Microspore culture in Corchorus olitorius: effect of growth regulators, temperature and sucrose on callus formation

Culture of isolated microspores and of anthers on media containing IAA directed free microspore development to an embryogenic pathway in C. olitorius. The first division of microspores on transfer to culture media was symmetrical in contrast to the asymmetrical division seen in normal development in vivo. Initially, 10-30% microspores divided symmetrically, but only 0.2-1% of the dividing microspores continued dividing and produced multicellular microcalli. About 30% of these microcalli produced callus but only on medium with 2.0 mg/L zeatin and 0.1 mg/L IAA. Incubation in the dark at temperatures of 35 degrees C for 1 day and then 25 degrees C was found effective for induction of first embryonic division in Corchorus. The frequency of microspore callus formation was higher on medium containing either 3% or 5% sucrose. Addition of colchicine and addition of activated charcoal to the above medium did not enhance microspore division in Corchorus olitorius. On transfer to different media most calli produced roots but regeneration of shoots and embryos was not induced.     

茎用芥菜细胞质雄性不育系子叶原生质体培养和高效植株再生

利用茎用芥菜细胞质雄性不育系原生质体培养获得了再生植株,并研究了影响原生质体培养的因素.结果表明,子叶是茎用芥菜原生质体培养最佳的外植体,10 d苗龄的子叶原生质体在改良MS培养基上培养3 d后发生第1次细胞分裂,6 d后发生第2次分裂,3周后形成细胞团,5周后形成肉眼可见的小愈伤.培养基中缺少NAA或2,4-D都会降低愈伤组织的再生能力.在含一定浓度的NAA(0.25 mg/L)和2,4-D(0.25 mg/L)培养基上诱导的愈伤组织质地致密且有光泽,芽的分化能力高;在MS+BA l mg/L+NAA 0.2 mg/L的培养基上芽的分化频率高达近29%,再生芽在1/2MS+NAA0.1 mg/L培养基上生根,形成完整植株.     

茎用芥菜细胞质雄性不育系子叶原生质体培养和高效植株再生（英文）

利用茎用芥菜细胞质雄性不育系原生质体培养获得了再生植株,并研究了影响原生质体培养的因素.结果表明,子叶是茎用芥菜原生质体培养最佳的外植体,10 d苗龄的子叶原生质体在改良MS培养基上培养3 d后发生第1次细胞分裂,6 d后发生第2次分裂,3周后形成细胞团,5周后形成肉眼可见的小愈伤.培养基中缺少NAA或2,4-D都会降低愈伤组织的再生能力.在含一定浓度的NAA(0.25 mg/L)和2,4-D(0.25 mg/L)培养基上诱导的愈伤组织质地致密且有光泽,芽的分化能力高;在MS+BA l mg/L+NAA 0.2 mg/L的培养基上芽的分化频率高达近29%,再生芽在1/2MS+NAA0.1 mg/L培养基上生根,形成完整植株.     

Temporary chromosome number stabilization in potato cell cultures

Cell cultures of Solanum chacoense (monohaploid) and Solanum tuberosum (tetraploid cultivars and parthenogenetically derived dihaploid clones) were found to be highly mixoploid.Relative stabilization of chromosome number at the ploidy level of the original plant material was achieved in microcalli obtained from single cells or small cell colonies (up to about 5 cells) of stock callus lines. This relative stabilization was maintained over three subcultures, which is sufficient for selection procedures. It has been shown that the stabilization can be maintained during a number of further subcultures. Division centers were repeatedly observed in calli characterized by high mitotic activity. As has been shown for the first time there exist significant differences in the ploidy levels of several division centers within one and the same callus. This is of particular importance to callus subculture.     

