4,230 research outputs found
Improved micropropagation in Polygala myrtifolia
No full textStem segments from apical shoot tips of Polygala myrtifolia were used as primary explants to establish in vitro cultures. Axillary shoots produced on noncontaminated explants were excised and recultured in the same medium to increase the stock of shoot cultures. Equal molar concentrations of five cytokinins 2-isopentenyladenine (2iP), kinetin, zeatin, N6-benzyladenine (BA) and adenine were tested for ability to induce axillary shoot development from double node stem segments. The highest rate of axillary shoot proliferation was induced on Murashige and Skoog agar medium supplemented with 1.8 M BA. Seven indole-3-acetic acid (IAA) concentrations (2.8, 5.7, 8.6, 11.4, 14.3, 17.1 M) were tested to determine the optimum conditions for in vitro rooting of microshoots. Up to 72 % of the microshoots rooted with 14.3 M IAA. Other auxins tested, -naphthaleneacetic acid (NAA) and indole-3-butyric acid (IBA), were less effective than IAA in inducing adventitious root formation. All rooted plantlets having more than 3 roots were successfully established in soil
Micropropagation of Globe Artichoke (Cynara cardunculus L. var. scolymus).
No full textThe globe artichoke (Cynara cardunculus L. var. scolymus) is a perennial plant cultivated in the Mediterranean region and the Americas for its edible young flower heads. Although vegetative propagation by offshoots or by “ovoli” (underground dormant axillary buds) has been the primary method of propagation, the potential for the diffusion of diseases and the phenotypic variability can be very high. The propagation of this species by axillary shoot proliferation from in vitro cultured meristems produces systemic pathogen free plants and a higher multiplication rate as compared to that obtained by conventional agamic multiplication. Axillary shoot proliferation can be induced from excised shoot apices cultured on Murashige and Skoog agar solidified medium supplemented with various concentrations of cytokinins and auxins, depending on genotype. For the production of virus-free plants, meristems, 0.3-0.8 mm long, are excised from shoot apices and surface sterilized. The transfer of artichoke microshoots to a medium lacking cytokinins or with low cytokinin concentration is critical for rooting. Adventitious roots develop within three to five weeks after transfer to root induction MS medium containing NAA or IAA at various concentrations. However, in vitro rooting frequency rate is dependent on the genotype and the protocol used. Acclimatization of in vitro microshoots having 3-4 roots is successfully accomplished; plantlets develop new roots in ex vitro conditions and continue to grow
In vitro propagation of Lithodora rosmarinifolia (Ten.) Johnst., a rare endemic Sicilian shrub with potential as ornamental plant.
No full textLithodora rosmarinifolia is a rare shrub endemic to the Mediterranean island of Sicily and its minor islands. Propagation of Lithodora rosmarinifolia by standard methods is difficult due to erratic seed production and low percentage of rooted cuttings. As the plant is suited for domestication, the possibility of establishing an efficient in vitro technique for propagation and conservation of this threatened species was investigated. Nodal segments from shoot tips were used as primary explants to establish in vitro culture. A 2 X 5 factorial experiment with five concentrations (0 to 17.74 mM) of N6-benzyladenine (BA) and two concentrations (0 and 2.46 mM) of indole-3-butyric acid (IBA) was used to determine the optimum growth regulator combination for axillary shoot multiplication by nodal segments. In the subsequent experiment equal molar concentrations of three cytokinins [2-isopenthenyladenine (2iP), kinetin, and BA] in combination with equal molar concentrations of three auxins [indole-3-acetic acid (IAA), a-naphthaleneacetic acid (NAA) and IBA] were tested for ability to induce shoot proliferation. The highest rate of axillary shoot proliferation was induced on Murashige and Skoog (MS) agar medium to which 4.44 mM BA and either 2.46 mM IBA or 2.46 mM IAA were added. In vitro rooting was efficiently accomplished in a medium containing 1⁄2 MS salts and vitamins, 20 g l-1 sucrose, 8 g l-1 agar and augmented with IAA at 0.11 mM. Rooted plants, transferred into soil, grew vigorously and flowered profusely during winter
Improved Propagation and Growing Techniques for Oleander Nursery Production
