Meta-Topolin mediated in vitro propagation in an ornamentally important crop Iris × hollandica Tub. cv. Professor Blaauw and genetic fidelity studies using SCOT markers (original) (raw)
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Preliminary results on the in vitro propagation by leaf explants and axillary buds of Iris aphylla L
In order to develop an in vitro micropropagation protocol of the rare, endangered and ornamental plant Iris aphilla L., leaf explants and explants of rhizome buds cultivated on normal-strenght Murashige and Skoog (MS) basal media, supplemented with growth regulators. Explant types were disinfected by standard methods. The higher percent of contamination was recorded for the rhizomes explants with axillary buds (86%). The potency of cytokine-like thidiazuron (TDZ) combined with auxin alpha naphtyl acetic acid (NAA) as plant growth regulators in evoking morphogenic responses from leaf explants and explants of rhizome buds in Iris aphilla L. was evaluated. Maximum percentage of callus induction was obtained from the leaf explants of Iris aphilla L. cultured on MS basal medium augmented with 2.0 mg l-1 TDZ and 3.0 mg l-1 NAA.
Journal of Plant Growth Regulation, 2019
Meta-topolin (mT), a benzyladenine analog [N 6-(3-hydroxybenzylamino) purine] is a highly active cytokinin. The present study evaluates the efficiency of two aromatic cytokinins, mT and BA for inducing in vitro regeneration in a woody legume Pterocarpus marsupium (Roxb.) using cotyledonary node (CN) explants. Of the two cytokinins tested, mT-derived cultures resulted in better shoot multiplication and rhizogenesis than BA. Among the different doses of mT, maximum shoot (9.58 ± 0.30) induction per explant and average shoot length (4.12 ± 0.05 cm) were recorded on Murashige and Skoog (Physiol Plant 15:473-497, 1962) medium containing 7.5 µM mT, after 6 weeks of culture. The combined effect of cytokinin and auxin was tested, auxin was mixed with optimum doses of BA or mT separately and the effect of combination was studied. Among the cytokinin-auxin combinations, the highest number of shoots (17.44 ± 0.25) per explant and average shoot length (5.72 ± 0.18 cm) were achieved on MS medium containing 7.5 µM mT with 1.0 µM αnaphthalene acetic acid in 85% of the cultures after 12 weeks. Meta-topolin alone or in combination with auxin has shown an increase in the quality and number of shoots in comparison to BA. In vitro rhizogenesis in individually regenerated microshoots was carried out on half-strength MS medium augmented with 1.0 µM indole-3-butyric acid via a two-step procedure method. After 4 weeks, 7.35 ± 0.11 roots per shootlet with an average root length of 4.54 ± 0.10 cm were recorded in mT-derived microshoots. The well-developed plantlets were acclimatized in a separate batch of single CN explant-derived plantlets. About 80% survival rate was recorded for mT-derived plantlets. Biomass and photosynthetic pigments were also improved in mT-derived plantlets, when compared with the BA derived. Analysis of genetic homogeneity of ten micropropagated plantlets was done through RAPD. Out of 40 RAPD primers, 29 primers produced clearly scorable monomorphic bands, thus exhibiting complete genetic uniformity among in vitro regenerated plantlets.
