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Polyploids exhibit significant breeding value because of their better vegetative yields, higher agronomic characteristics, and greater tolerance to stress. The present study reports the effective in vitro induction of tetraploidy in ginger (Zingiber officinale Rosc.) cv. Himgiri using different concentrations of colchicine (0.1%, 0.2%, 0.3%, and 0.4%) for different durations (6 to 48 h). The 0.1% colchicine treatment for 6 h had the best outcomes, with a maximum bud survival percentage of 73.33%, which decreased with the increase in colchicine concentration and treatment periods. Shoots regenerated from buds treated with 0.2% colchicine for 24 h showed good multiplication and elongation. The lethal time (LT50) values declined as colchicine concentration increased, emphasizing its influence on the survival of treated buds over time. The maximum induction of polyploidy (50%) was achieved with 0.2% colchicine treatment for 6 and 24 h, whereas no polyploidy was induced with 0.4% colchicine treatment, which was reported to be lethal to the cells. After repeated subculturing, flow cytometric investigation indicated varied ploidy levels in regenerated shoots, with stable tetraploids. The morphological features, physiological characteristics, and biochemical compositions were evaluated, and substantial increases in plant height, leaf dimensions, tiller numbers, photosynthetic rates, and oleoresin content were observed. HPLC analysis depicted maximum gingerol content (498.36 µg g−1) in harvested rhizomes of tetraploid induced with 0.2% colchicine treatment for 24 h. Molecular analysis employing SCoT and CBDP revealed significant genomic alteration with polymorphism of 1.087% and 35.67%, respectively. The stable tetraploids developed in the present study will provide excellent resources for future ginger production and genetic improvement. [ABSTRACT FROM AUTHOR]

Summary: The strawberry genus, Fragaria, exhibits a wide range of sexual systems and natural ploidy variation. Nearly, all polyploid strawberry species exhibit separate sexes (dioecy). Research has identified the sex‐determining sequences as roughly conserved but with repeatedly changed genomic locations across octoploid strawberries. However, it remains unclear whether tetraploid wild strawberries evolved dioecy independently or shared a common origin with octoploid strawberries. In this study, we investigated the sex determinants of F. moupinensis, a dioecious plant with heterogametic females (ZW). Utilizing a combination of haplotype‐resolved genome sequencing of the female F. moupinensis, k‐mer‐based and coverage‐based genome‐wide association studies (GWAS), and transcriptomic analysis, we discovered a non‐recombining, approximately 33.6 kb W‐specific region on chromosome 2a. Within this region, only one candidate sex‐determining gene (FmoAFT) was identified. Furthermore, an extensive resequencing of the entire Fragaria genus indicated that the W‐specific region displays conservative female specificity across all tetraploid species. This observation suggests that dioecy evolved independently in tetraploid and octoploid strawberries. Moreover, employing virus‐induced gene silencing (VIGS), we knocked down the expression of the FmoAFT homologue transcript in cultivated strawberries, revealing its potential role in promoting female functions during early carpel development. We also applied DNA affinity purification sequencing (DAP‐seq) and yeast one‐hybrid assays to identify potential direct targets of FmoAFT. These insights shed new light on the genetic basis and evolutionary history of sex determination in strawberries, thereby facilitating the formulation of strategies to manipulate sex determination in breeding programs. [ABSTRACT FROM AUTHOR]

Cannabis (Cannabis sativa) grown for flowers containing cannabinoids requires all female plants, which are susceptible to seed set from exposure to pollen. Created triploids demonstrated reduced seed production compared with diploids in field and greenhouse studies in which plants were challenged with pollen from males. In the field, seed production as a percent of floral biomass ranged from 6.7% to 18.0% for triploids and from 52.6% to 57.1% for diploids. The photoperiod-insensitive triploid genotype ‘Purple Star’ × ‘Wilhelmina’ had 98.5% fewer filled (containing a developed embryo) seeds than the photoperiod-insensitive diploid genotype ‘Tsunami’ × ‘Wilhelmina’. In the greenhouse, triploid ‘Wife’ had 99.5% fewer filled seeds than diploid ‘Wife’. Plant growth and flower production were similar with eight triploid and seven diploid genotypes evaluated over three greenhouse studies. There were a few superior triploid and diploid genotypes; however, their performance was more likely attributable to the parental cultivar combination than ploidy level. The optimal cross direction for producing triploid seed in large quantities is tetraploid × diploid because the diploid × tetraploid cross exhibits triploid block caused by endosperm paternal excess. Colchicine-induced tetraploid parent plants should be tested over a prolonged period to eliminate cryptic chimeral mixoploids or tetraploid plants should be derived from seed produced by crossing two colchicine-induced putative tetraploid plants to ensure that seeds from tetraploid × diploid crosses will be triploid. The latter approach is necessary for photoperiod-insensitive cultivars because a prolonged period of ploidy testing is not possible for these plants. These findings indicate that triploid plants have significantly reduced fertility and are a suitable alternative to diploids in situations in which pollen exposure is possible.

Somatic hybridization has emerged as a valuable tool for developing novel genetic combinations in citrus breeding programs, including the creation of salt-tolerant rootstocks. In this study, the performance of a tetraploid somatic hybrid, obtained by fusing protoplasts derived from salt-tolerant Cleopatra mandarin (Citrus reshni hort. ex Tanaka) and salt-sensitive Carrizo citrange (Citrus sinensis L. Osbeck × Poncirus trifoliata L. Raf), was assessed under in vitro salt stress. Hybrid plants were characterized by leaf morphology, and ploidy level by flow cytometry and molecular markers. In vitro shoots were generated from the micropropagation of mature stem pieces of the somatic hybrid and its parents, and these were challenged by exposure to NaCl (0, 50, or 100 mM) supplemented to the media for three weeks to induce salt stress. The leaves of the somatic hybrid display intermediate morphology compared to the parental Cleopatra mandarin and Carrizo citrange rootstocks. All molecular markers successfully amplified DNA from the three cultivars; however, only 11 of 14 unequivocally confirmed somatic hybridity. The physiological and biochemical parameters, including chlorophyll content, lipid peroxidation, total phenolic compounds, antioxidants activity and proline content, were measured in the leaves. The somatic hybrid exhibited superior salt stress tolerance compared to the parent varieties, as evidenced by the reduced cellular membrane damage indicated by the lower levels of malondialdehyde and electrolyte leakage, particularly under 100 mM NaCl treatment. The somatic tetraploid hybrid also displayed higher total phenolic content than either parent, while Cleopatra mandarin exhibited the highest proline levels under 50 mm NaCl. These results demonstrate the enhanced salinity stress tolerance of the somatic hybrid compared to its parent lines, highlighting its potential as a valuable candidate for developing salt-tolerant citrus rootstocks. [ABSTRACT FROM AUTHOR]

Obtaining citrus polyploids, especially from triploid individuals, is of great importance for genetic improvement programs, as they produce seedless fruits. Therefore, the aim of this study was to use flow cytometry analyses to identify polyploid individuals among tangerine-type seedlings originating from seeds germinated in vitro. Fruits were collected from 13 different genotypes in the municipality of Mucugê (state of Bahia, Brazil). The seeds were then removed and classified as developed (seeds with well-formed integument), underdeveloped (seeds with wrinkled integument) and small (seeds of 1/3 to 1/6 of normal size). After the integument was removed, the seeds were disinfected and introduced into a WPM culture medium, in which they remained for 120 days. After this period, the percentage of germinated seeds and growth variables were evaluated, and ploidy analysis was conducted using flow cytometry. The developed seeds displayed a higher germination rate (91.5%) than the others. The small and underdeveloped seeds resulted in a considerable frequency of spontaneous polyploids (11%), and one haploid plant was also obtained from the latter class. Key message: The ploidy of 13 citrus genotypes was investigated using flow cytometry. In addition to polyploid plants that are of interest to breeding programs, there was the identification of a haploid plant. [ABSTRACT FROM AUTHOR]

