Chromosome Counts Research Articles

Determination of Genome Size and Chromosome Number of a Ziziphus Species (Z. mauritiana Lam.) from Eastern Senegal

Ziziphus mauritiana Lam. is a widespread shrub or tree of the Sahel region, where it grows wild and is used for various purposes, including nutrition, medicine, and firewood. Current domestication programs focus on using the local species as rootstock for the improved imported Asian cultivars to provide tolerance to pests and diseases. The plant plays an increasing economic role in the livelihoods of local Sahelian populations, but despite this there is little genetic information about it. The purpose of our study was to determine the genome size estimate and chromosome numbers of Z. mauritiana germplasm collected from eastern Senegal, West Africa. Genome size estimates were determined using flow cytometry, and chromosome count was achieved using chromosome spreads of actively growing root tips. The mean, median, minimum, and maximum genome size estimates (1Cx-DNA) of Z. mauritiana were 418.74 Mb, 417.45 Mb, 410.72 Mb, and 432.12 Mb, respectively. Plants of the germplasm investigated were found to be octoploid with a chromosome number of 2n = 8x = 96. The genetic information gathered in this study can be useful for phylogenetic studies, sequencing projects, and domestication programs that focus on controlled pollination for the development of improved Z. Mauritania cultivars in the Sahel region.

Genome Sizes, Ploidy Levels, and Base Compositions of Styrax Species and Cultivars

Styrax L. is a genus of ≈130 species, many with horticultural traits of interest, though sparsely represented in cultivation. Previous studies reporting chromosome counts have established a base chromosome number of x = 8 and provided evidence of diploid, tetraploid, pentaploid, and hexaploid levels within the genus, including the more commonly cultivated Styrax japonicus Siebold & Zucc. being reported as pentaploid. Little has been reported relative to genome size within the Styracaceae. We conducted flow cytometry using fluorochromes propidium iodide (PI) and 4′,6-diamidino-2-phenylindole (DAPI) to estimate relative 2C genome size and ploidy of 47 accessions representing 15 species of Styrax and base composition of a subset of 9 accessions representing 6 species. Cytologic analysis of chromosomes was completed on Styrax confusus Hemsl. for ploidy calibration to genome size. Diploids, tetraploids, pentaploids, hexaploids, and octoploids were identified. Relative 2C genome size ranged from 1.38 to 6.61 pg. This survey confirms published ploidy for Styrax americanus Lam., Styrax obassia Siebold & Zucc., Styrax redivivus (Torr.) L.C.Wheeler (diploid), and S. japonicus (pentaploid); suggests alternate ploidy levels and/or ploidy series for Styrax grandifolius Aiton (diploid) and Styrax hookeri C.B.Clarke (octoploid); and establishes ploidy levels for Styrax glabrescens Benth., Styrax odoratissimus Champ. ex Benth., Styrax officinalis L., Styrax platanifolius Engelm. ex Torr., Styrax ramirezii Greenm., Styrax wilsonii Rehder (diploid), Styrax confusus, Styrax hemsleyanus Diels (tetraploid), and Styrax fortunei Hance (diploid and hexaploid).

Complex patterns of ploidy in a holocentric plant clade (Schoenus, Cyperaceae) in the Cape biodiversity hotspot.

It is unclear how widespread polyploidy is throughout the largest holocentric plant family - the Cyperaceae. Because of the prevalence of chromosomal fusions and fissions, which affect chromosome number but not genome size, it can be impossible to distinguish if individual plants are polyploids in holocentric lineages based on chromosome count data alone. Furthermore, it is unclear how differences in genome size and ploidy levels relate to environmental correlates within holocentric lineages, such as the Cyperaceae. We focus our analyses on tribe Schoeneae, and more specifically the southern African clade of Schoenus. We examine broad-scale patterns of genome size evolution in tribe Schoeneae and focus more intensely on determining the prevalence of polyploidy across the southern African Schoenus by inferring ploidy level with the program ChromEvol, as well as interpreting chromosome number and genome size data. We further investigate whether there are relationships between genome size/ploidy level and environmental variables across the nutrient-poor and summer-arid Cape biodiversity hotspot. Our results show a large increase in genome size, but not chromosome number, within Schoenus compared to other species in tribe Schoeneae. Across Schoenus, there is a positive relationship between chromosome number and genome size, and our results suggest that polyploidy is a relatively common process throughout the southern African Schoenus. At the regional scale of the Cape, we show that polyploids are more often associated with drier locations that have more variation in precipitation between dry and wet months, but these results are sensitive to the classification of ploidy level. Polyploidy is relatively common in the southern African Schoenus, where a positive relationship is observed between chromosome number and genome size. Thus, there may be a high incidence of polyploidy in holocentric plants, whose cell division properties differ from monocentrics.

