Highest Regeneration Percentage Research Articles

Micropropagation of strawberry (Fragaria ananassa “pajaro”)by meristem culture method

Experiments were carried out to examine the effects of different combinations of plant growth regulators in vitro micropropagation of strawberry plants. Specimens were sterilised by a different concentration of sodium hypochlorite - NaOCl (1, 2, and 3%) for 20 mins. A meristem was separated and cultured on Murashige and Skoog (MS) containing 0.3 mg/l BAP for 8 weeks. Initial shoots were transferred to MS with various concentrations of BAP (0, 0.1, 0.3, and 0.5 mg/l) and kinetin (0, 0.1, 0.2, and 0.3 mg/l) in either single or combination. After 6 weeks of culture, the regenerated shoots were transferred on 1/2 MS with different concentrations of NAA (0, 0.1, 0.3, 0.5, 0.7, and 1.0 mg/l) and BAP (0, 0.1, 0.3, and 0.5 mg/l) in either single or combination. The results showed that the lowest percentage of contamination (10%) and the highest percentage of regeneration (80%) response were achieved on MS media by sterilisation with 3% NaOCl for 20 mins. The highest shoot proliferation per explant (16.2 shoots/explant) was reached on MS with 0.3 mg/l BAP plus 0.1 mg/l kinetin. 1/2 MS media with 0.1 mg/l NAA plus 0.1 mg/l BAP induced 14.4 roots per shoot and produced the longest roots (9.1 cm). However, the higher concentration of NAA (0.3-1.0 mg/l) or in combination with BAP resulted in callus formation. The plantlets, thus developed, were hardened and successfully established in soil containing organic fertiliser: Trichoderma: coconut peat (1:1:1 v/v/v).

Stem cell induction and plant regeneration are affected by medium components in maca (Lepidium meyenii Walp)

In medicinal plants, selection, reproduction and preservation of important genotypes are very necessary. Nowadays, using tissue culture and regeneration techniques of medicinal plants under in vitro conditions has been able to proliferate medicinal plants widely, which is much higher than traditional methods of vegetative propagation. Maca (Lepidium meyenii), is an industrial plant whose root is the usable part. Maca has valuable medicinal effects such as sexual enhancement and reproductive power, infertility treatment, improved sperm count and quality, anti-stress, osteoporosis prevention and more. This study was conducted to induce callus and regeneration of Maca. First, MS medium supplemented with different concentrations of Kinetin, Naphthaleneacetic acid and 2,4-Dichlorophenoxyacetic acid [0.5, 1 and 2 µM respectively] and control were compared for callus induction from root and leaves. After 38 days of incubation, the first callus appeared, after 50 days of callus induction and after 79 days regeneration occurred. The callus induction experiment was performed for the study of the effect of three explants (leaf, stem and root) and seven hormone levels. The regeneration experiment was carried out by studying the effect of three explants (leaf, stem and root) on eight levels of the hormone. The results of data analysis on callus induction showed that the effects of explants, hormones and their interactions on callus induction percentage were highly significant but not significant on callus growth rate. The results of regression analysis showed that explants, hormones and their interactions had no significant effect on regeneration percentage. Based on our results, the best medium for inducing callus was Hormone 2,4-D [2 µM] and Kinetin [0.5 µM], in which the highest percentage of callus induction was in leaf explants (62%). And the lowest were in stem (30%) and root (27%) explants. According to the comparison of the mean, the best environment for regeneration of the environment was 4 µM 6-Benzylaminopurine 2.5 + Thidiazuron, in which the highest percentage of regeneration was in leaf explant (87%) and stem (69%) and the lowest in root explant (12). %).