Development of Plantlets from Leaf Protoplast Culture in Brassica juncea var. tsatsi

Protoplast of two mustard cultivars: Brassica juncea var. tsatsi cv. “Quxian Jiaoercai” and “Bangbangcai”, were isolated by enzymolysis from leaf grown in vitro. Protoplasts were suspended in liquid medium and semi-solidified medium with 0.35% low melting point agarose which formed a thin layer floating on the surface of the liquid medium. The first division appeared after 48h in the culture. One week after the original culture, a diluted medium with gradual dicrease of mannitol concentrations (6%→4%→zero) was then added to the culture three times respectively at one week's interval. In this culture method cell division and formation of microcalli were achieved. During the liquid culture of protoplasts, shaking at 20 rpm from time to time was beneficial in the formation of cell colonies and microcalli. Cell colonies developed into calli of approx 0.5—1mm in diameter one month after culture. The plating efficiency, which defined as the percentage of microcatli to numbers of protoplasts, was 0.2%—1%. Shoot regeneration occured when leaf protoplast-derived calli of “Quxian Jiaoercai” were transferred onto the modified MS medium supplemented with BAP 2.0mg/L, KT 1.0mg/L and NAA 0.2mg/L, and those of -'Bangbangcai" were transferred onto the modified MS medium supplemented with BAP 2.0mg/L. Individual shoot was rooted on a rooting medium supplemented with NAA 0.2 or 0.4 mg/L.     

Plant Regeneration from Callus Protoplasts of Codonopsis pilosula

Embryogenic cell line was established from hypocotyl segments of Codonopsis pilosula (Franch.)Nannf. 4--8 day old embryogenic callus was used to isolate protoplasts in an enzyme solution containing 1.5 % cellulase Onozuka R-10 and 3 % pectinase. Protoplasts were cultured in MS,C81V,DPD and KMSp basal medium supplemented with 1.2 mg/L 2,4-D, 0.2 mg/L NAA, 0. 2 mg/L BAP, 0. 1 mg/L ZT,and different combinations of glucose and mannitol . Protoplast-derived cells underwent sustained divisions in KM8p medium. As an osmoticum, glucose was more beneficial to protoplast division. A combination of 0. 30 mol/L glucose with 0.10 mol/L mannitol gave the best result. Under proper conditions , protoplasts underwent the first division on the 3rd day of culture,formed colonies within 30 days , and developed into microcalli in 6 weeks. Plantlets were regenerated from protoplast-derived calli through somatic embryogenesis. 0.2 % activated charcoal promoted embryoid formation and root development.     

Enzyme fingerprint analyses in tissue regenerated from anther culture of maize

The objectives of our studies were to investigate the effect of cold pre-treatment duration and the effect of two different culture media (YP and N6) on maize anther culture response in two maize genotypes (A 18 and A 19) and to identify the gametic origin of the maize regenerants. Androgenic induction and callus formation was compared in anther cultures following pre-treatment applied to both media tested and with both maize genotypes. Higher plant regeneration was observed in case of YP media independently of the genotype used. The best results were achieved when 12 days (genotype A 18) or 14 days (in case of genotype A 19) cold pre-treatment at 10°C was applied. We have tested the possibility of using enzyme isoform analyses to identify the microspore origin of calli and plants derived from anther cultures. The 11 enzymes tested in our experiments were acid phosphatase, alcohol dehydrogenase, catalase, diaphorase, β-glucosidase, glutamate oxaloacetate transaminase, isocitrate dehydrogenase, malate dehydrogenase, 6-phosphogluconate dehydrogenase, phosphoglucomutase and phosphoglucoisomerase. Analysis of malate dehydrogenase proved the gametic origin of the calli initiated and of the DH plants regenerated from anther culture, when the coleoptile of the donor plant material showed two forms of enzyme 3/6 and the analysed calli showed only one of the two forms (3 or 6).     

An optimising protocol for protoplast regeneration of three peppermint cultivars ( Mentha x piperita)

An efficient protocol for plant regeneration from protoplasts of peppermint ‘Mitcham Digne 38’, ‘Mitcham Ribecourt 19’ and ‘Todd's#x2019; was developed by stepwise optimization of first cell division, microcalli formation and shoot differentiation. The rate of first cell divisions was strongly dependent on the addition of 2,4-D to callus induction medium. Best results were obtained with 1 μM 2,4-D in combination with NAA (2.5 μM) and BA (4 μM). Although liquid medium was more efficient to support first protoplast divisions, solid medium was clearly more suitable to sustain subsequent cell divisions leading to the formation of microcalli. Shoot organogenesis was induced from protoplast-derived calli by using reduced auxin concentration (0.5 μM NAA) and high concentration of cytokinins. Addition of 2.3 μM thidiazuron increased bud formation, allowing a regeneration frequency of more than 50% from calli of ‘Mitcham Digne 38’ and ‘Todd's’. Genotypic differences were noticed for regeneration capability and the pathway of shoot regeneration. This revised version was published online in June 2006 with corrections to the Cover Date.     

