Showing papers on "Kinetin published in 1990"
TL;DR: In vitro plants were successfully established in the field and were morphologically uniform and a simple method to extend the subculture interval was used and its relevance to germplasm conservation is discussed.
Abstract: Rhizome buds, excised from threeCurcuma spp., and ginger, inoculated aseptically on MS medium with varying levels of BAP and kinetin, produced multiple shoots. For shoot multiplication, a concentration of 3.0 mg/l BAP was found to be optimum for all the species.In vitro plants were successfully established in the field and were morphologically uniform. A simple method to extend the subculture interval was used and its relevance to germplasm conservation is discussed.
198 citations
TL;DR: All cytokinins tested were equally effective in promoting shoot formation, except that kinetin was inhibitory to shoot regeneration from hypocotyls of B. campestris ssp.
Abstract: The presence of 1–10 μM aminoethoxyvinylglycine (AVG) or 5–30 μM AgNO3 markedly enhanced shoot regeneration from cotyledon and hypocotyl cultures of eight recalcitrant Brassica campestris and B. juncea genotypes tested. Expiants of B. campestris ssp. chinensis and ssp. parachinensis grown with a high AVG concentration (20 μM), regenerated poorly. All cytokinins tested were equally effective in promoting shoot formation, except that kinetin was inhibitory to shoot regeneration from hypocotyls of B. campestris ssp. pekinensis (cv. Wong Bok). Both AgNO3 and AVG had no effect on percent rooting and number of roots per rooted cutting of Wong Bok, White Sun and Leaf Heading, but AgNO3 was inhibitory to rooting of India Mustard. However, root elongation of all cuttings was markedly inhibited by AVG at concentrations of 5 and 10 μM.
141 citations
TL;DR: Immature zygotic embryos from open-pollinated and selfed Carica papaya L. fruits produced somatic embryos that matured on half-strength MS medium, germinated onMS medium containing 5 mg l−1 kinetin, and grew large enough for greenhouse culture on MS medium.
Abstract: Immature zygotic embryos from open-pollinated and selfed Carica papaya L fruits, 90 to 114 days post-anthesis, produced 2 to 20 somatic embryos on apical domes, cotyledonary nodes, and radicle meristems after culture for three weeks on half-strength Murashige and Skoog (MS) medium supplemented with 01 to 25 mg l(-1) 2,4-dichlorophenoxyacetic acid (2,4-D), 400 mg l(-1) glutamine, and 6% sucrose After six weeks of culture, about 40 to 50% of the zygotic embryos had become embryogenic, and each embryogenic embryo yielded hundreds of somatic embryos within five months of culture on media supplemented with 2,4-D Somatic embryos matured on half-strength MS medium, germinated on MS medium containing 5 mg l(-1) kinetin, and grew large enough for greenhouse culture on MS medium Shoots were rooted in vermiculite and grown in the greenhouse
110 citations
TL;DR: The frequency of induction of embryogenic callus was significantly improved by incubation at 25 °C and by a 4-h imbibition of the seeds, and a significant correlation was found between the yield of embryogenie callus and the percentage of germination of the seedlot used.
Abstract: White spruce (Picea glauca) embryogenic callus was obtained using 3- to 11-year-old seeds as a source of zygotic embryos. They were cultured on half-strength Litvay's medium supplemented with 10 μM 2,4-dichlorophenoxyacetic acid, 5 μM benzylaminopurine, 1 g/L casein hydrolysate, 500 mg/L glutamine, and 1% sucrose. The frequency of induction of embryogenic callus was significantly improved by incubation at 25 °C and by a 4-h imbibition of the seeds. The yield of embryogenic callus was significantly affected by the geographic provenance of the seeds and by their number of years in storage. A significant correlation was also found between the yield of embryogenie callus and the percentage of germination of the seedlot used. Even after 11 years of storage, 40% of the zygotic embryos could produce an embryogenic callus when dissected from seeds with a high germination rate. Somatic embryos were matured after transfer onto an embryo development medium composed of the same medium but including 6% sucrose, 1 μM 2...
110 citations
TL;DR: The stage of zygotic embryo development for optimal somatic embryogenesis was found to be the early stage of polyembryony and the appearance and nutritional requirements of the established protoplast-derived cell suspension were similar to those of the original cell suspension.
