Morphologic variation in the USDA/ARS rhubarb germplasm collection

2009 ◽  
Vol 8 (1) ◽  
pp. 35-41 ◽  
Author(s):  
Alberto Pantoja ◽  
Joseph C. Kuhl
Keyword(s):  
Germplasm Collection ◽  
Morphological Characters ◽  
Morphological Data ◽  
Skin Colour ◽  
Base Thickness ◽  
Flesh Colour ◽  
Combining Data ◽  
Wide Range ◽  
Morphologic Variation ◽  
The Mean

Rhubarb includes approximately 60 species in the genusRheum. It has been utilized for thousands of years for medicinal purposes, but only recently identified for its culinary use. In the mid 1700s, edible petioles were discovered on seedlings from rhubarb species. Hundreds of cultivars have since been identified for a wide range of uses from tarts to wine. Unfortunately, propagation by seed and irregular naming has resulted in a plethora of similarly named cultivars and multitude of phenotypes. Fifteen morphological characters were evaluated to differentiate rhubarb cultivars in the USDA, ARSRheumcollection in Palmer, Alaska. Two years of morphological data, focusing on horticultural characteristics indicated variation between the years. To improve cultivar resolution, the results suggest using 1 year's data instead of combining data from different years. The mean °Brix observed was 3.8, with a range from 2.2 to 6.1. Flesh colour and basal skin colour were poorly correlated (R2 = 0.462); overall skin colour was more red at the base than in the middle of the petiole. Rhubarb character categories, in particular petiole number and petiole base thickness, need to be modified to better anticipate the range of expected values, and thereby contribute improved reproducibility and reliability to separate cultivars based on morphological characters.

Karyotypes and morphological variation in the sessile-flowered trilliums of North Carolina

1969 ◽  
Vol 47 (8) ◽  
pp. 1223-1232 ◽  
Author(s):  
Cornelia Ann Serota
Keyword(s):  
North Carolina ◽  
Cold Treatment ◽  
Morphological Data ◽  
Geographic Isolation ◽  
Flower Scent ◽  
Cross Pollination ◽  
Western North Carolina ◽  
Wide Range ◽  
Coefficient Of Variability ◽  
The Mean

Six populations of apparently morphologically similar sessile-flowered Trillium (known taxonomically as T. cuneatum Raf. and T. luteum (Muhl.) Harb.) observed growing at elevations between 800 and 1700 ft in the Appalachians of western North Carolina and eastern Tennessee exhibit a wide range of variability by observation. The extent of variability was assessed by using statistical and karyotypic methods of analysis and by intraspecific cross-pollination. A correlation exists between the mean coefficient of variability and (1) the size of the population and (2) the degree of geographic isolation. The number of types of each kind of chromosome (A–E), as resolved by cold treatment, varies by one type from population to population. The homozygosity for the six populations is 85.8%, and the distribution of euchromatin is not complex. Intraspecific cross-pollination was effective among 76% of the test crosses. A review of the statistics and other morphological data indicates that the presence or absence of anthocyanins, flower scent, and the degree of geographic isolation are the three major variants among the six populations. These kinds of Trillium grow sympatrically with T. grandiflorum (Michx.) Salisb., T. simile Gleason, T. erectum var. album (Michx.) Pursh, T. flexipes Raf. (T. gleasoni Fern.), and T. erectum L. The cumulative karyotype for the six stands indicates that these plants have not hybridized with any of the above species and varieties. Although these plants have been classified as T. cuneatum Raf. in some stands and as T. luteum (Muhl.) Harb. in others the data demonstrate that these six stands represent one discontinuous population of a sessile-flowered Trillium. Trillium discolor Wray, although relatively rare in western North Carolina, also grows here. Although T. discolor is not directly involved in this problem, its description and distinctive karyotype are included.

scholarly journals A Simulation-Based Evaluation of Tip-Dating Under the Fossilized Birth–Death Process

