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Showing papers on "Kinetin published in 1984"


Journal ArticleDOI
01 Apr 1984-Planta
TL;DR: The results indicate that increased peroxide metabolism accompanies the senescence of detached leaves, and do not, however, support the free-radical theory that an accumulation of activated oxygen initiates leafsenescence.
Abstract: The activities of several enzymes either generating or decomposing O2-or H2O2, were investigated during the course of senescence of detached wheat (Triticum aestivum L.) and rye (Secale cereale L.) leaves in light and in darkness. Most of the activities, although not in full synchrony, declined with the degradation of chlorophyll and protein. The decline was slower in light than in darkness (e.g. glycolate oxidase, EC 1.1.3.1; urate oxidase, EC 1.7.3.3.; catalase, EC 1.11.1.6) and was further retarded after application of kinetin. The activity of superoxide dismutase (EC 1.15.1.1) declined only very little or, in detached rye leaves, even remained unchanged. For lipoxygenase (EC 1.13.11.12) the decline was enhanced in light and not affected by kinetin. Total peroxidase (EC 1.11.1.7) activity strikingly increased after excision of the leaves. The increase was higher in the dark than in light and further enhanced by kinetin. Activity of l-amino-acid oxidase (EC 1.4.3.2) was not detected. The peroxide content of the detached leaves slowly increased during senescence, being higher in light than in darkness. The malondialdehyde content strongly increased in light, but not in darkness. Application of several chemicals known as scavengers for oxygen radicals (1,4-diazobicyclo(2,2,2)octane, α-tocopherol acetate, p-benzoquinone, d-penicillamine copper, 2-amino-2-(hydroxymethyl)-1,3-propanediol, formate) did not notably retard chlorophyll degradation in senescencing leaves. Thiourea and urate retarded chlorophyll breakdown in light, obviously because they were used as nitrogen sources. Chlorophyll breakdown was greatly accelerated by D2O, particularly in light, presumably by enhancing photooxidative damage. The results indicate that increased peroxide metabolism accompanies the senescence of detached leaves. They do not, however, support the free-radical theory that an accumulation of activated oxygen initiates leaf senescence.

110 citations


Journal ArticleDOI
TL;DR: A rice lamina inclination test that is simple and specific for brassinosteroids was used as a microquantitative bioassay for Brassinolide 1 and its 6-keto congener, castasterone 2, in the concentration range of 5 x 10−5 /ig/ml to 5 × 10−3μg/ml, when uniform seedlings of the rice cultivars Arborio J-l and Nihonbare were selected.
Abstract: A rice lamina inclination test that is simple and specific for brassinosteroids was used as a micro-quantitative bioassay for brassinolide 1 and its 6-keto congener, castasterone 2, in the concentration range of 5 x 10–5 /ig/ml to 5 x 10–3μg/ml, when uniform seedlings of the rice cultivars Arborio J-l and Nihonbare were selected. A phytohormone, indole-3-acetic acid (IAA), showed similar activity in this bioassay. Its lowest effective concentration, however, was 50 /ig/μl, about five orders of magnitude greater than that of brassinolide. Other phytohormones, abscisic acid (ABA) and the cytokinins kinetin and A6-benzyladenine, inhibited the lamina inclination of rice seedlings. The addition of a cytokinin reduced the promoting effect of brassinolide. Thus, the rice lamina inclination test can be used both as a micro-quantitative bioassay for brassinosteroids and as a method for detecting antibrassinolide compouds.

89 citations


Journal ArticleDOI
TL;DR: Clonal propagation of Stevia rebaudiana has been established by culturing stem-tips with a few leaf primordia on an agar medium supplemented with a high concentration (10 mg/l) of kinetin.
Abstract: Clonal propagation of Stevia rebaudiana has been established by culturing stem-tips with a few leaf primordia on an agar medium supplemented with a high concentration (10 mg/l) of kinetin. Anatomical examination has suggested that these multiple shoots originate from a number of adventitious buds formed on the margin of the leaf. Innumerable shoots can be obtained by repeating the cycle of multiple-shoot formation from a single stem-tip of Stevia. These shoots produce roots when transferred to a medium containing NAA (0.1 mg/l) without kinetin. The regenerated plantlets can be transplanted to soil.