Genus Barleria L. (Acanthaceae): a review of its taxonomy, cytogenetics, phytochemistry and pharmacological potential.

Barleria, a large genus of the Acanthaceae family, comprises more than 300 species with diverse taxonomy, cytogenetics, phytochemistry and pharmacological potential. Therefore, the aim of this review is to critically assess the research on Barleria and provide guidance for future investigations. The data were obtained from different sources, such as books, theses, journals and some of the websites and internet-based searches, published from 1901 to 2020. Data obtained from PubMed, Google Scholar, ScienceDirect, online electronic journals, SpringerLink, Wiley, etc. have also been used. The species of this genus exhibit considerable medicinal properties. Cytogenetical data are scantily available with chromosome counts available for only 24 species. The most common chromosome number is 2n = 2x = 40. So far, 187 compounds are reported from Barleria species. The active principles, their uses, toxicity and pharmacological effects are discussed. Essential oils, flavones, flavonoids, glycosides, terpenes and terpenoids form the major compounds. It is highly recommended that the pharmacological and economic potential of Barleria species should be exploited and more detailed studies and attention be geared towards its utilization and conservation. In addition, to ensure maximum pharmacological benefits and sustainable use, it is necessary to have empirical information explaining its ethnobotanical values as well as commercial potential.

Chromosome counting in the mouse zygote using low-invasive super-resolution live-cell imaging.

In preimplantation embryos, an abnormal chromosome number causes developmental failure and a reduction in the pregnancy rate. Conventional chromosome testing methods requiring biopsy reduce the risk of associated genetic diseases; nevertheless, the reduction in cell number also reduces the pregnancy rate. Therefore, we attempted to count the chromosomes in mouse embryos using super-resolution live-cell imaging as a new method of chromosome counting that does not reduce the cell number or viability. We counted the 40 chromosomes at the first mitosis by injecting embryos with histone H2B-mCherry mRNA under conditions by which pups could be obtained; however, the results were often an underestimation of chromosome number and varied by embryo and time point. Therefore, we developed a method to count the chromosomes via CRISPR/dCas-mediated live-cell fluorescence in situ hybridization targeting the sequence of the centromere region, enabling us to count the chromosomes more accurately in mouse embryos. The methodology presented here may provide useful information for assisted reproductive technologies, such as those used in livestock animals/humans, as a technique for assessing the chromosomal integrity of embryos prior to transfer.

Genome Size and Chromosome Number Evaluation of Astragalus L. sect. Hymenostegis Bunge (Fabaceae).

Astragalus section Hymenostegis is one of the important characteristic elements of thorn-cushion formations in the Irano-Turanian floristic region. In this paper, we examined the chromosome number of 17 species (15 new reports) and provide estimates of genome size for 62 individuals belonging to 38 taxa of A. sect. Hymenostegis, some species outside this section, plus two Oxytropis species. Based on chromosome counts 11 species were found to be diploid (2n = 16), four species tetraploid (2n = 32) and two taxa hexaploid (2n = 48). From genome size measurements on silica-gel dried material, three ploidy levels (2x, 4x and 6x) were inferred, with a majority of species being diploid. The 2C values reach from 2.07 pg in diploid Astragalus zohrabi to 7.16 pg in hexaploid A. rubrostriatus. We found indications that species might occur with different cytotypes. A phylogenetic framework using nrDNA ITS sequences was constructed to understand the evolution of ploidy changes and genome sizes. It showed that genome size values among the studied taxa differ only slightly within ploidy levels and are nearly constant within most species and groups of closely related taxa within the genus Astragalus. The results of this study show that there is a rather strong correlation between genome sizes and chromosome numbers in sect. Hymenostegis. The resolution of the ITS-based phylogenetic tree is too low to infer evolutionary or environmental correlations of genome size differences. Polyploidization seems to contribute to the high species number in Astragalus, however, in sect. Hymenostegis it is not the main driver of speciation.