2019 ◽  
Vol 69 (2) ◽  
pp. 325-344 ◽  
Author(s):  
Arong Luo ◽  
David A Duchêne ◽  
Chi Zhang ◽  
Chao-Dong Zhu ◽  
Simon Y W Ho
Keyword(s):  
Morphological Characters ◽  
Nucleotide Sequences ◽  
Tree Topology ◽  
Molecular Dating ◽  
Morphological Data ◽  
Death Process ◽  
Joint Analysis ◽  
Nucleotide Sequence Data ◽  
Wide Range ◽  
Birth Death

Abstract Bayesian molecular dating is widely used to study evolutionary timescales. This procedure usually involves phylogenetic analysis of nucleotide sequence data, with fossil-based calibrations applied as age constraints on internal nodes of the tree. An alternative approach is tip-dating, which explicitly includes fossil data in the analysis. This can be done, for example, through the joint analysis of molecular data from present-day taxa and morphological data from both extant and fossil taxa. In the context of tip-dating, an important development has been the fossilized birth–death process, which allows non-contemporaneous tips and sampled ancestors while providing a model of lineage diversification for the prior on the tree topology and internal node times. However, tip-dating with fossils faces a number of considerable challenges, especially, those associated with fossil sampling and evolutionary models for morphological characters. We conducted a simulation study to evaluate the performance of tip-dating using the fossilized birth–death model. We simulated fossil occurrences and the evolution of nucleotide sequences and morphological characters under a wide range of conditions. Our analyses of these data show that the number and the maximum age of fossil occurrences have a greater influence than the degree of among-lineage rate variation or the number of morphological characters on estimates of node times and the tree topology. Tip-dating with the fossilized birth–death model generally performs well in recovering the relationships among extant taxa but has difficulties in correctly placing fossil taxa in the tree and identifying the number of sampled ancestors. The method yields accurate estimates of the ages of the root and crown group, although the precision of these estimates varies with the probability of fossil occurrence. The exclusion of morphological characters results in a slight overestimation of node times, whereas the exclusion of nucleotide sequences has a negative impact on inference of the tree topology. Our results provide an overview of the performance of tip-dating using the fossilized birth–death model, which will inform further development of the method and its application to key questions in evolutionary biology.

scholarly journals Genetic Variability and Diversity Analysis in Pod and Seed Characters of Some Neglected and Underutilized Legumes (NULs)

2019 ◽  
pp. 1-8
Author(s):  
J. O. Agbolade ◽  
T. P. Olakunle ◽  
K. M. Popoola ◽  
J. A. Idowu ◽  
A. I. Isiaka ◽  
...  
Keyword(s):  
Genetic Variability ◽  
Principal Component ◽  
Morphological Characters ◽  
Morphological Data ◽  
Diversity Analysis ◽  
International Institute ◽  
Mean Values ◽  
The Mean ◽  
Pod Length ◽  
100 Seed Weight

In response to the paucity of information challenge on the neglected and underutilized legumes, this paper explored pods and seeds morphological data of the twenty-four accessions of these crops with a view to establishing the occurrence of genetic variability and diversity analysis among the studied taxa. Twenty-four accessions of neglected and underutilized legumes (NULs) obtained from International Institute of Tropical Agriculture (IITA), Ibadan, Nigeria were assessed for genetic variability and diversity analysis through Pod and seed morphological characters. Each accession was planted into plot of 5 ridges of 5 meter long, spaced 1 meter apart and replicated three times at the teaching and research farm of the Federal University Oye Ekiti, Ekiti State, Nigeria. Descriptive statistics was employed to evaluate differences in the mean values of the accessions while discriminatory traits among accessions were identified by Principal Component Analysis (PCA). Similarities among the studied plants were assessed by cluster analysis. The first two principal component axes explained 72% of the total variation. Pod length, pod width and 100-seed weight were traits that contributed most of the variations in the legume accessions. There was a display of intra-species similarities and inter-specific genetic diversity among the studied accessions.

scholarly journals Craniodental morphology and phylogeny of marsupials

2021 ◽  
Author(s):  
Robin M. D. Beck ◽  
Robert Voss ◽  
Sharon Jansa
Keyword(s):  
Phylogenetic Analysis ◽  
Dna Sequences ◽  
Morphological Characters ◽  
Molecular Data ◽  
Morphological Data ◽  
Future Research ◽  
Data Types ◽  
Wide Range ◽  
Morphological And Molecular Data ◽  
Dense Sampling