Natural Regeneration status of conifers along Altitudinal Gradient in Shopain Forest Range of J&K, India

Natural regeneration of conifers is essential for preservation and maintenance of biodiversity. Therefore present study was conducted to study natural regeneration status of conifers in Shopain Forest Range of J&K. To assess the natural regeneration of conifers, at three elevations along altitudinal gradient (Aj, 1800–2100 m amsl; A2, 2100–2400 m amsl; A3, 2400–2700 m amsl), the vegetation analysis was carried out by stratified random sampling. Quadrates of 2 x 2 m were laid at all the three sites. The regeneration status of the tree species was determined for recruits, un-established regeneration, established regeneration and regeneration success was determined. The maximum number of recruits (3521.58/ha), unestablished (1983.33/ha) and established regeneration (600.00/ha) was recorded for Pinus wallichiana at altitude A2 while as the minimum number of recruits (666.67/ha), unestablished (350.00/ha) and established regeneration (100.00/ha) was recorded for Picea smithiana at altitude A3. The maximum regeneration success percent was recorded for Pinus wallichiana at middle altitude with 41.23% and minimum regeneration success was recorded for cedrus deodara at lower altitude with 4.18% The study conducted revealed that maximum regeneration percentage of Pinus wallichiana and Cedrus deodara was recorded at middle altitude while as that of Abies pindrow and Picea smithiana was at upper altitude. The assessment of natural regeneration of conifers also envisaged that Pinus wallichiana has the highest regeneration percentage and Picea smithiana gave the lowest regeneration success percentage.

High-Frequency Plant Regeneration, Genetic Uniformity, and Flow Cytometric Analysis of Regenerants in Rutachalepensis L.

Ruta chalepensis L., an evergreen shrub in the citrus family, is well-known around the world for its essential oils and variety of bioactivities, indicating its potential medicinal applications. In this study, we investigated the effect of different culture conditions, including plant growth regulators, media types, pH of the medium, and carbon sources, on in vitro regeneration from nodal explants of R. chalepensis. Following 8 weeks of culture, the highest percentage of regeneration (96.3%) and maximum number of shoots (40.3 shoot/explant) with a length of 4.8 cm were obtained with Murashige and Skoog (MS) medium at pH 5.8, supplemented with 3.0% sucrose and 5.0 µM 6-Benzyladenine (BA) in combination with 1.0 µM 1-naphthaleneacetic acid (NAA). For rooting, individually harvested shootlets were transferred on ½ MS (half-strength) supplemented with IAA (indole-3-acetic acid), IBA (indole 3-butyric acid), or NAA, and the best response in terms of root induction (91.6%), number of roots (5.3), and root mean length (4.9 cm) was achieved with 0.5 µM IBA after 6 weeks. An average of 95.2 percent of healthy, in vitro regenerated plantlets survived after being transplanted into potting soil, indicating that they were effectively hardened. DNA assays (PCR-based markers) such as random amplification of polymorphic DNA (RAPD) and directed amplification of minisatellite-region (DAMD) were employed to assess in vitro cultivated R. chalepensis plantlets that produced a monomorphic banding pattern confirming the genetic stability. Additionally, no changes in the flow cytometric profile of ploidy between regenerated plantlets and donor plants were detected. Regeneration of this valuable medicinal plant in vitro will open up new avenues in pharmaceutical biotechnology by providing an unconventional steadfast system for mass multiplication and might be effectively used in genetic manipulation for enhanced bioactive constituents.

Comparison between the field plants and their micropropagated plants of four Mentha spp. using molecular markers and phytochemical analyses

The efficient micropropagation procedures among four Mentha species (M. longifolia, M. spicata, M. viridis, and M. piperita) were established. In addition, the shoots were produced in 3.0 mg/l BA. M. longifolia had the highest percentage of regeneration (70%), whereas M. piperita recorded that the lowest value (47%). The micropropagated plants and field plants were subjected to phytochemical analyses. The gas chromatography and spectrophotometer results indicated that the active ingredients were changed in the regenerated plants. Nevertheless, the results of molecular markers showed that the thirteen SRAP primer combinations had 80 scorable bands; of them, 58 were polymorphic (72%). Nine ISSR markers showed a total of 60 scorable bands; of them, 44 were polymorphic (73%). Twelve out of the 102 polymorphic SRAP and ISSR markers were found to be genotype unique specific markers.