International Journal of Current Microbiology and Applied Sciences, 2019
The experiment was carried out in two consecutive years 2016 and 2017 at Uttar BangaKrishiViswavidyalaya, CoochBehar, West Bengal to Studies on the effect of cytokinin on growth of African Marigold (Tagetes erectaL.) cv. PusaNarangiGainda. I was taken twelve different dose such as 25ppm, 50ppm,75ppm, 100ppm, 125ppm, 150ppm, 175ppm, 200ppm, 225ppm, 250ppm, 275ppm, 300ppm and one control.The experiment was conducted following RBD with 12 different levels of cytokinin ranging from 25 ppm, 50 ppm, 75 ppm, 100 ppm, 125 ppm. 150 ppm, 175 ppm, 200 ppm, 225 ppm, 250 ppm, 275 ppm and 300 ppm and compared to control (distilled water spray). The 13 treatments were replicated thrice. Results revealed that application of 25 ppm BA increased the plant height at 21 days after transplanting (23.19 cm), plant height at 42 days after transplanting (48.13cm), leaflet length at 21 days after transplanting (4.32 cm), Leaflet length at 42 days after transplanting (6.80 cm), Increase in the girth of stem at 42 days after transplanting was noticed with 275 ppm BA application (9.36 mm). Initially, side-shoot production was increased with 200 ppm BA application (4.80 cm) but at 42 days after transplanting higher number of side-shoots was obtained with 150 ppm BA application (10.80 cm). Shoot length was found maximum with 175 BA application both at 21 days (2.88 cm) and 42 days after transplanting (14.0 cm). Leaf production was found maximum with 250 ppm BA application in both at 21 days (3.80) and 42 days (13.07) after transplanting. The same treatment also showed higher leaf length at 42 days after transplanting (21.86 cm).Though at 21 days leaflet production was higher with 225 ppm BA application (16.07) but at 42 days after transplanting 300 ppm BA application showed higher leaflet production (24.07). Initially 200 ppm BA application improved leaflet length (4.93 cm) but finally maximum leaflet length was found with 25 ppm BA application. Leaf expansion was observed higher with foliar application of 200 ppm BA in both at 21 days (0.96 cm) and 42 days after transplanting (1.33 cm). Plants treated with same concentration reached the flower bud initiation stage earliest (46.60 days after transplanting). Whereas, 200 ppm solution showed least time period (6.66 days) for flower bud development and from the developing bud to full bloom stage, 25 ppm BA concentration showed the earliness (6.60 days).
Revista Ceres, 2020
The availability of reliable and reproducible micropropagation systems is a decisive step to successfully propagate plant species with slow growth and low germination rate. The effect was investigated of gibberellin (GA) and cytokinin (CK) in the in vitro germination and development of Dietes bicolor (Steud.) Sweet ex Klatt. Seeds were inoculated in Water + Agar; in Murashige e Skoog (MS) medium without plant growth regulators (PGRs) and in MS medium supplemented with 1 or 2 mg L-1 gibberellic acid or 6-benzylaminopurine. The germination, growth, and architecture of the plants presented significant alterations according to the treatments. Germination percentage increased at 2 mg L-1 GA. Plants grown on the GA-supplemented medium also showed larger leaves. The presence of CK in the culture medium induced the activation of axillary shoot buds and reduced the root length. CK and GA had antagonistic effects on the thickness of the leaf tissues. The activation of multiple shoots in plants cultured with CK in the medium allowed the in vitro propagation of approximately three plants per germinated seed. The results obtained in the present study bring an unprecedented description of a germination system for a higher yield in D. bicolor micropropagation.
Topolins: A panacea to plant tissue culture challenges?
Plant Cell, Tissue and Organ Culture (PCTOC), 2012
Since the discovery of topolins as naturally occurring aromatic cytokinins (CKs), they have emerged as genuine alternatives to the long serving CKs such as benzyladenine, zeatin and kinetin in plant tissue culture (PTC). Globally, the past 15 years has witnessed a surge in the use of topolins and their derivatives in research laboratories. Topolins, especially the meta-topolin and its derivatives have been employed for culture initiation, protocol optimization and for counteracting various in vitro induced physiological disorders in many species. Evidence from various studies indicate the rising popularity and advantages (although not universal for all species) of topolins compared to other CKs. In this review, we assess the use of topolins in PTC with emphasis on their metabolism, structure-activity relations and effect on morphogenesis in vitro. In addition, the review provides a detailed list of species that have been used to study the effect of topolins in comparison with other CKs, the growth parameters affected and recommended concentrations are also provided.