103 citations
TL;DR: An efficient protocol has been developed for the in vitro propagation of Bambusa tulda through shoot proliferation and continuous shoot proliferation at a rate of 4–5 fold every three weeks was achieved through forced axillary branching.
Abstract: An efficient protocol has been developed for the in vitro propagation of Bambusa tulda through shoot proliferation. Shoots from 3-week-old aseptically grown seedlings were used to initiate cultures. Multiple shoots were obtained on liquid Murashige and Skoog (MS) medium supplemented with 6-benzylaminopurine (8×10(-6)M) and kinetin (4×10(-6)M). Continuous shoot proliferation at a rate of 4-5 fold every three weeks was achieved through forced axillary branching. More than 90% of the shoots could be rooted on a modified MS medium containing indoleacetic acid (1×10(-5)M) and coumarin (6.8×10(-5)M). Following simple hardening procedures, the in vitro raised plants were transferred to the soil with more than 80% success.
90 citations
TL;DR: A method for rapid and highly effective plant micropropagation from vegetative meristems was established for Aloe barbadensis Mill and high morphogenetic ability was maintained by transferring explants (after 60 days) on media containing 0.2 μM 6-benzylaminopurine.
Abstract: A method for rapid and highly effective plant micropropagation from vegetative meristems was established for Aloe barbadensis Mill. Plant micropropagation was achieved culturing apices on medium containing 1.1 μM 2,4-dichlorophenoxyacetic acid and 2.3 μM kinetin for 15–30 days. High morphogenetic ability was maintained by transferring explants (after 60 days) on media containing 0.11 μM 2,4-dichlorophenoxyacetic acid and 2.2 μM 6-benzylaminopurine.
83 citations
TL;DR: Cytological analysis of regenerated plants showed normal diploid chromosome number in their root tips, and incorporation of different antibiotics such as carbenicillin, cefotaxime and streptomycin sulfate enhanced plant differentiation from somatic embryos.
Abstract: Cultured caryopses of finger millet (Eleusine coracana GAERTN) produced callus from shoot apices or mesocotyls depending upon the concentration of picloram and combination of cytokinins in MS basal medium. On subsequent subcultures, numerous somatic embryos differentiated from the callus on MS medium supplemented with picloram and kinetin. The embryos germinated into complete plants on medium devoid of phytohormones. When different carbohydrates were tested, basal medium containing glucose and sucrose produced the highest frequency of germinating somatic embryos. Supplementation of MS basal medium with a variety of aminoacids, osmotic agents and growth supplements had an adverse effect on the germination of embryos. Incorporation of different antibiotics such as carbenicillin, cefotaxime and streptomycin sulfate enhanced plant differentiation from somatic embryos. Cytological analysis of regenerated plants showed normal diploid chromosome number in their root tips.
81 citations
TL;DR: The induction with senescence, and the repression with kinetin and glucosamine, suggest chat chloroplast isoperoxidase C4 may function as a chlorophyll-degrading enzyme during barley leaf senescences.
Abstract: Total peroxidase activity increased during senescence of excised barley (Hordeum vulgare L. cv. Kashimamugi) leaves. Kinetin treatment furter increased total peroxidase activity but repressed chlorophyll degradation in excised barley leaves. When isoperoxidases were extracted from barley leaf segments. 4 cationic and 4 anionic isozymes were found in polyacrylamide gel electrophorests during leaf senescence. The chloroplasts contained only two cationic isoperoxidase activities. One (designated C4) was repressed by kinetin. and the other (C3) was increased by kinetin. Glucosamine, which also repressed the degradation of chlorophyll, completely repressed C4 activity but did not affect C3 activity. The induction with senescence, and the repression with kinetin and glucosamine, suggest chat chloroplast isoperoxidase C4 may function as a chlorophyll-degrading enzyme during barley leaf senescence.
75 citations
TL;DR: A simple procedure for regeneration of cucumber plants from cotyledon and hypocotyl explants has been developed and eighty-five percent of the mature somatic embryos formed showed a typical bipolar structure.