Comparative Study of Three Vitrification Solutions for an Effective Droplet-vitrification Cryopreservation Procedure for Pfaffia Glomerata (Spreng.) Pedersen

Aims: The objective of this research was to establish a cryopreservation protocol for shoot tips (ST) of in vitro P. glomerata using the droplet-vitrification technique.
 Study Design: The experimental design was a factorial, with four factors, arranged in a completely randomized design. Three vitrification solutions (PVS2, PVS3, PVS4), three times (20, 40, 60 min) and two temperatures (25 ± 2 °C and 0 °C) of treatment with the solutions, followed by freezing (LN+) or not (LN-) with liquid nitrogen (LN) were tested. All tests were performed using six replicates and the results analysed using Two-way ANOVA and Tukey’s tests and expressed as the mean ± the standard error of the means (SEM) deviation.
 Place and Duration of Study: Laboratory of Plant Cryobiology, Embrapa Genetic Resources and Biotechnology, over a two-year period.
 Methodology: ST excised from in vitro plantlets were pre-cultured overnight (19h), treated with a loading solution (LS) and three different vitrification solutions (PVS2, PVS3, PVS4) prior to freezing in LN. Treatment with the vitrification solutions was carried out at 0 or 25°C, for 20, 40 or 60 min. For freezing, drops of the vitrification solutions containing a single ST were dispensed on aluminum foil strips and the strips were submerged in LN (-196°C). For thawing, foil strips were submerged into unloading solution (US) at 40 ± 2°C, for three min. Thawed ST were transferred to regeneration medium and cultured in vitro.
 Results: Highest regeneration percentages after cryopreservation were 82% for ST treated with PVS3, at 0°C, for 60 min; 32% for ST treated with PVS4 at 25°C for 60 min or 0°C for 40 min and 22% for those treated with PVS2 at 0°C for 60 min.
 Conclusion: Droplet-vitrification is a suitable technique to ensure survival of P. glomerata ST after cryopreservation. This procedure can be applied to establish germplasm collections of this medicinal species in gene banks.

In vitro propagation of the Chinese traditional and medicinal plant Heracleum scabridum Franch

Three explants such as stem tips, leaves and petioles of Heracleum scabridum were compared for their shoot development/differentiation ability by using different plant growth regulators (PGRs). The most effective PGRs combination for callus induction and organogenesis was determined. TDZ, Kn, Zn and IAA were used to induce multiple shoots. For indirect organogenesis (from the calli), the best response (27.25 ± 4.19 shoot per stem tips) and (18.23 ± 2.12 per leaves) were obtained in Murashige and Skoog (MS) medium fortified with 0.5 mg/l IAA and 3.0 mg/l Zn with 100, 97.3% induction rate, respectively. MS medium containing 0.5 mg/l IAA and 3.0 mg/l Zn was also found to be optimal for shoot regeneration from petioles. The highest percentage of regeneration (94.6) with mean number of shoots 17.83 ± 4.87 from petioles were produced. For direct organogenesis (from axillary bud shoot clumps), 0.1 mg/l IAA and 1.5 mg/l TDZ were found to be optimal for shoot regeneration of stem tips, with mean numbers of axillary bud shoot clumps 7.12 ± 1.23 were produced. Plantlets were transferred to soil with 95% of plants acclimatized recovered successfully.

In vitro propagation of Coccinia indica (L.) Voigt. from internodal segments.

An efficient, rapid, reproducible and prolific protocol has been established for in vitro plant propagation via direct and indirect regeneration from internodal explants of Coccinia indica. The direct and indirect regeneration capability of internodal segments was studied on Murashige and Skoog (MS) medium supplemented with different concentrations of cytokinins and auxins either alone or in combinations. In direct regeneration, the highest regeneration percentage (90%) with maximum frequency of shoot length (7.2 cm) was achieved on D6: MS + 2.5 mg/L BAP (6-Benzylaminopurine) + 1.0 mg/L Kn (Kinetin). In indirect regeneration, the highest regeneration percentage (91.6%) was achieved on I5: MS + 1.0 mg/L BAP + 0.3 mg/L NAA(1-Napthaleneaceticacid). The highest frequency of shoot induction with shoot number (5) and shoot length (8.52 cm) was achieved on IS2: MS + 1.0 mg/L BAP + 0.5 mg/L Kn. Microshoots obtained best rooting response on IR3: MS + 1.0 mg/L IAA and 0.5 mg/L Kn by producing a highest frequency of root number (4.7) and root length (7.03 cm). The rooted microshoots were successfully hardened and were acclimatized in green house and subsequently established in soil with survival rate of 90%.

