• Korean Journal of Plant Tissue Culture
• /
• v.25 no.4
• /
• pp.273-276
• /
• 1998

Chinese foxglove (Rehmannia glutinosa) is receiving much attention as one of the principal medicinal crops and the crude drug damand expands rapidly. This study was conducted to obtain the basic breeding information of Chinese foxglove. Meristem culture was employed for virus free seedling production and miropropagation. Both Jiwhang 1 and domestic local were severely infected by potexvirus and TMV. Several growth regulators were used for the virus free stock production from Jiwhang 1 and Danyang local. Shoot formation and callus induction from the meristem culture seemed to be influenced by the content of various kinds of plant growth regulators. Kinetin supplement was the most effective on shoot formation and NAA addition was good on callus induction among the treatments. The acquired virus free stocks were confirmed using transmission electron microscope and indicate plants.

• The Plant Pathology Journal
• /
• v.33 no.3
• /
• pp.288-295
• /
• 2017

Fig mosaic disease (FMD) is a viral disease that spreads in all Tunisian fig (Ficus carica L.) orchards. RT-PCR technique was applied to leaf samples of 29 fig accessions of 15 fig varieties from the fig germplasm collection of High Agronomic Institute (I.S.A) of ChattMariem, to detect viruses associated to FMD. Analysis results show that 65.5% of the accessions (19/29) and 80.0% (12/15) of the fig varieties are infected by FMD-associated viruses. From all fig accessions, 41.4% of them are with single infection (one virus) and 24.1% are with multi-infections (2 virus and more). Viruses infecting fig leaf samples are Fig mosaic virus (FMV) (20.7%), Fig milde-mottle-associated virus (FMMaV) (17.25%), Fig fleck associated virus (FFkaV) (3.45%), and Fig cryptic virus (FCV) (55.17%). A reliable protocol for FCV and FMMaV elimination from 4 local fig varieties Zidi (ZDI), Soltani (SNI), Bither Abiadh (BA), and Assafri (ASF) via in vitro culture of 3 meristem sizes was established and optimized. With this protocol, global sanitation rates of 79.46%, 65.55%, 68.75%, and 70.83% respectively for ZDI, SNI, BA, and ASF are achieved. For all sanitized varieties, the effectiveness of meristem culture for the elimination of FCV and FMMaV viruses was related to meristem size. Meristem size 0.5 mm provides the highest sanitation rates ranging from 70% to 90%.

• Proceedings of the Plant Resources Society of Korea Conference
• /
• 2019.04a
• /
• pp.55-55
• /
• 2019

Strawberry which is the genus Fragaria under family Rosaceae is one of the most important fruit plants for both fresh consumption and food processing in the temperate and subtropical countries. Propagation of strawberry is achieved either through runners or by in vitro micropropagation. Meristem tips, generally obtained from runners of virus-free plants, are commonly used to establish in vitro cultures, which are employed for mass propagation or as a source of plant material for regeneration and transformation experiments. This study was conducted to determine the optimal natural additives strength to improve sprouting shoot rate of apical meristem of strawberry 'Seolhyang'. Strawberry apical meristem at size (0.2 mm to 0.3 mm) with leaf primordials were cultured on the 1/3MS(Murashige & Skoog) medium supplemented with five natural additives such as coconut milk, maple sap, banana powder and peptone. The sprouting ratio and growth characteristics were evaluated after eight weeks after in vitro culture. Shoot ratio of 'Seolhyang' apical meristem was 72.9% in 1/3MS medium supplemented with maple sap. On the other hand, the low shoot ratio was observed 47.7% in 1/3MS medium supplemented with banana powder. Shoot length was different as natural additives but numbers of leaf was not significantiy different among the natural additives. As a result, the sprouting ratio and plant growth were enhanced effectively in 1/3MS medium with maple sap compared to the others.

• Proceedings of the Plant Resources Society of Korea Conference
• /
• 2021.04a
• /
• pp.23-23
• /
• 2021

Apple (Malus×domestica Borkh.; Rosaceae) is an important fruit crop grown mainly in temperate regions of the world. Tissue culture in vitro is a biotechnological technique that has been used to genetically improve cultivars (scions) and rootstocks. This could be important in the production of genetically uniform scions and rootstocks for commercial apple production. In nurseries, apple plants are produced by grafting scions onto rootstocks. The Cornell-Geneva (Geneva® series) breeding program has bred several dwarf rootstocks that are resistant to diseases and pests and are also cold hardy. This study was conducted to determine the optimal medium strength to improve sprouting shoot rate of apical meristem of the apple rootstocks of fire blight resistance. The apple rootstocks apical meristem at size (0.2 mm to 0.3 mm) with axillary buds were cultured on the MS(Murashige & Skoog) medium supplemented with plant growth regulators. The sprouting ratio and growth characteristics was evaluated after eight weeks in vitro culture. The highest rate of bud differentiation and shoot formation were 23.8% and 55.6%, respectively. After 6 weeks, shoots were regenerated from apical meristem, and their growth characteristics was significantly varied on the respective basal medium with different plant growth regulators. Our studies showed that the apple rootstocks the apple rootstocks of fire blight resistance plantlets could be successfully produced from apical meristem differentiated out of young twigs via organogenic regeneration.

• Molecules and Cells
• /
• v.27 no.6
• /
• pp.615-620
• /
• 2009

The plant shoot meristem maintains a group of stem cells that remain active throughout the plant life. They continuously generate new cells that are then recruited for organ initiation in the peripheral zone. Stem cell proliferation and daughter cell differentiation has to be integrated with overall growth and development of the diverse functional domains within the shoot apex. Several studies have revealed extensive communication between these domains. The signaling mechanisms employed comprise diffusible peptides, directional transport of plant hormones, but also complex interactions between transcription factors, that together establish a panoply of regulatory inputs that fine-tune stem cell behavior in the shoot meristem.