74 citations


Journal ArticleDOI
TL;DR: A number of plant growth regulators and environmental conditions had no effect on flowering which supports the determinate apex theory for sunflower.
Abstract: Shoot multiplication of Helianthus annuus was optimal from half shoot apices cultured on MS media with 0.1-1.0 mg/l benzyl adenine or kinetin. Auxins inhibited multiplication and promoted callusing. Rooting was poor and was not promoted by auxins. Flowering of multiple shoots was observed after as little as 3 wk of culture. A number of plant growth regulators and environmental conditions had no effect on flowering which supports the determinate apex theory for sunflower (Habermann and Sekulow, 1972). Adventitious shoots were induced on leaves of the multiple shoots in some inbreds.

67 citations


Journal ArticleDOI
01 Jun 1984-Botany
TL;DR: Somatic embryogenesis was induced in callus previously initiated from immature embryos of barley using homogenized suspension-grown aggregates when plated on modified B5 media with 2,4-dichlorophenoxyacetic acid.
Abstract: Somatic embryogenesis was induced in callus previously initiated from immature embryos of barley. These cultures ranged in age from 6 weeks to 30 months. Embryoids were readily initiated from homogenized suspension-grown aggregates when plated on modified B5 media with 2,4-dichlorophenoxyacetic acid. Low concentrations (0.1 and 0.05 mg∙L−1) of abscisic acid promoted further maturation of embryoids, while gibberellic acid (1 mg∙L−1) and kinetin (0.1 mg∙L−1) were used in the media to encourage embryoid germination. The development of somatic embryoids from initiation through maturation and germination is described.

66 citations


Journal ArticleDOI
TL;DR: The influence of temperature, illumination, hormonal levels, carbon to nitrogen ratios, antibiotics, and precursor feeding on phenolics production by Nicotiana tabacum was studied to learn more about secondary product formation in plant cell tissue cultures.
Abstract: The influence of temperature, illumination, hormonal levels (2,4-D and kinetin), carbon to nitrogen ratios, antibiotics, and precursor feeding on phenolics production by Nicotiana tabacum (tobacco) was studied. This plant cell system was chosen as a model system to learn more about secondary product formation in plant cell tissue cultures. This is the first study to manipulate all of these environmental parameters with a single plant cell system. The most striking results were with 2,4-D manipulation. The removal of 2,4-D resulted in significant phenolics production during the stationary phase, while normal levels strongly suppressed phenolics production during the stationary phase. The addition of phenylalanine stimulated phenolics production per gram of cells but strongly inhibited growth.

62 citations


Journal ArticleDOI
TL;DR: The pattern of changes of the enzyme activities provides an explanation for the amino acid transformations and the flow of amino nitrogen into transport metabolites in senescing leaves.
Abstract: The activities of several enzymes related to amino acid metabolism were investigated in senescing detached wheat leaves (Triticum aestivum L. cv. Diplomat) in light and darkness and after kinetin treatment. Glutamine synthetase and glutamate synthase activities rapidly declined in darkness. In light, the decline of glutamate synthase activity was retarded, while the activity of glutamine synthetase remained high and even increased transitorily. Kinetin treatment counteracted the decline of the activities of both enzymes. The activity of glutamate dehydrogenase markedly increased during senescence, particularly in light, and kinetin treatment lowered its activity. The activities of glutamate-oxaloacetate and glutamate-pyruvate amino-transferases and of NADP-dependent isocitrate dehydrogenase also increased in detached wheat leaves in light. Kinetin treatment prevented the rise of these enzyme activities. In darkness, the activities of glutamate-oxaloacetate aminotransferase and NADP-dependent isocitrate dehydrogenase decreased slowly while the decline of glutamate-pyruvate aminotransferase activity was more rapid. The activity of NAD-dependent malate dehydrogenase decreased both in light and, more rapidly, in darkness. The pattern of changes of the enzyme activities provides an explanation for the amino acid transformations and the flow of amino nitrogen into transport metabolites in senescing leaves.

54 citations


Journal ArticleDOI
TL;DR: Fragments of maize leaves were incubated at controlled temperature and irradiance either on distilled water or on one of three concentrations of cytokinin, and the effects of zeatin or kinetin on stomatal aperture were determined by stripping abaxial epidermis from the fragments after incubation and immediately measuringStomatal apertures under the microscope.
Abstract: Fragments of maize leaves were incubated at controlled temperature and irradiance either on distilled water or on one of three concentrations of cytokinin (10"', 10"2 and 10"3 mol m~3). The effects of zeatin or kinetin on stomatal aperture were determined by stripping abaxial epidermis from the fragments after incubation and immediately measuring stomatal apertures under the microscope. At each cytokinin concentration leaf pieces were incubated at 5 or 350 //mol mol"1 CO, with or without ABA ( 10 1 mol m"3). At 5-0 //mol mol"' C02 increasing the concentrations of zeatin had a negligible effect upon stomatal aperture. When air containing 350 //mol mol"1 CO, was bubbled through the incubation solutions, apertures of stomata incubated on water were more than halved. Increasing cytokinin concentrations reduced the effect of CO, on stomata and incubation on 10"1 mol m"3 zeatin completely removed any C02 response. The addition of ABA restored the effect of C02, even at the highest cytokinin concentration.