In vitro culture of zygotic embryos and seeds of Caesalpinia ferrea Martius

ABSTRACT The aim of this study was to evaluate the in vitro germination of zygotic embryos and seeds of Caesalpinia ferrea Martius and the morphogenetic responses of the explants to different concentrations of growth regulators. Seeds and zygotic embryos were inoculated in MS culture medium and kept in a growth room at a temperature of 25 ± 2 ºC for 16 hours of photoperiod for 30 days. The seeds had a higher in vitro germination rate than the explants from zygotic embryos. However, zygotic embryos in MS medium supplemented with 0.9 mg L-1 BAP had the highest percentage of regeneration (50%), number of shoots (3.25), buds (2.85) and leaves (3.15), multiplication rate (27.75), and length of shoots (1.96 cm). The in vitro culture of zygotic embryos and seeds made possible the multiplication of a higher number of healthy seedlings. Thus, it can be used as an alternative technique for the propagation of this species.

Optimasi Sistem Transformasi Gen Xiloglukanase Pada Eucalyptus pellita F. Muell Menggunakan Agrobacterium tumefaciens

Eucalyptus pellita is a type of woody plant that is widely used as raw materials of pulp and paper so that the need for wood from this type of plant is increasing. Improvements in wood quality such as cellulose deposition and increased growth rates are needed to support the supply of raw materials for the pulp and paper industry. One technology to change the composition of wood is the modification of plant cell walls through the transformation of xylolukanase gene which in other plants such as Populus alba and Acacia mangium have been shown to increase cellulose deposition and spur growth. The purpose of this study was to obtain an efficient xyloglucanase transformation method in E. pellita using Agrobacterium tumefaciens. Sprouts E. pellita 006 and 06A with different ages of 8 and 15 days are used as plant material for transformation. The sonication treatment of the sprouts prior to the transformation was also applied to determine the effect on transformation efficiency. Transformation is done by soaking the seeds that have been through the treatment of sonication and without sonication on the suspension of Agrobacterium carrying plasmid pAa XEG300 and subsequently grown on the selection medium. Sprouts E. pellita 006 aged 15 days without sonication treatment showed the highest percentage of regeneration in the selection media that is equal to 72%. Gene integration testing through DNA amplification with specific primers showed a ribbon of xyloglucanase with a size of 709 bp.

Efficient In Vitro Somatic Embryogenesis and Plant Regeneration from Mature and Immature Embryos of Wheat ( Triticum aestivum L.)

ABSTRACT An efficient regeneration system is a pre-requisite for the application of genetic transformation and functional genomics study of important plants. In this study, the effect of different factors (plant growth regulators, casein hydrolysate, aspartic acid and ascorbic acid) on in vitro embryogenesis and regeneration of Arta, Bahar and Zagros cultivars from mature and immature explants were investigated. Immature and mature embryos were dissected from disinfected seeds 20-25 days after pollination and imbedded mature seeds, respectively, and cultured on MS (Murashige and Skoog) medium supplemented with different compounds. The results showed that immature embryos expose high capacity of embryogenesis and regeneration in comparison with mature embryos. There were significant differences between cultivars in terms of the percentage of callus induction and regeneration. Plant growth regulators had significant effect on percentage of callus induction in mature explants and percentage of regeneration from both explants. In immature explants, the highest percentage of regeneration (65%) was achieved with the Arta cultivar calli derived from MS medium supplemented with 1mg/L 2,4-D, 2 mg/L Picloram and 200 mg/L casein hydrolysate, and subcultured on MS medium. Also, the highest percentage of regeneration (52.38%) from mature embryo explants was achieved in the Arta cultivar with callus induction on MS medium supplemented with 1 mg/L 2,4-D, 2 mg/L Picloram and 200 mg/L casein hydrolysate and regeneration on MS medium containing 0.05 mg/L NAA.

