Tetraploid Plants Research Articles

Effect of Changes in Genome Ploidy on the Mosaic Character of nptII Gene Expression in Epialleles of the Transgenic Tobacco Line Nu21

The influence of changes in the genome ploidy and the gene dose on the mosaic pattern of expression of the nptII gene in epialleles of the Nu21 transgenic tobacco line was evaluated. The general preservation of the expression profile of the marker gene nptII is shown (high in the Nu5 epiallele and low in the Nu6 epiallele) in heteroploid crosses of diploid transgenic plants (2n = 48) with polyploid nontransgenic plants (3n = 72, 4n = 96), as well as in self-pollination of experimentally obtained tetraploid transgenic plants of the Nu21 line (4n = 96) and in their hybrids from crossing with nontransgenic diploid plants. It has been established that the stability of expression of the nptII marker gene is influenced by the initial epigenetic status of epialleles and the direction of crossing in hybridization of tetraploid nontransgenic tobacco plants with diploid transgenic plants of the Nu21 line.

Morphological and anatomical characters of diploid and tetraploid taro (Colocasia esculenta L. Schott) cv. Bentul grown in lathhouse

A number of tetraploid taros Bentul has been produced by in vitro polyploidization with oryzalin treatment to achieve optimal production and to overcome pests, diseases and drought stress. Planlets achieved from polyploidization had high survival rate on acclimatization process. Characterization was conducted for diploid and tetraploid Taro plants grown in Lathhouse. The aim of morphology and anatomy characterization of tetraploid taro was to compare those with diploid one. The results showed that the morphological characters of seven clones of tetraploid taro Bentul presented 56% similarity with the diploid and divided into three different subgroups with 63% similarity. The thickness of leaves tissue was not significantly different. Stomata size of tetraploid taro was larger than diploids but the stomata density was lower. Thickness of petiole epidermis of diploid taro was significantly different with tetraploid 75.2.1. Thickness of root epidermis of diploid taro was significantly different with tetraploid 7,5.12.2; 30.4.6; 60.2.6 and 75.2.3. Diameter of root stele of taro Bentul was not significantly different between diploid and tetraploid clones.

Development and characterization of tetraploid castor plants

AbstractCastor is a prime industrial crop belonging to a monotypic genus and its genetic improvement depends on creating desired variability in the primary gene pool. This study reports the development of tetraploid castor plants through colchicine treatment. Seeds of three castor genotypes were soaked in aqueous solutions of colchicine with variable concentrations, and the LD50value was determined. Of 1010 treated field-raised plants, three were identified as potential polyploids based on increases in a guard cell size and reductions in the number of stomata. The putative polyploid plants were selfed and the progeny were subjected to meiotic analysis. All the progeny were found to be tetraploid. The pairing of chromosomes was abnormal with univalent to octavalent configurations during meiosis-I, but the later parts of meiosis were normal. Seasonal variations in pollen fertility indicated the possible role of temperature-sensitive male sterility in causing the sterility in tetraploid plants. The tetraploid plants were phenotypically comparable with their diploid counterparts, but produced substantially bigger seeds. Thus, these tetraploid plants are valuable resources for basic and applied research in castor.

Successful induction and the systematic characterization of tetraploids in cerasus humilis for subsequent breeding

The Chinese dwarf cherry (Cerasus humilis; 2n = 16) has been increasingly prized for its colorful fruits, high economic values, nutraceutical benefits, and wide adaptability for diverse soil and environmental conditions. Polyploid induction is an efficient way to develop new selections and cultivars of horticultural crops. In this study, successful induction of tetraploids (2n = 32) in C. humilis (cultivar: ‘Nongda 7’) was achieved and the tetraploid plants were subsequently characterized. The highest mutagenesis rate reached in our study was 30.0 % with 80 mg/L colchicine added to the solid Murashige and Skoog (MS) media for both the embryo and stem tip. In liquid media, the highest mutagenesis rate achieved was 16.7 % with the addition of 60 mg/L colchicine. Systematic examination of the induced tetraploid mutants, significant morphological differences were observed in leaves, stems, and roots. Tetraploid mutants exhibited larger leaves, shorter internodes, and thicker roots than their diploid counterparts. Moreover, average stomatal size of the tetraploid mutants was significantly larger than that of the diploids. At the same time, the stomatal density of tetraploid plants decreased significantly in comparison to the that of diploids. The tetraploid mutants have been and will be used in our breeding efforts of new cultivars with higher yields, better fruit quality and wider adaptability.