No full textIn the first trial, we examined rooting of stem cuttings in relation to number of nodes and indole-3-butyric acid (IBA) treatment in several Nerium oleander clones grown in Sicily. In a second trial, we tested the effect of different forcing dates and shading on oleander plants for gardens and natural landscapes. Three- and four-node cuttings, ranging in length from 10 to 14 cm, were significantly superior to two-node cuttings (8–10 cm long) in terms of rooting percentage and number of roots per cutting. The application of IBA improved rooting percentage and root number as compared to untreated control. Irrespective of IBA, rooting percentages ranged from 94% in clone 1 to 52% in clone 4. Shaded plants forced in October were significantly higher than those forced in November and in December. Beginning of flowering was delayed in unforced plants. Plants forced in October flowered significantly sooner (first decade of March) than unforced ones (first decade of May) and reached complete flowering almost two months earlier (last week of March).Shading had little effect on plants forced in October and in November as compared to unshaded plants in terms of start of flowering, but it slightly hastened beginning of flowering of December forced plants as compared to their unshaded counterparts
Micropropagazione di Thymus capitatus
No full textThymus capitatus is a compact woody
shrub, endemic to the Mediterranean region, with attractive pink flowers. Although conventional vegetative
propagation of T. capitatus is currently used,
micropropagation could be effective for rapid mass
propagation of selected clones and would preserve
wild plants. Shoot tips of T. capitatus cultured on a
gelled MS medium, supplemented with 0.4 mg l-1 2-iP,
were used as primary explants to establish in vitro culture.
Axillary shoots produced on uncontaminated
explants were excised and subcultured to increase
the stock of shoot cultures. To determine the optimal
medium for shoot multiplication, increasing concentrations
(0, 0.4, 0.8, 1.6 e 3.2 mg l-1) of 2-iP and increasing
concentrations (0, 0.4, 0.8 mg l-1) of IAA were tested
in a factorial experiment. The highest multiplication
rate (8.5 microshoots per explant) was obtained with
the combination of 3.2 mg l-1 2-iP and 0.4 mg l-1 IAA.
Five IAA concentrations (0, 0.4, 0.8, 1.6 e 3.2 mg l-1)
were also tested to determine the optimum conditions
for in vitro rooting of microshoots. A very high rooting
percentage (95%) was achieved. IAA concentrations
equal or higher than 0.8 mg l-1 increased the number
of roots per microcutting. All rooted plantlets were
successfully established in soil
Iberis semperflorens L. An attractive Italian endemic shrub with high potential as flowering potted plant.
No full text
The effect of nickel on seed germination and plant sprouting in the case of some Alyssum species
No full textThe aim of the researches was to establish the upper limit of nickel concentration in soils that the Alyssum maritimum and Alyssum murale species could tolerate without significantly affecting the germination and the plant sprouting process. The experiment was conducted in 4 variants of 3 repetitions, each repetition including 50 seeds. The watering process of the substrate was performed using distilled water for the control variant (M) and NiSO4 solutions that represented the intervention threshold (V1 – 150 mg/kg) and doses that exceeded the intervention threshold (V2 – 350 mg/kg; V3 – 550 mg/kg and V4 – 750 mg/kg). The Ni influence on seed germination was assessed based on sprouting percentage, sprouting rate and sprouting velocity. In the case of Alyssum maritimum species as compared to the control variant, the germination percentage of the nickel contaminated variants showed significant negative differences for the variant V3 (53%) and V4 (46%). In the case of the Alyssum murale species, the obtained results for the nickel contaminated variants registered highly significant decreases as compared to the control variant for the variant V4 (56%). In Alyssum maritimum the highest percentages of germination rate were obtained in variants V3 – 8.83% and V4 – 5.75%. The percentage of velocity in this species ranged from 11.80% in variant V1 and 2.96% in variant V4. In Alyssum murale the highest percentages of germination rate were obtained in variants V3 – 5.22% and V4 – 3.80%. The percentage of velocity in this species ranged from 7.48% in variant V1 and 1.48% in variant V4
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