<b>Behavior of lateral buds of <i>Hancornia speciosa</i> after cryopreservation by encapsulation-vitrification

Hancornia speciosa is a fruitful species from Cerrado biome with high economic potential. However, the intense and disordered extractivism have caused a reduction of its population in its endemic area. In addition, seed recalcitrance negatively affects the conventional conservation of the species. Aiming to find alternatives that enable the long-term conservation of this species, the study’s objective was to assess the behavior of lateral bud’s regrowth after cryopreservation procedures by encapsulation-vitrification technique. Sodium alginate capsules containing lateral buds were pre-cultured in liquid WPM supplemented with 1.0 M glycerol, and subsequently exposed to different concentrations of sucrose (0.3; 0.75 and 1.0 M) for 24 or 48 hours. The capsules were subjected to dehydration in silica gel or airflow hood for 0, 1, 2 and 3 hours before different incubation times in PVS2 (0, 15, 30, 60 and 120 minutes) at 0°C. A high regeneration percentage of lateral buds was observed after cryopreservation of capsules treated with 0.75 M sucrose plus 1.0 M glycerol (24 hours), associated with dehydration in an airflow hood (1 hour) and immersion in PVS2 (15 minutes). Encapsulation-vitrification allowed the long-term conservation, and provided high plant material survival rates after cryopreservation of Hancornia speciosa sensitive explants.

Induksi dan Regenerasi Kalus Jagung yang Ditransformasi dengan Gen CsNitr1-L melalui Penembakan Partikel

<p>The success in development of transgenic plants is influenced by the regeneration system. The objective of the study was to<br />assess the response of maize genotypes to regeneration system of organogenesis and embryogenesis, after transformed with<br />CsNitr1-L gene through particle bombardment. Induction and callus regeneration of maize immature embryos of inbred lines<br />Ult:cm.1#, ARC 178-123-112-XB3, and AZ2 were conducted through organogenesis, whereas those inbred lines AZ1, AZ2,<br />P4G19(S)C2.59.3.3.1.3 and P4S3.29.4.4.1 were conducted through embryogenesis somatic. Transformation of CsNitr1-L gene was<br />done with the distance of bombardment of 7 cm and 9 cm and calli were then selected using 10 mg/l hygromycin. All explants<br />(100%) of inbred lines Ult:cm.1# formed organogenic callus, while callus formation of ARC 178-123-112-XB3 was 94.3% and AZ2<br />was 60.5%. Ult:cm.1# was the most responsive line to the regeneration of organogenesis and produced 24 green shoots,<br />compared with ARC 178-123-112-XB3 which produced one green shoot and AZ2 that did not produce green shoots. The highest<br />percentage of embryogenic calli formed through somatic embryogenesis was obtained on inbred lines AZ1 (85.4%) and the<br />lowest was on P4S3.29.4.4.1 (18.9%). Inbred lines AZ1 had the highest percentage of regeneration (50.7%) and produced 62<br />plants, followed by P4G19(S)C2.59.3.3.1.3 that produced 17 plants (2.8%) and P4S3.29.4.4.1 which produced two plants.<br />Preliminary identification on 31 putative transgenic plants through PCR analysis produced 22 plants (70.96%) that contained nptII<br />gene.</p>

