mapping the population’s location with respect to the topographic features of the landscape could inform us on the selective forces operating on the traits that underlie performance. Here, we used a mechanistic model derived from first principles of hydrodynamics to construct a hypothetical performance landscape for zooplankton prey capture using suction feeding. We then used the landscape to test whether a population of Chromis viridis, a coral reef zooplanktivore, is located on a performance peak or ridge based on measurements of kinematic variables recorded in-situ during undisturbed foraging. Observed trait combinations in the wild population closely matched regions of high feeding performance in the landscape, however the population was not located on a local performance peak. This sub-optimal performance was not due to constraints stemming from the observed trait correlations. The predominant directions of variation of the phenotypic traits was tangent to the ‘path of steepest ascent’ that points towards the local peak, indicating that the population does not reside on a “performance ridge”. Rather, our analysis suggests that feeding performance is constrained by stabilizing selection, possibly reflecting a balance between selection on feeding performance and mechanical or genetic constraints.

scholarly journals Testing the neutral hypothesis of phenotypic evolution

2017 ◽  
Vol 114 (46) ◽  
pp. 12219-12224 ◽  
Author(s):  
Wei-Chin Ho ◽  
Yoshikazu Ohya ◽  
Jianzhi Zhang
Keyword(s):  
Morphological Traits ◽  
Genetic Model ◽  
Morphological Evolution ◽  
Model Organisms ◽  
Functional Genes ◽  
Phenotypic Traits ◽  
Phenotypic Evolution ◽  
Important Principle ◽  
Phenotypic Variations ◽  
Evolution By Natural Selection

Although evolution by natural selection is widely regarded as the most important principle of biology, it is unknown whether phenotypic variations within and between species are mostly adaptive or neutral due to the lack of relevant studies of large, unbiased samples of phenotypic traits. Here, we examine 210 yeast morphological traits chosen because of experimental feasibility irrespective of their potential adaptive values. Our analysis is based on the premise that, under neutrality, the rate of phenotypic evolution measured in the unit of mutational size declines as the trait becomes more important to fitness, analogous to the neutral paradigm that functional genes evolve more slowly than functionless pseudogenes. However, we find faster evolution of more important morphological traits within and between species, rejecting the neutral hypothesis. By contrast, an analysis of 3,466 gene expression traits fails to refute neutrality. Thus, at least in yeast, morphological evolution appears largely adaptive, but the same may not apply to other classes of phenotypes. Our neutrality test is applicable to other species, especially genetic model organisms, for which estimations of mutational size and trait importance are relatively straightforward.

scholarly journals Heritability and genetic correlations of personality, life history and morphology in the grey mouse lemur ( Microcebus murinus )

2019 ◽  
Vol 6 (10) ◽  
pp. 190632 ◽  
Author(s):  
Pauline B. Zablocki-Thomas ◽  
Anthony Herrel ◽  
Caitlin J. Karanewsky ◽  
Fabienne Aujard ◽  
Emmanuelle Pouydebat
Keyword(s):  
Life History ◽  
Personality Traits ◽  
Maternal Effects ◽  
Morphological Traits ◽  
Life History Traits ◽  
Genetic Correlations ◽  
Microcebus Murinus ◽  
Phenotypic Traits ◽  
Pace Of Life ◽  
Sources Of Variation

The recent interest in animal personality has sparked a number of studies on the heritability of personality traits. Yet, how the sources variance these traits can be decomposed remains unclear. Moreover, whether genetic correlations with life-history traits, personality traits and other phenotypic traits exist as predicted by the pace-of-life syndrome hypothesis remains poorly understood. Our aim was to compare the heritability of personality, life-history and morphological traits and their potential genetic correlations in a small primate ( Microcebus murinus ). We performed an animal model analysis on six traits measured in a large sample of captive mouse lemurs ( N = 486). We chose two personality traits, two life-history traits and two morphological traits to (i) estimate the genetic and/or environmental contribution to their variance, and (ii) test for genetic correlations between these traits. We found modest narrow-sense heritability for personality traits, morphological traits and life-history traits. Other factors including maternal effects also influence the sources of variation in life-history and morphological traits. We found genetic correlations between emergence latency on the one hand and radius length and growth rate on the other hand. Emergence latency was also genetically correlated with birth weight and was influenced by maternal identity. These results provide insights into the influence of genes and maternal effects on the partitioning of sources of variation in personality, life-history and morphological traits in a captive primate model and suggest that the pace-of-life syndrome may be partly explained by genetic trait covariances.

scholarly journals Antropogenic transformation features of dark grey podzolik light loamy soils of Goshchanske plateu