Chemical polyploidization of Chrysanthemum boreale

Chrysanthemum boreale (Asteraceae) is a wild flowering plant that has both ornamental and herbal uses. In the present study, colchicine was used as a chemical mutagen to induce polyploidy using in vitro shoots, which were cultured from C. boreale (2n = 2x = 18) nodal segments, and the efficacy of various colchicine concentrations and treatment durations were investigated. The results demonstrated that the induction of tetraploid plants by colchicine treatment were clearly successful. A total of 21 tetraploid and 110 chimera plants were identified using the chromosome counting method, and the colchicine concentrations of 200 ppm (48 h) and 300 ppm (12 and 24 h) were the most effective for inducing tetraploidy. Details about the successful induction, morphological characteristics, and cytology of the polyploids are described and compared with those of control plants. The tetraploid plants exhibited thicker and larger leaves, as well as larger and fewer stomata than the diploid plants. In this study, the polyploid plants of Chrysanthemum were induced successfully using colchicine treatment. This procedure contributed to the improvement of high-value species in the Chrysanthemum breeding program.

A highly efficient organogenesis protocol based on zeatin riboside for in vitro regeneration of eggplant

BackgroundEfficient 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.ResultsIn 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.ConclusionsAn 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.

Induction of new tetraploid genotypes and heat tolerance assessment in Asparagus officinalis L

Tetraploid induction is an effective way to generate new genotypes. In this study, tetraploid inductions of asparagus (Asparagus officinalis L.) were obtained by applying several treatments with colchicine. Optimal results (31 %) were obtained by applying 0.15 % colchicine plus 2 % dimethyl sulphoxide (DMSO) to recently germinated seeds (5 days old) for 16 h. Sixty-five tetraploid plants were recovered from this treatment and diploid and tetraploid plants showed significant differences in morphology. The stomatal density of tetraploid asparagus was approximately half than that of diploid plants, whereas the chloroplast number of tetraploid plants was twice that of diploid plants; moreover, the stomatal length and breadth were slightly larger in tetraploid plants than in diploid plants. Furthermore, in tetraploid genotypes the chlorophyl A content was double than that of diploid plants, whereas chlorophyl B and total chlorophyl contents were three times higher than in diploid plants. The tetraploid plants showed better growth, more flowering flourish, deeper color, and bulkier leaves in comparison to the diploid plants. Moreover, tetraploid plants had lower malonaldehyde (MDA) and higher activity of superoxide dismutase (SOD), peroxidase (POD) and free proline (Pro), the differences were all significant, indicating that tetraploid plants had increased heat resistance however there was no significant difference in the heat tolerance between plants of the same ploidy. Tetraploid plants with strong heat resistance broaden the asparagus gene pool and could aid future breeding work in asparagus.

Identification of Ploidy Variation of Ponkan Embryo Rescue Plants

China has abundant of local citrus resources, which had many seeds. The Seedless is the aim of the local citrus breeding. Triploid citurs resources usually obtained by crosssing breeding between the diploid and tetraploid plants. However, the resources of tetraploid citrus are limited. It has been reported that the hybrid between diploid and diploid plants can produce triploid citrus, which not only saves the breeding time, but also shortens the breeding cycles. In this project, flow cytometry detection assisted by embryo rescue system and SSR identification technology were used to improve the probability of obtaining polyploidy from the hybrid offspring, and provide technical support for obtaining polyploidy from large-scale hybridization between diploid and diploid. plants. Three diploid pollen cultivars were crossbred with Hunan local cultivar 8306, immature seeds were collected for embryo rescue to obtain regenerative plants, plant ploidy was detected by flow cytometry and stoma electron microscope, and offspring genotypes were identified by SSR. After 100 d hybrid between three diploid pollens and Ponkan 8 306, 405 plants were obtained by embryo rescue technique. And 70 plants survived in the greenhouse after transplantation. Through flow cytometry instrument and stomatal electron microscope inspection, the results showed that SSR analysis validated that there are 13 polyploid plants, including 1 tetraploid plant and 12 triploid plants. The ratio of polyploidy was 18.57%. This study is obtained triploid and tetraploid plants by Ponkan embryo rescue from diploid interspecific hybridization. In this study, the embryo rescue technology system and the early identification system for polyploid hybridization were established, and a lot of new polyploid germplasm were obtained.