Abstract: A simple procedure for regeneration of cucumber plants (Cucumis sativus L. cv. Poinsett 76) from cotyledon and hypocotyl explants has been developed. Somatic embryogenesis was induced on Murashige and Skoog (MS) salts and vitamins medium supplemented with 2,4-D at 2.0 mg·liter -1 and kinetin at 0.5 mg·liter -1 . Development of embryos was accomplished on MS medium with NAA at 1.0 mg·liter -1 and kinetin at 0.5 mg·liter -1 . Eighty-five percent of the mature somatic embryos formed showed a typical bipolar structure. All developed into morphologically normal plantlets when transferred to MS medium containing no growth regulators. Chemical name used: 2,4- dichlorophenoxyacetic acid (2,4-D). Previous reports have described proce- dures for cucumber plant regeneration from leaf callus (Malepszy and Nadolska-Orczyk, 1983; Nadolska-Orczyk and Malepszy, 1984),
75 citations
TL;DR: Two distinct types of somatic embryos were induced from the cotyledonary region of callused zygotic embryos of Feijoa sellowiana cultured in MS medium supplemented with a wide range of 2,4-dichlorophenoxyacetic acid concentrations to induce somatic embryogenesis.
TL;DR: Out of 6-benzyl aminopurine (BAP), kinetin (KIN), N (Δ−2 isopentyl) adenine (2iP) andAdenine sulphate (AS), only BAP and KIN were found to be more effective in enhancing the frequency of shoot regeneration.
Abstract: Conditions for plant regeneration from excised cotyledons of Vigna radiata were studied. Complete plant developed from the uncallused proximal ends of cotyledons on Murashige & Skoog's (MS), Gamborg's (B5) and ‘C’ (MS salts + B5 vitamins) basal media. The basal medium ‘C’ was found to be best for plant regeneration. Regeneration frequency, however, varied with genotype, size, orientation and age of explant and the different plant growth regulators combination in the medium. Addition of cytokinins induced callusing at the proximal ends of cotyledons followed by multiple shoot formation. Out of 6-benzyl aminopurine (BAP), kinetin (KIN), N (Δ−2 isopentyl) adenine (2iP) and adenine sulphate (AS), only BAP and KIN were found to be more effective in enhancing the frequency of shoot regeneration. BAP at 1×10-1M induced maximum (60%) shoot regeneration whereas maximum number of shoots (8 to 9 shoots) per explant was observed with 5×10-6M BAP. Cotyledons excised from two-day old seedlings were most regenerative. The regenerative response of cotyledons decreased when sliced into two equal parts either longitudinally or transversely. Callusing and organogenic differentiation occured only if the petiolar end of cotyledons was in contact with medium. None of the tested treatments were effective in inducing shoot bud differentiation from subcultured callus. Well developed shoots rooted when incubated on half strength MS, MS and MS basal medium supplemented with IAA (5×10-6M). The rooted plants were transferred to pots and later established in the field with 60% success.
TL;DR: Multiple shoots were proliferated from shoot tip and nodal explants of a mature tree of mulberry cultured on Murashige and Skoog's medium supplemented with 6-benzylaminopurine or K and transferred to rooting medium containing indole-3-butyric acid.
01 Jan 1990
TL;DR: The application of high temperature stress was found as reversible in lettuce, and as irreversible in barley, Nevertheless, the salinity stress was osmotic and reversible in both seeds.
Abstract: KABAR K. & BALTEPE S. 1990. Effects of kinetin and gibberellic acid in overcoming high temperature and salinity (NaCl) stresses on the germination of barley and lettuce seeds. Phyton (Horn, Austria) 30 (1): 65-74, 2 figures. English with German summary. Gibberellic acid (GA3), kinetin, and a combination of these two hormones applied axternally to dry seeds of barley (Hordeum distichon L.) and lettuce (Lactuca sativa L.) removed high temperature and/or salinity (NaCl) stresses on the germination of these seeds to varying extents. Kinetin alone had more effect on lettuce, while GA3 was more effective on barley. However, as the germination temperature and salt levels were increased, the synergistic effect of GA3 and kinetin combination was required. The application of high temperature stress (35° C) was found as reversible in lettuce, and as irreversible in barley. Nevertheless, the salinity stress was osmotic and reversible in both seeds.
TL;DR: Somatic embryos of the cut rose cultivars ‘Domingo’ and ‘Vickey Brown’ were obtained from callus derived from leaf explants on half strength Murashige and Skoog medium with low concentrations of kinetin and 1-naphthyl acetic acid or 2-nAPHthyloxyacetic acid.
