Showing papers on "Murashige and Skoog medium published in 1992"
TL;DR: Of various cytokinins or compounds with cytokinin-like activity tested for inducing shoot formation in pea seeds cultures,TDZ was found to be most effective and inductive capability of TDZ was then tested in several other genotypes of Pisum sativum and two other large-seeded grain legumes.
Abstract: Axenic seedling cultures of chickpea (Cicer arietinum L.), lentil (Lens culinaris Medik.) and garden pea (Pisum sativum L.) were established by culturing mature seeds on Murashige and Skoog medium (MS) supplemented with thidiazuron (TDZ). Of various cytokinins or compounds with cytokinin-like activity (Kinetin, TDZ, Zeatin) tested for inducing shoot formation in pea seeds cultures, TDZ was found to be most effective. Pea seedlings exhibited a unique pattern of shoot formation which was accomplished in two distinct phases. Multiple shoots developed within a week, from the nodal and basal regions of the primary epicotyl in a medium that contained 5-50 μM TDZ. When these seedlings were exposed for a prolonged time period (3-4 weeks), to the same medium, numerous shoot buds emerged de novo from the base and/or from the upper part of multiple shoots. These shoots had no apparent vascular connection with parent tissues. The inductive capability of TDZ was then tested in several other genotypes of Pisum sativum and two other large-seeded grain legumes, Cicer arietinum, and Lens culinaris. In Cicer arietinum, and Lens culinaris, multiple shoots developed after 1 week of seed culture on media that contained 1-50 μM TDZ. However, de novo differentiation of shoot buds occurred in cultures exposed to TDZ for 4-6 weeks, only from nodal and subjacent areas. Secondary shoot formation occurred frequently in all of the species tested. Developing shoots were able to form roots and eventually whole plants on a modified MS medium containing 2.5 μM NAA. No genotypic difference for morphogenesis was observed.
191 citations
TL;DR: The efficiency of somatic embryo germination was as high as 77% from semi-wild soybean and 60–64% from cultivated soybeans, showing that the plant regeneration system developed in this study was efficient and practical.
Abstract: The effects of sucrose on maturation and of plant growth regulators on germination of soybean somatic embryos were investigated for the purpose of developing an efficient culture method for plant recovery. Somatic embryos produced on medium with a low sucrose concentration (5 gl-1), less than 1 mm in length, 0.6 mg in fresh weight, and green in color, were grown for 2 weeks on MS medium containing 5 gl-1 or 30 gl-1 sucrose and then for another 5 weeks on MS medium containing 5–90 gl-1 sucrose. The highest increase in fresh weight of somatic embryos was obtained in the treatment of transferring from 30 gl-1 sucrose (2 weeks) to 60 gl-1 (5 weeks). With the increase in fresh weight, the somatic embryos gradually changed color from green to yellow, and finally to white, when they stopped growth. Soybean seed storage proteins (β-conglycinin and glycinin) were accumulated in somatic embryos under tissue specific and stage specific control analogous to that in zygotic embryos. Exogenous gibberellic acid was effective in promoting precocious germination of premature soybean somatic embryos, but was not necessary for the germination of mature somatic embryos. The efficiency of somatic embryo germination was as high as 77% from semi-wild soybean and 60–64% from cultivated soybeans, showing that the plant regeneration system developed in this study was efficient and practical.
180 citations
TL;DR: In vitro-grown shoot tips of apples (Malus domestica Borkh. cv. Fuji) and pear cultivars were successfully cryopreserved by vitrification and this method appears to be a promising technique forCryopreserving shoot tips from in vitro- grown plantlets of fruit trees.
Abstract: In vitro-grown shoot tips of apples (Malus domestica Borkh. cv. Fuji) were successfully cryopreserved by vitrification. Three-week-old in vitro apple plantlets were cold-hardened at 5°C for 3 weeks. Excised shoot tips from hardened plantlets were precultured on a solidified Murashige & Skoog agar medium (MS) supplemented with 0.7 M sucrose for 1 day at 5°C. Following preculture shoot tips were transferred to a 2 ml plastic cryotube and a highly concentrated cryoprotective solution (designated PVS2) was then added at 25°C. The PVS2 contains (W/V) 30% glycerol, 15% ethylene glycol and 15% dimethylsulfoxide in medium containing 0.4 M sucrose. After dehydration at 25°C for 80 min, the shoot tips were directly plunged into liquid nitrogen. After rapid warming, the shoot tips were expelled into 2 ml of MS medium containing 1.2 M sucrose and then plated on agar MS medium. Direct shoot elongation was observed in approximately 3 weeks. The average rate of shoot formation was about 80%. This vitrification method was successfully applied to five apple species or cultivars and eight pear cultivars. This method appears to be a promising technique for cryopreserving shoot tips from in vitro-grown plantlets of fruit trees.