The highly variable tufted hairgrass Deschampsia cespitosa is a tussock-forming plant especially of cool and humid environments. Although common and widespread, its phylogeographic structure and the significance of polyploidy for its evolution are poorly understood. Here we used a phylogenomic approach to study the genetic structure of this species in Europe and how the polyploid cytotypes/subspecies are related to the diploids. Using genomic data (RADseq and whole plastid sequencing) we found a highly divergent Iberian group, including the Spanish Deschampsia cespitosa subsp. cespitosa (diploid and tetraploid) and the Macaronesian island endemic diploid Deschampsia argentea. Moreover, we found substantial divergence of pseudoviviparous tetraploids (Deschampsia cespitosa subspp. neoalpina and rhenana) from seminiferous tetraploids (except Deschampsia cespitosa subsp. littoralis) and all diploids of the remaining European samples. The divergent pseudoviviparous tetraploids (D. cespitosa subspp. neoalpina and rhenana) and the seminiferous tetraploid D. cespitosa subsp. littoralis probably represent periglacial and relict lineages of unknown origin regarding auto- and/or allo-polyploidy, whereas other seminiferous tetraploid variants of D. cespitosa are always nested in the diploid D. cespitosa , suggesting multiple autopolyploid origins. An analysis after excluding the Iberian Group and the highly divergent tetraploids revealed five genetic groups with overlapping geographical patterns. However, the recovered geographical structure, the overall low genetic divergence and the diffuse genetic structure point to recolonization from various refugial areas and secondary contact. Effective wind dispersal of pollen and seeds in an open early post-glacial tundra landscape and, finally, increasing human impact on dispersal of this grass since the Neolithic, may have enhanced admixture and resulted in the complex patterns detected today. [ABSTRACT FROM AUTHOR]

Somatic hybridization has emerged as a valuable tool for developing novel genetic combinations in citrus breeding programs, including the creation of salt-tolerant rootstocks. In this study, the performance of a tetraploid somatic hybrid, obtained by fusing protoplasts derived from salt-tolerant Cleopatra mandarin (Citrus reshni hort. ex Tanaka) and salt-sensitive Carrizo citrange (Citrus sinensis L. Osbeck × Poncirus trifoliata L. Raf), was assessed under in vitro salt stress. Hybrid plants were characterized by leaf morphology, and ploidy level by flow cytometry and molecular markers. In vitro shoots were generated from the micropropagation of mature stem pieces of the somatic hybrid and its parents, and these were challenged by exposure to NaCl (0, 50, or 100 mM) supplemented to the media for three weeks to induce salt stress. The leaves of the somatic hybrid display intermediate morphology compared to the parental Cleopatra mandarin and Carrizo citrange rootstocks. All molecular markers successfully amplified DNA from the three cultivars; however, only 11 of 14 unequivocally confirmed somatic hybridity. The physiological and biochemical parameters, including chlorophyll content, lipid peroxidation, total phenolic compounds, antioxidants activity and proline content, were measured in the leaves. The somatic hybrid exhibited superior salt stress tolerance compared to the parent varieties, as evidenced by the reduced cellular membrane damage indicated by the lower levels of malondialdehyde and electrolyte leakage, particularly under 100 mM NaCl treatment. The somatic tetraploid hybrid also displayed higher total phenolic content than either parent, while Cleopatra mandarin exhibited the highest proline levels under 50 mm NaCl. These results demonstrate the enhanced salinity stress tolerance of the somatic hybrid compared to its parent lines, highlighting its potential as a valuable candidate for developing salt-tolerant citrus rootstocks.

Potato tubers contain biochemical compounds with antioxidant properties that benefit human health. However, the genomic basis of the production of antioxidant compounds in potatoes has largely remained unexplored. Therefore, we report the first genome-wide association study (GWAS) based on 4488 single nucleotide polymorphism (SNP) markers and the phenotypic evaluation of Total Phenols Content (TPC), Ascorbic Acid Content (AAC), and Antioxidant Activity (AA) traits in 404 diverse potato genotypes (84 diploids and 320 tetraploids) conserved at the Colombian germplasm bank that administers AGROSAVIA. The concentration of antioxidant compounds correlated to the skin tuber color and ploidy level. Especially, purple-blackish tetraploid tubers had the highest TPC (2062.41 ± 547.37mg GAE), while diploid pink-red tubers presented the highest AA (DDPH: 14967.1 ± 4687.79 μmol TE; FRAP: 2208.63 ± 797.35 mg AAE) and AAC (4.52mg ± 0.68 AA). The index selection allowed us to choose 20 promising genotypes with the highest values for the antioxidant compounds. Genome Association mapping identified 58 SNP-Trait Associations (STAs) with single-locus models and 28 Quantitative Trait Nucleotide (QTNs) with multilocus models associated with the evaluated traits. Among models, eight STAs/QTNs related to TPC, AAC, and AA were detected in common, flanking seven candidate genes, from which four were pleiotropic. The combination in one population of diploid and tetraploid genotypes enabled the identification of more genetic associations. However, the GWAS analysis implemented independently in populations detected some regions in common between diploids and tetraploids not detected in the mixed population. Candidate genes have molecular functions involved in phenolic compounds, ascorbic acid biosynthesis, and antioxidant responses concerning plant abiotic stress. All candidate genes identified in this study can be used for further expression analysis validation and future implementation in marker-assisted selection prebreeding platforms targeting fortified materials. Our study further revealed the importance of potato germplasm conserved in national genebanks, such as AGROSAVIA's, as a valuable genetic resource to improve existing potato varieties. [ABSTRACT FROM AUTHOR]

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.

One of the most promising trends in apple breeding is polyploidy. Triploid cultivars show higher fruiting stability and increased self-fertility. The easiest way to obtain triploids is to cross diploid and tetraploid cultivars among themselves. The main limiting factor in this case is a restricted number of initial tetraploid forms whose characteristics affect the quality and prospects of the resulting hybrid progeny.The staff of Sverdlovsk Horticultural Breeding Station in the Middle Urals produced and analyzed 5 hybrid families using cv. ‘Papirovka tetraploidnaya’ as the paternal source; the latter’s pollen was supplied by Acad. E. N. Sedov from the All-Russian Research Institute of Fruit Crop Breeding. Ninety hybrid seedlings were studied.The study showed that ‘Papirovka tetraploidnaya’ with a high degree of probability conveyed the following traits to its progeny: large fruit size, fruit ripening in early summer, midsummer and autumn, loose or medium density of coarse fruit flesh, and nonoutstanding fruit taste (scoring 3.8–4.2 points).

