scholarly journals Sexual and Apomictic Seed Reproduction in Aronia Species with Different Ploidy Levels

HortScience ◽  
2019 ◽  
Vol 54 (4) ◽  
pp. 642-646
Author(s):  
Jonathan D. Mahoney ◽  
Thao M. Hau ◽  
Bryan A. Connolly ◽  
Mark H. Brand
Keyword(s):  
Genetic Variation ◽  
Fragment Length Polymorphism ◽  
Similarity Coefficient ◽  
Ploidy Levels ◽  
Black Chokeberry ◽  
Deciduous Shrubs ◽  
Rosaceae Family ◽  
The Individual ◽  
Tetraploid Progeny ◽  
Jaccard’S Similarity Coefficient

The genus Aronia Medik., also known as chokeberry, is a group of deciduous shrubs in the Rosaceae family, subtribe Pyrinae. The four commonly accepted species include A. arbutifolia (L.) Pers., red chokeberry; A. melanocarpa (Michx.) Elliott, black chokeberry; A. prunifolia (Marshall) Reheder, purple chokeberry; and A. mitschurinii (A.K. Skvortsov & Maitul). Wild and domesticated Aronia species are found as diploids, triploids, and tetraploids. Genetic improvement of polyploid Aronia genotypes has been limited by suspected apomixis, which may be widespread or distinct to tetraploids. The objectives of this study were to elucidate the reproductive mechanisms of Aronia species and reveal the occurrence of apomixis within the genus and along ploidy lines. Twenty-nine Aronia accessions [five A. melanocarpa (2×), five A. melanocarpa (4×), eight A. prunifolia (3×), four A. prunifolia (4×), six A. arbutifolia (4×), and one A. mitschurinii (4×)] were used in this study. Intra-accession variability was evaluated by growing out progeny from each open-pollinated maternal accession and comparing plant phenotypes, ploidy levels, and amplified fragment length polymorphism (AFLP) marker profiles between the progeny and maternal accession. Progeny of diploid and tetraploid maternal plants had ploidy levels identical to maternal plants, except for UC009 (A. melanocarpa, 2×) which produced a mix of diploids and tetraploids. UC143 and UC149 (A. prunifolia, 3×) produced all triploid offspring, whereas all other triploid accessions produced offspring with variable ploidy levels including 2×, 3×, 4×, and 5×. Pentaploid Aronia has not been previously reported. Diploid accessions produced significant AFLP genetic variation (0.68–0.78 Jaccard’s similarity coefficient) in progeny, which is indicative of sexual reproduction. Seedlings from tetraploid accessions had very little AFLP genetic variation (0.93–0.98 Jaccard’s similarity coefficient) in comparison with their maternal accession. The very limited genetic variation suggests the occurrence of limited diplosporous apomixis with one round of meiotic division in tetraploid progeny. Triploid accessions appear to reproduce sexually or apomictically, or both, depending on the individual. These results support our understanding of Aronia reproductive mechanisms and will help guide future breeding efforts of polyploid Aronia species.

Genetic variation in natural populations of Hordeum brevisubulatum native to the Songnen Prairie in northeastern China: Comparison of four nuclear DNA markers

2007 ◽  
Vol 87 (4) ◽  
pp. 773-780 ◽  
Author(s):  
Mu Li ◽  
Wanli Guo ◽  
Lanjuan Hu ◽  
Xiaoming Liu ◽  
Yufei Zhang ◽  
...  
Keyword(s):  
Genetic Variation ◽  
Nuclear Dna ◽  
Natural Populations ◽  
Similarity Coefficient ◽  
Northeastern China ◽  
Nuclear Dna Markers ◽  
The Individual ◽  
Genomic Regions ◽  
Hordeum Brevisubulatum ◽  
Issr Primers