Allium ducissae (A. subgen. Polyprason, Amaryllidaceae) a New Species from the Central Apennines (Italy).

In this paper, Allium ducissae (the LSID for the name Allium ducissae is: 77254606-1) is described as a new species based on morphological and molecular analyses, and its taxonomic relationships are discussed. It grows in crevices on calcareous rocks, rocky slopes and grassy ledges in the subalpine belt, within two regional protected areas in the Lazio and Abruzzo administrative regions (Central Apennines, Italy). Previously, these populations were attributed to A. strictum, a species described from Siberia, belonging to A. sect. Reticulatobulbosa. The new species is distinct from A. strictum in the morphology of vegetative and reproductive structures. Indeed, it is close to A. palentinum, an endemic species to Cantabrian Mountains (NW Spain). Both molecular and morphological data support the recognition of the Allium populations coming from the Central Apennines as a new species. Allium ducissae can be clearly distinguished from A. palentinum by longer and wider tepals, longer filaments, tooth of inner filament, flower pedicels, spathe appendage, and smaller seeds. Moreover, seed testa micro-sculptures revealed slight differences between A. ducissae and A. palentinum. Chromosome counts showed that A. ducissae is diploid with 2n = 16 chromosomes, as already known for A. palentinum. Molecular analyses support the affiliation of A. ducissae and A. palentinum to A. sect. Falcatifolia, contrary to what is known for the latter species, usually included in A. sect. Daghestanica. Finally, the IUCN assessment for the newly described species is proposed and briefly discussed.

Endemism in recently diverged angiosperms is associated with polyploidy

Endemic (range restricted or precinctive) plant species are frequently observed to exhibit polyploidy (chromosome set duplication), which can drive shifts in ecology for angiosperms, but whether endemism is generally associated with polyploidy throughout the flowering plants has not been determined. We tested the hypothesis that polyploidy is more frequent and more pronounced (higher evident ploidy levels) for recently evolved endemic angiosperms. Chromosome count data, molecular dating and distribution for 4210 species (representing all major clades of angiosperms and including the largest families) were mined from literature-based databases. Upper boundary regression was used to investigate the relationship between the maximum number of chromosomes and time since taxon divergence, across clades and separately for families, comparing endemic with non-endemic species. A significant negative exponential relationship between maximum number of chromosomes and taxon age was evident across angiosperms (R2adj = 0.48 for all species, R2adj = 0.49 for endemics; R2adj = 0.44 for non-endemics; p always < 0.0001), recent endemics demonstrating greater maximum chromosome numbers (y intercept = 164 cf. 111) declining more rapidly with taxon age (decay constant = 0.12, cf. 0.04) with respect to non-endemics. The majority of families exhibited this relationship, with a steeper regression slope for endemic Campanulaceae, Asteraceae, Fabaceae, Poaceae, Caryophyllaceae and Rosaceae, cf. non-endemics. Chromosome set duplication is more frequent and extensive in recent angiosperms, particularly young endemics, supporting the hypothesis of recent polyploidy as a key explanation of range restriction. However, as young endemics may also be diploid, polyploidy is not an exclusive driver of endemism.

