Search Results (61)

Background: Bahiagrass (Paspalum notatum), a key cultivated grass worldwide, includes both sexual diploid and apomictic tetraploid cytotypes. Finding new diploid populations is crucial for the species’ genetic improvement and conservation. Objectives: We aimed to determine the ploidy levels of 168 P. notatum accessions from subtropical South America, analyze the geographic distribution of cytotype diversity, and identify new diploid zones. Methods: Using chromosome counts and flow cytometry, we georeferenced our data with existing literature to map cytotype distribution. Results: We discovered five previously unknown diploid centers in Argentina, Brazil, and Paraguay, two of which resulted from the naturalization of diploid cultivars. One location hosted a mixed-ploidy population (diploid, tetraploid, and pentaploid), confirming ongoing hybridization. Our results show that human activity actively creates new centers of genetic diversity, serving as a dynamic source of raw material for crop resilience. These neonative diversification zones are not only of scientific interest but also vital, evolving hotspots for germplasm conservation. Conclusions: This study presents a new framework for understanding the interactions between crop and wild relatives and highlights the urgent need for conservation in the rapidly changing South American grasslands. Full article

Duckweeds are aquatic plants with a worldwide distribution that can thrive under very contrasting ambient conditions due to their diversity and high phenotypic plasticity. In this study, we analyzed and compared the responses of four clones (i.e., distinct accessions) of Lemna gibba to two different light intensities. The clones represented different geographical origins and, in addition to two diploid cytotypes, included one tetraploid mutant and a triploid interspecific hybrid. We hypothesized that clonal origin had an effect on light acclimation. We studied growth, morphological (frond size and shape, mass-to-area ratio), and photosynthetic (pigment composition, chlorophyll fluorescence induction) traits of these clones to test whether light acclimation was a conserved process or whether clone-specific strategies could be found. We also analyzed frond-level photosynthetic adjustment during ontogenesis to track how light acclimation evolved in developing fronds. Our results confirmed that even clones of the same duckweed species and a hybrid of closely related species followed partially different strategies in acclimation to ambient conditions. This acclimation involved various morphological, physiological, and biochemical adjustments but happened in a very short time window at the early life stage when young, still-developing fronds could flexibly achieve an optimized phenotype. In addition to explaining the worldwide success of duckweeds in colonizing very contrasting habitats, our results also highlight the importance of approaching duckweed responses at the frond level, where the actual acclimation takes place. Full article

Amberboa moschata (L.) DC. (Asteraceae) is an endangered species, listed in the Red Book of Plants of the Republic of Armenia. The restricted extent of occurrence and habitat degradation necessitate conservation measures of this species, not only in the wild but also through ex situ cultivation. This study examines the comprehensive morpho-phenological, karyological, palynological, eco-physiological, and ornamental characteristics of A. moschata in the context of ex situ conservation. A. moschata plants cultivated ex situ demonstrated high adaptive traits, undergoing a full development cycle and experiencing less water stress compared to wild populations. The diploid cytotype has been found for the species to be 2n = 32, the karyotype is asymmetric, with chromosomes, 0.77–1.91 µm in size. The average pollen fertility of A. moschata is high, 96.7–96.9% in both natural and cultivated samples. A scale of decorativeness was developed, which includes 15 characteristics of the plant, providing an objective means to assess its visual appeal. The scale can be useful for integrating A. moschata into various landscaping schemes. Under cultivation, the total ornamental period lasts approximately 98 days, with the peak ornamental effect observed during the flowering phase, which spans 68–70 days. The study recommends A. moschata for inclusion in living collections in botanical gardens and for use in ornamental gardening and landscaping as part of its ex situ conservation strategy. A map, original photographs, and tables illustrate the article. Full article

The chromosome numbers of 56 populations belonging to 25 species and 4 varieties of Artemisia L. (Asteraceae) from China were examined, and those of 13 species and four varieties are reported here for the first time. The karyotypes of 39 populations in 23 species and four varieties were also studied. Among them, twelve species and one variety were found to be diploid, with 2n = 16 or 18; nine species and three varieties were found to be tetraploid, with 2n = 32 or 36; and two species were found to have both diploid and tetraploid cytotypes. Two species were found to have aneuploid cytotypes. The karyotypes of Artemisia are similar, with most chromosomes belonging to median-centromeric (m) and a few belonging to submedian-centromeric (sm) or subterminal-centromeric (st). The high level of polyploids in Artemisia from the Qinghai–Tibetan Plateau indicates that polyploidy has played an important role in the evolutionary speciation of this highly diversified genus in this region. Full article