135 citations
TL;DR: Results support use of particle bombardment for transformation of this important ornamental monocot.
Abstract: Transformed dendrobium orchids (Dendrobium x Jaquelyn Thomas hybrids) were recovered from protocorms bombarded by particles coated with the plasmid pGA482GG/cpPRV4, which contains the plant expressible Nos-NPT II and papaya ringspot virus (PRV) coat protein (CP) genes. Approximately 280 protocorms from four crosses were bombarded and potentially transformed tissues were identified by growth and green color on half-strength Murashige and Skoog medium supplemented with 2% sucrose and 50–100 mg 1−1 kanamycin sulfate. Kanamycin concentrations that prevented growth of nontransformed tissues could not be used for long-term selection because such levels suppressed the regeneration of potentially transformed tissues. PCR and restriction analysis 21 months after treatment found 13 of 13 plants from two crosses, which appeared kanamycin-tolerant, to contain the Nos-NPT II gene, while only one of these plants carried the vector-linked PRV CP-gene. These results support use of particle bombardment for transformation of this important ornamental monocot.
107 citations
TL;DR: For 18 sugarcane cultivars, four distinct callus types developed on leaf explant tissue cultured on modified MS medium, but only Type 3 (embryogenic) and Type 4 (organogenic) were capable of plant regeneration, and plants could not be regenerated from homogeneous cell suspension cultures.
Abstract: For 18 sugarcane cultivars, four distinct callus types developed on leaf explant tissue cultured on modified MS medium, but only Type 3 (embryogenic) and Type 4 (organogenic) were capable of plant regeneration. Cell suspension cultures were initiated from embryogenic callus incubated in a liquid medium. In stage one the callus adapted to the liquid medium. In stage two a heterogeneous cell suspension culture formed in 14 cultivars after five to eight weeks of culture. In stage three a homogeneous cell suspension culture was developed in six cultivars after 10 to 14 weeks by selective subculturing to increase the proportion of actively dividing cells from the heterogeneous cell suspension culture. Plants were regenerated from cell aggregates in heterogeneous cell suspension cultures for up to 148 days of culture but plants could not be regenerated from homogeneous cell suspension cultures. High yields of protoplasts were obtained from homogeneous cell suspension cultures (3.4 to 5.2 × 106 protoplasts per gram fresh weight of cells [gfwt-1]) compared to heterogeneous cell suspension cultures (0.1 × 106 protoplasts gfwt-1). Higher yields of protoplasts were obtained from homogeneous cell suspension cultures for cultivars Q63 and Q96 after regenerating callus from the cell suspension cultures, then recycling this callus to liquid medium (S-cell suspension cultures). This process increased protoplast yield to 9.4 × 106 protoplasts gfwt-1. Protoplasts isolated from S-cell suspension cultures were regenerated to callus and recycled to produce SP-cell suspension cultures yielding 6.4 to 13.2 × 106 protoplasts gfwt-1. This recycling of callus to produce S-cell suspension cultures allowed protoplasts to be isolated for the first time from cell lines of cultivars Q110 and Q138.
99 citations
TL;DR: In-vitro methods have been developed to regenerate clumps of multiple shoots and somatic embryos at high frequency from shoot tips of aseptically-grown seedlings as well as from shoot apices of precociously-germinated immature zygotic embryos of corn.
Abstract: In-vitro methods have been developed to regenerate clumps of multiple shoots and somatic embryos at high frequency from shoot tips of aseptically-grown seedlings as well as from shoot apices of precociously-germinated immature zygotic embryos of corn (Zea mays L.). About 500 shoots were produced from a shoot tip after eight weeks of culture (primary culture and one subculture of four weeks) in darkness on Murashige and Skoog basal medium (MS) supplemented with 500 mg/L casein hydrolysate (CH) and 9 μM N(6)-benzyladenine (BA). In this medium, shoots formed in shoot tips as tightly packed "multiple shoot clumps" (MSC), which were composed of some axillary shoots and many adventitious shoots. When the shoot tips were cultured on MS medium containing 500 mg/L CH, 9 μM BA and 2.25 μM 2,4-dichlorophenoxyacetic acid (2,4-D), most of the shoots in the clumps were adventitious in origin. Similar shoot tips cultured on MS medium containing 500 mg/L CH, 4.5 μM BA and 2.25 μM 2,4-D regenerated many somatic embryos within eight weeks of culture. Somatic embryos were produced either directly from the shoot apical meristems or from calli derived from the shoots apices. Both the MSC and the embryos produced normal shoots on MS medium containing 2.25 μM BA and 1.8 μM indole-3-butyric acid (IBA). These shoots were rooted on MS medium containing 3.6 μM IBA, and fertile corn plants were grown in the greenhouse. The sweet-corn genotype, Honey N Pearl, was used for the experiments described above, but shoot-tip cultures from all of 19 other corn genotypes tested also formed MSC on MS medium containing 500 mg/L CH and 9 μM BA.