Abstract: Somatic embryos of the cut rose cultivars 'Domingo' and 'Vickey Brown' were obtained from callus derived from leaf explants on half strength Murashige and Skoog medium with low concentrations of kinetin and 1-naphthyl acetic acid or 2-naphthyloxyacetic acid. Somatic embryos were first observed after 6 to 12 weeks of culture on callus formed at the basis or midrib of the leaf. Embryos could be grown to phenotypically true to type greenhouse plants.
TL;DR: A procedure for in vitro propagation of dioecious papaya clones is described and a high rate of success in culture estbalishment was obtained when axillary buds were taken from lateral shoots of hedged rooted cuttings grown in a greenhouse.
Abstract: A procedure for in vitro propagation of dioecious papaya clones is described. A high rate of success in culture estbalishment was obtained when axillary buds were taken from lateral shoots of hedged rooted cuttings grown in a greenhouse. Seasonal endophytic contamination was suppressed by shaking propagules for 24 h in 300 mgl-1 rifampicin or by incorporating it at 50 mgl-1 into the medium. Murashige & Skoog (MS) basal medium supplemented with 0.5 mgl-1 6-benzyladenine and 0.1 mgl-1 naphthaleneacetic acid was used for establishment and proliferation. The addition of 160 mgl-1 adenine sulfate improved multiplication and shoot growth. An elongation stage on MS medium supplemented with 1.0 mgl-1 kinetin and 0.05 mgl-1 naphthaleneacetic acid was necessary before rooting. Rooting was obtained at a high rate on half-strength macroelements of MS medium supplemented with 1.0 mgl-1 indole-3-butyric acid. Commercial plots of papaya plants obtained through this procedure already exist.
TL;DR: Evaluation of the organogenesis that occurred in TCLs cultured on a medium containing a range of IBA and kinetin concentrations showed that the number and type of organs formed, and overall growth, were dependent upon the initial concentrations of auxin and cytokinin.
Abstract: Thin cell-layer explants (TCLs) have been proposed as favorable tissues for the study of root, vegetative shoot and flower formation. We tested the effects of pH, light quality, light quantity, and IBA and kinetin concentrations on the morphogenesis of TCLs cultured individually on a liquid medium. Alterations of the amounts of exogenously supplied IBA and kinetin were sufficient to induce the formation of roots, vegetative shoots and flowers on TCLs cultured on otherwise identical media. The type and number of organs formed were sensitive to the intensity of light (55, 75, 100 and 120 muEinsteins m-2 sec-1) under which TCLs were grown. Evidence was obtained that the effects of light on TCL morphogenesis were associated with photochemical degradation of IBA in the medium. Evaluation of the organogenesis that occurred in TCLs cultured on a medium containing a range of IBA and kinetin concentrations showed that the number and type of organs formed, and overall growth, were dependent upon the initial concentrations of auxin and cytokinin. We have developed the TCL culture system into a sensitive and reproducible bioassay for the study of morphogenesis. The advantages of using the TCL morphogenesis bioassay for the identification and study of molecules (e.g. cell wall oligosaccharides) that may regulate morphogenesis are discussed.
TL;DR: Higher concentrations of proteins and enhanced activity of starch synthetase at low level of salinity suggest the salutary effect of Na+ in metabolic functions of plant cells and it is argued that salt tolerance limit can be extended upto certain level ofsalinity by pre-kinetin treatment in potato plants.
Abstract: Different potato cultivars were subjected to 10 −6M kinetin treatment prior to the transplantation in saline soils (pre-kinetin treatment) and to the plants already growing on the saline soils (post-kinetin treatment). The kinetine when applied before the exposure of plants to saline soils showed promotory effects on growth, tuberization and some biochemical parameters of potato at 0.5 % salinity. The degree of inhibition in number of tubers and yield was reduced at 1 % salinity due to pre-kinetin treatment. The level of proline, reducing sugars and sodium was increased in different plant parts to maintain the osmoregulation. However, kinetin did not play any specific role in reducing down the increase in proline content resulted due to salinity. The level of K+ was found to be higher at low salinity in all the cultivars of potato. Higher concentrations of proteins and enhanced activity of starch synthetase at low level of salinity suggest the salutary effect of Na+ in metabolic functions of plant cells. The nitrate reductase (NR) activity was appeared to be more sensitive than starch synthetase. This could possibly be due to the localization of the enzyme and the cellular concentration of toxic substances increased under stress. Total Glyoalkaloids (TGA) content was reduced at both the salinity levels irrespective of kinetin treatments. On the contrary Na+ content was increased in all the treatments of kinetin at both levels of salinity. During this study cvs. Red Lasoda, Patrones and Atom alue approved to be more tolerant as compare to rest of the cultivars tested. This could be a combined effect of genetic setup, amendments in saline soils and pre-kinetin treatments of plants exposed to various regimes of salinity. Furthermore it is argued that salt tolerance limit can be extended upto certain level of salinity by pre-kinetin treatment in potato plants.