53 citations


Journal ArticleDOI
TL;DR: The technique is based on hormonal stimulation of growth and development of quiescent meristems in vitro and consists in cultivating sterilized shoot fragments on agar nutrient media with the addition of low concentrations of auxins and cytokinins, promising higher genetic stability and uniformity of cloned plants than earlier methods.
Abstract: SummaryThe technique is based on hormonal stimulation of growth and development of quiescent meristems in vitro and consists in cultivating sterilized shoot fragments, including axillary buds, on agar nutrient media with the addition of low concentrations (0.5-5 mg l-1) of auxins (IAA or NAA) and cytokinins (kinetin or BAP). In these conditions the production of new entire shoots occurs directly from the sites of axillary meristems. The method was successfully applied in Mammillaria carmenae, M. prolifera (cultivated mammillae with adjacent meristems), Astrophytum myriostigma and Trichocereus spachianus (explanted areoles). The method promises higher genetic stability and uniformity of cloned plants than earlier methods.

49 citations


Journal ArticleDOI
TL;DR: Roots can be readily induced with IBA, but salt concentration and the physical support on which shoot-tips are grown influence both root initiation and growth, and half-strength salts and 1 μM IBA gave best root initiation.

49 citations


Journal ArticleDOI
TL;DR: Besides normal plant regeneration, cultures showed various responses such as massive rooting without shoot formation, retention of green pigmented region without further development, and occurence of necrotic dead tissue.
Abstract: Tissue cultures were initiated from root sections excised from 5∼7 day-old seedling, in 60 varieties including various ecospecies i.e. japonica, indica, japonica-iridica hybrids, and large grain varieties (assumed to be javanica type) in rice (Oryza sativa L.) on basal Murashige and Skoog's (1962) medium containing 3.0 mg/l 2, 4-dichlorophenoxyacetic acid (2, 4-D), 2.O g/l of casein hydrolysate, and 30 g/l sucrose. Cultures were maintained on the same medium with 2.O mg/l 2, 4-D. Plant regeneration was accomplished by subculturing for 2 to 3 passages to the same basal medium with 0.02mg/l 2, 4-D and 10mg/l kinetin. Remarkable variability in plant regeneration was observed among varieties tested. All the cultures of the japonica varieties had good capacity for regeneration, while some of the cultures of indica, japonica-indica hybrids, and large grain varieties were poor. It was observed that 11 of 28 cultures in japonica, 2 of 16 in indica, and 1 of 10 in large grain varieties had relatively high potential for regeneration at more than 30%. Besides normal plant regeneration, cultures showed various responses such as massive rooting without shoot formation, retention of green pigmented region without further development, and occurence of necrotic dead tissue. Two distinct types of plant regeneration were observed, one of which was organogenesis, and other was somatic embryogenesis. Most of the cultures from the indica varieties, Chyokoto and Gaiya Dhan Tosar, initiated plantlet through somatic embryogenesis.

Journal ArticleDOI
TL;DR: The regulatory effect of cytokinin on the formation of secondary xylem fibers was studied in the hypocotyl of young Helianthus annuus L plants and positive correlation was found between the kinetin supplied to the growth medium and the rate of fiber formation within and between the vascular bundles.
Abstract: The regulatory effect of cytokinin on the formation of secondary xylem fibers was studied in the hypocotyl of young Helianthus annuus L. plants. Positive correlation was found between the kinetin supplied (0.25-0.5 micrograms/gram) to the growth medium and the rate of fiber formation within and between the vascular bundles. Reducing the root originated cytokinin supply, either by root removal or by lowering the transpiration rate, diminished the number of newly formed secondary xylem fibers. This decrease was considerably reversed in the presence of 0.5 microgram/gram kinetin. Early pulse exposure of kinetin had a temporary promoting effect on fiber differentiation at low concentrations and a permanent inhibitory effect at high concentration.