Polyploidy is often associated with the ability to grow under harsh conditions. The objective of this study was to test whether genome doubling in Acacia senegal confers superiority for growth under saline conditions. For this purpose, we assessed the cytotype distribution across ten natural stands in Senegal, representing different soil salinities. We further compared the growth of diploid and tetraploid A. senegal seedlings in a shared-pot greenhouse experiment, in which seedling pairs (diploids and polyploids) were irrigated with and without added NaCl. We found polyploids in six stands, and the proportion of polyploids in these stands was significantly and positively correlated with their level of soil salinity. Under experimental conditions, we found that the growth rate of diploid and tetraploid seedlings was equally depressed by salt stress, but the mortality rate for tetraploids was lower than that for diploids (34% versus 54%). In addition, the root-top ratio was higher in tetraploids compared to diploids, which may influence fitness under harsh conditions. Overall, this study provides support for polyploid superiority in A. senegal growing in saline soils. The findings of this study may have practical implications for the reforestation of saline soils with polyploid A. senegal, and we recommend further studies to elucidate their potential. Full article

Background/Objectives: Paspalum notatum is a key multipurpose species native to American grasslands. This study provides, for the first time, a detailed karyotype analysis of diploid (2n = 2x = 20) and tetraploid (2n = 4x = 40) accessions of P. notatum, the most common cytotypes within the species. Methods: The constitutive heterochromatin patterns revealed using CMA-DA-DAPI staining and genome size estimations are novel contributions to the understanding of the N genome in Paspalum. Results: Chromosomes were small (1.1–2.3 µm), with the diploid karyotype comprising nine metacentric pairs (one bearing microsatellites on the short arms, pair 6) and one submetacentric pair. In tetraploids, the diploid karyotype was duplicated. Heterochromatin analysis revealed two CMA⁺⁺/DAPI⁻ bands located on the short arm and satellite of chromosome 6 in diploids, while tetraploids exhibited two to three CMA⁺⁺/DAPI⁻ and one to two CMA⁺⁺/DAPI⁰ bands. The proportion of GC-rich heterochromatin represented 2.8 and 3.47% of the total chromosome length in diploid and tetraploid cytotypes, respectively. Genome size analysis revealed a reduction in monoploid genome size in tetraploids (1Cx = 0.678 pg) compared to diploids (1Cx = 0.71 pg), consistent with the autopolyploid origin hypothesis. Conclusions: These findings provide essential cytogenetic insights and suggest only minor structural changes in the N genome following polyploidization, which could guide future studies integrating genomic and cytogenetic maps of P. notatum. Full article

Polyploidy is a powerful mechanism driving genetic, physiological, and phenotypic changes among cytotypes of the same species across both large and small geographic scales. These changes can significantly shape population structure and increase the evolutionary and adaptation potential of cytotypes. Alyssum moellendorfianum, an edaphic steno-endemic species with a narrow distribution in the Balkan Peninsula, serves as an intriguing case study. We conducted a comprehensive analysis of genetic diversity and population structure across the species’ range, employing an array of genetic techniques (nuclear microsatellites, amplified fragment length polymorphisms, and plastid DNA sequences), flow cytometry (FCM), morphometry, and pollen analysis. The study reveals two genetic lineages: spatially distributed diploid and tetraploid cytotypes. Clear divergence between diploids and tetraploids was shown by AFLP, while plastid DNA sequences confirmed private haplotypes in each of the studied populations. Higher genetic diversity and allelic richness following the north-south pattern were documented in tetraploids compared to diploids, as indicated by nuclear microsatellites. Morphometric analysis via principal component analysis (PCA) and canonical discriminant analysis (CDA) did not reveal any divergence between diploid and tetraploid cytotypes. Nonetheless, a distinction in pollen size was clearly observed. The results suggest an autopolyploid origin of tetraploids from diploid ancestors. Despite the population fragmentation in a very small geographic range, these populations harbour high genetic diversity, which would allow them to remain stable if natural processes remain undisturbed. Full article

