scholarly journals 307 Growth Regulator Pretreatments Significantly Enhance the Efficiency of Shoot Organogenesis from Leaf Explants of Highbush Blueberry Cultivar Bluecrop

HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 445A-445
Author(s):  
X. Cao ◽  
F. Hammerschlag
Keyword(s):  
Shoot Regeneration ◽  
Growth Regulators ◽  
High Efficiency ◽  
Shoot Organogenesis ◽  
Leaf Explants ◽  
Vaccinium Corymbosum ◽  
Zeatin Riboside ◽  
Highbush Blueberry ◽  
Shoot Cultures ◽  
Regeneration Medium

As part of a program to develop transgenic highbush blueberry (Vaccinium corymbosum L.) cultivars, studies were conducted to determine optimum conditions for high-efficiency shoot regeneration from leaf explants of in vitro propagated, commercially important, tissue culture-recalcitrant `Bluecrop' shoot cultures. The effects of pretreatments, growth regulators, and age of explant source on shoot organogenesis were investigated. A maximum of 98% shoot regeneration and 10 shoots regenerating per leaf explant occurred when explants of 2-week-old shoot cultures were incubated in the dark (for a total of 14 days) on pretreatment medium #1 containing 2.6 μM NAA and 5 μM TDZ for 4 days, next on pretreatment medium #2 containing 2.6 μM NAA and 7 μM zeatin riboside for 3 days, then on regeneration medium containing 1 μM TDZ for 6 weeks, and last on medium without growth regulators for 10 days. No shoot regeneration occurred if explants were incubated without exposure to pretreatments before incubation on regeneration medium. There were no significant differences in percentage of regeneration or the number of shoots regenerating per explant from leaf explants derived from either 1-, 2-, or 3-week-old shoot cultures. Shoot production per explant on 1 μM TDZ was about three times that on either 0.5 μM TDZ or 20 μM zeatin riboside, and nine times that on 5 μM TDZ.

scholarly journals 112 The Influence of Plant Growth Regulators and Light Levels on Shoot Morphogenesis from Leaf Explants of Highbush Blueberry

HortScience ◽  
1999 ◽  
Vol 34 (3) ◽  
pp. 460F-461
Author(s):  
Xiaoling Cao ◽  
F.A. Hammerschlag
Keyword(s):  
Light Intensity ◽  
Shoot Regeneration ◽  
High Efficiency ◽  
Leaf Explants ◽  
Vaccinium Corymbosum ◽  
Zeatin Riboside ◽  
Highbush Blueberry ◽  
Shoot Cultures ◽  
Regeneration Medium

As part of a program to develop transgenic highbush blueberry (Vaccinium corymbosum L.) cultivars, studies were conducted to determine optimum conditions for high efficiency shoot regeneration from leaf explants of in vitro-propagated shoot cultures. The effect of either thidiazuron at 1 or 5 μM, or zeatin riboside at 20 μM, and two lit levels (18 ± 5 or 55 ± 5 μmol·m-2·s-1) on shoot organogenesis were investigated. With the exception of `Bluecrop', which did not regenerate shoots, maximum shoot regeneration of 13, 12.7, 12.6 and 4.6 shoots per explant for cultivars Duke, Georgiagem, Sierra, and Jersey, respectively, occured on regeneration medium with zeatin riboside and under a light intensity of 55 μmol·m-2·s-1. Whereas `Duke' regenerated equally well on regeneration medium with either zeatin riboside or 5 μM thidiazuron, regeneration frequencies for `Georgiagem' and `Sierra' were significantly higher on zeatin riboside. A light intensity of 55 μmol·m-2·s-1 significantly increased regeneration of cultivars Duke, Jersey, and Sierra on zeatin riboside, but inhibited regeneration of Duke on 5 μM thidazuron.

scholarly journals A Two-step Pretreatment Significantly Enhances Shoot Organogenesis from Leaf Explants of Highbush Blueberry cv. Bluecrop