Effect of Colchicine treatment on the cariology and morphology signs of Polemonium caeruleum L.

The effect of colchicine treatment of P. caeruleum on morphological and economically valuable traits, pollen size and fertility, and karyotype of also was studied. Colchicine treatment increased in the size of pollen by 13 % compared to the control, pollen fertility decreased by 19 %. Stained chromosomes of the karyotype were identified, their sizes were determined for the first time, and karyotype formulas for diploid K = (5m + 2sm + 2st) and tetraploid forms K = 2 (10m + 4sm + 4st) were compiled. As a result of colchicine treatment, the plant height decreased by 35 %, the stem thickness by 47 %, the number of generative shoots 18 %, the leaf length 23 % and width increased 22 %, compared to the control. The productivity of raw by 32 % and seeds of tetraploid plants exceeds diploid plants by 22 %.This research was supported government as signment (No. 0576-2019-0008).

Autopolyploidy effect on morphological variation and essential oil content in Thymus vulgaris L.

Garden thyme (Thymus vulgaris L.) is well known for its aromatic, anti-pathogenic and antioxidant properties and is commonly cultivated for ornamental, culinary and medicinal uses. The aim of this study was to induce ployploidy in T. vulgaris in order to obtain tetraploid plants (2n = 4x = 60) with enhanced morphological traits and increased essential oil content from diploid plants (2n = 2x = 30) using in vitro-induced polyploidization. Nodal segments were treated with four different concentrations of oryzalin (20, 40, 60 and 80 μM) for 24 and 48 h. The ploidy levels of treated and regenerated plants were determined by flow cytometry analysis. The chemical composition of hydrodistilled essential oil was analysed by gas chromatography with quadrupole time-of-flight mass spectrometry systems. Oryzalin treatment resulted in three tetraploid plants at a concentration of 80 μM for 24 h. Obtained tetraploid plants presented several morphological changes (increased plant weight, height, leaf length, breadth and thickness) in comparison to diploid plants. Furthermore, polyploidization demonstrated an increase in the production of secondary metabolites; tetraploids yield of essential oil increased from 0.81 % to 1.19 % and the content of several main components increased, including thymol and carvacrol by 18.01 % and 0.49 %, respectively. The obtained genotype could be implemented as a new variety for commercial production of garden thyme.

A Comparative study of morphological and volatile oil composition characteristics in diploid and tetraploid garlic plants

A Comparative study of morphological and volatile oil composition characteristics in diploid and tetraploid garlic plants

Effects of methyl jasmonate on the growth and triterpenoid production of diploid and tetraploid Centella asiatica (L.) Urb. hairy root cultures

In this study, the effects of methyl jasmonate (MeJA) on the phytomass and triterpenoid production of diploid and tetraploid Centella asiatica hairy roots were investigated. Hairy root cultures were obtained from diploid and induced tetraploid plants of C. asiatica infected by Agrobacterium rhizogenes strain ATCC 43057. MeJA triggered triterpenoid production in both ploidy hairy roots, whereas triterpenoids were not produced in the untreated hairy roots. Among the treatments, the 50 µM MeJA treatment yielded the maximum triterpenoid production in diploid hairy roots of 27.25 ± 0.27 µg/mg Dry weight (DW) total triterpenoid at day 21. For the tetraploid hairy root cultures, the 28th-day hairy root culture produced a maximum amount of triterpenoids of 16.29 ± 6.32 µg/mg DW in response to the 50 µM MeJA treatment, whereas the 100 µM MeJA treatment produced a similar triterpenoid amount (16.31 ± 9.24 µg/mg DW) at day 14. Moreover, in response to 50 µM MeJA, we obtained different ratios of aglycone to glycoside, i.e., 1:7 and 1:2, between the diploid and tetraploid hairy root cultures. Asiaticoside was the dominant phytochemical, followed by asiatic acid and madecassic acid. This study provides valuable information for producing triterpenoids for C. asiatica commercial products and preparations by using hairy root cultures.