Protoplast culture of rice (Oryza sativa L.) using media solidified with agarose

A procedure is described for the reproducible establishment of rice cell suspension cultures from callus of embryo origin. Protoplasts were readily isolated from cell suspension of four rice cultivars, including japonica and indica types, when maintained in an amino acid-based culture medium. Sustained protoplast division from two japonica genotypes has been obtained in agarose solidified culture medium. An increase in the agarose concentration from 0.6% to 1.2% (w/v) produced a marked improvement in protoplast survival, division and plating efficiency. Protoplast division and plating efficiency frequencies of up to 26% and 0.5%, respectively, were obtained at the higher agarose level. The protoplast-derived calli were similar in appearance to explant-derived morphogenic callus and produced distinct embryo-like structures.     

Plant Regeneration from Protoplasts of Actinidia chinensis Planch.

Protoplasts isolated from cotyledon callus line of A14N7 of Actinidia Chinensis Planch. were cultured in the improved NN-69 medium. First division of regenerated cells occurred during 7–10 days of culture, and percentage of the cell division was about 10% at day 20. The best result of protoplast culture was achieved when protoplasts were cukured in liquid medium at a density of 5× 104/ml, About 4 months, procoplast-derived calli were transferred stepwisely onto differentiation media where they developed into green compact calli, from which the perfect plants were regenerated.     

Somatic embryogenesis in peach palm using the thin cell layer technique: induction, morpho-histological aspects and AFLP analysis of somaclonal variation

BACKGROUND AND AIMS: The thin cell layer (TCL) technique is based on the use of very small explants and has allowed enhanced in vitro morphogenesis in several plant species. The present study evaluated the TCL technique as a procedure for somatic embryo production and plantlet regeneration of peach palm. METHODS: TCL explants from different positions in the shoot apex and leaf sheath of peach palm were cultivated in MS culture medium supplemented with 0-600 microM Picloram in the presence of activated charcoal. The production of primary calli and embryogenic calli was evaluated in these different conditions. Histological and amplified fragment length polymorphism (AFLP) analyses were conducted to study in vitro morphogenetic responses and genetic stability, respectively, of the regenerated plantlets. KEY RESULTS: Abundant primary callus induction was observed from TCLs of the shoot meristem in culture media supplemented with 150-600 microM Picloram (83-97%, respectively). The production of embryogenic calli depends on Picloram concentration and explant position. The best response observed was 43% embryogenic callus production from shoot meristem TCL on 300 microM Picloram. In maturation conditions, 34+/-4 somatic embryos per embryogenic callus were obtained, and 45.0+/-3.4% of these fully developed somatic embryos were converted, resulting in plantlets ready for acclimatization, of which 80% survived. Histological studies revealed that the first cellular division events occurred in cells adjacent to vascular tissue, resulting in primary calli, whose growth was ensured by a meristematic zone. A multicellular origin of the resulting somatic embryos arising from the meristematic zone is suggested. During maturation, histological analyses revealed bipolarization of the somatic embryos, as well as the development of new somatic embryos. AFLP analyses revealed that 92% of the regenerated plantlets were true to type. The use of TCL explants considerably improves the number of calli and somatic embryos produced in comparison with previously described protocols for in vitro regeneration of peach palm. CONCLUSIONS: The present study suggests that the TCL somatic embryogenesis protocol developed is feasible, although it still requires further optimization for in vitro multiplication of peach palm, especially the use of similar explants obtained from adult palm trees.     