HortScience ◽  
2002 ◽  
Vol 37 (5) ◽  
pp. 819-821 ◽  
Author(s):  
Xiaoling Cao ◽  
Freddi A. Hammerschlag ◽  
Larry Douglass
Keyword(s):  
Growth Regulators ◽  
Shoot Organogenesis ◽  
Leaf Explants ◽  
Vaccinium Corymbosum ◽  
Zeatin Riboside ◽  
Highbush Blueberry ◽  
Shoot Cultures ◽  
Regeneration Medium ◽  
Explant Source ◽  
Shoot Production

As part of a program to improve highbush blueberry (Vaccinium corymbosum L.) cultivars via tissue culture and genetic engineering, studies were conducted to determine optimum conditions for organogenesis from leaf explants of the previously recalcitrant cv. Bluecrop. The effects of a pretreatment, growth regulators, and age of explant source on shoot organogenesis were investigated. A maximum of 98% explants regenerated shoots with a mean of 11 shoots per leaf explant after 62 days when explants of 2-week-old shoot cultures were incubated on the following regime: pretreatment medium #1 containing 5 μm TDZ and 2.6 μm NAA for 4 days, pretreatment medium #2 containing 7 μm zeatin riboside and 2.6 μm NAA for 3 days, regeneration medium containing 1 μm TDZ for 6 weeks, and last on medium without growth regulators for 10 days. No shoot regeneration occurred if explants were incubated without exposure to pretreatment prior to incubation on regeneration medium. There were no significant differences in percentage of regeneration or the number of shoots regenerating per explant from leaf explants derived from either 1-, 2-, or 3-week-old shoot cultures. Shoot production per explant on regeneration medium containing 1 μm TDZ was about three times that on 0.5 μm TDZ or 20 μm zeatin riboside, and nine times that on 5 μm TDZ. Chemical names used: 1-phenyl-3-(1,2,3-thiadiazol-5-yl)urea (thidiazuron, TDZ); 9-(β-D-ribofuranosyl)-6-(4-hydroxy-3-methyl-but-2-enylamino)purine (zeatin riboside).

scholarly journals Improved Shoot Organogenesis from Leaf Explants of Highbush Blueberry

HortScience ◽  
2000 ◽  
Vol 35 (5) ◽  
pp. 945-947 ◽  
Author(s):  
X. Cao ◽  
F.A. Hammerschlag
Keyword(s):  
High Efficiency ◽  
Shoot Organogenesis ◽  
Leaf Explants ◽  
Vaccinium Corymbosum ◽  
Zeatin Riboside ◽  
Photon Flux ◽  
Highbush Blueberry ◽  
Shoot Cultures ◽  
Regeneration Medium ◽  
Number Of Shoots

As part of a program to develop transgenic highbush blueberry (Vaccinium corymbosum L.) cultivars, studies were conducted to determine optimum conditions for high efficiency shoot regeneration from leaf explants of shoots propagated in vitro. The effects on shoot organogenesis of age of explant source, length of dark treatment, the addition of either thidiazuron (TDZ) at 1 or 5 μm, or zeatin riboside at 20 μm to the regeneration medium, and a photosynthetic photon flux (PPF) of either 18 ± 5 or 55 ± 5 μmol·m–2·s–1 were investigated. A maximum of 13.0, 13.0, 12.6, and 4.6 shoots regenerating per explant for cultivars Duke, Georgiagem, Sierra, and Jersey, respectively, occurred on regeneration medium with zeatin riboside and under a PPF of 55 ± 5 μmol·m–2·s–1. `Duke' regenerated equally well on medium with either zeatin riboside or 1 μm TDZ, whereas the number of shoots per explant for `Georgiagem' and `Sierra' was significantly higher on zeatin riboside. Regeneration of `Duke', `Jersey', and `Sierra' on zeatin riboside was significantly better under a PPF of 55 ± 5 μmol·m–2·s–1 than under 18 ± 5 μmol·m–2·s–1, but the higher PPF inhibited regeneration of `Duke' on 5 μm TDZ. There were no significant differences in percentage of regeneration or the number of shoots per explant from leaf explants derived from either 1-, 2-, or 3-week-old shoot cultures, or when either 1 week or 2 weeks of darkness preceded light treatments. Chemical names used: 1-phenyl-3-(1,2,3-thiadiazol-5-yl)urea (thidiazuron, TDZ); 9-(-β-ribofuranosyl)-6-(4-hydroxy-3-methyl-but-2-enylamino)purine (zeatin riboside).