Enhanced thebaine and noscapine production and modulated gene expression of tyrosine/dopa decarboxylase and salutaridinol 7-O-acetyltransferase genes in induced autotetraploid seedlings of Papaver bracteatum Lindl

Papaver bracteatum, belonging to Papaveraceae, is considered to be a primary ingredient in the production of codeine and anti-drug drugs (e.g., naloxone and Naltrexone) without the involvement of morphine. For polyploidy induction, papaver seedlings were treated with various colchicine concentrations (0, 0.05, 0.1, 0.2 and 0.5% w/v) in three time durations (24, 48 and 72 h). The effects of polyploidy induction on morphological, physiological, alkaloid production and gene expression levels in the pathway of benzylisoquinoline alkaloids were analyzed. High rates of seedling survival were observed at lower colchicine concentrations (0.05 and 0.1% w/v) versus higher concentrations (0.2 and 0.5% w/v). The best polyploidy treatment to induce P. bracteatum shoot tips was observed in plants treated with 0.2% colchicine for 72 h. P. bracteatum-induced tetraploids showed higher stomata and an increase in leaf area (mm2), chlorophyll (a, b and total) and a decrease in stomata density, leaf length (cm) and petiole length. Flow cytometry and chromosome counting analysis revealed that chromosome number was 2n = 2x = 14 in diploid plants and 2n = 4x = 28 in tetraploid plants. Gene expression analysis through semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) showed that the transcription level of sat and tydc genes of the benzylisoquinoline biosynthesis pathway was enhanced in tetraploid plants. The tetraploid plants of P. bracteatum also showed 5.86 and 30.55 times higher thebaine and noscapine contents than the diploid plants, respectively. Regarding the higher commercial value of thebaine and noscapine, tetraploids can efficiently be used to improve the thebaine and noscapine production of P. bracteatum.

Induction, identification and genetics analysis of tetraploid Actinidia chinensis.

Actinidia chinensis is a commercially important fruit, and tetraploid breeding of A. chinensis is of great significance for economic benefit. In order to obtain elite tetraploid cultivars, tetraploid plants were induced by colchicine treatment with leaves of diploid A. chinensis ‘SWFU03’. The results showed that the best treatment was dipping leaves 30 h in 60 mg l−1 colchicine solutions, with induction rate reaching 26%. Four methods, including external morphology comparison, stomatal guard cell observation, chromosome number observation and flow cytometry analysis were used to identify the tetraploid of A. chinensis. Using the induction system and flow cytometry analysis methods, 187 tetraploid plants were identified. Three randomly selected tetraploid plants and their starting diploid plants were further subjected to transcriptome analysis, real-time quantitative polymerase chain reaction (RT-qPCR) and methylation-sensitive amplification polymorphism (MSAP) analysis. The transcriptome analysis results showed that there were a total of 2230 differentially expressed genes (DEG) between the diploid and tetraploid plants, of which 660 were downregulated and 1570 upregulated. The DEGs were mainly the genes involved in growth and development, stress resistance and antibacterial ability in plants. RT-qPCR results showed that the gene expression levels of the growth and stress resistance of tetraploid plants were higher than those of diploid ones at the transcriptome level. MSAP analysis of DNA methylation results showed that tetraploid plants had lower methylation ratio than diploid ones. The present results were valuable to further explore the epigenetics of diploid and tetraploid kiwifruit plants.

Morphological, anatomical, physiological, and cytological studies in diploid and tetraploid plants of Ispaghul (Plantago ovata Forsk.)