Cytogeography of Solidago sect. Maritimae (Asteraceae: Astereae)

Chromosome numbers are reported for 53 individuals of 10 species of Solidago L. sect. Maritimae (Torr. &amp; A. Gray) Semple &amp; Beck from eastern Canada and the eastern United States: S. austrina Small, S. chrysopsis Small, S. gracillima Torr. &amp; A. Gray, S. mexicana L., S. pulchra Small, S. sempervirens L., S. simulans Fernald, S. stricta Aiton, S. uliginosa Nutt., and S. virgata Michx. Identifications of nearly all vouchers for 262 previously published counts for the section were confirmed or revised following the treatments of the section by Semple et al. No counts have been reported for the Mexican species S. maya Semple and S. paniculata DC. and for S. uliginosa var. terra-novae (Torr. &amp; A. Gray) Fernald from Newfoundland. Polyploids are documented in six of the 13 species: S. austrina, S. mexicana, S. pulchra, S. stricta, S. uliginosa, and S. virgata. In addition, we provide the first chromosome count for S. chrysopsis (2n = 18) from Florida. All 315 count reports from 231 locations were used to map the cytogeography of all species in the section.

In vitro propagation and cytogenetic stability of Tripleurospermum insularum (Asteraceae) – a critically endangered insular endemic species from Turkey

Tripleurospermum insularum (Asteraceae) is a critically endangered (CR) insular endemic species in Turkey and is facing high risk of extinction. Here, a rapid and efficient in vitro propagation protocol using nodal segments obtained from seedling shoots cultured on Murashige and Skoog (MS) basal medium supplemented with different plant growth regulators (PRGs) was developed to conserve T. insularum. Besides, the cytogenetic fidelity of propagated plants was tested with DNA ploidy level using flow cytometry (FCM) as well as chromosome counting. The highest shoot number and length of shoot per explant were achieved in MS medium containing 4.6 µM zeatin (ZEA) and 0.5 µM indole-3-acetic acid (IAA). No variation in DNA ploidy level (2x) and somatic chromosome number (2n = 18) of all propagated plants were observed. In vitro rooting of shoots was achieved at 100% efficiency in the medium supplemented with 2.9 µM IAA. The rooted plantlets were transferred ex vitro with 74% survival. This is the first report of a successfully developed micropropagation protocol for ex situ conservation of T. insularum.

Genome size variation in Deschampsia cespitosa sensu lato (Poaceae) in Eurasia

The grass Deschampsia cespitosa is a variable taxon out of which many varieties, subspecies and endemic species have been separated. In this paper, the variation in genome size (GS) and ploidy of this grass including several of its subspecies and two related species in Eurasia was investigated by flow cytometric (FCM) measurements. GS and ploidy data were also related to specific environments and reproduction mode. Ploidy levels found by FCM were confirmed by chromosome counts of diploid (2n = 26) and tetraploid (2n = 52) samples. Seminiferous (seed bearing) D. cespitosa was mainly diploid (GS between 3.754 and 5.438 pg/1C). GS variation in diploids showed a geographic pattern with a significant difference (H = 41,441, P < 0.001) between European (median = 4.377 pg) and Asian (median = 4.881 pg) accessions. Genome size (1C) in tetraploids ranged from 7.9426 to 9.0399 pg. Tetraploid seminiferous D. cespitosa was found mostly in disturbed habitats in western and southern Europe, while tetraploids in Asia were registered in wet Arctic habitats. Genome size (1C between 8.3278 and 8.8603 pg) of the pseudoviviparous plants (spikelets produce plantlets asexually) of wet habitats in central and northern Europe indicated tetraploidy. A putative triploid (GS 6.6817 pg) was detected in Iceland. Summing up, we found a high variation in GS on the geographic scale with significant regional differences in diploid D. cespitosa. Among the tetraploids, the asexually reproducing plants were bound to specific habitats, while the seminiferous plants showed a habitat preference similar to the diploids.

Mechanisms of sex determination and X-chromosome dosage compensation.