2013 ◽  
pp. 273-281
Author(s):  
Bohdan Svydnytskyi ◽  
Maria Paseka
Keyword(s):  
Soil Erosion ◽  
Key Words ◽  
Morphological Traits ◽  
Chemical Properties ◽  
Physico Chemical ◽  
Structural Coefficient

The task of soil erosion degradation and melioration cultivation of dark grey podzolic light loamy soils of Goshchanske plateu was lighted. Detailed description of changes in their morphological traits physical and physico-chemical properties has been conducted. Key words: degradation, cultivation, anthropogenius transformation, melioration, gleization, drainage, key plats, structural coefficient, water-resistant aggregates.

scholarly journals Artificially Induced Polyploidization in Lobularia maritima (L.) Desv. and Its Effect on Morphological Traits

HortScience ◽  
2015 ◽  
Vol 50 (5) ◽  
pp. 636-639 ◽  
Author(s):  
Renwei Huang ◽  
Daofeng Liu ◽  
Min Zhao ◽  
Zhineng Li ◽  
Mingyang Li ◽  
...  
Keyword(s):  
Chromosome Number ◽  
Efficient Method ◽  
Morphological Traits ◽  
Stomatal Density ◽  
Morphological Characteristics ◽  
Colchicine Treatment ◽  
Ornamental Plant ◽  
Lobularia Maritima ◽  
Ornamental Traits ◽  
Germinating Seeds

Lobularia maritima (L.) Desv. is an important ornamental plant. We investigated an efficient method to induce tetraploid plants of L. maritima (L.) Desv. by treating germinating seeds and apical growing points of seedlings with a range of concentrations of colchicine for different periods of time. Examination of the ploidy level by counting chromosome numbers at metaphase confirmed that the chromosome number of diploid plants was 2n = 2x = 24, whereas 2n = 4x = 48 was observed in tetraploid plants. The morphological characteristics of the diploid and colchicine-induced tetraploid plants were compared. Increases in the size of leaves, flowers, and stomata were observed in the tetraploid plants compared with the diploids. However, the stomatal density and plant height of the tetraploid plants were lower than for the diploid plants. This study presents the first report of autotetraploid plants of L. maritima (L.) Desv., and of the successful generation of tetraploid plants with improved ornamental traits by colchicine treatment.

Cytogenetics of a synthesized allopentaploid (2n = 5x = 100) in the genus Glycine subgenus Glycine

Genome ◽  
1991 ◽  
Vol 34 (5) ◽  
pp. 751-756 ◽  
Author(s):  
R. J. Singh ◽  
T. Hymowitz
Keyword(s):  
Chromosome Pairing ◽  
Morphological Traits ◽  
Colchicine Treatment ◽  
Close Similarity ◽  
Breeding Behavior ◽  
A Genome ◽  
Origin Identification

The objectives of this study were to provide information on the origin, identification, meiosis, and breeding behavior of a synthesized allopentaploid (2n = 5x = 100) in the genus Glycine (Willd.) subgenus Glycine. The origin of the pentaploid plant was as follows: G. clandestina, 2n = 2x = 40, A1A1 × G. canescens, 2n = 2x = 40, AA (designated as H119), F1 (2n = 2x = 40, AA1) × G. tomentella (2n = 4x = 80, AxAxDD) → F1 (2n = 3x = 60, AAxD (assuming A-genome chromosomes from G. canescens were transmitted)) → 0.1% colchicine treatment → 2n = 6x = 120 (AAAxAxDD) × G. tomentella (2n = 4x = 80, AxAxDD) → BC1, 2n = 5x = 100 (AAxAxDD). Morphologically, the pentaploid plant very closely resembled the tetraploid G. tomentella, PI 441005. Compared with hexaploids, the pentaploid plant was less vigorous for several morphological traits. However, it was not possible to distinguish visually among 4x, 5x, and 6x plants. Intergenomic chromosome pairing was followed in hexaploid (A–A, Ax–Ax, D–D) and pentaploid (A, Ax–Ax, D–D) plants. Despite a close similarity between A and Ax genomes (A- and Ax-genome chromosomes pair normally in the absence of their homologues) meiotic stages were highly abnormal in the pentaploid, with univalents, laggards, and micronuclei, but the plant set normal pods and seeds. The pentaploid plant did not breed true, as chromosomes in the 14 examined plants of the progeny ranged from 2n = 86 to 97. Furthermore, progeny of a plant with 2n = 90 segregated for plants with 2n = 81–86. These results indicate that the preferential elimination of G. canescens (A genome) chromosomes is rapid and eventually AxAxDD genome chromosomes will prevail. Thus, pentaploids will stabilize at the tetraploid level.Key words: Glycine spp., allopolyploidy, chromosome pairing, genome.

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