TL;DR: Plants regenerated from cryopreserved embryogenic cell suspension of sugarcane established from leaf derived callus, and grown to maturity in the greenhouse, were morphologically identical to regenerated control plants.
Abstract: Efficient plant regeneration was obtained from a cryopreserved embryogenic cell suspension of sugarcane established from leaf derived callus. Pregrowing the cells for three days in MS basal medium supplemented with 0.33 M sorbitol was essential to the process. The cells were cooled at a rate of 0.5°C/min to -40°C and then stored in liquid nitrogen. Thawing was carried out rapidly in water at +40°C, and the cells were then plated without washing onto filter paper discs placed on a semi-solid regeneration medium (MS basal + 3% sucrose + 0.13 mg/1 2,4-D +0.25 mg/1 BAP + 0.25 mg/1 kinetin + 0.25 mg/1 zeatin). The filter paper discs, along with the cells, were transferred to the same, fresh medium after five hours. After 24 hours the cells were scraped off, placed on fresh semi-solid medium and incubated at 28°C in the dark for two weeks before transfer to light. A regeneration efficiency of 92% was obtained (regenerated plants, expressed as a percent of unfrozen control). Plants regenerated from cryopreserved cells, and grown to maturity in the greenhouse, were morphologically identical to regenerated control plants.
TL;DR: New macro- and microelement solutions were formulated for stimulation of growth and embryogenesis in white and chlorophyllous megagametophyte and embryo callus lines of Picea abies (L.) Karst, and favourable combination of growth regulators and organic nitrogen were especially important.
Abstract: New macro- and microelement solutions were formulated for stimulation of growth and embryogenesis in white and chlorophyllous megagametophyte and embryo callus lines of Picea abies (L.) Karst. Macroelement media with different NHJ and KO:^ ratios (1:2 and 1:4), the increased level of several microelements and the effect of organic nitrogen (100 nag, T' casein hydrolysate, 0.25 mAf arginine and 0.5 mM glutamine) were tested with 4 combinations of growth regulators (2,4-dichlorophenoxyacetic acid or indole-3-butyric acid, kinetin). Green chlorophyll-containing, in contrast to white callus lines, grew quite well without exogeneously added organic nitrogen. The ratio between NHJ" and NOj was not significant. The increased levels (V.M) of several microelements: B (200), Zn (50), I (25), Cu (1), Co (0.5) and in addition Ni (0.1) improved callus growth in some lines more than 50% (DW) compared to cultures grown on the micronutrients of Murashige and Skoog. The response of different callus lines varied with the combinations of growth regulators. Embryogenesis did not occur in chlorophyllous callus lines in any of the 24 media combinations tested, but some very good media could be found for white megagametophyte and embryo callus lines. Microelements, favourable combination of growth regulators and organic nitrogen were especially important. A megagametophyte callus subcnltured for 4 years was also able to form numerous proembryos.
TL;DR: A technique is described for the production de novo of cucumber (Cucumis sativus L.) shoots in the presence of cytokinin using cotyledon explants, which may be useful for transformation studies in cucumber.
Abstract: A technique is described for the production de novo of cucumber (Cucumis sativus L.) shoots in the presence of cytokinin using cotyledon explants. The shoots, which arose from adventitious buds and not from enhanced axillary branching, are confined to a specific region at the base of the cotyledon. Concentrations (4 mgl−1 or less) of the cytokinins 6-benzylaminopurine, kinetin and N6-(2-isopentenyl)adenine, are all effective in producing adventitious buds. It is possible to achieve a yield of 23 shoots per cotyledon by removal of the axillary bud. The yield is increased to 50 shoots per cotyledon by cutting the basal region of the cotyledon into small pieces prior to culturing. These techniques may be useful for transformation studies in cucumber.
TL;DR: Some factors involved in shoot elongation and leaf enlargement of adventitious apple shoots in vitro were investigated and leaf expansion was significantly improved when shoots were grown on proliferation medium with either 2-isopentyladenine or kinetin alone.