The current literature on marsupial phylogenetics includes numerous studies based on analyses of morphological data with relatively limited sampling of Recent and fossil taxa, and many studies based on analyses of molecular data that include a dense sampling of Recent taxa, but relatively few that combine both data types. Another dichotomy in the marsupial phylogenetic literature is between studies that focus on New World taxa, others that focus on Sahulian taxa. To date, there has been no attempt to assess the phylogenetic relationships of the global marsupial fauna, based on combined analyses of morphology and molecular sequences, for a dense sampling of Recent and fossil taxa. For this report, we compiled morphological and molecular data from an unprecedented number of Recent and fossil marsupials. Our morphological data consist of 180 craniodental characters that we scored for 97 species representing every currently recognized Recent genus, 42 additional ingroup (crown-clade marsupial) taxa represented by well-preserved fossils, and 5 outgroups (non-marsupial metatherians). Our molecular data comprise 24.5 kb of DNA sequences from whole-mitochondrial genomes and six nuclear loci (APOB, BRCA1, GHR, RAG1, RBP3 and VWF) for 97 marsupial terminals (the same Recent taxa scored for craniodental morphology) and several placental and monotreme outgroups. The results of separate and combined analyses of these data using a wide range of phylogenetic methods support many currently accepted hypotheses of ingroup (marsupial) relationships, but they also underscore the difficulty of placing fossils with key missing data (e.g., †Evolestes), and the unique difficulty of placing others that exhibit mosaics of plesiomorphic and autapomorphic traits (e.g., †Yalkaparidon). Unique contributions of our study are (1) critical discussions and illustrations of marsupial craniodental morphology, including descriptions and illustrations of some features never previously coded for phylogenetic analysis; (2) critical assessments of relative support for many suprageneric clades; (3) estimates of divergence times derived from tip-and-node dating based on uniquely taxon-dense analyses; and (4) a revised, higher-order classification of marsupials accompanied by lists of supporting craniodental synapomorphies. Far from the last word on these topics, this report lays the foundation for future research that may be enabled by the discovery of new fossil taxa, better-preserved material of previously described taxa, novel morphological characters, and improved methods of phylogenetic analysis.

scholarly journals Species delimitation and inter-specific gene flow in Tamarix L. (Tamaricaceae)

Hacquetia ◽  
2019 ◽  
Vol 18 (2) ◽  
pp. 313-322
Author(s):  
Masoud Sheidai ◽  
Tahmineh Shagholi ◽  
Maryam Keshavarzi ◽  
Fahimeh Koohdar ◽  
Habibollah Ijbari
Keyword(s):  
Gene Flow ◽  
Molecular Phylogeny ◽  
Species Delimitation ◽  
Morphological Characters ◽  
Morphological Data ◽  
Specific Gene ◽  
Closely Related Species ◽  
Specific Hybridization ◽  
Wide Range ◽  
Semnan Province

Abstract Tamarix L. play important role in preventing deforestation in Iran. Tamarix species exhibit wide range of morphological variation therefore, the species delimitation become difficult. This is further complicated due to similarity of morphological characters in closely related species and the occurrence of inter-specific hybridization. The present study was performed to identify Tamarix species and their potential hybrids in Semnan Province of Iran. We used ITS and ISSR and 42 morphological characters for our investigation. Molecular phylogeny of the studied species and their relationship was not in agreement with the species tree of morphological characters and with taxonomic treatment of the genus. HGT tree of ITS and morphological data obtained revealed the occurrence of inter-specific hybridization or introgression between Tamarix species.

scholarly journals A Simulation-Based Evaluation of Total-Evidence Dating Under the Fossilized Birth-Death Process

2018 ◽  
Author(s):  
Arong Luo ◽  
David A. Duchêne ◽  
Chi Zhang ◽  
Chao-Dong Zhu ◽  
Simon Y.W. Ho
Keyword(s):  
Morphological Characters ◽  
Nucleotide Sequences ◽  
Tree Topology ◽  
Molecular Dating ◽  
Total Evidence ◽  
Morphological Data ◽  
Death Process ◽  
Nucleotide Sequence Data ◽  
Wide Range ◽  
Birth Death