Abnormalities in chromosome number have the potential to disrupt the balance of gene expression and thereby decrease organismal fitness and viability. Such abnormalities occur in most solid tumors and also cause severe developmental defects and spontaneous abortions. In contrast to the imbalances in chromosome dose that cause pathologies, the difference in X-chromosome dose used to determine sexual fate across diverse species is well tolerated. Dosage compensation mechanisms have evolved in such species to balance X-chromosome gene expression between the sexes, allowing them to tolerate the difference in X-chromosome dose. This review analyzes the chromosome counting mechanism that tallies X-chromosome number to determine sex (XO male and XX hermaphrodite) in the nematode Caenorhabditis elegans and the associated dosage compensation mechanism that balances X-chromosome gene expression between the sexes. Dissecting the molecular mechanisms underlying X-chromosome counting has revealed how small quantitative differences in intracellular signals can be translated into dramatically different fates. Dissecting the process of X-chromosome dosage compensation has revealed the interplay between chromatin modification and chromosome structure in regulating gene expression over vast chromosomal territories.

Chloroplast phylogenomics in Camelina (Brassicaceae) reveals multiple origins of polyploid species and the maternal lineage of C. sativa.

The genus Camelina (Brassicaceae) comprises 7-8 diploid, tetraploid, and hexaploid species. Of particular agricultural interest is the biofuel crop, C. sativa (gold-of-pleasure or false flax), an allohexaploid domesticated from the widespread weed, C. microcarpa. Recent cytogenetics and genomics work has uncovered the identity of the parental diploid species involved in ancient polyploidization events in Camelina. However, little is known about the maternal subgenome ancestry of contemporary polyploid species. To determine the diploid maternal contributors of polyploid Camelina lineages, we sequenced and assembled 84 Camelina chloroplast genomes for phylogenetic analysis. Divergence time estimation was used to infer the timing of polyploidization events. Chromosome counts were also determined for 82 individuals to assess ploidy and cytotypic variation. Chloroplast genomes showed minimal divergence across the genus, with no observed gene-loss or structural variation. Phylogenetic analyses revealed C. hispida as a maternal diploid parent to the allotetraploid Camelina rumelica, and C. neglecta as the closest extant diploid contributor to the allohexaploids C. microcarpa and C. sativa. The tetraploid C. rumelica appears to have evolved through multiple independent hybridization events. Divergence times for polyploid lineages closely related to C. sativa were all inferred to be very recent, at only ~65 thousand years ago. Chromosome counts confirm that there are two distinct cytotypes within C. microcarpa (2n = 38 and 2n = 40). Based on these findings and other recent research, we propose a model of Camelina subgenome relationships representing our current understanding of the hybridization and polyploidization history of this recently-diverged genus.

A new record of chromosome count in mixoploid karyotype of Strobilanthes hamiltoniana (Steud.) Bosser &amp; Heine (Acanthaceae)

The mixoploid karyotype found in the garden plant, Strobilanthes hamiltoniana, is a new record of chromosome count to the contemporary knowledge. The detailed karyomorphometrical analysis of the plant revealed a symmetric karyotype which is primitive. A hypoploid variant along with the normal chromosome complement was recorded within a root meristem with karyotype formulae as 10 nm and 20 nm respectively. In the diploid cells two pair of chromosomes have secondary constriction with an average chromosome length of 1.81 μm. The high values of symmetric indices and low values of asymmetric indices proved the primitive nature of the karyotype.

Chromosome numbers and genome size data on species of the genus Petrorhagia(Caryophyllaceae) from Turkey

Genome size, i.e. the total amount of DNA in an unreplicated somatic nucleus is considered an important character in the biology of organisms, and it is especially relevant for land plants given the extraordinary diversity reported. Despite the continuous growth of data and the efforts aimed at increasing our understanding of plant genome size diversity, more data are needed to have an evenly representation across lineages. With this premise in mind, in this work, we investigated genome size, complemented with chromosome data in eight species of the genus Petrorhagia (Caryophyllaceae) from Turkey. Chromosome counts made indicate that the species studied are diploid except for one species, P. saxifraga, which is probably a tetraploid, based on previously published estimations of nuclear DNA contents. The presence of both basic chromosome numbers x = 15 and x = 13 is confirmed, the latter being restricted to the species P. hispidula and P. cretica. The counts carried out for the Turkish endemic species, in P. hispidula (2n = 26), P. pamphylica (2n = 30) and P. peroninii (2n = 30) represent novel data for the genus. Nuclear DNA contents ranged from 1.24 to 2.32 pg/2C (varying 1.87-fold). Based on available data, genome expansions in the genus seem to have occurred through different evolutionary mechanisms, such as polyploidy and differential repetitive DNA activation, evidencing contrasting genomic trajectories between closely related taxa