Abstract: Some factors involved in shoot elongation and leaf enlargement of adventitious apple shoots in vitro were investigated. A system was established to produce large numbers of adventitious shoots for this study. Leaves were harvested from proliferating cultures of three apple scion cultivars, cut into two segments, and plated onto three regeneration media. Adventitious shoots formed best on a modified Murashige and Skoog medium supplemented with thidiazuron (3 |iM) and naphthaleneacetic acid (5.4 ^M). Large (15+ mm width) leaves regenerated significantly better than smaller ones. The cut surface of the leaf segments produced the highest number of regeneration sites. Shoot proliferation medium with 6-benzylaminopurine (4.44 (iM) and kinetin (13.95 (xM) was significantly better than the other media for producing tall shoots and satisfactory proliferation. Leaf expansion was significantly improved when shoots were grown on proliferation medium with either 2-isopentyladenine or kinetin alone.
TL;DR: Analysis of variance procedures revealed significant variability for callus initiation media, proliferation media (semi-solid or liquid, and an initiation medium x genotype interaction, which was influenced by genotype/initiation medium combination.
Abstract: A comparison of semi-solid vs liquid embryo proliferation media was made using two Gossypium hirsutum L genotypes (Coker 312 and T25) and two callus initiation media Sections of petioles from mature, flowering plants were cultured on two modified Murashige and Skoog media Medium 1 included 40 mg l-1 NAA and 10 mg l-1 kinetin; medium 2 contained 01 mg l-1 2,4-D and 01 mg l-1 kinetin After six weeks, callus was removed from each explant and divided in half One callus portion was placed in liquid proliferation medium and the other on semi-solid (02% Gelrite) proliferation medium Composition of proliferation medium was identical to that of initiation medium, except no growth regulators were added Embryos were counted after eight weeks The percentage of explants forming callus was influenced by genotype/initiation medium combination Analysis of variance procedures revealed significant variability for callus initiation media, proliferation media (semi-solid or liquid), and an initiation medium x genotype interaction Paired t-tests indicated that more embryos were produced in liquid proliferation medium (2273 embryos/culture) than on semi-solid proliferation medium (1346 embryos/culture)
TL;DR: A procedure for rapid propagation of Agave (A. cantala Roxb., A. fourcroydes Lem. and A. sisalana Perrine) has been developed and subcultures of these on the same medium were successful for the multiplication with an index of 3–4 times per 4 weeks subculture period.
Abstract: A procedure for rapid propagation of Agave (A. cantala Roxb., A. fourcroydes Lem. and A. sisalana Perrine, (Agavaceae) have been developed. The explants were excised from stolon plantlets, sterilized and cultivated on Murashige and Skoog (MS) basal medium containing 2% sucrose, 10% coconut water and 0.8% agar. The addition of following combination of growth substances—0.075 mgl-1 naphthalenacetic acid (NAA)+0.1 mgl-1 indolylbutyric acid (IBA)+0.5 mgl-1 kinetin (KIN) caused an extensive proliferation of multiple shoot primordia. Subcultures of these on the same medium were successful for the multiplication with an index of 3–4 times per 4 weeks subculture period. Shoots were rooted on hormone free MS medium and then transferred into a sand bed for acclimation before field planting.
TL;DR: In addition to their effects on vascular tissue regeneration, both cytokinins promoted callose production and were most evident on the sieve plates of the regenerated sieve tube members and on the walls of the parenchyma cells around the wound.
Abstract: Cytokinin proved to be a controlling factor in sieve tube regeneration around wounded collateral bundles in an in vivo system in which the endogenous cytokinin level had been minimized. Both kinetin and zeatin were applied in aqueous solution to the bases of excised, mature internodes of Coleus blumei Benth. that had an active vascular cambium. Each internode also received indoleacetic acid (IAA) in lanolin at its apical end. Under either low (0.1% w/w) or high (1.0% w/w) auxin concentrations, the control internodes (without exogenous cytokinin) exhibited small amounts of sieve tube regeneration. At appropriate concentrations, both kinetin and zeatin induced a significant increase in sieve tube regeneration around the wound. However, the highest concentration of kinetin tested (50 μg/mL) completely inhibited this process. Kinetin was the most effective with high auxin (1.0% IAA), while zeatin was the most effective with low auxin level (0.1% IAA). Kinetin and zeatin showed the strongest promotive effect at 10 μg/mL and 20 μg/mL, respectively. Both cytokinins also induced supplementary phloem regeneration further from the wound surface. In addition to their effects on vascular tissue regeneration, both cytokinins promoted callose production. This was most evident on the sieve plates of the regenerated sieve tube members and on the walls of the parenchyma cells around the wound. The largest deposits of callose were found in both regenerated sieve tube members and parenchyma cells at the highest cytokinin concentration tested (50 μg/mL). The possible role of cytokinin in controlling callose accumulation in the sieve tubes during autumn is discussed.