scholarly journals Use of a Cytokinin Conjugate for Efficient Shoot Regeneration from Leaf Sections of Highbush Blueberry

HortScience ◽  
1992 ◽  
Vol 27 (10) ◽  
pp. 1127-1129 ◽  
Author(s):  
Lisa J. Rowland ◽  
Elizabeth L. Ogden
Keyword(s):  
Tissue Culture ◽  
Shoot Regeneration ◽  
Culture Medium ◽  
Vaccinium Corymbosum ◽  
Zeatin Riboside ◽  
Tissue Culture Medium ◽  
Highbush Blueberry ◽  
Leaf Section ◽  
Number Of Shoots

Conditions for improving the efficiency of shoot regeneration from leaf sections of highbush blueberry (Vaccinium corymbosum L.) were investigated. Effectiveness of tissue culture medium supplemented with the cytokinin conjugate zeatin riboside or the cytokinin zeatin at 10, 20, or 30 μm was compared with medium supplemented with the optimum 2iP concentration of 15 μm. Use of 20 μm zeatin riboside resulted in the most shoots per leaf section, » 6-fold higher than the number of shoots produced on 2iP medium. The number of shoots produced on medium supplemented with zeatin was not significantly higher than the number of shoots produced on 2iP medium. Consequently, we concluded that the cytokinin conjugate zeatin riboside was more effective than either of the free cytokinins, 2iP or zeatin, in promoting shoot regeneration from leaf sections of highbush blueberry. Chemical names used: 6-(y,y-dimethylallylamino)-purine (2iP); 6-(4-hydroxy-3-methyl-but-2-enylamino)purine (zeatin).

scholarly journals Effects of different cytokinins on the shoot regeneration from apple leaves of 'Royal Gala' and 'M.26'

2004 ◽  
Vol 10 (1) ◽  
Author(s):  
J. Dobránszky ◽  
I. Hudák ◽  
K. Magyar-Tábori ◽  
E. Jámbor-Benczúr ◽  
Zs. Galli ◽  
...  
Keyword(s):  
Shoot Regeneration ◽  
Chemical Structure ◽  
Shoot Organogenesis ◽  
Leaf Explants ◽  
Similar Relationship ◽  
Regeneration Medium ◽  
Apple Rootstock ◽  
Apple Leaves ◽  
Shoot Number ◽  
Different Types