Ispaghul (Plantago ovata Forsk.) as an important medicinal plant has obtained a remarkable reputation due to therapeutic applications of seed mucilage. To determine the effect of in vitro-induced polyploidy on various characteristics of P. ovata, the terminal bud of two true leaves seedlings were separately treated with colchicine [0.1, 0.3 and 0.5% (w/v) for 6, 12 and 24 h] and trifluralin [7.5, 15 and 22.5% (w/v) for 24, 48 and 72 h] solutions. The ploidy level of induced tetraploids was determined via chromosome counting of root tip cells, and then confirmed through flow-cytometric analysis. Comparison the morphological, physiological, anatomical features of intact diploids and induced tetraploids revealed that tetraploids had considerable more height, thicker leaf, larger spike and seed, larger pollen grain and more seeds per spike. Moreover, the amount of chlorophyll (a, b, and total) and carotenoids, as well as chloroplast number in guard cells was further in tetraploids than diploids. Unlike density, stomata size in tetraploids was bigger than that one in diploids. It was also observed that seeds of tetraploids had more mucilage than diploids. In summary, we firstly developed the P. ovata tetraploids and suggested 0.3% colchicine for 24 h and 22.5% trifluralin for 72 h as the optimum treatments for inducing tetraploidy in P. ovata.

Biological and economic characteristics of the allotetraploid with genomic formula DDAuAu from the cereal family

The synthesis of new allopolyploid cereal genotypes is an important task aimed at involving new genetic resources in breeding programs. Diploid species of the genera Triticum and Aegilops – bread wheat relatives – are an important source of agronomically valuable traits. A tetraploid synthetic with genomic formula DDAuAu was obtained by N.A. Navruzbekov through crossing Aegilops tauschii Coss. and Triticum urartu Thum. ex Gandil. The purpose of this work was to study the chromosomal composition and biological and commercially important traits of the tetraploid. Cytogenetic analysis using fluorescent in situ hybridization showed the presence of all chromosomes of the D genome in the chromosomal complement of the synthetic. By means of stepwise vernalization, the winter habit was established for the tetraploid synthetic with the optimum vernalization requirement of 45 days. Under greenhouse conditions, two groups of genotypes were found whose flowering dates differed by 6.5 days, which may indicate an allelism at the Vrn-3 locus. The coloring of various organs of the tetraploid plant, such as coleoptile, stem, anthers, and glumes of the spike, was revealed. The coloration of the aleurone layer of the grain may indicate that the donor species T. urartu is a carrier of the Ba gene that controls its blue color. A new morphotype of leaf pubescence was found. In terms of productivity, the tetraploid is comparable to bread wheat. Grains are characterized by a supersoft structure and high wet gluten content, from 39–45 to 65 %, in the field and greenhouse conditions, respectively. Thus, the tetraploid can be used to create new wheat genotypes as a source of untapped genetic diversity, as well as a new genetic model for studying the patterns of evolution of polyploid plants.

Developing polyploid genotypes of Leptospermum scoparium

ABSTRACTLeptospermum scoparium (‘Mānuka’) is native to New Zealand and South Eastern Australia. Throughout this range the species typically exists as a diploid. Only a single tetraploid accession has ever been reported and all the polyploid cultivars currently available are derivatives of that plant. Polyploidy in other species is known to influence vegetative and floral form, phenology and fertility. Floral diameter was therefore measured for the tetraploid L. scoparium ‘Keatleyi’, the triploid L. scoparium ‘Martinii’ and three diploid seedlings. The floral diameters of the tetraploid and triploid were significantly greater than those from diploid plants. However, the diploid flowers were also significantly different from each other, indicating that factors other than polyploidy influence this trait. Additionally, given the very limited number of polyploid clones available, methods were tested to generate more tetraploid plants for future study. Colchicine was effective at producing tetraploid seedlings with 6 mg/ml, the highest concentration tested, yielding the largest number of tetraploids. This method is now being used to generate tetraploids from a range of L. scoparium material.