95 citations
TL;DR: Mature seed explants of white ash were more organogenic with shoots that elongated better than explants from immature seeds, and somatic embryogenesis was observed in cultures where mature seeds were first cultured for 4 weeks on a medium containing 10 μM adenine 2,4-dichlorophenoxyacetic acid.
Abstract: Immature and mature nonstratified seeds of white ash (Fraxinus americana L.) were dissected transversely and 2/3 of each seed was placed onto agar-solidified Murashige and Skoog medium. Adventitious buds, shoots, and somatic embryos formed on callus, cotyledons, and hypocotyls of the resulting seedlings. Shoot organogenesis was induced on explants cultured on medium with 10 μM thidiazuron but not on explants on media with benzyladenine (BA) or isopentenyladenine. Not all seed sources were equally capable of shoot organogenesis and embryogenesis. Atypical of adventitious regeneration of other woody plants, mature seed explants of white ash were more organogenic with shoots that elongated better than explants from immature seeds. Somatic embryogenesis was observed in cultures where mature seeds were first cultured for 4 weeks on a medium containing 10 μM adenine 2,4-dichlorophenoxyacetic acid in combination with 0.1 and 1.0 μM thidiazuron, followed by transfer to a medium containing 0.05 μM 6-benzyladenine and 0.5 μM naphthaleneacetic acid. Adventitious shoots and epicotyls from both seedlings and germinated somatic embryos were rooted under intermittent mist and acclimatized to the greenhouse.
88 citations
TL;DR: The objective of this research was to study the in-vitro morphogenetic pattern of corn shoot tips excised from aseptically-grown seedlings, and of expiants of axillary shoot buds, immature tassels and ears obtained from greenhouse-grown corn plants.
Abstract: The objective of this research was to study the in-vitro morphogenetic pattern of corn (Zea mays L.) shoot tips excised from aseptically-grown seedlings, and of expiants of axillary shoot buds, immature tassels and ears (staminate and pistillate inflorescences) obtained from greenhouse-grown corn plants. The seedling shoot tips and immature ears first regenerated clumps of multiple shoots within four weeks of culture on Murashige and Skoog (MS) basal medium supplemented with 500 mg/L casein hydrolysate (CH) and 9.0 μM N6-benzyladenine (BA). Multiple shoot clumps were also differentiated from spikelets of immature tassels cultured on MS medium containing 500 mg/L CH, 4.5 μM BA and 0.45 μM 2,4-dichlorophenoxy acetic acid (2,4-D). All these multiple shoot clumps in turn differentiated clusters of ears after further four subcultures at four-week intervals under light on MS medium supplemented with 500 mg/L CH and 2.25, 4.5, 9.0 or 18 μM BA. Axillary shoot buds readily differentiated clusters of ears within four weeks of the initial culture on these media. Secondary and tertiary ear clusters were initiated following subculture of primary ears on MS medium containing 500 mg/L CH and 4.5 or 9.0 μM BA. Most of the ear primordia developed into ears with well-developed ovaries and styles on subculture on MS medium containing 500 mg/L CH and 1.0 μM BA. Corn kernels were obtained after pollination of in-vitro-formed ears with pollens collected from greenhouse-grown corn. These kernels germinated in vitro and developed into mature corn plants in the greenhouse. Clusters of tassels were also differentiated in darkness from the multiple shoot clumps after six months successive subcultures but the spikelet primordia of tassels failed to develop fully under the in-vitro conditions tested. Somatic embryos arose directly from spikelet primordia of young tassels or ears on MS medium containing 500 mg/L CH and 4.5 μM 2,4-D, or indirectly from calli derived from spikelets of young tassels and ears on MS medium containing 500 mg/L CH and 9.0 μM 2.4-D.
87 citations
TL;DR: A novel type of somatic embryogenesis characterized by an efficient and highly synchronized embryo formation was observed in embryogenic callus of Coffea arabica initiated on Murashige and Skoog medium containing kinetin and 2,4-D, and the term self-Controlled Somatic Embryogenesis (SCSE) is proposed.