Genome size (GS) is an important characteristic that may be helpful in delimitation of taxa, and multiple studies have shown correlations between intraspecific GS variation and morphological or environmental factors, as well as its geographical segregation. We estimated a relative GS (RGS) of 707 individuals from 162 populations of Dianthus sylvestris with a geographic focus on the Balkan Peninsula, but also including several populations from the European Alps. Dianthus sylvestris is morphologically variable species thriving in various habitats and six subspecies have been recognized from the Balkan Peninsula. Our RGS data backed-up with chromosome counts revealed that the majority of populations were diploid (2n = 30), but ten tetraploid populations have been recorded in D. sylvestris subsp. sylvestris from Istria (Croatia, Italy). Their monoploid RGS is significantly lower than that of the diploids, indicating genome downsizing. In addition, the tetraploids significantly differ from their diploid counterparts in an array of morphological and environmental characteristics. Within the diploid populations, the RGS is geographically and only partly taxonomically correlated, with the highest RGS inferred in the southern Balkan Peninsula and the Alps. We demonstrate greater RGS variation among the Balkan populations compared to the Alps, which is likely a result of more pronounced evolutionary differentiation within the Balkan Peninsula. In addition, a deep RGS divergence within the Alps likely points to persistence of the alpine populations in different Pleistocene refugia. [ABSTRACT FROM AUTHOR]

Bird cherry occupies a special place among stone fruit plants. Its fruits, collected in nature, were widely used by local communities, native to regions with severe climate. Development of new bird cherry cultivars, well adapted to such environments, with stable productivity and larger fruit, is a necessity.Crossings were performed involving the most large-fruited genotypes of Prunus padus L. and P. virginiana L., selected during the study of their intraspecific variability and interspecific hybrids. A number of hybrids were identified for their considerably higher fruit weight than that of both parents. Crossing the most large-fruited hybrid cultivars ‘Pamyati Salamatova’ and ‘Cherny blesk’ with large-fruited P. padus samples from Bondarev No. 11-2-64, No. 11-2-70, No. 11-2-76, and P. virginiana samples No. 1-14-1 and No. 10-5-2, produced many hybrids with a fruit weight gain of 20–50% over the parent with the largest fruit. It can be explained by the polygenic nature of fruit weight inheritance. The samples with the largest fruits had an average fruit weight of 1.4–1.5 g and maximum weight of 1.8–1.9 g. Many of them combined large fruit size with good quality and high productivity. Brief descriptions of fruit traits are presented for several hybrids. Suppositions are made about the prospects of further breeding for the large fruit trait on the basis of the same genetic sources or with the use of other sources of large fruit size in hybridization.Thus, preliminary selection of the best genotypes in nature and in introduced populations, followed by their crossing within their own species and with other species, makes it possible to produce genotypes with larger fruits than the average fruit size for a population and considerably larger than in their parents. It would help to develop bird cherry cultivars, well adapted to local conditions, for amateur and industrial horticulture under different climate conditions of Russia.

Abstract Background Efficient organogenesis induction in eggplant (Solanum melongena L.) is required for multiple in vitro culture applications. In this work, we aimed at developing a universal protocol for efficient in vitro regeneration of eggplant mainly based on the use of zeatin riboside (ZR). We evaluated the effect of seven combinations of ZR with indoleacetic acid (IAA) for organogenic regeneration in five genetically diverse S. melongena and one S. insanum L. accessions using two photoperiod conditions. In addition, the effect of six different concentrations of indolebutyric acid (IBA) in order to promote rooting was assessed to facilitate subsequent acclimatization of plants. The ploidy level of regenerated plants was studied. Results In a first experiment with accessions MEL1 and MEL3, significant (p

Genome size (GS) is an important characteristic that may be helpful in delimitation of taxa, and multiple studies have shown correlations between intraspecific GS variation and morphological or environmental factors, as well as its geographical segregation. We estimated a relative GS (RGS) of 707 individuals from 162 populations of Dianthus sylvestris with a geographic focus on the Balkan Peninsula, but also including several populations from the European Alps. Dianthus sylvestris is morphologically variable species thriving in various habitats and six subspecies have been recognized from the Balkan Peninsula. Our RGS data backed-up with chromosome counts revealed that the majority of populations were diploid (2n = 30), but ten tetraploid populations have been recorded in D. sylvestris subsp. sylvestris from Istria (Croatia, Italy). Their monoploid RGS is significantly lower than that of the diploids, indicating genome downsizing. In addition, the tetraploids significantly differ from their diploid counterparts in an array of morphological and environmental characteristics. Within the diploid populations, the RGS is geographically and only partly taxonomically correlated, with the highest RGS inferred in the southern Balkan Peninsula and the Alps. We demonstrate greater RGS variation among the Balkan populations compared to the Alps, which is likely a result of more pronounced evolutionary differentiation within the Balkan Peninsula. In addition, a deep RGS divergence within the Alps likely points to persistence of the alpine populations in different Pleistocene refugia.

Artemisia herba-alba is an important component of Mediterranean dry steppe floras, being widely distributed in arid areas of the Iberian Peninsula and North-West Africa. In this study, we use genetic, cytogenetic and niche modelling tools to investigate the natural history of the species, focusing particularly on the role played by polyploidization to explain current diversity patterns throughout the main distribution range of the plant. Our sequencing data indicate a complex phylogeographical structure showing similar haplotype diversity patterns on both sides of the Strait of Gibraltar and no clear signals of genetic refugia. According to our cytogeographical results, we inferred multiple polyploidization events, which probably took place on the Iberian Peninsula and in North Africa independently. Environmental niche modelling suggested stable potential distributions of A. herba-alba on both sides of the Mediterranean Sea under present and past Last Glacial Maximum conditions, which could be related to the intricate spatial genetic and cytogenetic patterns shown by the species. Finally, environmental modelling comparison among cytotypes revealed that the niche of tetraploids is narrower and nested in that of diploids, a result that could indicate environmental specialization and could potentially explain recurrent establishment success of tetraploids. [ABSTRACT FROM AUTHOR]

Polyploidization is a widespread mechanism of evolutionary divergence in flowering plants. Ecological divergence of polyploid lineages has been proposed as a key process shaping the distribution of cytotypes in nature (niche shift hypothesis); however, evidence for the role of niche separation in replicated diploid-polyploid species pairs is still needed. This study aimed to assess the role of abiotic factors shaping current cytotype distributions. For that, we examined the distribution and environmental niches of two varieties recognized in diploid-tetraploid Jasione maritima across the species range and within a putative contact zone on the Iberian Peninsula. We counted chromosomes, screened for ploidy across Iberian Peninsula and characterized environmental requirements using niche modeling tools. We found that J. maritima var. maritima is composed by diploids with disjunct distribution in the west coast of France and northwest Iberian Peninsula, and by tetraploids in Iberian Peninsula, while var. sabularia is tetraploid. In the Iberian Peninsula, two parapatric contact zones along a linear coastal distribution were detected, one between diploid and tetraploid var. maritima, and the other between tetraploids of the two varieties. Environmental variables of diploid populations from France are distinct from those of southern diploid populations, which are more similar to tetraploids. In general, niche modeling results are congruent with the observed distribution patterns, although the results suggest a wider contact zone between varieties and cytotypes. Tetraploids of both varieties revealed different degrees of environmental divergence in comparison with their diploid counterpart. Tetraploid var. sabularia differed environmentally from diploids suggesting niche divergence. In contrast, tetraploid var. maritima overlapped with diploid environmental niche and currently occupies its entire predicted range, whereas diploids are restricted to northern areas of their suitable environment. Differences in ecological envelopes facilitate the recognition of functional units of biodiversity within polyploid groups, allowing the study of factors related to post-polyploidization divergence. Thus, whereas changes in environmental requirements may have allowed tetraploid var. sabularia to spread in habitats not favorable to diploids, other factors are involved with the distribution of diploid and tetraploid var. maritima.