Micropropagation of Eucalyptus grandis × E. urophylla AEC 224 clone

Genetic transformation systems require protocols that allow regenerating transgenic plants from transformed tissues. This study aimed to establish a protocol for indirect organogenesis in leaf explants of a Eucalyptus grandis × E. urophylla AEC 224 clone. During callogenesis stage, several concentrations of NAA and then NAA or 2,4-D combined with TDZ were tested in JADS culture medium for 30 days, followed by subculture of the explants in the regeneration medium, containing 5.0 µM BA and 0.5 µM NAA for another 30 days. In these media, the explant oxidation rate was high (95 %). Thus, in order to reduce oxidation, different culture media were compared: WPM, MS, JADS and modified QL, followed by explant transfer onto regeneration medium. The highest percentage of regeneration and the lowest oxidation rate were achieved on WPM medium. Then, NAA and 2,4-D were tested in combination with TDZ and also TDZ and BA combined with NAA in WPM medium. The most efficient culture media in terms of shoot regeneration were WPM supplemented with 0.25 µM TDZ and 0.1 µM NAA during 30 days for callus induction and then with 5.0 µM BA and 0.5 µM NAA for another 30 days. This protocol yielded a regeneration rate of 43 %, with a low oxidation of tissues. A rooting experiment was conducted using half strength MS medium and comparing three concentrations of IBA (2.46, 4.90 and 7.35 µM). The highest rooting percentage (35 %) was obtained on medium containing 2.46 µM IBA. Once the shoots were rooted, acclimatization in a greenhouse was not challenging and plant survival reached 100 %.

Comparative Organogenic Response of Six Clonal Apple Rootstock Cultivars

The organogenesis potential is different among cultivars and must be optimized for individual genotype. Shoot organogenesis capacity from in vitro leaves and root organogenesis capacity of in vitro shoots in six clonal apple rootstock cultivars were compared. The shoot organogenesis capacity was highly genotype dependent. ‘GM256’ was found to be the most responsive genotype for shoot regeneration from leaf explants among the cultivars, showing high regeneration percentage on all tested media. The effects of basal medium composition and cytokinins on shoot regeneration were different depending on rootstock genotype. Optimum regeneration occurred on Murashige and Skoog (MS) basal medium for ‘71-3-150’, and optimum regeneration occurred on Quoirin and Lepoivre (QL) basal medium for ‘60-160’ and ‘ПБ’. Thidiazuron (TDZ) was more effective than 6-benzylaminopurine (BA) for Malus prunifolia (Y), whereas TDZ and BA were not significantly different for the other cultivars. All rootstock cultivars showed high root organogenic capacity. The percentage of rooting reached more than 90% and the mean root number per plantlet ranged from three to five. The optimum rooting medium was different for different rootstock cultivars. Optimum root organogenesis occurred on half-strength QL medium for ‘GM256’ and ‘Y’, and for ‘ПБ’ and ‘JM7’ on one-quarter-strength MS medium.

Batch Studies on Remedy for Cr(VI) and Ni(II) onto Sludge-based Carbons (PMSC & APMSC)

Advantages such as environmental friendly material, low cost and high regeneration percentage of sludge-based adsorbents like Paper Mill Sludge carbon (PMSC) and Activated Paper Mill Sludge Carbon (APMSC) make them as suitable adsorbents for the removal of toxic metals such as Cr(VI) and Ni(II) ions from water and wastewater. These mesoporous carbons namely PMSC and APMSC were most effective in adsorption of cationic pollutants than anionic pollutants. Isotherms data indicated that these activated carbons have high adsorption capacity. The dimensionless factor, RL of the adsorption isotherms revealed that the adsorption process for both ions on both adsorbents was very favorable. The results suggest the feasibility of a good substitute than other commercially available activated carbons produced from natural resources. So, the reuse of organic wastes from any industrial process is a high priority today. Adsorption of Ni (II) ions and Cr (VI) ions using PMSC and APMSC was more effective at pH 5 and pH 2, respectively. Various isotherm, kinetic models and Activation parameters were fitted with experimental data to describe the behavior of diffusion mechanism, solute interaction and nature of adsorption with the adsorbents through batch studies. The best isotherm in these studies was selected by error analysis and the stability of adsorbents was also confirmed through desorption studies.

Regeneration of Adventitious Shoots from Callus and Leaf Explants in Jatropha curcas L. ‘Phetchaburi’

The effect of cytokinins and auxins was evaluated in inducing a physic nut (Jatropha curcas L.) callus while the effect of the combinations of cytokinin and either indole-3-butyric acid (IBA) or some growth additives was determined in regenerating adventitious shoot from a leaf segment. The results showed MS medium containing only 0.1 or 1.0 mg/l thidiazuron (TDZ) was the most effective medium for inducing morphogenic callus. MS medium supplemented with 2.0 mg/l 6-benzylaminopurine (BA) and 0.5 mg/l indole-3-acetic acid (IAA) gave the highest shoot regeneration percentage and shoot height from the callus. On the other hand, the MS medium supplemented with 0.5 mg/l BA and 1.0 mg/l IBA was the most effective medium for adventitious shoot regeneration and shoot height from the leaf segments.