TL;DR: Results provide further evidence that growth regulators can be used for the tissue culture of seaweeds and for the study of developmental phenomena in these plants.
Abstract: We examined whether auxins and cytokinins, either singly or in combination, stimulate cell division in tissue cultures of a red seaweed. Our experimental model consisted of filamentous and callus-like growths that developed from cross-sectional discs cut from young branches of Agardhiella subulata. Plant growth regulators were added to the medium to give combinations of an auxin with a cytokinin over a range of concentrations (1 µg L−1 −10 mg L−1). Several mixtures of auxins and cytokinins, as well as some single auxins, cytokinins and phenolics, stimulated cell division and growth in the tissue cultures beyond that of controls. The treatments that were effective included: phenylacetic acid/zeatin; phenylacetic acid/6-benzylaminopurine; α-naphthaleneacetic acid/zeatin; 2,4,5-trichlorophenoxyacetic acid/6-benzylaminopurine; and indoleacetic acid/kinetin. High concentrations of cytokinins (i.e. 10 mg L−1) inhibited the regeneration of plants in some of the cell cultures. These results provide further evidence that growth regulators can be used for the tissue culture of seaweeds and for the study of developmental phenomena in these plants.
TL;DR: Callus was induced from juice vesicles of satsuma mandarin on Murashige & Skoog medium supplemented with α-naphthaleneacetic acid (NAA), kinetin (K) and gibberellin and grew into embryos which resulted in a plantlet on medium containing 1 mgl−1 GA.
Abstract: Callus was induced from juice vesicles of satsuma mandarin on Murashige & Skoog medium supplemented with α-naphthaleneacetic acid (NAA), kinetin (K) and gibberellin (GA). Adventitious embryoids arose from the callus tissue on the medium containing 1 mgl−1 NAA alone. The embryoids grew into embryos which resulted in a plantlet on medium containing 1 mgl−1 GA.
TL;DR: Calli were obtained from Ginkgo biloba embryos grown on Murashige and Skoog (MS) medium and best growth and maintenance of callus cultures were achieved using MS medium supplemented with 2 mg·L−1 NAA and 1 mg· L−1 K (N2K1MS).
Abstract: Calli were obtained from Ginkgo biloba embryos grown on Murashige and Skoog (MS) medium. The G. biloba cells could grow on either MS or Gamborg B5 mineral salt medium supplemented with sucrose (3% and 2%, respectively) and naphthaleneacetic acid (NAA) and kinetin (K) in concentrations ranging from 0.1 to 2.0 mg·L−1. Best growth and maintenance of callus cultures were achieved using MS medium supplemented with 2 mg·L−1 NAA and 1 mg·L−1 K (N2K1MS). Light was required to maintain healthy growth of the callus tissue.
TL;DR: The influence of jasmonic acid on differentiation of meristems of the potato,Solanum tuberosum cv.
Abstract: The influence of jasmonic acid (JA) on differentiation of meristems of the potato,Solanum tuberosum cv. Vesna, was investigated in vitro. Meristems were grown on Murashige and Skoog (MS) medium supplemented with indole-3-acetic acid (IAA) (10 μM), kinetin (10 μM), gibberellic acid (3 μM), as modified by Bang. Addition of JA in concentrations of 0.5–10 μM increased the number of meristems that developed into buds, particularly in meristems isolated from shoots grown from tubers in the dark. JA had no noticeable effect on meristems from germs grown in light. All added concentrations of JA retarded callus and root formation. The inhibitory effect on rhizogenesis disappeared immediately after transfer of the developed buds to medium without JA.
TL;DR: Among the three media compared, N6AA medium including l -proline and four other amino acids as an organic nitrogen source was found to be the most suitable for the maintenance of suspension cultures.