Drought is one of the critical abiotic stresses that significantly affect agricultural production, and current models predict an increase in its severity and intensity in the future. Generally, polyploidy has been found to improve the resistance of plants to abiotic stress. Understanding the role of ploidy in resistance to drought was achieved by comparing the response between diploids and their respective induced autotetraploids of Westerwolths ryegrass (Lolium multiflorum ssp. multiflorum). Field trials were carried out in the 2017 and 2018 growing seasons, and mild drought simulation experiments in controlled conditions were carried out to validate the effect of chromosome duplication. Results obtained from morphological traits in the field experiment revealed that the induced tetraploids were significantly (p < 0.05) taller, had longer inflorescences and larger flag leaf area than their diploid counterparts, especially in the year 2018 characterized by the prolonged drought. This study also revealed that the induced tetraploids produced more dry matter yield than their diploid progenitors, especially in drought periods. The induced tetraploids had significantly higher antiradical activity and phenolic content than the diploid progenitors in response to mild drought, and this significantly correlated with the plant performance in 2018 field trials, indicating that increased ploidy level plays an important role in conferring resistance to drought in Westerwolths ryegrass. Furthermore, the antiradical activity and total phenolic content proved to be a good tool to evaluate drought tolerance at the vegetative stage in Westerwolths ryegrass. [ABSTRACT FROM AUTHOR]

Polyploidization is a widespread mechanism of evolutionary divergence in flowering plants. Ecological divergence of polyploid lineages has been proposed as a key process shaping the distribution of cytotypes in nature (niche shift hypothesis); however, evidence for the role of niche separation in replicated diploid-polyploid species pairs is still needed. This study aimed to assess the role of abiotic factors shaping current cytotype distributions. For that, we examined the distribution and environmental niches of two varieties recognized in diploid-tetraploid Jasione maritima across the species range and within a putative contact zone on the Iberian Peninsula. We counted chromosomes, screened for ploidy across Iberian Peninsula and characterized environmental requirements using niche modeling tools. We found that J. maritima var. maritima is composed by diploids with disjunct distribution in the west coast of France and northwest Iberian Peninsula, and by tetraploids in Iberian Peninsula, while var. sabularia is tetraploid. In the Iberian Peninsula, two parapatric contact zones along a linear coastal distribution were detected, one between diploid and tetraploid var. maritima , and the other between tetraploids of the two varieties. Environmental variables of diploid populations from France are distinct from those of southern diploid populations, which are more similar to tetraploids. In general, niche modeling results are congruent with the observed distribution patterns, although the results suggest a wider contact zone between varieties and cytotypes. Tetraploids of both varieties revealed different degrees of environmental divergence in comparison with their diploid counterpart. Tetraploid var. sabularia differed environmentally from diploids suggesting niche divergence. In contrast, tetraploid var. maritima overlapped with diploid environmental niche and currently occupies its entire predicted range, whereas diploids are restricted to northern areas of their suitable environment. Differences in ecological envelopes facilitate the recognition of functional units of biodiversity within polyploid groups, allowing the study of factors related to post-polyploidization divergence. Thus, whereas changes in environmental requirements may have allowed tetraploid var. sabularia to spread in habitats not favorable to diploids, other factors are involved with the distribution of diploid and tetraploid var. maritima. [ABSTRACT FROM AUTHOR]

The Pacific oyster occurs on all continents but Antarctica (Mann 1979) and for the past several years has had the highest annual production of any freshwater or marine organism (4.2 million metric tons in 2002, worth $3.5 billion; FAO 2004). About 92 million pounds of Pacific oyster meat were produced on the West Coast in 2000, with a farm-gate value of nearly $70 million (Toba and Chew 1999). West Coast production exceeds the harvest of Eastern oysters on either the Gulf or Atlantic Coasts, primarily because diseases have wiped out those natural stocks. As the Pacific oyster does not naturally reproduce along much of the West Coast, seed was imported from Japan for decades (Chew 1984). In the early 1980s, however, the industry adopted hatchery techniques and now relies mainly on hatchery seed. This sets the stage not only for commercial breeding programs, which industry identifies as a top priority (Pacific Shellfish Institute 1999), but also for development in the future of a mature seed industry servicing global markets.

For breeding purposes, the number of neo-tetraploids of apple cultivars have been derived by in vitro technique. The first attempts at rooting and acclimatization of tetraploid shoots failed. The aim of the study was to develop an effective method for rooting microcuttings of apple neo-tetraploids. In the first stage of the study, in vitro rooting method was optimized for the shoots of diploid donor cultivars. Shoots were rooted on Murashige and Skoog [1962] (MS) medium with a reduced content of nitrogen, in the presence of auxins alone or in combination (indole-3-butyric acid – IBA, 1-naphthaleneacetic acid – NAA and indole--3-acetic acid – IAA) with addition of putrescine, arginine or ornithine. The compounds were applied continuously for 25 days (one-step rooting system) or for seven days with subsequent transplanting shoots onto a medium without these compounds (two-step rooting method). Tetraploid microcuttings of the cultivars ‘Free Redstar’, ‘Gala Must’, ‘Pinova’ and ‘Redchief’ were evaluated for rooting on the selected medium considered optimal for their diploid counterparts. The shoots of all diploid apple scion cultivars had low rooting capacity. IBA alone poorly stimulated root formation. Significant improvement of rooting to 60–80% was achieved through the application of auxins, 2.5 µM IBA or 1.3 µM NAA combined with 5 µM IAA and 50 µM putrescine in the two-step rooting system with darkness and increased temperature of 26°C during seven-day induction phase. The replacement of benzyladenine (BA) by meta-Topolin (m-T) in the last multiplication subculture influenced positively shoot acclimatization. Tetraploids had comparable or slightly lower rooting and acclimatization ability compared to their diploid counterparts.

Background: Efficient organogenesis induction in eggplant (Solanum melongena L.) is required for multiple in vitro culture applications. In this work, we aimed at developing a universal protocol for efficient in vitro regeneration of eggplant mainly based on the use of zeatin riboside (ZR). We evaluated the effect of seven combinations of ZR with indoleacetic acid (IAA) for organogenic regeneration in five genetically diverse S. melongena and one S. insanum L. accessions using two photoperiod conditions. In addition, the effect of six different concentrations of indolebutyric acid (IBA) in order to promote rooting was assessed to facilitate subsequent acclimatization of plants. The ploidy level of regenerated plants was studied. Results: In a first experiment with accessions MEL1 and MEL3, significant (p < 0.05) differences were observed for the four factors evaluated for organogenesis from cotyledon, hypocotyl and leaf explants, with the best results obtained (9 and 11 shoots for MEL1 and MEL3, respectively) using cotyledon tissue, 16 h light / 8 h dark photoperiod conditions, and medium E6 (2 mg/L of ZR and 0 mg/L of IAA). The best combination of conditions was tested in the other four accessions and confirmed its high regeneration efficiency per explant when using both cotyledon and hypocotyl tissues. The best rooting media was R2 (1 mg/L IBA). The analysis of ploidy level revealed that between 25 and 50% of the regenerated plantlets were tetraploid. Conclusions: An efficient protocol for organogenesis of both cultivated and wild accessions of eggplant, based on the use of ZR, is proposed. The universal protocol developed may be useful for fostering in vitro culture applications in eggplant requiring regeneration of plants and, in addition, allows developing tetraploid plants without the need of antimitotic chemicals. [ABSTRACT FROM AUTHOR]

