Cymbopogon olivieri is one of the important species belonging to the family Poaceae. The natural habitat of this plant is tropical regions. In particular, it is distributed in tropical and ...subtropical regions of Africa, Asia, and America. Two species, C. olivieri and C. parkeri have been reported in Iran. The genus has been proven to possess antioxidant, antimicrobial, and antibacterial properties. Taxonomic identification and species classifying of Lemongrass is very difficult due to the ease of cross-breeding and the existence of a large number of species and races. This study aimed to study variations and clustering of 10 Iranian endemic populations of C. olivieri (Boiss.) Bor based on chromosomal and holoploid genome size features. The results of karyotype analysis clearly showed the mixed-ploidy. Among which, six populations were diploids (2n=2x=20), three tetraploids (2n=4x=40), and a hexaploid (2n=6x=60). The mean chromosome length (CL) was determined as 1.87 µm for diploids, 1.73 µm for tetraploids, and 1.25 µm for a hexaploid. The average holoploid genome sizes of the diploids, tetraploids, and a hexaploid were 4.42, 4.64, and 4.91 pg, respectively. These results may provide relevant information for Cymbopogon breeding studies.
Plant polyploidy often occurs along with higher yield and superior quality. Therefore, obtaining polyploid germplasms is a significant part of breeding. The oil-tea Camellia tree, an important native ...woody plant that produces high-quality edible oil, includes many species of Camellia with different ploidies. However, whether higher ploidy levels in oil-tea Camellia trees are related to better traits remains unclear. In this study, the ploidy levels of 30 different oil-tea Camellia strains in 3 different species in the sect. Paracamellia were determined by flow cytometry and chromosome preparation, and the phenotypic characteristics and fatty acid composition of the fruits were examined by field observations and laboratory analyses. The correlations between the ploidy level of oil-tea Camellia and the main traits of the fruit were investigated . Our results showed that 10 Camellia lanceoleosa strains were diploid, 10 Camellia meiocarpa strains were tetraploid and 10 Camellia oleifera strains were hexaploid. Hexaploid C. oleifera had larger fruit size and weight, more seeds per fruit, larger seed weight per fruit, higher oil contents and larger yield per crown width than tetraploid C. meiocarpa and diploid C. lanceoleosa, but their fruit peel thickness and fresh seed rate were significantly lower, and these traits were significantly correlated with ploidy. In addition, in terms of fatty acid composition, hexaploid C. oleifera had a higher oleic acid content than tetraploid C. meiocarpa and diploid C. lanceoleosa, but their linoleic acid, linolenic acid and arachidonic acid contents were lower. The contents of palmitic acid, stearic acid and total unsaturated fatty acids were not significantly correlated with ploidy level. In conclusion, there were certain correlations between the main characteristics of oil-tea Camellia fruit and the ploidy level, and increasing ploidy level led to an increase in fruit yield, with no effect on oil composition. The discovery of the variation in the main characteristics of oil-tea Camellia fruit with different ploidies will facilitate germplasm innovation and lay a foundation for ploidy breeding and mechanistic research on fruit traits.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The genus Ilex (Aquifoliaceae) has several species appreciated by their ornamental value and nutraceutical and medicinal properties. Southern South America is a major center of biodiversity, with ca. ...13-15 species. However, they have been scarcely studied, particularly regarding cytogenetics. For instance, chromosome numbers have been solely documented in eight species, while the DNA content (genome size or 2C-value) has been recorded just for three species. To contribute to the characterization of Ilex species from southern South America, here we established the genome size of I. brasiliensis, I. brevicuspis, I. integerrima, I. microdonta, I. pseudobuxus, I. taubertiana and I. theezans as novel data, and verified the DNA content for I. argentina, I. dumosa and I. paraguariensis. Our results indicate that the mean DNA content at the interspecific level ranges between 1.691 pg, as in I. pseudobuxus and 3.600 pg as in I. theezans. Yet, an individual of I. theezans from Paraguay showed about half the genome size. These unexpected outcomes for I. theezans lead us to propose the coexistence of diploid and polyploid cytotypes for this species. I. brasiliensis was determined to have 2n=40 chromosomes and regular meiosis, for the first time. In sum, this work is a contribution to the knowledge of an understudied plant family. Gaining insight on genetic biodiversity is relevant for the potential use of non-industrialized species for the improvement of economically significant ones.