Hordeum brevisubulatum (Trin) Link, a perennial wild grass, shows high tolerance to salinity- and/or alkaline-eroded soil, and is an important forage grass. Nonetheless, the genetic variation within and among natural populations of this species has not been investigated. In this study, four PCR-based dominant nuclear DNA markers, i.e., amplified fragment length polymorphism (AFLP), inter-simple sequence repeat (ISSR), retrotransposon-microsatellite-amplifiedpolymorphism (REMAP), and random amplified polymor phic DNA (RAPD) were used to investigate the genetic variation of a total of 80 plants with an average of 20 individual plants randomly collected from each of the four natural populations of H. brevisubulatum distributed in the Songnen Prairie in northeastern China. Results indicated that all four markers detected a surprisingly high level of genetic variation among the individual genotypes both within and among populations. Specifically, (i) of the 708 bands produced by 10 AFLP primer pairs, 223 (32%) were polymorphic, corresponding to a genetic similarity coefficient (Dice) range of 0.703 to 0.895 with a mean of 0.793; (ii) of the 174 bands produced by 12 ISSR primers, 149 (85%) were polymorphic, corresponding to a genetic similarity coefficient range of 0.524 to 0.826 with a mean of 0.676; (iii) of the 104 bands produced by REMAP (one retrotransopon-specific primer in combination with each of 8 ISSR primers), 89 (85%) were polymorphic, leading to an average similarity coefficient range of 0.494–0.840 with a mean of 0.688, and; (iv) of the 150 bands produced by 17 RAPD primers, 117 (77%) were polymorphic, giving a similarity coefficient range of 0.526–0.909 with a mean of 0.713. Thus, all four markers are highly informative in detecting genetic variations among the individual genotypes in natural populations of H. brevisubulatum. Nevertheless, no correlation was detected among the markers, suggesting that they likely targeted to different genomic regions of H. brevisubulatum. Whereas ISSR, REMAP and RAPD showed significantly higher levels of polymorphism than AFLP, only the latter was capable of grouping some of the plants largely in accordance with their geographic localities, suggesting population differentiation probably occurred preferentially at genomic regions targeted to by AFLP primers. Key words: Genetic diversity, Hordeum brevisubulatum, Molecular markers, Population differentiation

scholarly journals Variations in Triterpenoid Deposition in Cuticular Waxes during Development and Maturation of Selected Fruits of Rosaceae Family

2020 ◽  
Vol 21 (24) ◽  
pp. 9762
Author(s):  
Soyol Dashbaldan ◽  
Cezary Pączkowski ◽  
Anna Szakiel
Keyword(s):  
Metabolic Pathways ◽  
Cuticular Waxes ◽  
Rosa Rugosa ◽  
Phenological Stages ◽  
Aronia Melanocarpa ◽  
Fruit Samples ◽  
Black Chokeberry ◽  
Rosaceae Family ◽  
Fruit Surface

The process of fruit ripening involves many chemical changes occurring not only in the mesocarp but also in the epicarp, including changes in the triterpenoid content of fruit cuticular waxes that can modify the susceptibility to pathogens and mechanical properties of the fruit surface. The aim of the study was the determination of the ripening-related changes in the triterpenoid content of fruit cuticular waxes of three plant species from the Rosaceae family, including rugosa rose (Rosa rugosa), black chokeberry (Aronia melanocarpa var. “Galicjanka”) and apple (Malus domestica var. “Antonovka”). The triterpenoid and steroid content in chloroform-soluble cuticular waxes was determined by a GC-MS/FID method at four different phenological stages. The profile of identified compounds was rather similar in selected fruit samples with triterpenoids with ursane-, oleanane- and lupane-type carbon skeletons, prevalence of ursolic acid and the composition of steroids. Increasing accumulation of triterpenoids and steroids, as well as the progressive enrichment of the composition of these compounds in cuticular wax during fruit development, was observed. The changes in triterpenoid content resulted from modifications of metabolic pathways, particularly hydroxylation and esterification, that can alter interactions with complementary functional groups of aliphatic constituents and lead to important changes in fruit surface quality.

scholarly journals Increasing plant group productivity through latent genetic variation for cooperation

2019 ◽  
Author(s):  
Samuel E. Wuest ◽  
Nuno D. Pires ◽  
Shan Luo ◽  
Francois Vasseur ◽  
Julie Messier ◽  
...  
Keyword(s):  
Genetic Variation ◽  
Group Testing ◽  
Individual Performance ◽  
Major Effect ◽  
Root Competition ◽  
Simple Method ◽  
Pleiotropic Gene ◽  
Selective Forces ◽  
Future Demands ◽  
The Individual