埃斯基红豆草下胚轴愈伤组织原生质体的培养与植株再生

埃斯基红豆幼苗的下胚轴切段在附加２,４－Ｄ０．５ｍｇ／Ｌ,ＫＴ１ｍｇ／Ｌ的ＭＳ中形成胚性愈伤组织。来自１１－１３个月龄、继代６－１５天的愈伤组织的原生质体,在改良的Ｖ－ＫＭ液体培养基中可持续分裂形成细胞团,培养１０天时的分裂率和克隆率分别为６５．８８％和５３．３８％周后就可将将原生质体形成的小愈伤组织转于培养基上。原生质体在改良的Ｂ５液体培养基也可以分裂形成小愈伤组织,但分裂率低于Ｖ－ＫＭ。来自原     

Analysis of biochemical and physiological changes in wheat tissue culture using different germplasms and explant types

To select adequate wheat germplasms for genetic transformation, tissue culture efficiency of 21 different wheat lines (Einkorn, Emmer, Durum wheat, etc.) were compared, along with two different explants, namely, immature embryo and mature embryo. The results showed that the average differentiation rate and regeneration rate of immature embryo calli (46.5 and 20.82 %) were better than those for mature embryo calli (14.03 and 4.37 %). The best genotypes for immature embryo callus culture were ‘Ningchun 16’ and ‘Ei 15’, ‘Xiaoyan 22’, followed by ‘Durum 332’ and ‘Tr 256’. The best genotypes for mature embryo callus culture were ‘Ying 4286’, ‘Yunyin 01’, and ‘Xiaoyan 22’. To analyze how physiological and biochemical settings influence the totipotency of calli, different physiological and biochemical indices were analyzed. Differences between immature embryo callus and mature embryo callus were significant, as well as differences of most indices among different wheat types. The interaction effects between explant types and genotypes were also significant. Correlation analysis results showed that the total phenol and soluble sugar contents were significantly correlated with callus differentiation and regeneration rates.     

Somatic embryogenesis in pearl millet (Pennisetum glaucum): Strategies to reduce genotype limitation and to maintain long-term totipotency

Three genotypes of Pearl millet were screened in vitro for induction of embryogenic callus, somatic embryogenesis and regeneration. Shoot apices excised from in vitro germinated seedlings or immature embryos isolated from green house established plants were used as primary explants. The frequency of embryogenic callus initiation was significantly higher in shoot apices in comparison with immature zygotic embryos. Moreover, differences between genotypes were minimal when using shoot apices. Friable embryogenic calli (type II) developed on the initial nodular calli after 1 to 3 months of culture. The frequency of type II callus is related to the composition of the maintenance medium and they were more often found in ageing cultures. The transfer of embryogenic calli onto auxin-free medium was sufficient for inducing somatic embryo development in short-term culture (3 months) while a progressive loss in regeneration potential was observed with increasing time of subcultures. Maturation of embryogenic calli on medium supplemented with activated charcoal, followed by germination of somatic embryos on medium supplemented with gibberellic acid, restored regeneration in long-term cultures. This revised version was published online in June 2006 with corrections to the Cover Date.     

Plant regeneration from isolated cells ofLavandula latifolia medicus

Summary Single cells were obtained from hypocotyl-derived callus ofLavandula latifolia Medicus. Cells were plated in Murashige and Skoog medium supplemented with indoleacetic acid (IAA), benzyladenine (BA), and several IAA-BA combinations. Cell division required the simultaneous presence of IAA and BA in the culture medium, but callus formation was only achieved with 0.1 or 1 mg/liter IAA and 2 mg/liter BA. To induce organogenesis, calli were transferred to various regeneration media. Shoot-bud differentiation efficiency depended on the composition of both the callus induction and the shoot regeneration media, best results being obtained when calli grown in 1 mg/liter IAA and 2 mg/liter BA were subcultured to media containing 2 mg/liter BA and 15% coconut milk. Under these conditions, up to 75% of calli formed shoots that subsequently were rooted and established in soil.     

紫锥菊愈伤组织诱导及生物活性成分分析

以紫锥菊(Echinacea purpurea)无菌苗为材料,研究了不同激素配比条件下不同外值体愈伤组织的诱导及所诱导的愈伤组织中的主要成分多糖和总酚,并应用高效液相色谱法对根愈伤组织提取物与紫锥菊根提取物中的酚酸类物质进行了比较分析.结果表明,紫锥菊不同部位愈伤组织诱导的最适宜激素配比不同,其中根愈伤组织诱导的最佳激素配比为0.5 mg/L 2,4-D 0.5 mg/L 6-BA.叶、茎、根诱导愈伤组织的多糖含量分别为10.15、11.84、14.49 mg/g干重;总酚含量分别为52.16、28.144、7.99 mg/g干重.根愈伤组织总酚和多糖含量均较高,其提取物的酚酸类物质的高效液相色谱与紫锥菊根提取物图谱主峰一致,且生长速度快、质地疏松,是细胞培养获取紫锥菊主要生物活性成分的适宜材料.     