El género Ilex (Aquifoliaceae) posee especies muy apreciadas por su valor ornamental y sus propiedades nutracéuticas y medicinales. El sur de Sudamérica es un importante centro de diversificación, con ca. 13-15 especies registradas. Sin embargo, estas han sido escasamente estudiadas, particularmente en lo que respecta a la citogenética. Por ejemplo, el número de cromosomas se ha documentado únicamente en ocho especies, mientras que el contenido de ADN (tamaño del genoma o valor 2C) se ha reportado solo en tres especies. Para contribuir a la caracterización de las especies de Ilex del sur de Sudamérica, en el presente estudio se determinó el tamaño del genoma de I. brasiliensis, I. brevicuspis, I. integerrima, I. microdonta, I. pseudobuxus, I. taubertiana e I. theezans, siendo estos datos novedosos, y se verificó el valor 2C para I. argentina, I. dumosa e I. paraguariensis. Nuestros resultados indican que el contenido promedio de ADN a nivel interespecífico oscila entre 1,691 pg, como en I. pseudobuxus, y 3,600 pg como en I. theezans. Sin embargo, para un individuo de I. theezans de Paraguay se obtuvo un valor 2C de aproximadamente la mitad. Estos resultados inesperados para I. theezans nos llevan a proponer la coexistencia de citotipos diploides y poliploides en esta especie. Además, se determinó por primera vez el número cromosómico de I. brasiliensis (2n=40) y se observó que la meiosis es regular. En suma, este trabajo contribuye al conocimiento de una familia de plantas poco estudiada. Conocer la biodiversidad genética en Ilex es básico para el potencial uso de las especies no industrializadas en el mejoramiento de las de importancia económica.
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BFBNIB, NMLJ, NUK, PNG, SAZU, UL, UM, UPUK
The parentage of the Potamogeton hybrids P. ×nomotoensis Kadono & T. Noguchi and P. ×yamaga- taensis Kadono & Wiegleb (Potamogetonaceae) was studied by analyzing the plastid-encoded rbcL gene and ...nuclear-encoded internal transcribed spacer (ITS) from the hybrids and putative parents. The results showed P. ×nomotoensis to be a hybrid between P. natans and P. maackianus and P. ×yamagataensis a hybrid between P. natans and P. oxyphyllus. The latter is the first documentation of a hybrid between diploid and tetraploid species in Japan.
•Cr-toxicity inhibited the growth and physio-biochemcial attributes in citrus.•Ploidy level of rootstock had significant impact on Cr-tolerance in Kinnow mandarin.•High Cr-tolerance of 4x plants to ...Cr-toxicity is highly associated with Cr-accumulation in leaves.•Plants with tetraploid rootstocks had more Cr concentration in their roots than leaves.
