• Asian Journal of Turfgrass Science
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• v.23 no.2
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• pp.345-352
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• 2009

Zoysiagrass (Zoysia japonica Steud) is a warm season turfgrass species widely used for sports field and golf courses. Many cultivars are propagated through vegetative methods. This study was conducted to develop an optimum culture medium and culture conditions for embryogenic callus induction and plant regeneration, and to establish a cell suspension culture system for use in zoysiagrass breeding and propagation. The results indicated that adding $Cu^{++}$ at 2.5 mg $L^{-1}$ to the induction medium was optimum for callus induction. Increasing the numbers of sub-culture cycles improved the quality of calli. The optimum dosage for cell suspension culture ranged from 2.5 to 10 mL. The embryogenic callus suspension used in this study had a plant regeneration rate of 58%.

• Journal of The Korean Society of Grassland and Forage Science
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• v.24 no.1
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• pp.29-36
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• 2004

In an effort to optimize tissue culture responses of zoysiagrass(Zoysia japonica Steud.) for genetic transformation, factors affecting callus induction and plant regeneration were investigated. MS medium containing 3 mg/L 2,4-D was optimal for embryogenic callus induction from mature seed. The plant regeneration frequency of 73.3% was observed when embryogenic calli induced in this medium were transferred to N6 medium supplemented with 0.1 mg/L 2,4-D and 5 mg/L BA. Among several basic media, MS and N6 medium were optimal for callus induction and plant regeneration, respectively. Regenerated plants were grown normally when shoots transplanted to the soil. A rapid and efficient plant regeneration system established in this study will be useful for molecular breeding of turfgrass through genetic transformation.

• Journal of Korean Society of Forest Science
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• v.94 no.1 s.158
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• pp.39-44
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• 2005

An effective micropropagation system for Liriodendron tulipifera L via somatic embryogenesis was established using immature seeds. Immature seeds from five individual trees were bisected longitudinally and cultured on two basal media (MS and B5) containing different combinations of 2,4-D and TDZ to induce callus and embryogenic tissue under light ($40{\mu}mol\;m^{-2}s^{-1}$, 16 hr/day) or complete darkness at $25{\pm}2^{\circ}C$. There was no distinctive difference on callus and embryogenic tissue induction between the two basal media with PGRs. Optimum culture medium appeared to be MS medium supplemented with 1.0mg/L 2,4-D and 0.01mg/L TDZ plus 3% sucrose. Nonembryogenic callus induction rate was not significantly different among the genotypes. However, However, the embryogenic callus induction frequency differed greatly by the genotypes ranging from 55% to 72% when cultured in the dark. Generally, the cultures maintained in the dark tended to show normal somatic embryo development as well as embryogenic tissue formation and this was confirmed by histological examination. Above results suggest that a proper selection of mother tree and dark culture condition are necessary to optimize somatic embryogenesis system of Liriodendron tulipifera.

• Current Research on Agriculture and Life Sciences
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• v.9
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• pp.21-28
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• 1991

The effect of subculture intervals and passages on plant regeneration from seed-derived callus was determined. Regeneration capacity of callus varied with rice cultivars and subculture intervars tested. The callus subcultured every 2 weeks produced more plants than that of 4 weeks. The calli from a Tongil-type rice cultivar, Milyang 23, lost easily their regeneration ability when the calli were subcultured every 2 weeks and 4 weeks. The callus induced from a japonica cultivar, "Yeongdeogbyeo", showed to maintain high frequency(>70%) of plant regeneration when it was subcultured every 2-week intervals. Casein hydrolysate supplemented in callus induction medium enhanced callus growth and its regeneration. High frequency of plant regeneration was obtained from the calli transferred on $N_6$ medium supplemented with kinetin(2mg/1) and NAA(1mg/1). The subcultured calli in the medium supplemented with casein hydrolysate(2 g/1), myo-inositol(200mg/1) and thiamine-HCl(2mg/1) increased the frequency of embryogenic callus formation and plant regeneration.

• Korean Journal of Plant Tissue Culture
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• v.25 no.2
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• pp.125-129
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• 1998

Cucumber (Cucumis sativus L.) plants were regenerated through organogenesis and somatic embryogenesis in cotyledon and hypocotyl cultures. The shoots were efficiently formed on the basal region of cotyledons cultured on MS medium containing 1.0㎎/L zeatin and 0.1㎎/L IAA in all cultivars used. Embryogenic calli were formed on hypocotyl segments cultured on MS medium containing 1.0㎎/L 2,4-D in cv. group 'Nakhab' and maintained by consecutive subculture on the same medium every 2-3 weeks without loss of embryogenic ability. Upon transfer to MS basal medium, high frequency somatic embryogenesis was achieved easily from embryogenic callus. Regenerated plantlets through organogenesis and somatic embryogenesis were transplanted to pots and gradually acclimatized to greenhouse condition where they subsequently produced fruits.