The ploidy level can be useful in evaluating reproductive and somatic compatibility, an important parameter in scion and rootstock breeding programs. Evaluation of nuclear DNA content was performed in order to determine ploidy level of 31 rootstocks of genus Prunus for plum, sour cherry and sweet cherry. In the first stage of the research, the conditions of flow cytometry analysis with application of propidium iodide for DNA staining were optimized. Repeatable results and relatively good-quality histograms were obtained using Partec extraction buffer with 1% PVP (polyvinylpyrrolidone) addition, with incubation time from 50 to 90 min. The best internal standard for flow cytometry analysis proved to be tomato (Solanum lycopersicum L.) 2C = 1.96 pg for rootstocks with a nuclear DNA content from 0.55 to 1.64 pg, and soybean (Glycine max (L.) Merr.) 2.50 pg for rootstocks with a larger nuclear DNA contents from 1.8 to 2.3 pg. In five plum rootstocks, 2C values ranged from 0.61 to 0.67 pg indicating their diploid chromosome number. One rootstock was identified as tetraploid (2C = 1.34 pg), and four rootstocks as hexaploids owing to their DNA contents from 2.07 to 2.23 pg. One rootstock was considered a pentaploid due to its 2C value of 1.64 pg which was approximately two and a half times more than in diploid Prunus sp. In nine cherry rootstocks, 2C DNA values ranged from 0.74 to 0.86 pg indicating their diploid chromosome number. Nine cherry rootstocks were identified as triploids with their 2C DNA contents from 1.03 to 1.24 pg. Two cherry rootstocks were considered as tetraploids having 2C DNA of 1.39 pg. The ploidy level of cherry and plum rootstocks was evaluated in relation to morphological and agronomic traits. The tendency to increase the size of stomata and leaves along with an increase in the ploidy level was observed within Prunus rootstock genotypes; however, the correlations between these traits were not so evident. Therefore, stomata and leaf size cannot be considered as a morphological marker indicating ploidy level. The evaluated nuclear DNA contents / ploidy levels as well as stomata and leaf size are the additional descriptors of Prunus rootstocks that can be useful for identifying genotypes. [ABSTRACT FROM AUTHOR]

Tetraploid line development is beset with poor germination and seedling vigour of tetraploid seeds primarily due to thick seed coat and under-developed embryo. Tetraploid (T0) seeds generated through colchicine application on three watermelon genotypes (Sugar Baby, California Sweet and 5255-1-3-1) were subjected to priming treatments viz; Gibbrellic acid (GA3) @ 100 ppm, Ethrel @ 100 ppm, Potassium nitrate (KNO3) @ 1% and Potassium dihydogen orthophosphate (KHjPO4) @ 10-2 M for 12 and 24 hours, respectively. Seeds primed for longer duration i.e. 24 hour exhibited better germination and growth characteristics than their respective 12 hour priming treatments. Seeds invigorated with KHjPO4 for 24 hours had the greatest germination (67.47%) and longest seedlings (10.423cm plumule, 7.261cm radicle). Ethrel @ 100 ppm for 24 hours produced the seedling having the highest dry weight (0.125g). Non primed seeds fared poorly in all parameters. California Sweet responded best to seed priming treatments (65.21% germination; 0.124g, seedling dry weight). In a first report, KHjPO4 priming treatment can be effectively used to enhance the emergence and other seed attributes of tetraploid watermelon in early generations. [ABSTRACT FROM AUTHOR]

Polyploids often have divergent geographical ranges compared to their diploid progenitors, but the causes of such differentiation are poorly understood. The geographical ranges of cytotypes within polyploid complexes may be caused by multiple factors, including historical events, interactions among cytotypes and divergent environmental tolerances, but the fine-scale geographical arrangement of cytotypes is rarely known for most mixed-ploidy species. In this study, we assessed cytotype diversity and distribution patterns in the Jasione montana polyploid complex and examined whether environmental factors can explain the occurrence of tetraploids. Specifically, we reviewed all chromosome counts available in the literature, examined cytotype distributions in a large-scale population survey using flow cytometry (N = 278 populations, N = 3396 plants), and used niche modelling to compare cytotype environmental associations. Two cytotypes were detected: diploids, which are widespread across Europe, and tetraploids, restricted to the north-west quadrant of the Iberian Peninsula. The two cytotypes were distributed in a mosaic with areas dominated by diploids intermixed with those dominated by tetraploids, rarely forming mixed-ploidy populations (1.4%). Although having low geographical overlap, the tetraploid niche is fully nested within the diploid niche breadth and occupies only a subset of the environmental envelope of the diploid progenitor, suggesting that polyploidization has not caused niche expansion due to novel environmental preferences. The mosaic diploid-tetraploid contact zones and the lack of mixed-ploidy populations suggest that frequency-dependent selection may play a role in excluding minority cytotypes. Under this scenario, tetraploids would have to disperse to places unoccupied by diploids to successfully establish. The aggregation of tetraploid populations in areas suitable for diploids suggests that tetraploids may also outcompete diploids in certain areas. Collectively, our results indicate that environmental sorting has played a role, at least on a broader scale, in the successful establishment of polyploids in J. montana. [ABSTRACT FROM AUTHOR]

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The aim of this work was to find an effective protocol for in vitro propagation and to perform the in vitro polyploidization of diploid Thymus vulgaris (2n = 30) using two experimental methods based on the use of oryzalin, an antimitotic agent. The ploidy level of the obtained shoots was checked by flow cytometric analysis. The most efficient conditions for inducing polyploidy were oryzalin concentrations of 0.346 and 1.73 mg L−1 present in the medium for two weeks. The vital polyploid shoots were multiplied for further evaluation, rooting and final transfer to nonsterile glasshouse and field conditions. The chemical compositions of the essential oils (EOs)—which were obtained from dried field grown plants by steam distillation—were analyzed by gas chromatography/mass spectrometry (GC/MS). The identified substances contributed approximately 95% to the total peak area. Statistical analysis revealed that the tetraploid subclone and the diploid reference plant do not differ in total terpene content, but they do differ in the relative proportions of all the individual terpenes with the exception of α-pinene and UN5, indicating that both clones produce EOs of different quality. The obtained results showed the possibility of developing more efficient botanical insecticides based on EOs obtained from the tetraploid plants.

The identity of Barbus capensis, as described by Andrew Smith (1841), is reviewed following a careful examination of the lectotype in the Natural History Museum, London. Evidence shows clearly that it represents a specimen of the Berg-Breede River whitefish or ‘witvis’ and not the species known as the Clanwilliam yellowfish, to which it was attributed until recently. The original illustration of the species is shown to be a composite of these two different species. A replacement name for the Clanwilliam yellowfish is drawn from the earliest described synonym, Labeobarbus seeberi (Gilchrist & Thompson, 1913). Following widespread recognition that the genus Barbus Daudin, 1805 does not occur in sub-Saharan Africa, the generic status of the Berg-Breede River whitefish (witvis) and other tetraploid cyprinines of southern Africa is reviewed, taking genetic and morphological characters into account. Five distinct lineages, each representing a genus, are recognized, including the genera Pseudobarbus Smith, 1841 and Cheilobarbus Smith, 1841, and three new genera described herein: Amatolacypris gen. nov., Sedercypris gen. nov. and Namaquacypris gen. nov.

Plant cell, tissue, and organ cultures (PCTOC) have been used as experimental systems in basic research, allowing gene function demonstration through gene overexpression or repression and investigating the processes involved in embryogenesis and organogenesis or those related to the potential production of secondary metabolites, among others. On the other hand, PCTOC has also been applied at the commercial level for the vegetative multiplication (micropropagation) of diverse plant species, mainly ornamentals but also horticultural crops such as potato or fruit and tree species, and to produce high-quality disease-free plants. Moreover, PCTOC protocols are important auxiliary systems in crop breeding crops to generate pure lines (homozygous) to produce hybrids for the obtention of polyploid plants with higher yields or better performance. PCTOC has been utilized to preserve and conserve the germplasm of different crops or threatened species. Plant genetic improvement through genetic engineering and genome editing has been only possible thanks to the establishment of efficient in vitro plant regeneration protocols. Different companies currently focus on commercializing plant secondary metabolites with interesting biological activities using in vitro PCTOC. The impact of omics on PCTOC is discussed., (© 2024. The Author(s), under exclusive license to Springer Science+Business Media, LLC, part of Springer Nature.)