Indirect Organogenesis in Bittergourd (Momordica charantiaL.) Using Shoot tips as Explant

The induction of potentially organogenic callus and better proliferation of callus successfully from shoot tip explants of bittergourd was obtained either on the MS medium supplemented with IBA (4.00 mg l−1) + BA (0.50 mg l−1) + 2, 4-D (2.00 mg l−1) or NAA (2.00 mg l−1) + BA (0.50 mg l−1) + 2, 4-D (2.00 mg l−1) in combination with 30.00 g l−1 sucrose and 6.30 g l−1 agar level. Shoot regeneration response from shoot tip derived callus was best on MS medium fortified with 0.05% AC + 1.00 mg l−1 BA with earlier regeneration, highest regeneration percentage, lengthy adventitious shoot and more number of leaves under light conditions. Efficient rooting was achieved on MS fortified with IBA (1.00 mg l1).

Efficiency of In Vitro Regeneration is Dependent on the Genotype and Size of Explant in Tef [Eragrostis tef (Zucc.) Trotter

Tef [Eragrostis tef (Zucc.) Trotter] is the major cereal crop in the Horn of Africa particularly in Ethiopia where it is staple food for about 50 million people. Its resilience to extreme environmental conditions and high in nutrition makes tef the preferred crop among both farmers and consumers. The efficiency of in vitro regeneration plays significant role in the improvement of crops. We investigated the efficiency of regeneration in 18 tef genotypes (15 landraces and three improved varieties) using three sizes of immature embryos (small, intermediate and large) as an explant. In vitro regeneration was significantly affected by the genotype and the size of the immature embryo used as a donor. Intermediate-size immature embryos which were 101-350 µm long led to the highest percentage of regeneration. Interestingly, the three improved varieties presented very low regeneration efficiencies whereas the landrace Manyi resulted in consistently superior percentage of in vitro regeneration from all three sizes of explants. The findings of this work provide useful insight into the tef germplasm amenable for the regeneration technique which has direct application in techniques such as transformation. It also signifies the importance of using tef landraces instead of improved varieties for in vitro regeneration.

Adventitious shoot regeneration from leaves of apple rootstock ‘Pingyitiancha’ (Malus hupehensis var. pinyiensis) and genetic fidelity of regenerated plantlets using SSR markers

Jin, W., Wang, Y. and Wang, H. 2014. Adventitious shoot regeneration from leaves of apple rootstock ‘Pingyitiancha’ (Malus hupehensis var. pinyiensis) and genetic fidelity of regenerated plantlets using SSR markers. Can. J. Plant Sci. 94: 1345-1354. Apple is one of the major fruit tree species in China, its cultivation area and total output rank first in the world. ‘Pingyitiancha’ (Malus hupehensis var. pinyiensis) is a widely used rootstock for apple cultivation in China. Several factors affecting leaf regeneration were investigated. In this study, a successful adventitious shoot regeneration protocol for this cultivar was established. ‘Pingyitiancha’ leaves were a suitable source of explants for regeneration of adventitious shoots. The optimal adventitious shoot regeneration protocol involved subculturing seedling leaves for 30-35 d. The optimum medium was Murashige and Skoog (MS) medium containing 2.0 mg L-1 thidiazuron and 0.2 mg L-1 indole-3-butyric acid. Explants with the abaxial surface in contact with the medium kept for 14 d in the dark showed the highest regeneration percentage of adventitious shoots of explants (100%), and produced an average of 3.6 shoots per regenerating explant. Shoots regenerated from leaves were rooted on half-strength MS medium containing 0.4 mg L-1 1-naphthalene acetic acid. The rooting percentage was 94.4%. Using SSR markers, all banding profiles from regenerated plantlets were monomorphic and same to those of the mother plant. It showed that the uniformity of the in vitro regenerated plantlets was maintained.