• Journal of Plant Biology
• /
• v.11 no.3
• /
• pp.23-30
• /
• 1968

Using several varieties of Cymbidium, investigations were carried out to make clear how the protocormic tissue develops from the cultured explant. Explant to be cultured were prepared in several ways: exclusively apical meristem, apical meristem dissected out with the basal part attached, axillary bud primordia in their initial stage of development, or apical or axillary bud dissected out as a whole etc. It was observed that protocorms or protocormic tissues were developed from the explant's meristematic tissues regardless of where these tissues were located. Apical meristem, leaf primordia, leaf axil, or internodal part of young bud turned easily protocormic, while the scaly leaves of axillary bud or stem tissue of mother shoot turned quickly brwonish and died away. Both in axillary and apical bud explant alike, whether they were cultured whole or divided, some took quickly green color while others were slower, and some developed protocorms easily while others remained unchanged for months. Varietal difference as well as environmental factors seemed to be responsible for it. Further details should be clarified by histogenetical investigations.

• Journal of Microbiology and Biotechnology
• /
• v.19 no.6
• /
• pp.542-546
• /
• 2009

Leaves are the major biomass-producing organs in herbaceous plants and mainly develop during vegetative stage by activities of shoot apical meristem. There is a strong correlation between leaf number and bolting, a characteristic phenotype during the transition to reproductive phase in Arabidopsis thaliana. In order to study interactions between leaf number and bolting, we isolated a Landsberg erecta-derived mutant named multifolial (mfo1) that produces increased number of leaves and bolts at the same time as the wild type. Through positional cloning and allelism test, mfo1 was found to be an allele of a previously reported mutant, altered meristem program1-1 (amp1-1) that is defective in a glutamate carboxypeptidase and bolts earlier than its wild type, Columbia ecotype, with the increased number of leaves. The bolting time differences between mfo1 and amp1, despite the same phenotype of many leaves, suggest the existence of genetic factor(s) differently function in each ecotype in the presence of mfo1/amp1 mutation.

• Korean Journal of Plant Resources
• /
• v.7 no.1
• /
• pp.17-22
• /
• 1994

This study was carried out to investigate the optimum medium and concentrations of growth regulators for induction of multiple shoot by meristem culture of floe otorefcenf Mill. MS medium supple-mented with 3${\mu}{\textrm}{m}$ TDZ was effective for induction of multiple shoot. Shoot multiplication was more ef-fective when 2mg/1 BA combined with 0.Img/1 IAA than when only BA were treated on medium. Halfstrength of MS medium supplemented with 2mg/L IAA was effective for rooting of shoots regenerated.When plantlets regenerated from meristem culture were transferred to pot, survival rate of plantletswas 80% on perlite and was 95% on vermiculite, respectively.

• Journal of Plant Biology
• /
• v.33 no.1
• /
• pp.31-40
• /
• 1990

Procambium developed in the histogenetical zone below the marginal meristem. The development of procambium is correlated with the developmental stage of the leaf. As long as the marginal cells are crescent-shaped, the first-order procambium develops. When the marginal cell becomes wedge-shaped, the higher order procambium appears. The reticulated venation is developed through forking and anastomosis. The meshes of the first order enlarge in the process of leaf growth and the meshes of the second and third order develop in the meshes of the first-order through the differentiation of the residual meristem. Therefore, the venation is hierachically arranged and is as recognizable from the thickening of the veins. The outermost vein is produced parallel to the leaf margin, in which the differences between the costal and intercostal parts of the marginal meristem are removed. The endodermis and pericycle differentiate from the same mother cell. The procambium and sclerenchyma originate from a common source during the first developmental stage. A small cellular cluster lies within the parenchyma at the upper and lower sides of the procambial trace and differentiates into sclerenchyma.

• Plant Biotechnology Reports
• /
• v.3 no.4
• /
• pp.333-340
• /
• 2009

Developmental anomalies in the plumule meristem of peanut (Arachis hypogaea L.) somatic embryos resulted in poor shoot differentiation and reduced plant recovery. Existing meristems with caulogenic potential have never been tested for embryogenesis in peanut. The present experiment was designed to test the mature zygotic embryo axis derived plumule with three meristems for somatic embryogenesis. Embryogenic masses and embryos developed from the caulogenic meristems in the axils. Exposure of 2 weeks in primary medium with $90.5{\mu}M$ 2,4-D suppressed the shoot tip differentiation temporarily which then regained the ability to form the shoot on withdrawal of 2,4-D. Exposure of 4 weeks in primary medium with $90.5{\mu}M$ 2,4-D suppressed the shoot tip differentiation irreversibly. No shoot formation was noted from the tips in any of the cultures which were in secondary medium with $13.6{\mu}M$ 2,4-D. Development of somatic embryos directly from axillary meristems was confirmed histologically. Conversion frequency of these embryos was 11%. Thus, in this report, we describe a method to obtain somatic embryos from the determined organogenic buds of the axillary meristem, by culturing the nodal explant vertically on embryo induction medium. It also displays the possibility of obtaining both embryogenic and organogenic potential in two parts of the same explant simultaneously. The possibility of extending this approach for genetic transformation in in vivo system through direct DNA delivery or Agrobacterium injection in meristems can also be explored. Using Agrobacterium rhizogenes, we have demonstrated the possibility of gene transfer in the axillary meristems of seed-derived plumule explant.