Abstract: A novel type of somatic embryogenesis characterized by an efficient and highly synchronized embryo formation was observed in embryogenic callus of Coffea arabica initiated on Murashige and Skoog medium containing kinetin (4 mg/l) and 2,4-D (1 mg/l). It occurs in suspension and goes along with the suppression of “High Frequency Somatic Embryo Induction” (HFSE). This is achieved by favoring during cultivation senescence-or necrosis-like processes which apparently do not impair the competence for embryogenesis. Since the resulting embryos germinate at a rate of 94.5 % without the need of a maturation step, we propose the term “Self-Controlled Somatic Embryogenesis” (SCSE). In addition, HFSE was optimized using half-strength liquid medium with 0.1 mg/l kinetin and 0.25 mg/l 2,4-D for proliferation of embryonic tissue, and 2.6 mg/l ABA for maturation of embryos. Yields as well as germination rates of HFSE embryos were markedly lower as compared to SCSE.
73 citations
TL;DR: Rooted hypocotyls from three cultivars of chili pepper were inverted onto Murashige and Skoog medium with three combinations of benzyladenine and indoleacetic acid in order to induce buds in the exposed cortex, allowing the elongation of shoots during a period of 15–30 days.
67 citations
TL;DR: The results suggest that stevioside biosynthesis is a function of tissue differentiation since both roots and leaves are required for cultured S. rebaudiana to biosynthesize stEVioside from acetate, while the final biosynthetic steps can be performed at all levels of differentiation.
Abstract: Leaf explants of Stevia rebaudiana Bertoni (Compositae), an herb which produces the sweet ent-kaurene glycoside stevioside, were cultured in Murashige and Skoog medium with vitamins, sucrose (30 g l−1), agar (0.9% w/v) and supplemented with naphthaleneacetic acid (NAA, 0.5 mg l−1) and benzylaminopurine (BAP, 0.5 mg l−1). These conditions yielded friable callus cultures. Differentiation of the callus tissue was then achieved by eliminating the agar and modulating the medium's hormone concentrations. Thus, medium containing increased auxin concentration (1.0 mg l−1) and no cytokinin or increased cytokinin (1.0 mg l−1) and no auxin yielded root or shoot cultures respectively. Supplementation of the shoot medium with NAA (1.0 mg ml−1) induced shoot cultures to grow roots thereby differentiating into rooted-shoot cultures. Only the rooted-shoot cultures tasted sweet. Feedings of [2-14C]acetic acid to callus, shoot or rooted-shoot cultures demonstrated that only the rooted-shoot cultures are capable of de novo biosynthesis of the aglycone moiety of stevioside (steviol). In addition, [methyl-3H(N)steviol feedings to shoot or rooted-shoot cultures illustrated that both types of cultures are capable of the glycosylation reaction. The ability of these tissues to glycosylate steviol to stevioside was also demonstrated employing crude enzyme preparations derived from shoot or rooted-shoot cultures. These results suggest that stevioside biosynthesis is a function of tissue differentiation since both roots and leaves are required for cultured S. rebaudiana to biosynthesize stevioside from acetate, while the final biosynthetic steps can be performed at all levels of differentiation.
TL;DR: The inclusion of a desiccation period during embryo development enhanced conversion four-fold and the cultures exhibited exponential growth, and have been maintained for over one year without apparent loss of embryogenic potential.
Abstract: A regeneration system based on repetitive somatic embryogenesis was developed for peanut (Arachis hypogaea L.). Embryogenic suspension cultures were initiated using individual somatic embryos induced from immature cotyledons cultured on a modified Murashige and Skoog medium containing 40 mg/l 2,4-D for 30 days. After transfer to a modified MS liquid medium, the somatic embryos produced masses of secondary and tertiary embryos which continued to proliferate following manual separation and subculture of the embryogenic clumps. The cultures exhibited exponential growth, and have been maintained for over one year without apparent loss of embryogenic potential. Further embryo development, germination, and conversion were achieved by placing embryo clumps onto hormone-free, solid medium. The inclusion of a desiccation period during embryo development enhanced conversion four-fold. Plants have been established in soil and appear to be phenotypically normal.
TL;DR: Embryogenic cell lines of Vitis rotundifolia were produced from immature zygotic embryo explants obtained by culturing ovules, harvested at 20 d postanthesis, for 8 wk and then dissecting embryos from them, which produced a heterogenous callus from which eventually emerged embryogeniccell lines.