• Asian Journal of Turfgrass Science
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• v.15 no.1
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• pp.9-14
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• 2001

Callus formation and plant regeneration from the seeds of zoysiagrass cv. Zenith was tested on MS basal medium supplemented with various concentrations of 2,4-dichlorophenoxyacetic acid(2,4-D) and of several cytokinins. A concentration of 1mg/L 2,4-D on medium stimulated callus formation. In the presence of 5mg/L 2,4-D, addition of 1mg/L kinetin significantly enhanced callus formation and plant regeneration over 2,4-D alone. To transfer foreign DNA into turfgrass, parameters for the bombardment of embryogenic callus with the particle bombardment were partially optimized using transient expression assay of a $chimeric \beta$-glucuronidase(GUS) gene driven by the CaMV 35S promoter. GUS gene was strongly expressed at helium pressure 1,100 psi and 6~9cm target distance.

• Journal of Plant Biotechnology
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• v.32 no.3
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• pp.187-193
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• 2005

In an effort to optimize tissue culture conditions for genetic transformation of tall fescue (Festuca arundinacea Schreb.), an efficient plant regeneration system from seed-derived calli was established. MS medium containing 6 mg/L 2,4-dichlorophenoxy acetic acid (2,4-D) and 0.1 mg/L benzyladenine (BA) were optimal for embryogenic callus formation from mature seed and had a strong effect on successive plant regeneration. The plant regeneration frequency above 50% was observed when embryogenic calli induced in this medium were transferred to N6 medium supplemented with 1 mg/L 2,4-D and 3 mg/L BA. Among several basic media, MS and N6 medium were optimal for callus induction and plant regeneration, respectively. 'Kentucky-31' showed to have high frequencies of embryogenic callus induction and plant regeneration up to 58.3 and 50%, respectively. Addition of sucrose to the regeneration medium as a carbon source increased regeneration frequency up to 55%. A short tissue culture period and high-frequency regeneration system established in this study will be useful for molecular breeding of tall fescue through genetic transformation.

• Journal of Plant Biotechnology
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• v.36 no.3
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• pp.236-243
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• 2009

The halophyte Leymus chinensis (Trin.) is a perennial rhizome grass (tribe Gramineae) that is widely distributed throughout China, Mongolia and Siberia. This study was conducted to investigate an optimal condition for plant regeneration from mature seeds, leaf base segments, and root segments in L. chinensis. Plant growth regulators affecting embryogenic callus induction and plant regeneration were investigated by four-factor-three-level [L9 (34)] orthogonal test in this study. The effects of explants types (mature seeds, leaf base segments and root segments), callus types, medium types were examined in this study. Wild type (WT) and Jisheng No. 1 plants (JS) were used for primary callus induction. A clear explants difference was seen during callus induction; mature seeds were considered as the preferred explants; and the highest frequency of callus induction was obtained in Medium 6 using mature seeds as explants in WT. Plant regeneration ability was evaluated by frequencies of green callus forming, shooting, rooting, and shooting with roots. Effect of α-naphthalene acetic acid (NAA) on shoot regeneration was remarkable with the highest frequency of 70.8% in WT after 2-month culture. The medium with 0.2- 0.5 mg/L NAA was found to have the highest shoot induction. All regenerated shoots were successfully rooted when transferred on half-strength Murashige and Skoog (MS) basal medium. The acclimatized plantlets were grown to mature with flowering and seeds setting in green house conditions.

• Journal of Plant Biotechnology
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• v.2 no.2
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• pp.109-113
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• 2000

Somatic hybrids were produced by electrofusion between embryogenic callus protoplasts of 'Syougun' mandarin and leaf protoplasts of grapefruit. Hybridity of the two plants was confirmed by leaf morphological characteristics and random amplified polymorphic DNA (RAPD) analysis. The cpDNA analysis using PCR-RFLP could not distinguish those of both parents. These plants showed normal growth and had chromosome number of 27. These unexpected triploid somatic hybrids might be derived from fused cells between diaploid protoplast of embryogenic calli and diploid protoplast of leaf, because polysomaty, a mixture of haploid cells and diploid cells was observed in the lactose medium-pretreated embryogenic calli of 'Syougun' by flow cytomehy analysis.

• KSBB Journal
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• v.6 no.2
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• pp.201-205
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• 1991

We have investigated influencing factors on viability of Bletilla striata protoplasts electroporated in the presence of various electrical conditions. Cultures of embryogenic callus and embryogenic cell suspension were established with immature seeds of Bletilla striata. Viabilty of electroporated protoplasts was decreased according to the increaseing of electroporation voltage and capacitance. An optimal condition of electroporation for viable protoplasts was in HBM buffer at $4^{\circ}C$.