Induced androgenesis in tomato (Lycopersicon esculentum Mill.) I. Influence of genotype on androgenetic ability

The androgenetic ability of 85 Lycopersicon esculentum Mill. genotypes was tested. Callus was induced from anthers of 53 lines and hybrids. Regeneration of plants was obtained only from calli of 15 genotypes. The data obtained clearly showed that the genotype affects induced androgenesis in tomato. The in vitro response of anthers from the cultivars Roma, Pearson, San Marzano, Por, Sar, Vigapol, Day, David and Start, containing the ms 10³⁵ gene, which is responsible for male sterility in tomato, confirm the strongly expressed dependence of both callus induction and organogenetic potential on the homozygous or heterozygous state of that gene. A protocol of callus induction, organogenesis and plant regeneration has been developed. More than 6000 regenerants have been obtained. Most of them showed different morphological alterations and variations in chromosome number (n, 2n, 4n). Some are interesting as source material for tomato breeding. Received: 17 April 1997 / Revision received: 4 August 1997 / Accepted: 15 October 1997     

土人参的组织和单细胞培养及试管苗开花结实

以土人参的花梗、茎和叶片为外植体在ＭＳ培养基上诱导出愈伤组织,诱导率为７５％－９０％。愈伤组织经分化和生根培养再生了完整植株。由组织培养再生苗的幼茎诱导的愈伤组织建立悬浮系。由悬浮系分离的单细胞在２／３ＭＳ液体培养基中振荡培养或振荡培养３周后转入双层培养均再生了愈伤组织,再生率分别为０．２８％和０．４１％。愈伤组织在含有较低浓度６－ＢＡ的培养基上分化出苗。幼苗生长迅速,每３周扩增６．７倍,再生植株     

Wheat anther culture: effect of genotype and environmental conditions

Twenty-two cultivars and lines of winter and spring wheat (Triticum aestivum L.) were studied, most for the first time, for their anther culture response. The response was genotype dependent. Plants grown in the field gave higher callus induction frequency than those grown in the greenhouse and the controlled environment chamber. Donor plants grown in a season of low drought stress as compared to a season of severe drought stress resulted in a higher frequency of callus induction. Spherical microcalli were observed in two wheat genotypes in some of only those anthers that were placed with only one loculus in contact with the medium. Wheat lines that were more responsive to anther culture were identified.     

Plant Eegeneration from Protoplasts of Brassica carinata Braun

Protoplasts of Brassica carinata Braun. (accession No. 84A165) were enzymatically isolated from hypocotyls and cotyledons of 3–5 day-old test-tube seedlings or first true leaves taken from greenhouse grown plants at a three-leaf stage. The protoplasts were suspended in a P-B liquid medium solidified with 0.15%–0.3% low melting agarose which formed a thin layer floating on the surface of the liquid medium. The optimum protoplast density was ranging from 5× l03 to 1 × 104/ml. As for the hypocotyl protoplasts, the first division was observed after 48 h in the culture. The division frequency reached 21% and 34% at day 3 and 6 respectively. The initiation of cell division in the case of cotyledon and mesophyll protoplast culture was late, usually at day 5, and the division frequency was also somewhat lower. One week after culture, the cultures were transferred to fluorescent light condition with an intensity of about 1000 lx. A dilution medium DPDK3 was then added and the dilution procedure was repeated at one week interval thereafter. One month after culture, microcalli with 300–500 μm in size were formed. It was also found that in some cases globular embryoid structure protruded on the callus surface. Totally, a 2%–3% plating efficiency was achieved. Shoot regeneration occurred when cotyledon and mesophyll protoplast-derived calli were transferred onto a modified MS medium supplemented with NAA 0.1, BA 3 mg/l. Individual shoots were rooted on a rooting medium supplemented with 0.2 mg/l of IAA. Intact plants with normal morphology were eventually produced.