Abstract: Embryogenic cell lines of Vitis rotundifolia were produced from immature zygotic embryo explants obtained by culturing ovules, harvested at 20 d postanthesis, for 8 wk and then dissecting embryos from them. Ovules cultured on Nitsch and Nitsch medium with naphthoxyacetic acid and benzyladenine (BA) produced a brown exudate, necessitating three transfers to fresh medium at 2-wk intervals during the 8-wk culture cycle. Zygotic embryos that were subsequently isolated from cultured ovules and placed on the same medium produced a heterogenous callus from which eventually emerged embryogenic cell lines. A higher percentage of ovules from cultivars 'Dixie', 'Fry', 'Nesbitt', and 'Welder' produced zygotic embryos (3 1/%-o39%) than did those from 'Carlos' (3%). A higher percentage of 'Fry' ovules produced embryogenic lines from cultured zygotic embryos (6.3%) than did those of the other four cultivars (1/%-1 .6%). Embryogenic cell lines were white and composed of variably sized cell clusters, somatic embryos, and embryonic tissue embedded in a watery matrix. These lines were maintained for over 1 yr on modified Murashige and Skoog (MS) medium lacking growth regulators by transfer of selected cell clusters every 6 wk. White, opaque somatic embryos grew directly from cell clusters and passed through recognizable developmental stages. Germination was induced by transfer of somatic embryos to MS medium with BA. Although 80%/o-. 100% of embryos germinated, plant recovery was low due to poor shoot development.
TL;DR: The effect of major nutrients on growth and alkaloid production by plant cell culture of Holarrhena antidysenterica was studied with a view to increasing the yield of the alkaloids conessine, a therapeutic drug used for treatment of dysentery and helminthic disorders.
Abstract: The effect of major nutrients on growth and alkaloid production by plant cell culture of Holarrhena antidysenterica was studied with a view to increasing the yield of the alkaloid conessine, a therapeutic drug used for treatment of dysentery and helminthic disorders. The studies resulted in development of a modified Murashige and Skoog (MS) medium that contained 60 mM total nitrogen with a NH(4) (+)-to-NO(3) (-) ratio of 5:1, 0.25 mM phosphate, and 40 g/L sucrose. The growth regulators 2,4-dichlorophenoxy acetic acid (2,4-D) and kinetin (Kn) were also found to affect the synthesis of alkaloid. Using an optimal level of inoculum (3 g/L), the modified medium resulted in alkaloid synthesis of 0.66 g/100 g dry cell weight, which represented a 4.25-fold increase over that obtained in standard MS medium.
TL;DR: For all accessions tested plants could be regenerated at a high frequency from this compact callus through somatic embryogenesis, when using kinetin supplemented MS medium (regeneration medium).
Abstract: The plant regeneration ability of zygotic embryo-derived callus cultures was studied for 12 A. cepa varieties and accessions, two A. fistulosum varieties, one A. fistulosum x A. cepa interspecific hybrid and two A. porrum varieties. Compact embryogenic callus was induced on Murashige and Skoog (MS) medium supplemented with 2,4-dichlorophenoxyacetic acid. The embryogenic calluses of all three Allium species were similar in appearance. For all accessions tested plants could be regenerated at a high frequency from this compact callus through somatic embryogenesis, when using kinetin supplemented MS medium (regeneration medium). Addition of abscisic acid to the regeneration medium stimulated the formation of both somatic embryos and shoots for a number of varieties. Concerning shoot regeneration from callus cultures, significant differences existed between genotypes of all accessions except one.
TL;DR: Embryogenesis was induced with three genotypes using a modified half-strength Murashige and Skoog (MS) medium supplemented with 1.0 to 4.0 mg l−1 2, 4-dichlorophenoxyacetic acid (2,4-D) and 0.7% Bacto-agar and a combination of 2% sucrose with 1% glucose in the medium favored embryogenesis over 3% Sucrose alone.
Abstract: A method for the production of somatic embryos and subsequent plant regeneration for Anthurium andraeanum Linden ex Andre (Monocotyledonae) hybrids is described. Whole leaf blade explants, derived from plantlets grown in vitro, formed translucent embryogenic calli at their basal ends within one month of culture in the dark. Secondary somatic embryos formed frequently and without an intervening callus on surfaces of primary embryos. Embryogenesis was induced with three genotypes using a modified half-strength Murashige and Skoog (MS) medium supplemented with 1.0 to 4.0 mg l−1 2,4-dichlorophenoxyacetic acid (2,4-D) and 0.33 to 1.0 mg l−1 kinetin. A combination of 2% sucrose with 1% glucose in the medium favored embryogenesis over 3% sucrose alone. Whole leaf blades on medium solidified with 0.18% Gelrite produced more somatic embryos than leaves on medium with 0.7% Bacto-agar. Within two to three months after culture initiation, embryos were transferred to modified MS medium containing 0.2 mg l−1 6-benzyladenine (BA) and 2% sucrose and placed in the light for conversion into plantlets. Rooted plantlets were recovered and transferred into pots with tree fern fiber medium and grown in the greenhouse.
TL;DR: Differences in ploidy were observed in plants derived from both short term and long-term callus cultures; diploid true-to-type regenerants were 96% and 83%, respectively, from shortterm andlong-termcallus cultures.