Purpose. Determination of peculiarities of anatomical and morphological characters of stevia plants to accelerate the identification of tetraploid forms. Methods. Field, laboratory and analysis-of-variance methods. Results. It was established that larger leaf area index (19–38%), fewer stomata per unit area (by 39–48%), larger diameter of pollen grains (by 42–92%) is a characteristic feature of anatomical and morphological characters of stevia tetraploid forms as compared to diploid ones. Conclusions. The parameters of leaf plate, the size of stomata and diameter of pollen grains are auxiliary selection criteria (rapid test). For tetraploid forms of stevia, leaf area index (the ratio of leaf blade length to width), size of stomata and diameter of pollen grains is truly larger as compared to diploid forms. Chromosomes number determination based on cytological analysis is the major and the most accurate criterion for selection of tetraploid forms, that seems advisable to use it at later stages of selection.

The aim of the study was to determine the hybridity of the F1 generation of Vaccinium cf. uliginosum × V. vitis-idaea × Oxycoccus macrocarpus created through the consecutive crossing of some common berry species of the family Ericaceae (bog whortleberry, cowberry and marsh cranberry) at the tetraploid level. Certain aspects of phenology and morphometric parameters of vegetative organs of the supposed hybrid and parent plants were analysed using traditional methods of comparative analysis. Molecular genetic assay, including random amplification of polymorphic DNA, simple sequence repeat and sequencing, were also used. Comparison of the phenological and morphometric features of the experimental plant and its parents allows suggesting that in the combination of crossing of (V. uliginosum × V. vitis-idaea) × O. macrocarpus (the cultivar Searles), a three-species hybrid was created. The allelic variants, specific for V. uliginosum, V. vitis-idaea and O. macrocarpus, were detected in the V. cf. uliginosum × V. vitis-idaea × O. macrocarpus genotype. A next-generation sequencing approach is suggested for estimating the share of the genomes of Vaccinium spp. in the formation of the interspecies hybrid. [ABSTRACT FROM AUTHOR]

Fertility of backcross triploid hybrids containing one genome of Prussian carp and two genomes of common carp is investigated. The females of hybrids of Prussian carp and common carp (Prussian × common carp) are prolific and produce diploid gametes. Since males of such hybrids are sterile, their reproduction is realized by means of induced gynogenesis. Triploid progeny is obtained by backcrossing female Prussian × common carp with carp males. Among triploids obtained from hybrids F and among hybrids of the first gynogenetic generation, there were no prolific specimens. However, in reproduction of diploid hybrids by means of gynogenesis during six generations, the female fertility in the backcross progeny is restored. From backcross triploid females (daughters of Prussian × common carp of the sixth gynogenetic generation), a viable triploid gynogenetic progeny and a tetraploid backcross (by carp) progeny are obtained. The obtained data may be considered as the experimental proof of the hypothesis of reticular speciation. [ABSTRACT FROM AUTHOR]

An earlier software application of ours, TetraploidMap for Windows, enabled linkage analysis and quantitative trait locus interval mapping to be carried out in an experimental cross of an autotetraploid species, using both dominant markers such as amplified fragment length polymorphisms and codominant markers such as simple sequence repeats. The size was limited to 800 markers, and quantitative trait locus mapping was conducted for each parent separately due to the difficulties in obtaining a reliable consensus map for the 2 parents. Modern genotyping technologies now give rise to datasets of thousands of single nucleotide polymorphisms, and these can be scored in autotetraploid species as single nucleotide polymorphism dosages, distinguishing among the heterozygotes AAAB, AABB, and ABBB, rather than simply using the presence or absence of an allele. The dosage data is more informative about recombination and leads to higher density linkage maps. The current program, TetraploidSNPMap, makes full use of the dosage data, and has new facilities for displaying the clustering of single nucleotide polymorphisms, rapid ordering of large numbers of single nucleotide polymorphisms using a multidimensional scaling analysis, and phase calling. It also has new routines for quantitative trait locus mapping based on a hidden Markov model, which use the dosage data to model the effects of alleles from both parents simultaneously. A Windows-based interface facilitates data entry and exploration. It is distributed with a detailed user guide. TetraploidSNPMap is freely available from our GitHub repository. [ABSTRACT FROM AUTHOR]

The most intriguing karyological features of the genus Allium are polyploidy and the frequent appearance of supernumerary or B chromosomes (Bs). Specimens of Allium flavum from natural populations at the Gornjačka Gorge in the vicinity of Gornjak Monastery, Serbia, were analyzed karyologically. All studied plants were tetraploid (2n = 32). One submetacentric B chromosome representing 1% of the genome, smaller than the smallest chromosomes of the standard set, was present in some plants. This is the first finding of Bs in tetraploid A. flavum. [Projekat Ministarstva nauke Republike Srbije, br. 173003]

O objetivo deste trabalho foi avaliar características agronômicas de genótipos de bananeira, em três ciclos de produção. O experimento foi realizado em blocos ao acaso, com parcelas subdivididas e cinco repetições, em Rio Branco, AC. Os genótipos Preciosa, Japira, Pacovan Ken, Pacovan, PA42-44, Prata-anã, ST12-31, FHIA 02, Nanicão, Grande Naine, Calipso, Ambrósia e Bucaneiro foram avaliados quanto aos caracteres: altura da planta; diâmetro do pseudocaule; número de folhas vivas na floração e na colheita; ciclo de formação do cacho da floração à colheita; número de pencas por cacho; massa do fruto e do cacho; e produtividade. As cultivares Preciosa e Pacovan Ken apresentaram as maiores alturas, e os híbridos PA42-44 e FHIA 02, e as cultivares Prata-anã, Nanicão e Grande Naine, o porte mais baixo. As cultivares Nanicão, Ambrósia, Bucaneiro, Pacovan, Prata-anã e Grande Naine e o híbrido ST12-31 apresentaram os menores números de folhas vivas na colheita. A cultivar Preciosa e o híbrido FHIA 02 foram os mais produtivos. Os híbridos PA42-44 e FHIA 02 apresentam características agronômicas promissoras e podem ser incorporados ao sistema produtivo, assim como os híbridos de Pacovan, já adaptados e recomendados para o cultivo no Estado do Acre.This work aimed to evaluate agronomic traits of banana genotypes, in three production cycles. The experimental design was a complete randomized block in split plot arrangement, with five replicates, in Rio Branco, AC, Brazil. The genotypes Preciosa, Japira, Pacovan Ken, Pacovan, PA42-44, Prata-anã, ST12-31, FHIA 02, Nanicão, Grande Naine, Calipso, Ambrosia, and Bucaneiro were evaluated regarding the characters: plant height; pseudostem diameter; number of green leaves at flowering and at harvesting; bunch development period from flowering to harvesting; number of hands per bunch; mean fruit weight; bunch weight; and yield. The cultivars Preciosa and Pacovan Ken were the tallest ones; and the hybrids PA42-44 and FHIA 02, and the cultivars Prata-anã, Nanicão and Grande Naine were the shortest ones. The cultivars Nanicão, Ambrosia, Bucaneiro, Pacovan, Prata-anã and Grande Naine and the hybrid ST12-31 had the smallest numbers of green leaves at harvesting. The cultivar Preciosa and the hybrid FHIA 02 were the most productive. The hybrids PA42-44 and FHIA 02 show promising agronomic traits and can be incorporated to the productive system, as well as the Pacovan hybrids, already adapted and recommended for cultivation in Acre State.