AbstractTechnologies for crop breeding have become increasingly sophisticated, yet it remains unclear whether these advances are sufficient to meet future demands. A major challenge with current crop selection regimes is that they are often based on individual performance. This tends to select for plants with “selfish” traits, which leads to a yield loss when they compete in high-density stands. In traditional breeding, this well-known “tragedy of the commons” has been addressed by anticipating ideotypes with presumably preferential characteristics. However, this approach is limited to obvious architectural and physiological traits, and it depends on a mechanistic understanding of how these modulate growth and competition. Here, we developed a general and simple method for the discovery of alleles promoting cooperation of plants in stands; it is based on the game-theoretical premise that alleles increasing cooperation incur a cost to the individual but benefit the monoculture group. Testing the approach using the model plant Arabidopsis thaliana, we found a single major effect locus where the rarer allele was associated with increased levels of cooperation and superior monoculture productivity. We show that the allele likely affects a pleiotropic regulator of growth and defense, since it is also associated with reduced root competition but higher race-specific resistance against a specialized parasite. Even though cooperation is considered evolutionarily unstable, conflicting selective forces acting on a pleiotropic gene might thus maintain latent genetic variation for it in nature. Such variation, once identified in a crop, could be rapidly leveraged in modern breeding programs and provide efficient routes to increase yields.

scholarly journals Semi-Siamese U-Net for separation of lung and heart bioimpedance images: A simulation study of thorax EIT

PLoS ONE ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. e0246071
Author(s):  
Yen-Fen Ko ◽  
Kuo-Sheng Cheng
Keyword(s):  
Mean Absolute Error ◽  
Lung Ventilation ◽  
Semantic Segmentation ◽  
Absolute Error ◽  
Similarity Coefficient ◽  
Dice Similarity Coefficient ◽  
Linear Transformations ◽  
Impedance Tomography ◽  
Performance Improvements ◽  
The Individual

Electrical impedance tomography (EIT) is widely used for bedside monitoring of lung ventilation status. Its goal is to reflect the internal conductivity changes and estimate the electrical properties of the tissues in the thorax. However, poor spatial resolution affects EIT image reconstruction to the extent that the heart and lung-related impedance images are barely distinguishable. Several studies have attempted to tackle this problem, and approaches based on decomposition of EIT images using linear transformations have been developed, and recently, U-Net has become a prominent architecture for semantic segmentation. In this paper, we propose a novel semi-Siamese U-Net specifically tailored for EIT application. It is based on the state-of-the-art U-Net, whose structure is modified and extended, forming shared encoder with parallel decoders and has multi-task weighted losses added to adapt to the individual separation tasks. The trained semi-Siamese U-Net model was evaluated with a test dataset, and the results were compared with those of the classical U-Net in terms of Dice similarity coefficient and mean absolute error. Results showed that compared with the classical U-Net, semi-Siamese U-Net exhibited performance improvements of 11.37% and 3.2% in Dice similarity coefficient, and 3.16% and 5.54% in mean absolute error, in terms of heart and lung-impedance image separation, respectively.

scholarly journals Genetic variation in the oxytocin system and its link to social motivation in human infants

2021 ◽  
Author(s):  
Kathleen Marie Krol ◽  
Nauder Namaky ◽  
Mikhail Monakhov ◽  
Poh San Lai ◽  
Richard Ebstein ◽  
...  
Keyword(s):  
Genetic Variation ◽  
Near Infrared ◽  
Social Motivation ◽  
Autism Spectrum ◽  
Brain Asymmetry ◽  
Functional Near Infrared Spectroscopy ◽  
Human Infants ◽  
Frontal Asymmetry ◽  
Frontal Brain ◽  
The Individual

Introduction. Variability in the motivation to approach or withdraw from others displayed in infancy is thought to have long-term effects on human social development. Frontal brain asymmetry has been linked to motivational processes in infants and adults, with greater left frontal asymmetry reflecting motivation to approach and greater right frontal asymmetry reflecting motivation to withdraw. We examined the hypothesis that variability in infants’ social motivation is linked to genetic variation in the endogenous oxytocin system. Specifically, we measured infants’ frontal brain asymmetry and later looking preferences to smiling and frowning individuals and assayed a single-nucleotide polymorphism in the CD38 gene (rs3796863) linked to autism spectrum disorder and reduced peripheral oxytocin levels. Methods. 77 11-month-old infants’ (36 female) brain responses were measured via functional near-infrared spectroscopy (fNIRS) while viewing four individuals display either smiles or frowns directed toward or away from them. This was followed by a person preference test using eyetracking. Results. Frontal brain asymmetry patterns evoked by direct-gaze faces significantly differed as a function of CD38 genotype. Specifically, while non-risk A-allele carriers displayed greater left lateralization to smiling faces (approach) and greater right lateralization to frowning faces (withdrawal), infants with the CC (ASD risk) genotype displayed withdrawal from smiling faces. During eyetracking, A-allele carriers showed a heightened preference for the individual who smiled, while CC infants preferred the individual who frowned.Conclusions. Our findings demonstrate that, from early in human ontogeny, genetic variation in the oxytocin system is linked to variability in brain and behavioral markers of social motivation.