Abstract: A simple and reproducible protocol for regeneration of sugarbeet plants from hypocotyl expiants derived from 21 day-old-seedlings has been developed. Expiants were cultured on MS medium containing 0.3 mg/l N6-Benzylaminopurine, 0.1 mg/l Naphthalene Acetic Acid, 50 mg/l adenine and 0.5% (w/v) fructose, 0.5% (w/v) sucrose and 0.5% (w/v) glucose to induce the formation of organogenic calli (2.3% to 46.5% organogenic efficiency, depending on populations). Shoot formation was induced in callus cultures of more than 1600 genotypes. Physiological age affected culture response and different genotypes had different temperature optima for organogenesis. Following transfer of regenerated plants to the greenhouse, DNA determinations were made to study the stability of ploidy. Differences in ploidy were observed in plants derived from both shortterm and long-term callus cultures; diploid true-to-type regenerants were 96% and 83%, respectively, from shortterm and long-term callus cultures.
TL;DR: Fifty-four out of 67 species of bamboo tested were successfully propagated in vitro and, for nearly every species, multiple shoots were produced from axillary buds on stem node segments cultured on Murashige and Skoog medium containing BA.
Abstract: Fifty-four out of 67 species of bamboo tested were successfully propagated in vitro. For nearly every species, multiple shoots were produced from axillary buds on stem node segments cultured on Murashige and Skoog medium containing BA. In a very few species plants could be regenerated adventitiously from callus. This method of propagation was not very efficient or reliable. Rooting occurred in media containing NAA at 2.7 to 5.4 µM. Several species could be stored in vitro on half-strength medium at room temperature > 15 months without transfer. Chemical names used: N6-benzyl- amino purine (BA); napthyleneacetic acid (NAA). Bamboo is an economically important multipurpose crop. It is used as a source of food, fiber, building materials, and biofuel. Most bamboo is harvested from naturally oc- curring stands with minimal conservation or reforestation. Many species of bamboo are endangered because of harvesting and the lack of knowledge on propagation methods and flowering control (most species die after flowering). Current methods of bamboo propagation rely on culm cutting, rhizome division, or seed. These methods are expen- sive and inefficient. Micropropagation offers the potential for rapidly increasing select bamboo clones for reforestation and conser- vation. At a recent conference in Singapore there were several oral reports describing the successful use of tissue culture to microprop agate bamboo (Rao et al., 1990). In only two instances have sufficient data been obtained to allow the publication of the results (Huang et al., 1988; Hassan and Debergh, 1987). In our investigation, we studied the response of an additional 52 species and 12 genera (Ta- ble 1).
TL;DR: The morphogenetic potential of shoot tip explants of black pepper (Piper nigrum) was investigated and an effective multiple-shoot propagation method is described.
Abstract: The morphogenetic potential of shoot tip explants of black pepper (Piper nigrum) was investigated and an effective multiple-shoot propagation method is described. Various combinations of media, growth regulators and sterilization treatments were compared. Problems with establishment in tissue culture sometimes occurred, probably caused by endogenous pathogens associated with tissue exudates. The best establishment and proliferation of shoot tip explants was obtained on MS medium containing 1.5 mg l−1 BAP alone; subsequent growth and development of lateral branches was best on media containing 1.5 mg l−1 BAP plus 3.0 mg l−1 IBA. Adenine sulphate inhibited the number of explants showing regeneration but increased the number of shoot buds per regenerating explant. Shoots were rooted on a 50% strength medium containing 1mg l−1 NAA.
TL;DR: Dopamine inhibited IAA oxidase activity by 60 to 100% in crude enzyme extracts from tobacco roots and etiolated corn coleoptiles, but had no effect on peroxidase activity in the same extracts.
Abstract: Addition of catecholamines at micromolar concentrations caused a dramatic stimulation of growth of tobacco (Nicotiana tabacum) thin cell layers (TCLs) and Acmella oppositifolia "hairy" root cultures. A threefold increase in the rate of ethylene evolution was observed in the catecholamine-treated explants. Aminooxyacetic acid and silver thiosulfate, inhibitors of ethylene biosynthesis and action, respectively, reduced the growth-promoting effect of dopamine. However, these compounds alone could also inhibit the growth of the TCL explants. When ethylene in the culture vessel was depleted by trapping with mercuric perchlorate, dopamine-stimulated growth was still obtained, suggesting that ethylene does not mediate the dopamine effect. Dopamine potentiated the growth of TCLs grown in Murashige and Skoog medium supplemented with indoleacetic acid (IAA) and kinetin. When IAA was replaced by 2,4-dichlorophenoxyacetic acid, dopamine addition showed no growth-promoting effect. Instead, 2,4-dichlorophenoxyacetic acid stimulated the growth of TCL explants to the same extent as that obtained with IAA plus dopamine. Because synthetic auxins do not appear to be substrates for IAA oxidizing enzymes, we hypothesized that catecholamines exert their effect by preventing IAA oxidation. Consistent with this explanation, dopamine (25 micromolar) inhibited IAA oxidase activity by 60 to 100% in crude enzyme extracts from tobacco roots and etiolated corn coleoptiles, but had no effect on peroxidase activity in the same extracts. Furthermore, addition of dopamine to TCL cultures resulted in a fourfold reduction in the oxidative degradation of [1-(14)C]IAA fed to the explants. Because the growth enhancement by catecholamines is observed in both IAA-requiring and IAA-independent cultures, we suggest that these aromatic amines may have a role in the regulation of IAA levels in vivo.