A new hexaploid cytotype of Aegilops crassa has been identified in Türkiye. To assess the ploidy levels of native populations, 50 samples from Adıyaman, Batman, Bitlis, Diyarbakır, Hakkari, Mardin, Siirt, Şanlıurfa, Şırnak, and Van were analyzed using flow cytometry and cytogenetic techniques. DNA content was determined by comparison with standard plants. Results confirmed two cytotypes in Türkiye: tetraploid populations from Batman, Bitlis, Diyarbakır, Hakkari, Mardin, Siirt, Şanlıurfa, and Şırnak, and hexaploid accessions from Adıyaman and Van. Ten metaphase plates were analyzed. The tetraploid cytotype exhibited chromosome lengths of 8.95 ± 0.27 to 13.96 ± 0.13 µm, a total genome length of 165.51 ± 0.34 µm, and nuclear DNA content of 18.53 ± 0.29 to 20.37 ± 0.49 pg. Most chromosomes were metacentric, except for chromosomes 7, 8, 10, and 12, which were submetacentric. Two satellite pairs were found on chromosomes 4 and 10. The hexaploid cytotype showed chromosome lengths of 8.90 ± 0.16 to 14.06 ± 0.06 µm, a total genome length of 230.47 ± 0.23 µm, and nuclear DNA content of 33.40 ± 0.52 to 35.01 ± 0.31 pg. Most chromosomes were also metacentric, with three satellite pairs on chromosomes 3, 6, and 10. In conclusion, both tetraploid (2n = 2x = 28) and hexaploid (2n = 6x = 42) cytotypes of Ae. crassa exist in Türkiye, with the hexaploid cytotype having potential for wheat breeding programs. Full article

Previous studies on the mountain plant Ranunculus kuepferi concluded that apomictic self-compatible tetraploids have experienced a niche shift toward a colder climate during the Holocene, which suggests a fitness advantage over the sexual, self-sterile diploid parents under cold and stressful high-mountain conditions. However, there is still a lack of information on whether reproductive development would be advantageous for tetraploids. Here, we report on microsporogenesis, megagametogenesis, the dynamics of flower and seed development, and the consequences for reproductive success in a common garden experiment along a 1000 m climatic elevation gradient and in natural populations. Flower buds were initiated in the year preceding anthesis and passed winter in a pre-meiotic stage. Flower morphology differed in the known cytotype-specific way in that tetraploid flowers produced about twice as many carpels and fewer petals, stamens, and pollen grains than diploid flowers. Tetraploids developed precociously aposporous embryo sacs and showed a high rate of developmental disturbances. Sexual seed formation prevailed in diploids and pseudogamous apomixis in tetraploids. Along the elevation gradient, stigma pollen load, pollen performance, and seed output decreased. Combinations of reproductive traits, namely, bypass of meiosis irregularities and uniparental reproduction, might have promoted the vast expansion of apomictic R. kuepferi lines across the European Alps. Full article

Leaf functional traits reflect species’ adaptive strategies and habitat requirements. Examining intra-specific variations and their underlying drivers can aid in comprehending species differentiation and adaptation. Here, we investigated the leaf functional traits of Buddleja macrostachya tetraploids and octaploids across 18 sites in the Sino-Himalayan region. The habitat environmental variables were also recorded. In this study, leaf functional traits showed a considerable differentiation in both tetraploid and octaploid B. macrostachya. Redundancy analysis (RDA) revealed that the octaploid cytotypes displayed higher specific leaf area, leaf total nitrogen and phosphorus concentrations, water-use efficiency, and light-use efficiency in contrast to the tetraploid plants. These functional leaf traits exhibited different plasticity levels in both taxa. A positive link was found between habitat altitude and soil total P concentration and the geographic distribution of the B. macrostachya complex, using RDA and Pearson’s correlation. Our findings suggest that both tetraploid and octaploid B. macrostachya exhibited divergent ecological strategies, conservative and acquisitive strategies, respectively. The ecological adaptability of species within the B. macrostachya complex is enhanced by the combination of divergent ecological strategies and high phenotypic plasticity of distinct key ecological traits. Furthermore, abiotic environmental factors influenced the allopatric geographic distribution pattern of the B. macrostachya complex in the Sino-Himalayan region. Full article

Previous reports on the benefits of using local therapy with azelastine in rhinitis focus on the assessment of clinical symptoms and the analysis of nasal lavage for the presence of inflammatory cells and the expression of adhesion molecules. Little attention has been paid to studies assessing the effect of azelastine on individual cytotypes of the nasal mucosa, especially epithelial cells, also in the context of inducing morphological changes. The aim of this study was the cytological analysis of swabs taken from the surface of the nasal mucosa of patients with allergic rhinitis (AR) and nonallergic/vasomotor rhinitis (NAR/VMR) who were subjected to 4 weeks of therapy with azelastine and then comparing the obtained results with the pre-treatment condition. The technique of obtaining materials for cytoanalysis included sampling, staining of smears, microscopic analysis, and preparation of cytograms. Our studies confirmed the therapeutic benefits of azelastine in both study groups. Significant changes were demonstrated, confirming the regeneration of ciliated cells and the induction of autophagy and apoptosis in epithelial cells. Such changes indicate new mechanisms of action of azelastine, which play a significant role in restoring homeostasis in the nasal mucosa. The presented research also results in a detailed description of cytological changes in both studied rhinitis types, which complements the knowledge regarding prognostic indicators. Full article

