Hybridization with introduced genetic resources is commonly practiced in ornamental plant breeding to introgress desired traits. The 19th century was a golden age for rose breeding in France. The ...objective here was to study the evolution of rose genetic diversity over this period, which included the introduction of Asian genotypes into Europe. A large sample of 1228 garden roses encompassing the conserved diversity cultivated during the 18th and 19th centuries was genotyped with 32 microsatellite primer pairs. Its genetic diversity and structure were clarified. Wide diversity structured in 16 genetic groups was observed. Genetic differentiation was detected between ancient European and Asian accessions, and a temporal shift from a European to an Asian genetic background was observed in cultivated European hybrids during the 19th century. Frequent crosses with Asian roses throughout the 19th century and/or selection for Asiatic traits may have induced this shift. In addition, the consistency of the results with respect to a horticultural classification is discussed. Some horticultural groups, defined according to phenotype and/or knowledge of their pedigree, seem to be genetically more consistent than others, highlighting the difficulty of classifying cultivated plants. Therefore, the horticultural classification is probably more appropriate for commercial purposes rather than genetic relatedness, especially to define preservation and breeding strategies.
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BFBNIB, NMLJ, NUK, PNG, SAZU, UL, UM, UPUK
The distribution of cytotypes and its potential correlation with environmental variables represent a cornerstone to understanding the origin and maintenance of polyploid lineages. Although many ...studies have addressed this question in single species at a regional scale, only a few have attempted to decipher this enigma in groups of closely related species at a broad intercontinental geographical scale. Here, we consider approx. 20 species of a diploid-polyploid complex (Veronica subsect. Pentasepalae) of recent and rapid diversification represented in Europe and North Africa to study the frequency and distribution of cytotypes and their relationship to environmental variables.
A total of 680 individuals (207 populations) were sampled. Ploidy levels were determined using flow cytometry. Ecological differentiation among cytotypes was tested using climatic and environmental variables related to temperature, precipitation, vegetation and biogeographical region, among others, and by performing univariate and multivariate (constrained principal coordinates analysis) analyses.
Four ploidy levels (2x, 4x, 6x and 8x) were found and genome downsizing was observed to occur within the group. Plants of different ploidy level are ecologically differentiated, with hexaploids and octoploids occurring in wetter and colder habitats with a higher seasonality than diploids. A south to north distribution pattern was found, with diploids occupying southern refugial areas and octoploids being more frequent in northern regions of Europe above the permafrost boundary.
The distribution of cytotypes can be explained by ecological differentiation, the geographical position of refuge areas during the Quaternary climatic oscillations as well as by ice and permafrost retreat patterns. The Balkan Peninsula constitutes the most important contact zone between cytotypes. This work provides the first comprehensive ploidy screening within V. subsect. Pentasepalae at a broad scale and indicates that polyploidy and genome downsizing might have contributed to the colonization of new habitats in a recently diverged polyploid complex.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
ABSTRACT
Endopolyploidy – the existence of higher‐ploidy cells within organisms that are otherwise of a lower ploidy level (generally diploid) – was discovered decades ago, but remains poorly studied ...relative to other genomic phenomena, especially in animals. Our synthetic review suggests that endopolyploidy is more common in animals than often recognized and probably influences a number of fitness‐related and ecologically important traits. In particular, we argue that endopolyploidy is likely to play a central role in key traits such as gene expression, body and cell size, and growth rate, and in a variety of cell types, including those responsible for tissue regeneration, nutrient storage, and inducible anti‐predator defences. We also summarize evidence for intraspecific genetic variation in endopolyploid levels and make the case that the existence of this variation suggests that endopolyploid levels are likely to be heritable and thus a potential target for natural selection. We then discuss why, in light of evident benefits of endopolyploidy, animals remain primarily diploid. We conclude by highlighting key areas for future research such as comprehensive evaluation of the heritability of endopolyploidy and the adaptive scope of endopolyploid‐related traits, the extent to which endopolyploid induction incurs costs, and characterization of the relationships between environmental variability and endopolyploid levels.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