Patent
16 Mar 1984
TL;DR: In this paper, the regeneration of plants from cotton callus (Gossypium hirsutum L. cv Coker 310) is described, where Somatic proembryoids developed spontaneously after two years in culture on a modified Linsmaier and Skoog medium.
Abstract: The regeneration of plants from cotton callus (Gossypium hirsutum L. cv Coker 310) is described. Somatic proembryoids developed spontaneously after two years in culture on a modified Linsmaier and Skoog medium. The percentage of calli forming proembryoids was increased to about 30% by prolonged culture without NAA and kinetin. Development of proembryoids was enhanced by transferring proembryoids to media lacking NH 4 NO 3 but containing double the standard KNO 3 concentration and gibberellic acid. Root initiation and growth was promoted by lowering the glucose concentration to 5 g/l.

Journal ArticleDOI
TL;DR: Multiple shoot formation was induced from excised leaf explants of Annona squamosa Linn on a Murashige and Skoog basal medium containing benzylaminopurine and kinetin and the process of development of adventitious buds in leaf culture was analysed histologically.
Abstract: Multiple shoot formation was induced from excised leaf explants of Annona squamosa Linn. (custard apple) seedlings on a Murashige and Skoog basal medium containing benzylaminopurine and kinetin. Various auxins in combination with the above medium produced callusing of the explants. In an investigation of environmental factors affecting shoot induction it was seen that the maximum number of shoots were obtained using the leaf base with petiole at a temperature of 27°C and a light intensity of 1000 lux. Roots were initiated erratically when individual shoots were treated with an auxin and then transferred to an auxin free medium. The process of the development of adventitious buds in leaf culture was analysed histologically.

Journal ArticleDOI
TL;DR: The characteristic syndrome of foliar nitrogen deficiency is concluded to be partly that of senescence, and the stomata of N-deficient leaves after detachment and floating on water were largely closed in light, but could be partially induced to open by kinetin treatment.
Abstract: Because the “mobilization” of nitrogen resulting from nutritional nitrogen deficiency is also prominent during leaf senescence, the characteristics of these two syndromes were compared. Oat plants (Avena sativa L. cv. Victory) were raised on a nutrient solution, complete except for nitrogen supply (i.e., with only the seed protein as nitrogen source), and the senescence of their leaves was compared with that of controls grown on a full nutrient solution. The N-deficient plants flowered after forming only 4 leaves and each set a single seed. The nitrogen lack affected the content of chlorophyll somewhat more than the content of the amino acids or protein nitrogen. However, spraying the plants with kinetin solution was able to retain 20–30% of the chlorophyll and protein. During senescence, the chlorophyll appears to be less stable in the N-deficient leaves than in the controls, while the protein is somewhat more stable than in the controls. Also, when the detached leaves from N-deficient plants senesced in white light or in darkness, kinetin delayed their senescence almost as effectively as that of control leaves. Most strikingly, the stomata of N-deficient leaves after detachment and floating on water were largely closed in light, just as in senescence, but could be partially induced to open by kinetin treatment. Since stomatal closure has earlier been shown to cause senescence, the characteristic syndrome of foliar nitrogen deficiency is concluded to be partly that of senescence.

Journal ArticleDOI
TL;DR: In this paper, it was shown that the effect of cytokinins is to change the growth form in the tip region of the side branches of the caulas of Funaria hygrometrica.

Journal ArticleDOI
TL;DR: A method to produce 3-5 plantlets of Prosopis cineraria from a single bud expiant through in vitro culture in 100 days is described, with results found to be the best suited for multiple shoot differentiation.

Journal ArticleDOI
TL;DR: The influence of some nutritional factors affecting anthraquinone formation, i.e., sucrose, myoinositol, auxin, inorganic nitrogen source etc., were examined as mentioned in this paper.
Abstract: Rubia cordifolia cells reached a maximum dry weight 20 days after inoculation, while their anthraquinone content decreased during the early period of the logarithmic phase of growth and then increased to 50 µmol per g-dry weight after 25 days.The influence of some nutritional factors affecting anthraquinone formation, i.e. sucrose, myoinositol, auxin, inorganic nitrogen source etc. were examined. A high sucrose concentration, auxins, myoinositol and inorganic nitrogen sources brought about marked increases of anthraquinone formation. However, kinetin had scarcely any effect on anthraquinone formation.

Journal ArticleDOI
TL;DR: Of the different hormones tested, cytokinins stimulated nitrate-induced nitrate reductase activity in the dark and kinetin and red light, when given together, or given with a darkness interruption, stimulated the NR activity more than with either of them alone.