Biosynthetic and cytological studies in tissue cultures and regenerated plants of haploid Atropa belladonna

1978 ◽  
Vol 56 (21) ◽  
pp. 2781-2784 ◽  
Author(s):  
Susan Eapen ◽  
T. S. Rangan ◽  
M. S. Chadha ◽  
M. R. Heble
Keyword(s):  
Callus Cultures ◽  
Haploid Plant ◽  
Tissue Cultures ◽  
Atropa Belladonna ◽  
Ploidy Levels ◽  
Total Alkaloids ◽  
Regenerated Plants ◽  
The Individual ◽  
Different Levels ◽  
Alkaloid Contents

Tissue cultures have been established from leaves of one anther-derived haploid plant of Atropa belladonna L. Regenerants obtained from callus cultures were transferred to soil and reared to maturity. Callus cells and regenerants exhibited variable degrees of ploidy. The frequency of different ploidy levels in both the systems did not vary significantly during fifth to eighth serial passages.Callus tissue and regenerated plants (at flowering stage) were analyzed to determine the concentration of tropine, atropine, scopolamine, and total alkaloids. While the alkaloid content in callus cultures was very low (0.8 × 10−3%), the regenerated plants contained different levels of individual and total alkaloids. The ploidy of the plant had direct bearing on the individual and total alkaloid contents.

Patterns of morphological and genetic variation in western Indian Ocean members of the Chaerephon 'pumilus' complex (Chiroptera: Molossidae), with the description of a new species from Madagascar

Zootaxa ◽  
2010 ◽  
Vol 2551 (1) ◽  
pp. 1 ◽  
Author(s):  
STEVEN M. GOODMAN ◽  
WAHEEDA BUCCAS ◽  
THESHNIE NAIDOO ◽  
FANJA RATRIMOMANARIVO ◽  
PETER J. TAYLOR ◽  
...  
Keyword(s):  
Genetic Variation ◽  
Indian Ocean ◽  
Species Complex ◽  
Arabian Peninsula ◽  
Molecular Genetic ◽  
Western Indian Ocean ◽  
D Loop ◽  
Indian Ocean Island ◽  
The Individual ◽  
A New Species

The species delimitations of African, Arabian Peninsula, and western Indian Ocean island members of the Molossidae bat species complex Chaerephon pumilus remain largely unresolved. Based on genetic analyses this group is paraphyletic, with C. leucogaster nested within C. pumilus sensu lato, and the latter is composed of several distinct clades. DNA was isolated from a specimen of C. p. pumilus obtained at the type locality (Massawa, Eritrea). Although incomplete, this sequence allowed us to clearly define which clade is referable to nominate pumilus, a critical step in resolving the systematics of this species complex. Using morphological and molecular genetic (cytochrome b and D-loop sequences) characters, we establish that C. leucogaster and C. 'pumilus' on Madagascar represent two different lineages and that the Malagasy population referred to C. 'pumilus' is specifically distinct from those on Africa, the islands and mainland Africa. The population of C. pusillus from the western Seychelles atoll of Aldabra cluster with that of the Comoros, rather than Madagascar. For numerous other species of volant vertebrates (bats and birds), the origin of the Aldabra fauna is mixed between the Comoros and Madagascar (e.g., Goodman & Ranivo 2008; O'Brien et al. 2009; Pasquet et al. 2007; Warren et al. 2003). Hence, in the case of these 9-17 g Chaerephon bats, these water barriers have been associated with the isolation and subsequent differentiation of populations after successful dispersal and colonization events. In contrast, within the Comoros, there is no apparent genetic structure between with the individual islands, which are separated by 40 and 80 km, indicating that this distance is regularly traversed by these bats and giving rise to intra-archipelago panmixia of populations.