A diagnose foliar é bastante útil na determinação do estado nutricional das plantas. As exigências nutricionais da bananeira podem diferir em função das suas características genéticas. O trabalho objetivou determinar os teores de macro e micronutrientes na terceira folha de genótipos de bananeira. Foram selecionados 24 genótipos de bananeira (triplóides e tetraplóides), em dois ciclos de produção (1999 e 2000), do Banco Ativo de Germoplasma de Banana da Embrapa Mandioca e Fruticultura Tropical, determinando-se os teores foliares de macronutrientes (N, P, K, Ca, Mg e S) e de micronutrientes (B, Cl, Cu, Fe, Mn e Zn). Os resultados indicaram que existe variação nos teores foliares entre plantas do mesmo grupo genômico e entre os ciclos de produção, com teores médios mais elevados no segundo ciclo para N, P, Ca, Mg, S, Cu e Mn e mais baixos para K, Cl, B, Fe e Zn. O N variou de 21,6 a 28,5 g kg-1, o K de 13,7 a 30,8 g kg-1 e foram os macronutrientes com teores mais elevados nas folhas. O teor de Cl variou de 10,4 a 24,7 g kg-1, o Mn de 43 a 574 mg kg-1 e o Fe de 56 a 212 mg kg-1, sendo os micronutrientes com teores mais elevados nas folhas.The leaf diagnosis is quite useful for the determination of the nutritional state of plants. The nutritional banana tree demands can differ in accordance with genetic characteristics. The aim of present work was to determinate the macro and micronutrients contents in the third leaf of banana genotypes. Twenty four banana genotypes were selected (triploids and tetraploids), in two production cycles (1999 and 2000), in the Active Germoplasm Bank of Banana at Embrapa Mandioca e Fruticultura Tropical, in Cruz das Almas, Bahia, Brazil. The leaf contents of macronutrients (N, P, K, Ca, Mg and S) and micronutrients (B, Cl, Cu, Fe, Mn and Zn) were determined. The results showed that occurred variation in leaf contents among plants in the same genome group and between the first and second production cycles, with higher medium levels in the second cycle for N, P, Ca, Mg, S, Cu and Mn and lower ones for K, Cl, B, Fe and Zn. The nitrogen contents 21.6 to 28.5 g kg-1 and K 13.7 to 30.8 g kg-1 and they were the macronutrients with the highest contents in the leaves. The chlorine contents was 10.4 to 24.7 g kg-1, manganese 43 to 574 mg kg-1 and iron 56 to 212 mg kg-1,and they were the micronutrients with the highest contents in leaves.

The current study was set out to establish the efficacy of different mitosis inhibitors (colchicine, amiprophos-methyl, trifluralin and oryzalin) used in the production of red clover (Trifolium pratense L.) and alsike clover (Trifolium hybridum L.) polyploids and to assess the agrobiological traits of tetraploid populations. Four cultivars and five wild populations of T. pratense, one cultivar and three wild populations of T. hybridum were used for polyploidization. The effect of conventional soaking of germinating seeds in a colchicine solution was compared with that of colchicine treatment of embryos in an in vitro culture. Colchicine treatment of T. pratense embryos resulted in 3.3 times higher production of tetraploids (teraploid yield 55.0%) compared with colchicine treatment of seedlings, and the production of chimeric plants was 1.9 times lower. The different mitosis inhibitors were characterised by a diverse polyploidization effect. Tetraploid yield depended not only on the mitosis inhibitor used but also on the plant species. Treatment of T. pratense embryos with colchicine, amiprophosmethyl and oryzalin yielded similar results in terms of tetraploid production (31.3-40.7%) and chimeras (14.3-22.4%). The concentration of trifluralin used for the production of T. pratense tetraploids was ineffective. Colchicine solution was more efficient for the development of T. hybridum tetraploids whose yield was 2.5 times as high as that obtained having treated the embryos with amiprophos-methyl. Induced tetraploid populations were compared to reference cultivars in field trials. The two T. pratense populations 'Radviliai 4n' and 'Arimaičiai 4n' stood out in this respect - their plants accumulated higher dry matter contents, produced more inflorescences than those of the reference cultivar and exhibited prolific seed yield capacity. In relation to the agrobiological traits, the tetraploid populations of T. hybridum did not surpass the reference cultivar. [ABSTRACT FROM AUTHOR]

O Brasil dispõe de um grande número de variedades de bananeira, porém poucas atendem integralmente as exigências relativas à preferência dos consumidores, à produtividade e à resistência a doenças. O objetivo deste trabalho foi avaliar, durante dois ciclos produtivos, em Guanambi (BA), as variedades Nam (AAA), Caipira (AAA), Grande Naine (AAA) e Prata Anã (AAB) e os híbridos (AAAB) PA12-03, FHIA-01, SH3640 e FHIA-18 quanto ao porte, ao peso do cacho, ao número de pencas e de frutos, ao número de folhas no florescimento e na colheita e ao ciclo, no delineamento inteiramente casualizado. A 'Grande Naine' destacou-se nos dois ciclos, sobretudo na produtividade. No primeiro ciclo, a 'Caipira' e os híbridos FHIA-18 e SH3640 obtiveram, após a Grande Naine, os melhores rendimentos no peso do cacho. A Caipira também se destacou no número de frutos e os híbridos SH3640, FHIA-01 e FHIA-18 mostraram um bom desempenho no número de pencas, superando a 'Prata Anã'. O SH3640 apresentou o maior número de folhas na colheita e o PA12-03 foi o genótipo mais baixo e mais precoce. No segundo ciclo, o SH3640 foi um dos destaques quanto ao peso do cacho, ao número de pencas e ao número de folhas no florescimento e na colheita, perdendo apenas para a Grande Naine, nos dois primeiros caracteres, e para a Prata Anã, nos dois últimos. No número de frutos, a Caipira sobressaiu-se, superando a Grande Naine. Como no primeiro ciclo, o PA12-03 foi o genótipo mais precoce, ao lado do FHIA-18, e o segundo mais baixo, ao lado da Nam. O porte e o peso do cacho tiveram um acréscimo, entre os ciclos, nos genótipos avaliados. Os híbridos possuem potencial para ser lançados como cultivares.Brazil has a great number of banana varieties, however a few of them attend completely the exigencies related to the consumers preference requirements, productivity and diseases resistance. The objective of this work was to evaluate banana varieties and hybrids in Guanambi (BA), in two productive cycles, in a completely randomized design. The genotypes evaluated were the varieties Nam (AAA), Caipira (AAA), Grande Naine (AAA) and Prata Anã (AAB) and the hybrids (AAAB) PA12-03, FHIA-01, FHIA-18 and SH3640. The characters analyzed were plant height; number of leaves in the flowering, in the harvest and in the cycles; number of hands and fingers and bunch weight. The variety Grande Naine stood out in both cycles, specially in characters that expressed the productivity. In the first cycle, 'Caipira' and the hybrids FHIA-18 and SH3640 obtained the best behavior, after 'Grande Naine', for bunch weight. 'Caipira' also stood out in number of fingers, while, in number of hands, the hybrids SH3640, FHIA-01 and FHIA-18 showed a good performance, overcoming 'Prata Anã'. SH3640 presented the largest number of leaves at the harvest, while PA12-03 was the most precocious genotype and had the minor stature. In the second cycle, SH3640 was one of the outstanding genotypes in the characters: bunch weight, number of hands and number of leaves in the flowering and in the harvest, loosing only to 'Grande Naine', in the two first characterers, and to 'Prata Anã', in the two last ones. In number of fingers, 'Caipira' stood out, overcoming 'Grande Naine'. PA12-03 was, like in the first cycle, the material most precocious, together with FHIA-18, and also presenting, with 'Nam', the second best stature. Plant height and bunch weight had an elevation, from the first to the second cycle, in the evaluated genotypes. All hybrids evaluated presented potential to be recommended as varieties.