Journal ArticleDOI
TL;DR: Results show that ethylene will substitute qualitatively for cytokinin during auxin-induced xylogenesis, and suggest that both ethylene and auxin are required for xylem differentiation in Lactuca.
Abstract: Evidence was obtained to support the hypothesis that ethylene is involved in xylem differentiation in primary pith explants of Lactuca sativa L. cv Romaine cultured in vitro. Xylem elements differentiated when explants were supplied indole-3-acetic acid (IAA) in combination with either the ethylene biosynthetic precursor 1-aminocyclopropane-1-carboxylic acid (ACC), the ethylene-releasing agent 2-chloroethylphosphonic acid (CEPA), or kinetin. In contrast, no xylem elements differentiated in the presence of IAA, kinetin, ACC, or CEPA alone, or when kinetin was supplied together with ACC or CEPA. These results show that ethylene will substitute qualitatively for cytokinin during auxin-induced xylogenesis, and suggest that both ethylene and auxin are required for xylem differentiation in Lactuca.

Journal ArticleDOI
TL;DR: Single-node stem segments of Rosmarinus officinalis L. var.
Abstract: Single-node stem segments of Rosmarinus officinalis L. var. genuina forma erectus proved better explants than shoot tips (ca. 2 cm long) for extablishment of field-grown plants in aseptic cultures. Benzylaminopurine was far more effective than kinetin for shoot induction in shoot tips excised from aseptically-grown plants. Maximum numbers of shoot buds (ca. 14) were formed per explant at 0.2 mgl-1 benzylaminopurine in 30 days. After further growth of isolated shoots and treatment with 0.25 mgl-1 indolepropionic acid for 7 days, 80% shoots produced roots. In vitro raised plantlets were successfully grown in soil to plants. About 5,000 plants could be produced from a single nodal segment in 1 year.

Journal ArticleDOI
TL;DR: The growth and proliferation pattern of callus derived from seed and the pathways of in vitro morphogenesis in Arabidopsis thaliana were investigated, and the pathway of root formation from the meristematic centres within the nodules is described.

Journal ArticleDOI
TL;DR: The response of groundnut cotyledons to the presence of various growth regulators in concentrations from 0.1 to 5 mg/l has been studied in detail using several genotypes of ground nut on two different media to study the frequency of flower bud induction.
Abstract: The response of groundnut cotyledons to the presence of various growth regulators in concentrations from 0.1 to 5 mg/l has been studied in detail using several genotypes of groundnut on two different media. Cotyledons with embryo axis, cultured on Blaydes' medium with cytokinins, produced shoots, in the axils of which 2-7 flower buds could be seen. The frequency of flower bud induction in general increased with increasing concentrations of cytokinins, the optimal levels being 3 mg/l of KN or 4 mg/l of BAP. Cotyledons without embryo axis, cultured on Blaydes' medium with BAP (0.5 mg/l), produced a cluster of flower buds directly, ranging in number from 8-28, without any vegetative growth. Excised embryo axes cultured on the same medium gave plantlets without flower buds. The growth regulators IAA, NAA, GA3 and ABA failed to induce flower buds in independent treatments. However, lower concentrations of IAA and NAA in combination with cytokinins exerted a positive influence on flowering. The blooming of the flower buds was facilitated on media supplemented with low concentrations of cytokinins. Six percent of the induced flowers resulted in gynophore development and ultimately formed pods when cultured under complete dark conditions in modified MS medium supplemented with kinetin.

Journal ArticleDOI
TL;DR: In this paper, young leaf segments from plants growing both in vivo and in vitro were cultured on Mitra et al. medium (BM) supplemented variously with auxins (IAA, NAA, 2,4-D), kinetin (KN), GA3, and organic supplements (peptone, urea, casein hydrolysate, and yeast extract).
Abstract: Young leaf segments from plants growing both in vivo and in vitro were cultured on Mitra et al medium (BM) supplemented variously with auxins (IAA, NAA, 2,4-D), kinetin (KN), GA3, and organic supplements (peptone, urea, casein hydrolysate, and yeast extract). The explants from mature leaves did not show any growth and turned necrotic, while those obtained from juvenile leaves of 6-mo-old plantlets growing in vitro developed protocorm-like bodies (plbs) at their cut surfaces within 4-7 wk, depending on the growth medium. Histological studies revealed their epidermal origin. Formation of plbs subsequently spread all along the explant and suggests a meristematic/generative potential of the epidermal cells in immature leaves. Upon subculture in basal medium, the plbs differentiated into plantlets within 4-5 wk. Although regeneration of plbs was achieved in BM and the auxins or GA3, KN in combination with IAA/NAA in the presence of peptone accelerated their formation.