TL;DR: Embryos extracted from dried seeds of common ash (Fraxinus excelsior), were germinated on growth regulator-free culture medium and rooted plantlets tested have successfully established in soil.
Abstract: Embryos extracted from dried seeds of common ash (Fraxinus excelsior), were germinated on growth regulator-free culture medium. Cotyledonary nodes from these seedlings were placed onto Murashige and Skoog, Woody Plant or Driver and Kuniyuki culture media with 22.2 or 44.4 μM benzyladenine, on which they developed into shoot cultures following the outgrowth of axillary buds. With Murashige and Skoog medium, cultures often died. With Woody Plant Medium, survival of the cultures was considerably improved, but large amounts of callus were produced at the cut ends of the explants, and new axillary shoots had long internodes and small leaves. With Driver and Kuniyuki medium, both survival and callus formation were much improved, and the shoots produced were of high quality. Proliferation of axillary shoots was obtained from both shoot tip and nodal explants placed onto Driver and Kuniyuki medium with 22.2 μM benzyladenine. Adventitious root formation was best with shoots inserted into half-strength Woody Plant Medium containing 2.45, 4.9 or 9.8 μM indolebutyric acid. All of the rooted plantlets tested have successfully established in soil.
TL;DR: A procedure has been developed which allows high frequency adventitious shoot regeneration from immature cotyledons of pea and resulted in shoots with well developed tendrils and large stipules which had a reduced rooting capacity.
Abstract: A procedure has been developed which allows high frequency adventitious shoot regeneration from immature cotyledons of pea. Prolific shoot regeneration occurred following an initial callus growth on a Murashige and Skoog (MS) medium containing 0.5 mg/l 6-benzylaminopurine (BAP) and 4 mg/l α-naphthaleneacetic acid (NAA). Cotyledon expiants proximal to the embryonic axis had the highest regeneration potential, however, the presence of an embryonic axis inhibited adventitious shoot regeneration. Addition of silver nitrate (AgNO3) to the medium did not promote the number of regenerated shoots but resulted in shoots with well developed tendrils and large stipules which had a reduced rooting capacity. Regenerated shoots rooted readily (80-90%) in half strength MS medium containing 1 mg/l indole-butyric acid (IBA) and further established well in compost.
TL;DR: This study evaluated plant development via direct organogenesis from in vitro-cultured young seedling tissues of cultivated peanut, especially the valencia-type peanut, and found leaflet segments and petiole sections were less responsive for shoot formation.
Abstract: This study evaluated plant development via direct organogenesis from in vitro-cultured young seedling tissues of cultivated peanut, especially the valencia-type peanut. Complete plants were regenerated from in vitro-cultured petiolule-with-blade-attached explants, leaflet segments, and epicotyl andpetiole sections. Multiple shoots arose on Murashige and Skoog medium (MS) supplemented with 6-benzylaminopurine (BA) (5–25 mg/L) plus 1-naphthaleneacetic acid (NAA) (0.5–3 mg/L). After 30 d culture on 25 mg/L BA + 1 mg/L NAA, 1.6 buds or shoots/explant were regenerated from the petiolule-with-blade-attached explants. Comparable numbers of shoots were obtained from epicotyl sections of the first node region of the seedling after 60 d culture using 10 mg/L BA + 1 mg/L NAA. Leaflet segments and petiole sections were less responsive for shoot formation. Excised shoots developed roots in vitro upon transfer for 15 d to MS medium supplemented with NAA at 1 mg/L. Plantlets were transferred to soil and grown i...
TL;DR: Somatic embryos of Cyclamen persicum Mill could be produced through a callus phase from juvenile explant material including anthers, ovaries and zygotic embryos and germinated into plantlets in MS medium without growth regulators.