Cytological Study of &lt;i&gt;Begonia&lt;/i&gt; Sect. &lt;i&gt;Diploclinium&lt;/i&gt; (Begoniaceae)

Previous chromosome information is restricted to 13 species in the Asian Begonia sect. Diploclinium. Here we present the first chromosome counts of three species, as well as confirmed their chromosome numbers of five species. Among three species investigated for the first time, the chromosome number of 2n=18 and 2n=32 are new counts in the section. Additionally, we provide the karyotypes of eight species for the first time. Among ca. 135 species in sect. Diploclinium, chromosome numbers of 16 species are available together with the present and previous reports. Among 16 species, they show diverse chromosome numbers with 2n=18, 22, 24, 26, 30, 32, 36, 46, and 54. B. wenshanensis with 2n=18 is the lowest chromosome number in the section and the third lowest chromosome number in Begonia. We suggest that B. coptidimontana with 2n=32 is tetraploid origin with the basic chromosome number of x=8. We discussed the chromosome evolution in Begonia sect. Diploclinium.

The morphological, karyological and phylogenetic analyses of three Artemisia L. (Asteraceae) species that around the Van Lake in Turkey

Artemisia is one of the biggest genera in the family Asteraceae, with around 500-600 taxa at specific and sub-specific levels and organised in five subgenera. Due to the high number of taxa, a lot taxonomists are trying to solve the problem of its classification and phylogeny but its natural classification still has not been achieved. The aim of this study is to try to solve the problematic systematic relationship between three different Artemisia species growing in close proximity to each other in the light of morphological, karyological and molecular data. The roots, stems, leaves, flowers structures of the plant samples collected from different populations belong to these species were investigated within the framework of morphological studies. Additionally, the chromosome counts and karyotype analysises of these species were made and idiograms were drawn in the karyological studies. In the context of phylogenetic studies, ITS (ITS1-5.8S-ITS2) and trnT - trnL3’ regions of 22 individuals belonging to 3 taxa were studied. According to results of phylogenetic anlysis, it has been found that there is completed speciation genetic isolation mechanism between the species Artemisia spicigera, Artemisia taurica and Artemisia fragrans that inhibit gene flow. Also Artemisia fragrans and Artemisia spicigera species are very similar to each other in terms of morphological characteristics. However, since populations of the species Artemisia fragrans are autopolyploid, the dimensional values of their morphological squares are larger than those of the species Artemisia spicigera. This study is important as it is the first molecular based study relating with some species of Artemisia growing naturally in Turkey.

Ploidy level enhances the photosynthetic capacity of a tetraploid variety of Acer buergerianum Miq.