Journal ArticleDOI
TL;DR: A sucrose supply of 2% in conjunction with the combination of all three hormones, however, was needed to achieve maximal thylakoid formation including stacking in individual chloroplasts and for the very extensive chloroplast multiplication in explants growing with high cell division activity.
Abstract: Chromoplasts, which exist in the cells of freshly isolated carrot root explants, seemed to be transformed in thylakoid containing plastids, and chlorophyll formation was initiated if the explants were cultured in a liquid medium containing inositol and IAA as a hormonal supplement. This process was intensified when kinetin was also added, but no dependence on a sucrose supply could be found.

Journal ArticleDOI
TL;DR: Detailed dose-response curves were obtained for cytokinin-induced retention of chlorophyll in detached leaves of barley, Hordeum vulgare L. cv.
Abstract: Detailed dose-response curves were obtained for cytokinin-induced retention of chlorophyll in detached leaves of barley, Hordeum vulgare L. cv. Moyar, over a wide range, 10−10– 2.5 × 10−4M, of external concentrations of benzyladeninc or kinetin. The over-all shape of the curves was log-linear and the response was subsensitive. Benzyladenine was somewhat more effective than kinetin. In the curves there were pronounced local minima and maxima both at low, intermediate (10−7– 10−5M) and high concentrations. At low and high concentrations these deviations from the best smooth curves were reproducible, statistically significant and occurred at the same concentrations for benzyladenine and kinetin. In the intermediate range the deviations from the log-linear line were marked and statistically highly significant in some but not all experiments. The cause of the complexities in the dose response curve is not known, but multiphasic uptake of the cytokinins may be involved.

Journal ArticleDOI
TL;DR: Rhizome-like structures developed after 2–3 subcultures, which became a contimuous source of material for further propagation in true-to-type plants and formed complete plants which grew normally in soil.

Journal ArticleDOI
TL;DR: Treatment with 2,4-dichlorophenoxyacetic acid caused massive root and callus development along with delay in shoot development, while gibberellic acid occasioned marked extensions in the dormant period.
Abstract: The effects on dormancy of post-harvest application of growth regulators to bulbils, tubers and tuber pieces of tropical Dioscorea species were examined. Abscisic acid, kinetin, indole acetic acid and 2-chloroethyltrimethylammonium chloride were found to have little or no effect on either shoot or tuber-root production, while ethrel greatly promoted tuber-root production with little or no effect on shoot development. The germination of slices of tubers of D. alata was delayed by maleic hydrazide but there was no effect on intact tubers of D. alata and D. esculenta. Treatment with 2,4-dichlorophenoxyacetic acid caused massive root and callus development along with delay in shoot development, while gibberellic acid occasioned marked extensions in the dormant period.

Journal ArticleDOI
TL;DR: In this article, the authors used the Murashige and Skoog medium with or without indole-3-acetic acid (IAA) and kinetin at 28°C in darkness.
Abstract: Anther culture of‘Trovita’orange, a cultivar of sweet orange (Citrus sinensis Osbeck), was attempted.Anthers with microspores at uninucleate stage were cultured on the Murashige and Skoog′s medium(9) supplemented with or without indole-3-acetic acid (IAA) and kinetin at 28°C in darkness. Embryoids appeared directly from within anthers after about 10 weeks of culture. The media containing kinetin and IAA both at 0.002 or 0.02mg/l were effective in embryoid formation. In addition, 0.2 or 2.0mg/l kinetin and 0.2mg/l IAA seemed to be also favorable when combined with 0.002 or 0.02mg/l IAA and 0.002 or 0.02mg/l kinetin, respectively. Calli were formed well on the media with kinetin at 2.0mg/l followed by those with IAA at 2.0mg/l.After incubation in light with a 16-hour photoperiod, some embryoids differentiated shoots. Induction of roots was stimulated by transfer of embryoids from the embryoid induction media containing growth regulators to a medium without them.Some root tip cells of differentiated plantlets had a diploid chromosome number of 18.

Journal ArticleDOI
TL;DR: A tissue culture technique has been developed for the rapid multiplication of pumpkin clones and maximum shoot proliferation occurred on MS medium containing 1 mg l −1 BA and no auxin.