Targeted Editing of the StPDS Gene using the CRISPR/Cas9 system in Tetraploid Potato

The CRISPR/Cas9 system has been applied in a variety of plants for targeted gene editing due to its accuracy, high efficiency, and low price. It has been reported that the CRISPR/Cas9 system can lead to mutation in potato, however, the mutation patterns and genotypes of CRISPR/Cas9-induced mutants in tetraploid potato plants have not yet been disclosed in detail. In the present study, the Solanum tuberosum phytoene desaturase (StPDS) gene was selected for inducing targeted mutagenesis. The obtained StPDS knockout mutants exhibited a mutation frequency of 46.67% and clear albino phenotypes. All transgenic plants were tested for the hygromycin resistance gene and a high positive transformation frequency (96.77%) was observed in all tested resistant plants. Genotype analysis of the mutants revealed that heterozygotes accounted for 35.51%, chimeras accounted for 64.29%, and no homozygotes and biallelic mutations were detected. The patterns of the detected mutations consisted mainly of 1 to 2-nucleotide insertions and deletions, followed by 2-bp replacements. In short, the results of this study prove that the CRISPR/Cas9 system is an effective approach for cultivated potato gene engineering.

Comparative study of the morphological, physiological and molecular characteristics between diploid and tetraploid radish (Raphunas sativus L.)

Polyploidization has been widely used in breeding novel verities in crops and vegetables, since the polyploid plants have many advantages and better performance than their relative diploids. As one of the most favorite diploid vegetable crops cultivated worldwide, there were very limited reports about the induction of radish (Raphunas sativas) tetraploid. Moreover, premature-bolting has become the major limitation factor impacting the radish production and quality. Previous studies suggested that phytohormones play essential roles in the regulation of bolting and flowering. However, the morphological, physiological and biochemical features, as well as the relationship between endogenous phytohormones, flowering genes and bolting in tetraploid radish have not been extensively reported. In this study, we used colchicine to successfully induce tetraploid carmine radish plants, evidenced by flow cytometric quantification of DNA content and the cytological observations of stomata numbers and chloroplasts in pollen mother cells. The tetraploid plants displayed “gigas” effect, including greater size of both vegetative and reproductive organs. Furthermore, the physiological characterization demonstrated that tetraploid radish has improved antioxidant enzyme activity, soluble contents and better quality. Importantly, quantification of endogenous phytohormone levels showed that multiple phytohormones, including GAs, JAs, CTKs, and SA are negatively, whereas ABA and IAA are positively associated with the delayed bolting and flowering in tetraploid, which are contrast to that in diploid plants. Moreover, qRT-PCR analysis suggested that the gene negatively associated with flowering and bolting, FLC1.1, was highly expressed in tetraploid plants at flowering stage, whereas the expression levels of genes positively associated with flowering and bolting were much lower in tetraploid compared to diploid radish, at flowering and bolting stages. These data will provide evidences for breeding late-bolting radish variety through induction of tetraploids.

Morphological, anatomical, physiological, and cytological studies in diploid and tetraploid plants of Plantago psyllium

Plantago psylliumis is under development as the source of mucilage, but has not been entirely domesticated. Since mucilage content is low and variable in the medicinal plant, it is imperative to apply breeding approaches to accelerate the domestication process and improve the mucilage content in the seeds. One approach to achieve these purposes is polyploidy induction, which can increase the size of plants and their phyto-medicines. To conduct this approach and evaluate the effect of in vitro-induced polyploidy on different traits of P. psylliumis, a gradient of colchicine concentrations, 0.1, 0.3 and 0.5% (w/v), was used to treat the terminal buds for 6, 12 and 24 h. The terminal buds were separately treated with different trifluralin concentrations, 7.5, 15 and 22.5% (w/v), for 12, 24 and 48 h. The optimal treatments of 0.5% colchicine for 24 h, and of 22.5% (w/v) trifluralin for 72 h resulted in an induction efficiency of 23% and 19%, respectively. Chromosome counting revealed successful chromosome duplication in tetraploids (2n = 4x = 24), in contrast with intact diploids (2n = 2x = 12). Duplication of DNA size in tetraploids was also proved by flow-cytometry analysis. The tetraploids size was larger than their intact diploids for spike, seed and pollen grain, leaf thickness, and plant height. The stomata of tetraploids were larger with lower density than diploids. The chloroplast number in guard cells, along with chlorophyll and carotenoid content all were higher in tetraploids. In final, our study suggests that tetraploidization could be useful to improving the seed mucilage content for commercial use. We firstly fulfilled the in vitro induced tetraploidy in P. psyllium by 0.5% colchicine for 24 h and 22.5% (w/v) trifluralin for 72 h, and improved the mucilage content in the seeds.