Abstract: Somatic embryos of Cyclamen persicum Mill. could be produced through a callus phase from juvenile explant material including anthers, ovaries and zygotic embryos. The auxin 2,4-D (1.0–1.5 mg l-1) and coconut milk (10% v/v) in MS medium were important factors for the induction of somatic embryogenesis. Somatic embryos germinated into plantlets in MS medium without growth regulators. The plants grew well in the greenhouse and flowered normally. The plants were phenotypically identical to the mother plants with a few exceptions.
TL;DR: Southern blot hybridization of total DNA isolated from a greenhouse-grown transformed plant demonstrated integration of the translational fusion into the plant genome.
TL;DR: The chromosome analysis of the progeny derived from callus even from longterm culture, did not reveal any marked variability in chromosome morphology and the stable nature of callus maintained in modified MS medium in long term culture has been confirmed.
Abstract: Lilium longiflorum Thunb., commonly known as Easter Lily is widely propagated by vegetative means for its high ornamental value as a pot plant. Following in vitro technique, mass propagation has been achieved through direct production of bulblets from the explant as well as regeneration from callus. The chromosome analysis of the progeny derived from callus even from long term culture, did not reveal any marked variability in chromosome morphology. The stable nature of callus maintained in modified MS medium in long term culture has been confirmed. Along with rapid growth, the regenerating capacity of calli has been maintained for 3 years of culture in the above medium. Following shake culture, large number of bulblets could be obtained from such differentiated calli within 3–4 weeks. The shake culture technique of calli is ideally suited for securing stable regenerants on a mass scale in this species.
TL;DR: Excised tissues from young leaves of ginger cv.
Abstract: Excised tissues from young leaves of ginger cv. Maran were cultured on revised Murashige and Skoog medium supplemented with various concentrations of growth regulators. The presence of 2, 4-D in the culture medium at 9.0–22.6 μM resulted in callus growth. Organogenesis and plantlet formation occurred when the concentration of 2,4-D is reduced to 0.9 μM and with the addition of 44.4 μM BA into the medium. The rate of plant regeneration increased when the growth regulators are completely removed from the culture medium in the subsequent subcultures. The plantlets developed extensive root systems when they were put in MS liquid medium with 5.4 μM of NAA. The establishment of these plantlets in soil is about 80%.
TL;DR: Yellow pitaya (Mediocactus coccineus) seeds were sown on Murashige and Skoog mineral salt medium and Somatic embryos were induced on these media and then they normally developed on a growth regulator-free medium.
Abstract: Yellow pitaya (Mediocactus coccineus) seeds were sown on Murashige and Skoog (1962) mineral salt medium. After germination, epicotyls were placed on media enriched with a combination of naphthaleneacetic acid (NAA) (0.05, 0.27 or 0.54 μM) and benzyladenine (BA) (2.2 or 4.4 μM). The apical tip was excised from half of the shoots and the other half were kept intact. Different values for proliferation rate, shoot length and thickness were observed on each medium. The cotyledons and roots were placed on MS medium supplemented with NAA (2.7 or 5.4 μM) and embryogenic calluses were formed. Somatic embryos were induced on these media and then they normally developed on a growth regulator-free medium.
TL;DR: Multiple shoots were obtained from nodal explants of 10-year-old tree of Morus laevigata on Murashige and Skoog's medium supplemented with different concentrations of benzyladenine and regenerated plantlets were successfully established in soil under field conditions after a few days of indoor acclimatization.
Abstract: Multiple shoots were obtained from nodal explants of 10-year-old tree of Morus laevigata on Murashige and Skoog's medium supplemented with different concentrations (0.5–5.0 mg.l−1) of benzyladenine (BA). Nodal segments taken from in vitro proliferated shoots gave further multiple shoots when cultured on the same basal medium containing 2.5 mg.l−1 BA. Repeated subculture resulted in rapid shoot multiplication at the average rate of 6-fold per subculture. In vitro raised shoots rooted on MS medium containing 0.1 mg. l−1 each of 3-indolebutyric acid (ISA) and α-naphthaleneacetic acid (NAA). The regenerated plantlets were successfully established in soil under field conditions after a few days of indoor acclimatization.
TL;DR: Callus and shoot regeneration were achieved only in MS medium supplemented with 10.7 μM naphthaleneacetic acid and an increased concentration of kinetin during callusing.
Abstract: Protocols have been developed for the in vitro production of plants from callus derived from root explants of Lathyrus sativus cv. P-24. Callus and shoot regeneration were achieved only in MS medium supplemented with 10.7 μM naphthaleneacetic acid and an increased concentration of kinetin (0.9 μM for 14 days to 1.4 μM for 18 days) during callusing. The shoots obtained rooted in 1/2 MS supplemented with 0.5 μM indolebutyric acid. During the year plants have been regenerated several times. The requirement for growth regulators is very specific and narrow.