This study compared the effects of chromium toxicity on the biomass, photosynthesis, antioxidants, reactive oxygen species, and nutrient concentration in Kinnow mandarin (Citrus nobilis Lour x Citrus deliciosa Ten) plants grafted on diploids (2x) and tetraploids (4x) of Poncirus trifoliata L., Citrus reshni, and Citrus limonia Osbeck. Plants were grown under controlled conditions and irrigated with complete nutrient solution supplemented with chromium (0.75mM). After 120-d of growth under chromium stress, plant biomass, total chlorophyll concentrations, photosynthetic activity, stomatal conductance, transpiration rate, water use efficiency, H2O2 concentrations, rate of O2− generation, lipid peroxidation, antioxidant activities (superoxide dismutase, peroxidase, catalase) and mineral nutrient concentration (Ca, Mg, K, P and Cr) were determined. Chromium inhibited plant growth, and decreased chlorophyll concentration, photosynthetic activity, stomatal conductance, transpiration rate, water use efficiency, and activities of antioxidant enzymes, but the rate of lipid peroxidation and formation of reactive oxygen species were increased. Chromium stress also caused alterations in nutrients concentration in roots and leaves. Nevertheless, it was observed that Kinnow mandarin plants grafted on the tetraploid rootstocks showed high tolerance to chromium toxicity as reported by maintaining greater biomass accumulation and less reduction in the attributes commented before. In addition, plants with 4x rootstocks had higher Ca, Mg, K and P concentration in their roots and leaves in comparison to 2x rootstocks. Plants grafted on 4x rootstock presented higher quantity of chromium in roots than leaves, suggesting that the chromium tolerance of plants with tetraploid rootstocks may be attributed to chromium sequestration to roots with lower transfer to leaves; consequently avoiding oxidative damage to green pigments and the photosynthetic apparatus.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
The present research investigated induction of triploidy using a cold temperature shock in pikeperch, Sander lucioperca L. In this study, a cold shock treatment by immersing eggs in an ice-water bath ...(1.0–1.1 °C) at 5, 7, 10, 15, and 20 min post-activation at fertilization (PA) for 20, 40, 60, 90, and 120 min was applied. Three out of 25 tested combinations of initiation time and shock duration resulted in 100% triploidy: initiation at 5 min PA for 90 and 120 min and at 7 min PA for 120 min. Shock treatments initiated at 20 min PA resulted in all- diploid larvae. The control treatment showed hatching rate of 66.2%, without any triploid production and 2.7% malformed larvae. Cold shock initiated at 5 min PA for 120 min resulting in 100% triploidy and a hatching rate of 20.2%, malformed larvae accounted for 5.5% of larvae was considered as the most effective treatment for inducing 100% triploidy in pikeperch.
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•Cold shock treatment can induce triploidy in pikeperch.•Cold shock initiated at 5 min post-activation for 120 min was considered as the most effective combination for producing 100% triploidy in pikeperch.•No shock treatment initiated at 20 min post-activation affected ploidy.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The Greater Cape Floristic Region is one of the world's biodiversity hotspots and is considered poor in polyploids. To test this assumption, ploidy variation was investigated in a widespread Cape ...shrub, Dicerothamnus rhinocerotis (renosterbos, Asteraceae). The aim was to elucidate the cytotype distribution and population composition across the species range, and to assess differences in morphology, environmental niches and genetics.
Ploidy level and genome size were determined via flow cytometry and cytotype assignment was confirmed by chromosome counting. Restriction site-associated DNA sequencing (RADseq) analyses were used to infer genetic relationships. Cytotype climatic and environmental niches were compared using a range of environmental layers and a soil model, while morphological differences were examined using multivariate methods.
The survey of 171 populations and 2370 individuals showed that the species comprises diploid and tetraploid cytotypes, no intermediates and only 16.8 % of mixed populations. Mean 2C values were 1.80-2.06 pg for diploids and 3.48-3.80 pg for tetraploids, with very similar monoploid genome sizes. Intra-cytotype variation showed a significant positive correlation with altitude and longitude in both cytotypes and with latitude in diploids. Although niches of both cytotypes were highly equivalent and similar, their optima and breadth were shifted due to differences mainly in isothermality and available water capacity. Morphometric analyses showed significant differences in the leaves and corolla traits, the number of florets per capitulum, and cypsela dimensions between the two cytotypes. Genetic analyses revealed four groups, three of them including both cytotypes.
Dicerothamnus rhinocerotis includes two distinct cytotypes that are genetically similar. While tetraploids arise several times independently within different genetic groups, morphological and ecological differences are evident between cytotypes. Our results open up new avenues for questions regarding the importance of ploidy in the megadiverse Cape flora, and exemplify the need for population-based studies focused on ploidy variation.