The main objective of micropropagation after in vitro culture establishment is to work out an efficient and reliable method for shoot multiplication. The effect of isoprenoid (2-iP) and aromatic cytokinins (BA, BAR, KIN, TOP) were tested in experiments aimed on shoot multiplication. Beside the evaluation of the effects of different types and concentrations (1 to 20 M) of cytokinins, the influence of explant type (shoot tip, nodal segment) on efficient multiplication was also assessed. Both type and concentration of applied cytokinins and the type of explants had a strong effect on the shoot multiplication and on growth type of in vitro shoots. A very tight relationship between the cytokinins and explant types was observed. If meta-topolin was applied between 5 and 15 M and shoot tips were used as initial explants, high multiplication (3.05-3.49 shoots and 13.26-14.42 nodes per explant) could be achieved and the mean length of shoots was satisfactory (> 40 mm). Results obtained may contribute to the development of an efficient micropropagation protocol for common buckwheat.
This paper reports, for the first time, a rapid and reliable micropropagation protocol for high-frequency shoot regeneration and plant establishment of Thymus broussonetii, a vulnerable and highly valuable aromatic and medicinal plant. This plant species is threatened by over collection due to its socioeconomic importance. Hence, an attempt has been made for in vitro cultivation of this plant for large scale multiplication as well as conservation. Several treatments such as cytokinin types and concentrations, cytokinin/auxin ratio, gelling agents, and explant density were tested on the shoot bud induction. Effects of various concentrations of auxins were also examined on the micropropagated shoots during rooting stage. Fullstrength Murashige and Skoog (MS) medium supplemented with 6- benzylaminopurine (4.4 μM) and naphthalene acetic acid (1 μM) promoted significantly shoot bud induction while affecting shoot length. The use of 3 g/l of gellan gum (Phytagel™) promoted shoot bud induc...
South African Journal of Botany
Efficient protocols, safe from somaclonal variation, were developed for regeneration of Iris sibirica plants via organogenesis and somatic embryogenesis from leaf-base explants cultivated on Murashige and Skoog media supplemented with thidiazuron (TDZ, 1.0 mg/l) or 2,4-dichlorophenoxyacetic acid (2,4-D, 1.0 mg/l). The morphogenic response and callus formation efficiency differed significantly between 2,4-D (80.9%) and TDZ (67%) morphogenesis induction treatments. TDZ induced only organogenic calli, while calli obtained with 2,4-D were composed of three types differing in color and consistency: white, friable — embryogenic calli (4.5%, 3.8 mg/explant), green, compact — organogenic calli (12.4%, 48.4 mg/explants) and yellow — non-regenerative calli (77.3%, 254.4 mg/explant). The cultivation of embryogenic calli on medium with 2,4-D and Kinetin resulted in further development of somatic embryos (54 embryos/g of calli) which germinated with a frequency of 62% after being transferred to ...
Comparative studies of cytokinins on in vitro propagation of Bacopa monniera
Plant Cell Tissue and Organ Culture, 2001
A mass in vitro propagation system for Bacopa monniera (L.) Wettst. (Scrophulariaceae), a medicinally important plant, has been developed. A range of cytokinins have been investigated for multiple shoot induction with node, internode and leaf explants. Of the four cytokinins (6-benzyladenine, thidiazuron, kinetin and 2-isopentenyladenine) tested thidiazuron (6.8 μM) and 6-benzyladenine (8.9 μM) proved superior to other treatments. Optimum adventitious shoot buds induction occurred at 6.8 μM thidiazuron where an average of 93 shoot buds were produced in leaf explants after 7 weeks of incubation. However, subculture of leaf explants on medium containing 2.2 μM benzyladenine yielded a higher number (129.1) of adventitious shoot buds by the end of third subculture. The percentage shoot multiplication (100%) as well as the number of shoots per explant remained the high during the first 3 subculture cycles, facilitating their simultaneous harvest for rooting. In vitro derived shoots were elongated on growth regulator-free MS medium and exhibited better rooting response on medium containing 4.9 μM IBA. After a hardening phase of 3 weeks, there was an almost 100% transplantation success in the field.