The effects of different types of cytokinins on the shoot regeneration from leaf explants of apple scion 'Royal Gala' and apple rootstock 'M.26' were evaluated. Regeneration media contained either thidiazuron, or 6-benzylaminopurine, or meta-topolin, or zeatin, or kinetin, or their N9-ribosides, respectively, in the concentration range 0.5 to 8.0 mg 1-1. Effects of 'these cytokinins were evaluated on the percentage of regeneration (R%) and that of vitrification (V%) and on the number of regenerated shoots per explant (SN). Organogenetic index (0I) calculated from these data was used for the evaluation of efficacy of cytokinins. The course of shoot organogenesis also was followed using stereomicroscope. Types and concentrations of cytokinins applied in the regeneration media influenced each parameter significantly and the regeneration answer was strongly genotype-dependent. The best regeneration (SN: 11.08, 01: 7.5) was achieved in `Royal Gala' by using TDZ in concentration of 0.5 mg 1-1 (2.271,1M). There was a clear relationship between the effect on the regeneration efficacy and the chemical structure of cytokinins considering classical cytokinins, namely N9-ribosides applied in less concentration than non­ribosides have the same or best regeneration effects except for 6-benzylaminopurine riboside. However, similar relationship could not be detected in the case of 'M.26'. SN was the highest (3.22) using 6.5 mg 1-1 (18.2011M) 6-benzylaminopurine riboside or 8.0 mg 1-1 (21.44 µM) meta-topolin riboside (3.18). SN was not significantly lower (3.12) by using 2.0 mg 1-1 (9.08 1M) TDZ, however, OI was about half as big (0.63 compared to 1.29 or 1.74 with 6-benzylaminopurine riboside or meta-topolin riboside, respectively). 'Royal Gala' had higher organogenetic ability, than `M.26': 3.5-fold higher shoot number per explant and more than 4-fold higher organogenetic index was reached with this cultivar than with 'M.26'. Moreover, the similar developmental stage of shoots could be observed 3-5 days earlier than in 'M.26' and if explants of 'Royal Gala' were further cultured with 3 weeks, SN increased from 11.08 to 24.42 on TDZ-containing regeneration medium, which might suggest higher organogenetic ability, too.

scholarly journals Optimizing the concentrations of plant growth regulators for in vitro shoot cultures, callus induction and shoot regeneration from calluses of grapes

OENO One ◽  
2015 ◽  
Vol 49 (1) ◽  
pp. 37 ◽  
Author(s):  
Nadra Khan ◽  
Maqsood Ahmed ◽  
Ishfaq Hafiz ◽  
Nadeem Abbasi ◽  
Shaghef Ejaz ◽  
...  
Keyword(s):  
Shoot Regeneration ◽  
Growth Regulators ◽  
Callus Induction ◽  
Leaf Explants ◽  
Shoot Cultures ◽  
Ms Medium ◽  
Grape Cultivar ◽  
Half Strength ◽  
Number Of Shoots

<p style="text-align: justify;"><strong>Aim</strong>: To optimize the concentrations of growth regulators in the media for the proficient micropropagation of grapevine (<em>Vitis vinifera </em>L.) cv. King’s Ruby.</p><p style="text-align: justify;"><strong>Methods and results</strong>: Apical meristems of the grape cultivar were used to establish <em>in vitro</em> shoot cultures. Nodal explants, each containing an axillary bud, taken from <em>in vitro</em> grown shoots were inoculated in shoot proliferation medium, i.e., half strength Murashige and Skoog (MS) medium supplemented with benzyl aminopurine (BAP), kinetin, glycine and gibberellic acid (GA<sub>3</sub>). A higher number of shoots (5.33) with greater shoot length (2.75 cm) was produced in the medium supplemented with 1.0 mg L<sup>-1</sup> BAP and 0.1 mg L<sup>-1</sup> GA<sub>3</sub>. Calluses were induced from leaf explants taken from <em>in vitro</em> grown shoots. Callus induction was greater (73.00%) on the medium containing 2.0 mg L<sup>-1</sup> 2,4-dichlorophenoxyacetic acid (2,4-D), 0.3 mg L<sup>-1</sup> BAP and 0.2 mg L<sup>-1</sup> α-naphthaleneacetic acid (NAA). The maximum frequency of shoot regeneration (53.33%) was achieved on the medium supplemented with 1.5 mg L<sup>-1</sup> BAP and 0.5 mg L<sup>-1</sup> NAA, and the regenerated shoots successfully formed roots on growth regulator-free half strength MS medium.</p><p style="text-align: justify;"><strong>Conclusion</strong>: Optimizing the concentration of BAP and GA<sub>3</sub> and omitting the glycine and kinetin in the culture medium increased the number and length of shoots. Similarly, for inducing the callus of the leaf explants, taken from <em>in vitro</em> grown shoots, it is recommended to adjust the medium with the higher concentration of 2,4-D and lower concentrations of BAP. Moreover, the maximum number of shoots was regenerated on a medium supplemented with relatively high levels of both BAP and NAA (1.5 and 0.5 mg L<sup>-1</sup>, respectively). Finally, we suggest the half strength MS medium that is free from growth regulators for the root formation of the regenerated shoots.</p><p style="text-align: justify;"><strong>Significance and impact of the study</strong>: Optimizing the concentration of growth regulators is crucial for the efficient micropropagation of a grape cultivar. Knowing the specific balance between the growth regulators is necessary to establish <em>in vitro</em> shoot cultures, callus induction and shoot regeneration and, hence, to propagate disease-free true to type grape cultivars in a short time.</p>