AbstractBayesian molecular dating is widely used to study evolutionary timescales. This procedure usually involves phylogenetic analysis of nucleotide sequence data, with fossil-based calibrations applied as age constraints on internal nodes of the tree. An alternative approach is Bayesian total-evidence dating, which involves the joint analysis of molecular data from present-day taxa and morphological data from both extant and fossil taxa. Part of its appeal stems from the fossilized birth-death process, which provides a model of lineage diversification for the prior on the tree topology and node times. However, total-evidence dating faces a number of considerable challenges, especially those associated with fossil sampling and evolutionary models for morphological characters. We conducted a simulation study to evaluate the performance of total-evidence dating with the fossilized birth-death model. We simulated fossil occurrences and the evolution of nucleotide sequences and morphological characters under a wide range of conditions. Our analyses show that fossil occurrences have a greater influence than the degree of among-lineage rate variation or the number of morphological characters on estimates of node times and the tree topology. Total-evidence dating generally performs well in recovering the relationships among extant taxa, but has difficulties in correctly placing fossil taxa in the tree and identifying the number of sampled ancestors. The method yields accurate estimates of the origin time of the fossilized birth-death process and the ages of the root and crown group, although the precision of these estimates varies with the probability of fossil occurrence. The exclusion of morphological characters results in a slight overestimation of node times, whereas the exclusion of nucleotide sequences has a negative impact on inference of the tree topology. Overall, our results provide a detailed view of the performance of total-evidence dating, which will inform further development of the method and its application to key questions in evolutionary biology.

scholarly journals Morphological and molecular studies of three species of Boerhavia L. from Ile-Ife, Nigeria

2020 ◽  
Vol 22 (2) ◽  
pp. 225-236
Author(s):  
S.O. Azeez ◽  
J.O. Matthew ◽  
E.A. Olaoluwa ◽  
G.B. Adegboyega ◽  
I.O. Akinyoola
Keyword(s):  
Cluster Analysis ◽  
Phylogenetic Relationship ◽  
Random Amplified Polymorphic Dna ◽  
Rapd Marker ◽  
Pollen Grains ◽  
Morphological Characters ◽  
Morphological Data ◽  
Group Method ◽  
Wide Range ◽  
High Level

A wide range of plasticity and polymorphism have been documented in the genus Boerhavia. More so, the possible presence of natural hybrids  among the species of the genus has made species identification more difficult. This study employed morphological characters, pollen parameters as well as Random Amplified Polymorphic DNA (RAPD) to identify and elucidate the phylogenetic relationship that exists among the three species of Boerhavia distributed in Ile-Ife, Nigeria. Qualitative and quantitative morphological characters were observed and measured respectively. The acetolysis of the pollen grains was carried out according to Erdtman method. Fresh and young leaves of the Boerhavia species studied were  collected for genomic DNA extraction using modified Dellarpota procedure. The quality and concentration of DNA was assessed by gel electrophoresis on 2% agarose with known concentrations of undigested lambda DNA. Subsequently, the DNA quantification was done according to standard measurement. The Principal Components Analysis of the morphological traits and the pollen grain studies indicated that the three Boerhavia species studied have a very high level of relationship. However, the Single Linkage Cluster Analysis of the morphological data and the unweighted pair group method with arithmetic mean (UPGMA) cluster analysis of RAPD data revealed that B. erecta is distantly related to B. coccinea and B. diffusa. Despite the fact that the three Boerhavia species studied possess high level of similarity, they can still be distinguished from each other. In conclusion, B. coccinea and B. diffusa are more closely related to each other than B. erecta. Key words: RAPD marker, Pollen grains, Phylogenetic relationship, Polymorphism

Study of genetic diversity in wild raspberry (Rubus idaeus L.) germplasm collection using morphological characters and RAPD markers

Biologija ◽  
2008 ◽  
Vol 54 (2) ◽  
pp. 66-74 ◽  
Author(s):  
Jolanta Patamsytė ◽  
Donatas Žvingila ◽  
Juozas Labokas ◽  
Virgilijus Baliuckas ◽  
Laimutė Balčiūnienė ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Rapd Markers ◽  
Germplasm Collection ◽  
Morphological Characters ◽  
Rubus Idaeus