O conhecimento das características pós-colheita de novos híbridos de bananeira é uma importante informação que auxilia o melhorista em sua tomada de decisão. Este trabalho teve como objetivo avaliar genótipos de bananeira com relação às características de pós-colheita e resistência ao desprendimento do fruto. Foram utilizados frutos da segunda penca de 16 híbridos (Calipso, Bucaneiro, Ambrosia, YB42-21, PV42-53, PV42-68, PV42-81, PV42-85, PV42-129, PV42-142, PV42-143, ST12-31, ST42-08, PV03-44, FHIA-03 e SH 3640) e quatro cultivares (Pacovan, Prata Comum, Nam e Figue Pomme Naine), que foram avaliadas quanto ao peso, comprimento, circunferência, relação polpa/casca, resistência ao desprendimento, firmeza, sólidos solúveis totais (SST), acidez total titulável (ATT), relação SST/ATT e tempo de amadurecimento. Empregou-se um delineamento inteiramente casualizado, com cinco repetições para todas as características, exceto para a firmeza do fruto em que se utilizaram dez repetições. A unidade experimental foi constituída de um único fruto. Os dados foram submetidos à analise de variância e as médias comparadas pelo Teste Scott & Knott, a 5% de probabilidade. A cultivar Nam apresentou a menor acidez titulável e a maior relação SST/ATT, enquanto a maior firmeza do fruto foi apresentada pelos híbridos PV42-81 e PV42-53. Os frutos mais pesados foram do híbrido SH 3640, e os mais compridos foram dos híbridos Bucaneiro e PV42-81. Os híbridos PV42-85 e ST42-08 apresentaram maior resistência ao desprendimento, não diferindo da 'Pacovan'. No entanto, superaram a 'Prata Comum', que obteve a menor resistência. Os genótipos 'Nam', PV42-143 e PV42-129 apresentaram maior tempo de maturação após a colheita quando comparados, principalmente, à 'Prata Comum'. A 'Nam' deve ser considerada como uma nova alternativa na produção de banana. O SH3640, híbrido da Prata Anã, pode ser recomendado como nova cultivar. Os híbridos da Prata São Tomé (ST42-08) e Pacovan (PV42-85, PV42-81, PV42-68, PV42-53, PV42-129 e PV42-143) podem substituir as cultivares Prata Comum e Pacovan nos sitemas produção.The knowledge of the post-harvest characteristics of new banana hybrids is an important information that helps the breeder in making his decision. This work has the objective to evaluate banana genotypes in relation to their post-harvest characteristics and resistance to fruit drop. Fruits of the second hand of 16 hybrids (Calipso, Bucaneiro, Ambrosia, YB42-21, PV42-53, PV42-68, PV42-81, PV42-85, PV42-129, PV42-142, PV42-143, ST12-31, ST42-08, PV03-44, FHIA-03 and SH 3640) and four cultivars (Pacovan, Prata Comum, Nam and Figue Pomme Naine) were evaluated according to their weight, length, circumference, pulp/peel ratio, resistance to fruit drop, firmness, total soluble solids (TSS), total titratable acidity (TTA), TSS/TTA ratio and maturation period. A completely randomized experimental design was used, with five replications, except fruit firmness with ten replications, each unit was constituted by one fruit. The data were submitted to the analysis of variance and the means were compared by the Scott & Knott test at 5% of probability. The cultivar Nam had the lowest TTA and the highest TSS/TTA ratio, while the highest fruit firmness was observed in PV42-81 and PV42-53. The SH 3640 produced the heaviest fruits, and Bucaneiro and PV42-81 produced the longest ones. PV42-85 and ST42-08 showed high resistance to fruit drop, with no statistical difference from 'Pacovan'. 'Prata Comum' showed the lowest resistance. The genotypes ' Nam', PV42-143 and PV42-129 showed longer shelf life when compared to 'Prata Comum'. 'Nam' genotype can be considered as alternative in banana production. SH3640 the Prata dwarf hybrid, might be considered as a new cultivar. Hybrids from Prata São Tomé (ST42-08) and from Pacovan (PV42-68, PV42-81, PV42-85, PV42-129 e PV42-143) can replace Prata Comum and Pacovan in the banana production system.

Cyprininae is the largest subfamily (>1300 species) of the family Cyprinidae and contains more polyploid species (∼400) than any other group of fishes. We examined the phylogenetic relationships of the Cyprininae based on extensive taxon, geographical, and genomic sampling of the taxa, using both mitochondrial and nuclear genes to address the phylogenetic challenges posed by polyploidy. Four datasets were analyzed in this study: two mitochondrial gene datasets (465 and 791 taxa, 5604 bp), a mitogenome dataset (85 taxa, 14,771 bp), and a cloned nuclear RAG1 dataset (97 taxa, 1497 bp). Based on resulting trees, the subfamily Cyprininae was subdivided into 11 tribes: Probarbini (new; Probarbus + Catlocarpio ), Labeonini Bleeker, 1859 ( Labeo & allies), Torini Karaman, 1971 ( Tor , Labeobarbus & allies), Smiliogastrini Bleeker, 1863 ( Puntius , Enteromius & allies), Poropuntiini ( Poropuntius & allies), Cyprinini Rafinesque, 1815 ( Cyprinus & allies), Acrossocheilini (new; Acrossocheilus & allies), Spinibarbini (new; Spinibarbus ), Schizothoracini McClelland, 1842 ( Schizothorax & allies), Schizopygopsini Mirza, 1991 ( Schizopygopsis & allies), and Barbini Bleeker, 1859 ( Barbus & allies). Phylogenetic relationships within each tribe were discussed. Two or three distinct RAG1 lineages were identified for each of the following tribes Torini, Cyprinini, Spinibarbini, and Barbini, indicating their hybrid origin. The hexaploid African Labeobarbus & allies and Western Asian Capoeta are likely derived from two independent hybridization events between their respective maternal tetraploid ancestors and Cyprinion . [ABSTRACT FROM AUTHOR]

Genomic patterns of diversity and divergence are impacted by certain life history traits, reproductive systems, and demographic history. The latter is characterized by fluctuations in population sizes over time, as well as by temporal patterns of introgression. For a given organism, identifying a demographic history that deviates from the standard neutral model allows a better understanding of its evolution but also helps to reduce the risk of false positives when screening for molecular targets of natural selection. Tetraploid organisms and beyond have demographic histories that are complicated by the mode of polyploidization, the mode of inheritance, and different scenarios of gene flow between sub-genomes and diploid parental species. Here we provide guidelines for experimenters wishing to address these issues through a flexible statistical framework: approximate Bayesian computation (ABC). The emphasis is on the general philosophy of the approach to encourage future users to exploit the enormous flexibility of ABC beyond the limitations imposed by generalist data analysis pipelines., (© 2023. The Author(s), under exclusive license to Springer Science+Business Media, LLC, part of Springer Nature.)

Nodal segments of Hebe Comm. ex Juss. ‘Oratia Beauty’ were treated in vitro with colchicine (500 and 1000 μM) and oryzalin (11.5, 58 and 289 μM) to induce polyploid plants. Survival rates from treatments were greater than 73%. All explants were rooted, acclimatized and the morphological traits of plants with different ploidy levels were compared. Flow cytometry was used to confirm diploids, mixoploids and polyploids. The highest frequency of tetraploids was 45.7% using oryzalin (289 μM) and 28.6% using colchicine (1000 μM). Leaves of diploids and tetraploids were not significantly different for length and width, while some tetraploids showed altered phyllotaxis. Stomatal density was significantly lower and stomatal length was significantly higher in tetraploids when compared to diploids. Principal component analysis (PCA) revealed that stomatal traits accounted for a large proportion of variability. Tetraploids (4x) and controls (2x) were propagated vegetatively and morphology compared. Rooting percentage, number of nodes, height and stem diameter were recorded. There was no difference in the rooting percentage (100%), but tetraploids had thicker stems, were shorter and had fewer nodes than diploids. [ABSTRACT FROM AUTHOR]