Genetic structuring of the stream lily Helmholtzia glaberrima (Philydraceae) within Toolona Creek, south-eastern Queensland

2004 ◽  
Vol 52 (2) ◽  
pp. 201 ◽  
Author(s):  
Peter J. Prentis ◽  
A. Vesey ◽  
N. M. Meyers ◽  
P. B. Mather
Keyword(s):  
Population Structure ◽  
Genetic Variation ◽  
Linkage Disequilibrium ◽  
Fragment Length Polymorphism ◽  
Metapopulation Model ◽  
Genetic Structuring ◽  
Mantel Tests ◽  
Riparian Species ◽  
Site Diversity ◽  
Non Equilibrium

The distribution of genetic variation among five isolated sites of the riparian species Helmholtzia glaberrima (J.D.Hook) was examined in Toloona Creek (28�13′S, 153�07′E) by using dominant amplified fragment length polymorphism (AFLP) markers. From the 137 fragments assessed, analysis of molecular variance (AMOVA) showed that most genetic variability occurred within sites (68%), although high (32%) variation also occurred among sites. Highly significant pairwise θ estimates among all sampled sites suggest that gene flow is restricted in H. glaberrima. Levels of within-site diversity were intermediate and significantly different across the sampled sites. Significant levels of linkage disequilibrium were detected at all sites except TC3. Differences in linkage disequilibrium and genetic diversity among the sites suggest that sites may have been founded by different numbers of colonists. Mantel tests found no correlation between geographic and genetic distance and significant levels of linkage disequilibrium were detected at the total site level, supporting a non-equilibrium model of population structure. The observed pattern of non-equilibrium population structure and genetic variation in H. glaberrima are best explained by a classical metapopulation model.

scholarly journals Genetic diversity in wild and hatchery populations of stinging catfish (Heteropneustes fossilis Bloch) revealed by RAPD analysis

2012 ◽  
Vol 19 ◽  
pp. 81-87
Author(s):  
Md Nazrul Islam ◽  
Abhishak Basak ◽  
Dr Ashrafullah ◽  
Md Samsul Alam
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Length Polymorphism ◽  
Fragment Length ◽  
Fragment Length Polymorphism ◽  
Gene Diversity ◽  
Similarity Index ◽  
Heteropneustes Fossilis ◽  
Wild Populations ◽  
Polymorphic Loci

Context: DNA fingerprinting using genetic markers such as Random Amplification of Polymorphic DNA (RAPD), Restriction Fragment Length Polymorphism (RFLP), microsatellite (Simple sequence repeat), Amplified Fragment Length Polymorphism (AFLP) etc. can be successfully used to reveal genetic variation within and among different populations. Objective: The aim of the present study was to assess genetic diversity in two wild and one hatchery populations of stinging catfish Heteropneustes fossilis by RAPD fingerprinting. Materials and Methods: A total of 90 live fish (H. fossilis), 30 from each source, were collected from a beel in Patuakhali, a beel in Jessore and Rupali Hatchery, Mymensingh. Genomic DNA was extracted from fin tissues. The concentration of DNA was estimated using a spectrophotometer. Fifteen decamer primers of random sequence from three kits (six from kit A, seven from kit B and two from kit C) (Operon technologies, Inc., Alameda, CA, USA) were screened on sub-samples of one randomly chosen H. fossilis DNA sample from the each population to test their suitability for amplifying RAPDs. The amplified products from each sample were separated by electrophoresis on 1.4% agarose gel containing ethidium bromide. The sizes of the bands were calculated using the software DNAFRAG and the sizes in base pair (bp) were used for identification of the bands (RAPD markers). The similarity index values (SI) between the RAPD fingerprint of any two individuals on the same gel were calculated from RAPD band sharing. Results: A total of 28 RAPD bands were obtained using four decamer random primers, among which 21 bands were polymorphic. The percentage of polymorphic loci, intra-population similarity indices and Nei's gene diversity values were 85.71%, 78.75 and 0.304±0.183 for Jessore population, 83.71%, 82.62 and 0.280±0.159 for Patuakhali population, 82.14%, 85.25 and 0.271±0.165 for Rupali hatchery population, respectively. The overall gene flow (Nm) among the populations was 5.755. The highest inter-similarity (Sij) was found between Patuakhali - Rupali hatchery populations. Among the three populations, the highest genetic distance (0.069) was found between Jessore and Patuakhali population. Considering polymorphic loci, intrapopulation similarity index and gene diversity the genetic variation in the Jessore population was higher than the other two populations. The genetic variation of the hatchery population was found to be lower than the two wild populations. Conclusion: The result of the present study can be used as baseline information regarding the genetic variation and population structure before undertaking any breeding programme. Study indicated that the genetic variation in the hatchery populations were slightly lower than those of the wild populations. DOI: http://dx.doi.org/10.3329/jbs.v19i0.13005 J. bio-sci. 19 81-87, 2011

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