A Comparison of Physiological Demand between Self-Propelled and Motorized Treadmill Exercise

2018 ◽  
Vol 7 (4) ◽  
pp. 13-21
Author(s):  
Todd Backes ◽  
Charlene Takacs
Keyword(s):  
Respiratory Exchange Ratio ◽  
Treadmill Exercise ◽  
Cardiopulmonary Exercise Testing ◽  
Mean Value ◽  
The Self ◽  
Mixing Chamber ◽  
Wide Range ◽  
The Subject ◽  
The Mean ◽  
Computer Controlled

There are a wide range of options for individuals to choose from in order to engage in aerobic exercise; from outdoor running to computer controlled and self-propelled treadmills. Recently, self-propelled treadmills have increased in popularity and provide an alternative to a motorized treadmill. Twenty subjects (10 men, 10 women) ranging in age from 19-23 with a mean of 20.4 ± 0.8 SD were participants in this study. The subjects visited the laboratory on three occasions. The purpose of the first visit was to familiarize the subject with the self-propelled treadmill (Woodway Curve 3.0). The second visit, subjects were instructed to run on the self-propelled treadmill for 3km at a self-determined pace. Speed data were collected directly from the self-propelled treadmill. The third visit used speed data collected during the self-propelled treadmill run to create an identically paced 3km run for the subjects to perform on a motorized treadmill (COSMED T150). During both the second and third visit, oxygen consumption (VO2) and respiratory exchange ratio (R) data were collected with COSMED’s Quark cardiopulmonary exercise testing (CPET) metabolic mixing chamber system. The VO2 mean value for the self-propelled treadmill (44.90 ± 1.65 SE ml/kg/min) was significantly greater than the motorized treadmill (34.38 ± 1.39 SE ml/kg/min). The mean R value for the self-propelled treadmill (0.91 ± 0.01 SE) was significantly greater than the motorized treadmill (0.86 ± 0.01 SE). Our study demonstrated that a 3km run on a self-propelled treadmill does elicit a greater physiological response than a 3km run at on a standard motorized treadmill. Self-propelled treadmills provide a mode of exercise that offers increased training loads and should be considered as an alternative to motorized treadmills.

The way of value of Correlation of genomic DNA microsatellite loci and live weight of Chukchi reindeer

2020 ◽  
pp. 27-32
Author(s):  
V. Dodokhov ◽  
N. Pavlova ◽  
T. Rumyantseva ◽  
L. Kalashnikova
Keyword(s):  
Microsatellite Markers ◽  
Agricultural Production ◽  
Live Weight ◽  
Biodiversity Loss ◽  
Tribal Community ◽  
High Germination ◽  
Wide Range ◽  
The Mean ◽  
High Level ◽  
Dna Microsatellite

The article presents the genetic characteristic of the Chukchi reindeer breed. The object of the study was of the Chukchi reindeer. In recent years, the number of reindeer of the Chukchi breed has declined sharply. Reduced reindeer numbers could lead to biodiversity loss. The Chukchi breed of deer has good meat qualities, has high germination viability and is adapted in adverse tundra conditions of Yakutia. Herding of the Chukchi breed of deer in Yakutia are engaged only in the Nizhnekolymsky district. There are four generic communities and the largest of which is the agricultural production cooperative of nomadic tribal community «Turvaurgin», which was chosen to assess the genetic processes of breed using microsatellite markers: Rt6, BMS1788, Rt 30, Rt1, Rt9, FCB193, Rt7, BMS745, C 143, Rt24, OheQ, C217, C32, NVHRT16, T40, C276. It was found that microsatellite markers have a wide range of alleles and generally have a high informative value for identifying of genetic differences between animals and groups of animal. The number of identified alleles is one of the indicators of the genetic diversity of the population. The total number of detected alleles was 127. The Chukchi breed of deer is characterized by a high level of heterozygosity, and the random crossing system prevails over inbreeding in the population. On average, there were 7.9 alleles (Na) per locus, and the mean number of effective alleles (Ne) was 4.1. The index of fixation averaged 0.001. The polymorphism index (PIC) ranged from 0.217 to 0.946, with an average of 0.695.

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