Ferns are indicated could become polyploid organism due to altitude effect. In this research, the distribution of ploidy level on AdiantumdiaphanumBlume based on difference altitude was studied. This ...study was a survey research conducted in Probolinggo Regency which aims studying the effect of altitude on ploidy level in A. diaphanumBlume. Leces (50 masl), Lumbang (460 masl), and Sukapura (820 masl) were the tree research sampling areas that represent low, medium, and highland location, respectively. The determination of ploidy level was conducted by counting the chromosome number of cells root tips. The results showed that all ferns found in the medium and lowland were diploid organisms, whereas all ferns found in the highlands were triploid organism.
•Cerasus pseudocerasus including wild and cultivated populations were mainly tetraploid by root tips from both seedlings and softwood cutting, revealing this species evolved at the tetraploid ...level.•All Chinese cherries had karyotypes of “2B” type.•Four Cerasus relative species, C. avium, C. campanulata, C. serrulata var. lannesiana, and C. tomentosa were all diploid.•Based on the karyotype formula and characterization, we indicated that C. pseudocerasus showed close relationship with C. serrulata var. lannesiana rather than C. avium.
Chinese cherry Cerasus pseudocerasus (Lindl.) G. Don is a fruit tree species within the family Rosaceae, with high economic and ornamental values. To verify the ploidy level of this species and compare the karyotypes with relative species, the chromosome number and karyotype characterization of representative wild and cultivated Chinese cherry samples from sixteen natural populations in four Provinces in China, and four Cerasus relative species were investigated. No aneuploids were found in all samples studied and no diploids or triploids were observed among Chinese cherry by root tips from both seedlings and softwood cutting. The chromosomes were quite small in size and mainly composed by median-centromere (m) and submedian-centromere (sm) chromosomes. Fourteen wild and cultivated Chinese cherry samples were all tetraploid with main karyotype formula of 2n = 4x = 32 = 28m + 4sm, samples from Yingjing County as 2n = 5x = 40 and Fengxian County as 2n = 6x = 48, respectively. The ratio between the longest and shortest chromosome ranged from 2.05 to 2.32. All sixteen Chinese cherry samples had karyotypes of “2B” type. Cerasus avium (L.) Moench, C. campanulata (Maxim.) Yü et Li, C. serrulata G. Don var. lannesiana (Carr.), and C. tomentosa (Thunb.) Wall. were all diploid with 2n = 2x = 16, whose karyotypes were “2A”, “1A”, “2B”, and “1B” type, respectively. By comparison of the karyotype formula and characterization, we indicated that C. pseudocerasus showed close relationship with C. serrulata var. lannesiana rather than C. avium. The present study provided powerful important references for the confirmed ploidy level and the possible genome composition of C. pseudocerasus.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Bletilla is an Orchidaceae genus with high medical value, including detumescence, antibacterial, and hemostasis. In this study, detailed estimates of ploidy level, karyotype, and genome size were ...first obtained, and a comprehensive cytological analysis was carried out to better understand the evolution of the genus. The karyotypes of Bletilla were mainly composed of metacentric and submetacentric chromosomes with lengths ranging from 1.25 to 4.93 μm. There was moderate cytological variation in Bletilla (chromosome number 2n = 32 to 76). Diploid with 2n = 34 and 2n = 36 was detected in Bletilla ochracea and Bletilla formosana, respectively, whereas diploid (2n = 32) was dominant in Bletilla striata , dysploidy (2n = 34, 2n = 36) and polyploid (2n = 48, 51, 64, 76) variations were also observed. Three species had a relatively symmetric karyotype, and which of B. ochracea was more asymmetry. The genome size (1C-values) varied from 2.94 pg ( B. striata ) to 3.33 pg ( B. ochracea ), of which B. ochracea was significantly larger than the others ( P < 0.05). A positive correlation ( P < 0.01) between 1C x vs. haploid chromosome length (HCL) and asymmetry coefficient of karyotypes (AsK%) was observed.
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