The tea collection of the FRC SSC RAS (Sochi, Maykop in Russia) represents one of the northernmost germplasm comprising a number of locally derived cultivars and ɣ-irradiation mutants. The latter are ...often characterized by larger genome size, which may lead to better adaptation to biotic and abiotic stress. Such genotypes may be a valuable genetic resource for better adaptability to extreme environmental conditions, which could enable tea cultivation outside global growing regions. Microsatellite markers are often the best choice for genetic diversity analysis in genebank collections. However, their use in polyploid species is questionable because simple sequence repeat (SSR) allele dosage cannot be readily determined. Therefore, the efficiency of SSR and start codon targeted (SCoT) markers was investigated using 43 selected cultivars from the Russian genebank collection derived from mutant breeding and clonal selection. Previously, the increase in genome size was confirmed in 18 mutants within this collection. Despite the presence of polyploid tea genotypes, our study revealed higher efficiency of SSR markers than SCoT markers. Subsequent SSR analysis of the 106 genotypes in the Russian genebank collection revealed three distinct genetic clusters after STRUCTURE analysis. Greater genetic variation was observed within genetic clusters than between clusters, indicating low genetic variation between collections. Nevertheless, the northernmost tea collection exhibited a greater genetic distance from the other two clusters than they did from each other. Close genetic relationships were found between many cultivars with particularly large leaves and mutant forms. Pearson's correlation analysis revealed a significant, moderate correlation between genome size and leaf area size. Our study shows that microsatellite fingerprinting is useful to estimate the genetic diversity and genetic background of tea germplasm in Russia despite polyploid tea accessions. Thus, the results of our study contribute to the development of future tea germplasm conservation strategies and modern tea breeding programs.
•Stevia strains can be grown in temperate climate under the tunnel and in the field.•Differences between stevia strains resulted from differences in metabolic activity.•High photosynthetic efficiency ...is correlated with high steviol glycosides level.•Steviol glycosides might function in the protection of photosynthetic apparatus.
The objective of this study was to evaluate the development and the quality of leaves from several S. rebaudiana Bertoni strains cultivated under temperate climate conditions in the tunnel and in the open field in the relation to the photosynthetic activity. Investigated stevia strains differed significantly in terms of whole plant and leaf morphology, photosynthetic efficiency as well as in the content of steviol glycosides, and antioxidant capacity, independently of cultivation place. On the basis of several chlorophyll a fluorescence parameters analysis it was stated that plants of all examined strains, did not exhibit photosynthesis inhibition. The studies of the relationship between photosynthetic activity and the level of secondary metabolites indicated that the highest content of steviol glycosides and phenolic compounds had plants showing also the highest value of the energy fraction photochemically converted in PS II (YII), while the highest ratio of rebaudioside A to stevioside content corresponded with low amount of energy dissipated as a heat (YNPQ). This results might indicate that steviol glycosides play a role in the better adaptation to environmental conditions. Karyology and cytometric studies revealed that all investigated stevia strains were diploids without significant differences in 2C DNA amount. Therefore, observed diversity in the content of steviol glycosides and phenolic compounds between investigated S. rebaudiana strains was not the effect of polyploidization but probably resulted from the differences in the metabolic activity of the examined plants.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
•Chromosome ploidy of selected taxa from Prunus armeniaca by flow cytometry were diploids.•Genome size of P. armeniaca varied from 0.590 to 0.708 pg.•Genome size of P.armeniaca has no significant ...correlation with longitude, latitude and altitude.•Genome size of P. armeniaca was highly stable.