The cultivation of mango in Mediterranean-type climates is challenged by the depletion of freshwater. Polyploids are alternative genotypes with potential greater water use efficiency, but field evaluations of the anatomy and physiology of conspecific adult polyploid trees under water stress remain poorly explored. We combined field anatomical evaluations with measurements of leaf water potential (Ψ_l) and stomatal conductance (G_s) comparing one diploid and one autotetraploid tree per treatment with and without irrigation during dry summers (when fruits develop). Autotetraploid leaves displayed lower Ψ_l and G_s in both treatments, but the lack of irrigation only affected G_s. Foliar cells of the adaxial epidermis and the spongy mesophyll contained linear pectin epitopes, whereas branched pectins were localized in the abaxial epidermis, the chloroplast membrane, and the sieve tube elements of the phloem. Cell and fruit organ size was larger in autotetraploid than in diploid mango trees, but the sugar content in the fruits was similar between both cytotypes. Specific cell wall hygroscopic pectins correlate with more stable Ψ_l of autotetraploid leaves under soil water shortage, keeping lower G_s compared with diploids. These preliminary results point to diploids as more susceptible to water deficits than tetraploids. Full article

Moroccan populations of Alnus glutinosa (L.) Gaerth. (Betulaceae) are found at the southern limit of the species’ range and are represented by tetraploid cytotypes with no available pollen data. The objective of this study was to assess the morphological and morphometric variability of the pollen, specifically focusing on pollen diameters and the number of apertures. To achieve this, we sampled 11 populations that are representative of the Moroccan distribution area of this species. We employed a hierarchical sampling design (11 populations, 10 trees per population, and from 30 to 300 pollen grains per tree, depending on the character measured) to examine different levels of variability: interpopulation, intrapopulation, and intraindividual. The results demonstrate that there is no discernible difference in the morphology or size of the pollen among the Moroccan tetraploid populations. However, we observed a high degree of intraspecific variability in pollen morphometric traits, but most of this variability is associated with the intraindividual level. Full article

Green prickly ash (Zanthoxylum armatum) has edible and medicinal value and is an economically significant plant in many countries. Z. armatum has many cultivars and varieties with similar phenotypes that are difficult to distinguish via traditional methods. In this study, we utilized oligo-FISH to distinguish five varieties and cultivars of Z. armatum on the basis of three oligonucleotide probes of 5S rDNA, (AG₃T₃)₃, and (GAA)₆. Karyotype analysis of the five varieties and cultivars of Z. armatum showed that the Z. armatum ‘Tengjiao’ karyotype formula was 2n = 2x = 98m with karyotype type 1C and an arm ratio of 4.3237, including two pairs of 5S rDNA signals and five pairs of (GAA)₆ signals. The karyotype formula of Z. armatum ‘Youkangtengjiao’ was 2n = 2x = 128m + 8sm with karyotype type 2B and an arm ratio of 3.5336, including three pairs of 5S rDNA signals and 17 pairs of (GAA)₆ signals. The karyotype formula of Z. armatum var. novemfolius was 2n = 2x = 134m + 2sm with karyotype type 1C and an arm ratio of 5.5224, including two pairs of 5S rDNA signals and eight pairs of (GAA)₆ signals. The karyotype formula of Z. armatum ‘YT-03’ was 2n = 2x = 2M + 128m + 4sm + 2st with karyotype type 2C and an arm ratio of 4.1829, including three pairs of 5S rDNA signals and nine pairs of (GAA)₆ signals. The karyotype formula of Z. armatum ‘YT-06’ was 2n = 2x = 126m + 10sm with cytotype 2B and an arm ratio of 3.3011, including three pairs of 5S rDNA signals and two pairs of (GAA)₆ signals. The five varieties and cultivars of Z. armatum had (AG₃T₃)₃ signals on all chromosomes. The chromosomal symmetry of Z. armatum ‘Tengjiao’ was high, whereas the chromosomal symmetry of Z. armatum 'YT-03' was low, with the karyotypes of the five materials showing a trend toward polyploid evolution. The phylogenetic relationship between Z. armatum ‘Tengjiao’ and Z. armatum var. novemfolius was the closest, while that between Z. armatum ‘YT-03’ and Z. armatum ‘YT-06’ was closer than with Z. armatum ‘Youkangtengjiao’ according to oligo-FISH. The results provided a karyotype profile and a physical map that contributes to the distinction of varieties and cultivars of Z. armatum and provides strategies for distinguishing other cultivated species. Full article