BackgroundPolyploidy plays an important role in plant breeding and has widespread effects on photosynthetic capacity. To determine the photosynthetic capacity of the tetraploid variety Acer buergerianum Miq. ‘Xingwang’, we compared the gas exchange parameters, chloroplast structure, chlorophyll contents, and chlorophyll fluorescence parameters between the tetraploid Acer buergerianum ‘Xingwang’ and the diploid ‘S4’. To evaluate the effects of genome duplication on the photosynthetic capacity of Acer buergerianum ‘Xingwang’, the transcriptomes of the autotetraploid ‘Xingwang’ and the diploid ‘S4’ of A. buergerianum were compared.MethodsThe ploidy of Acer buergerianum ‘Xingwang’ was identified by flow cytometry and the chromosome counting method. An LI-6800 portable photosynthesis system analyzer was used to assess the gas exchange parameters of the tetraploid variety ‘Xingwang’ and diploid variety ‘S4’ of A. buergerianum. We used a BioMate 3S ultraviolet-visible spectrophotometer and portable modulated fluorometer to measure the chlorophyll contents and chlorophyll fluorescence parameters, respectively, of ‘Xingwang’ and ‘S4’. Illumina high-throughput sequencing technology was used to identify the differences in the genes involved in the photosynthetic differences and determine their expression characteristics.ResultsThe single-cell DNA content and chromosome number of the tetraploid ‘Xingwang’ were twice those found in the normal diploid ‘S4’. In terms of gas exchange parameters, the change in stomatal conductance, change in intercellular CO2 concentration, transpiration rate and net photosynthetic rate of ‘Xingwang’ were higher than those of the diploid ‘S4’. The chlorophyll contents, the maximal photochemical efficiency of PSII and the potential photochemical efficiency of PSII in ‘Xingwang’ were higher than those of ‘S4’. The chloroplasts of ‘Xingwang’ contained thicker thylakoid lamellae. By the use of Illumina sequencing technology, a total of 51,807 unigenes were obtained; they had an average length of 1,487 nt, and the average N50 was 2,034 nt. The lengths of most of the unigenes obtained ranged from 200–300 bp, with an average value of 5,262, followed by those longer than 3,000 bp, with an average value of 4,791. The data revealed numerous differences in gene expression between the two transcriptomes. In total, 24,221 differentially expressed genes were screened, and the percentage of differentially expressed genes was as high as 46.75% (24,224/51,807), of which 10,474 genes were upregulated and 13,747 genes were downregulated. We analyzed the key genes in the photosynthesis pathway and the porphyrin and chlorophyll metabolism pathway; the upregulation of HemB may promote an increase in the chlorophyll contents of ‘Xingwang’, and the upregulation of related genes in PSII and PSI may enhance the light harvesting of ‘Xingwang’, increasing its light energy conversion efficiency.

Chromosome numbers for the Italian flora: 12

In this contribution, new chromosome data obtained on material collected in Italy are presented. It includes the first counts for Hieracium glanduliferum s.str. and H. tenuiflorum, counts for two Armeria species endemic to Italy, and for Onopordum illyricum subsp. illyricum. We also present here the first chromosome count of Allium permixtum for Italy, where this species is known for few localities.

Production of Gynogenic Plants of Red Beet (Beta vulgaris L.) in Unpollinated Ovule Culture In Vitro

The unique and balanced components of the biochemical composition, together with high antioxidant activity, make the red beet necessary a dietary vegetable crop, much contributing to healthy food ration. The application of the technology for producing gynogenic plants in vitro increases the genetic diversity and significantly reduces the period of time required to obtain the appropriate homozygous lines used to create the F1 hybrids that are demanded in the market. For induction of gynogenesis, we used IMB medium developed by us with the addition of 55 g/L sucrose, 3 g/L phytogel, 200 mg/L ampicillin, and 0.4 mg/L thidiazuron (TDZ) and cultured at 28 °C in the dark for 4–6 weeks. Shoot regeneration from embryoids and callus was performed on MS medium with 20 g/L sucrose, 3 g/L phytogel, 1 mg/L 6-benzylaminopurine (BAP), and 0.1 mg/L gibberellic acid (GA3). Immersion of the obtained microshoots with 5–7 well-developed leaves for 10–15 s into concentrated sterile indole-3-butyric acid (IBA) solution (50 mg/L) followed by their cultivation on solid medium ½ IMB with 2% sucrose and 3 g/L phytogel was the most efficient method for root formation. The addition of silver nitrate (22 mg/L) to the nutrient medium provoked an increase in the number of induced ovules up to nine per Petri dish (up to 25% of induced ovules). Gynogenic development was produced in six out of 11 genotypes studied, and the plants that were then acclimatized to ex vitro conditions were obtained in three genotypes (Nezhnost’, Dobrynya, b/a 128). The evaluation of ploidy of gynogenic plants that was carried out by flow cytometry and direct counting of chromosomes stained with propion-lacmoide revealed that all obtained gynogenic plants were haploids (2n = x = 9).