The assessment of plant genome size is important in many research fields, including crop improvement and molecular genetics. However, studies on the genome size of Prunus armeniaca is limited. The purpose of this study was to evaluate the differences in the genome size of P. armeniaca in different geographic ecological groups and estimate the ranges in genome size. Nuclear suspension of P. armeniaca was prepared by Marie's isolation buffer and propidium iodide fluorescent dye. The genome size of 51, 60, 11 and 2 accessions from the Central Asian Ecological Group, Dzhungar-ili Ecological Group, North China Ecological Group and European Ecological Group, respectively, were assessed by flow cytometry, and the levels of ploidy were evaluated. There were no polyploids from different ecological groups of P. armeniaca; all accessions were diploids. The genome size of P. armeniaca varied from 0.590 to 0.708 pg, and the average genome size was 0.637 pg. The European Ecological Group had the largest genome size (0.661 pg/2C), which was the only group significantly different in size from the Central Asian, North China and Dzhungar-ili Ecological Group (P = 0.05), while the difference in genome size among these three ecological groups was small. There was no significant difference in genome size between different populations of wild accessions, and there was no significant correlation with longitude, latitude and altitude. The variation in the genome size of P. armeniaca was only 2.33%, and there was low intraspecies variation among the studied groups; the genome size of P. armeniaca is highly stable.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Summary
Spatiotemporal patterns of phenology may be affected by mosaics of environmental and genetic variation. Environmental drivers may have temporally lagged impacts, but patterns and mechanisms ...remain poorly known.
We combine multiple genomic, remotely sensed, and physically modeled datasets to determine the spatiotemporal patterns and drivers of canopy phenology in quaking aspen, a widespread clonal dioecious tree species with diploid and triploid cytotypes.
We show that over 391 km2 of southwestern Colorado: greenup date, greendown date, and growing season length vary by weeks and differ across sexes, cytotypes, and genotypes; phenology has high phenotypic plasticity and heritabilities of 31–61% (interquartile range); and snowmelt date, soil moisture, and air temperature predict phenology, at temporal lags of up to 3 yr.
Our study shows that lagged environmental effects are needed to explain phenological variation and that the effect of cytotype on phenology is obscured by its correlation with topography. Phenological patterns are consistent with responses to multiyear accumulation of carbon deficit or hydraulic damage.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Sexual vs. asexual reproduction—unisexual vs. bisexual populations—diploid vs. polyploid biotypes—genetic vs. environmental sex determination: all these natural phenomena are associated with the ...genus of teleost fish, Carassius. This review places emphasis on two Carassius entities with completely different biological characteristics: one globally widespread and invasive Carassius gibelio, and the other C. carassius with a decreasing trend of natural occurrence. Comprehensive biological and cytogenetic knowledge of both entities, including the physical interactions between them, can help to balance the advantages of highly invasive and disadvantages of threatened species. For example, the benefits of a wide-ranged colonization can lead to the extinction of native species or be compensated by parasitic enemies and lead to equilibrium. This review emphasizes the comprehensive biology and cytogenetic knowledge and the importance of the Carassius genus as one of the most useful experimental vertebrate models for evolutionary biology and genetics. Secondly, the review points out that effective molecular cytogenetics should be used for the identification of various species, ploidy levels, and hybrids. The proposed investigation of these hallmark characteristics in Carassius may be applied in conservation efforts to sustain threatened populations in their native ranges. Furthermore, the review focuses on the consequences of the co-occurrence of native and non-native species and outlines future perspectives of Carassius research.
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The total nuclear DNA amount (2C value) of 75 individuals of Krascheninnikovia ceratoides s. l. was assessed by flow cytometry in 16 populations. The mean 2C value in all samples ranged from 2.59 to ...6.99 pg. The relationship between total 2C values and ploidy level was calibrated using chromosome counting in four populations. Diploids (2n = 18) and tetraploids (2n = 36) were revealed. In diploid plants, mean 2C value varied between 2.59 to 3.72 pg, in tetraploids − from 6.04 to 6.99 pg. The GS of diploids is approximately half the GS of tetraploids. Diploids were observed in seven populations from the Orenburg Region and the Republic of Tyva (Russia), Kyzylorda and Almaty Regions (Kazakhstan). Tetraploids were recorded in eight populations from Kazakhstan, Orenburg and Novosibirsk Regions, from the Republics of Altai and Sakha (Yakutia). One mixed population was found in the Republic of Khakassia represented by di- and tetraploids. We did not find any regularity in the geographical distribution of the two cytotypes. The studied plants showed no significant morphological features of taxonomic value, therefore we consider all the samples belong to Krascheninnikovia ceratoides s. str.
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