scholarly journals Development of an in vitro Callus Induction Protocol and Shoot Proliferation for Selected Jatropha (Jatropha curcas) Accessions

2020 ◽  
Vol 30 (1) ◽  
pp. 131-141
Author(s):  
Hundessa Fufa ◽  
Jiregna Daksa
Keyword(s):  
Shoot Regeneration ◽  
Callus Induction ◽  
Jatropha Curcas ◽  
Plant Tissue ◽  
Leaf Explants ◽  
Shoot Proliferation ◽  
Adventitious Shoot ◽  
Regeneration Medium ◽  
Adventitious Shoot Buds

The present study was undertaken to establish a protocol for in vitro callusing of three Jatropha accessions, namely Metema, Adami Tulu and Shewa Robit from leaf explants. The medium supplemented with combination of 4.44 μM BAP and 4.52 μM 2,4-D resulted in maximum percentage of callus (100%) formed for all accessions. The maximum shoot regeneration (66.67%) from callus with 10.13 number of shoot was obtained from Shewa Robit in MS medum fortified with TDZ (2.27 μM ) and IBA (0.49 μM ). The presence of TDZ in the shoot regeneration medium has greater influence on the induction of adventitious shoot buds, whereas MS supplemented with BAP alone and combination with IBA did not induce shoot regeneration from callus culture. The results obtained in the present study would facilitate the high callus induction and regeneration responses in Jatropha for its improvement using biotechnological tools. Plant Tissue Cult. & Biotech. 30(1): 131-141, 2020 (June)

scholarly journals Particle Bombardment of Apple Leaf Explants Influences Adventitious Shoot Formation

HortScience ◽  
1994 ◽  
Vol 29 (12) ◽  
pp. 1536-1538 ◽  
Author(s):  
P. Gercheva ◽  
R.H. Zimmerman ◽  
L.D. Owens ◽  
C. Berry ◽  
F.A. Hammerschlag
Keyword(s):  
Shoot Regeneration ◽  
Particle Bombardment ◽  
Dark Period ◽  
Leaf Explants ◽  
Adventitious Shoot ◽  
Shoot Formation ◽  
Regeneration Medium ◽  
Adventitious Shoot Formation ◽  
Shoot Production ◽  
And Control

Shoot regeneration from apple (Malus domestica Borkh.) leaf explants following particle bombardment at various acceleration pressures was studied. Basal leaf segments of micropropagated `Royal Gala' apple were bombarded with 1 μm gold particles, accelerated using helium pressures of 4.5, 6.2, 7.6, 9.3, or 13.8 MPa (650–2000 psi), and cultured on shoot regeneration medium consisting of N6 salts supplemented with 10 μM TDZ for 5, 10, or 20 days in darkness. Bombarded and control explants exhibited 63% to 100% shoot regeneration. With a 5-day dark period, average shoot production per explant ranged from 6.1 to 14; bombardments of 4.5 and 6.2 MPa significantly increased shoot production over the controls. With a 10-day dark period, average shoot production per explant ranged from 9.1 to 22 following bombardment at 9.3 and 6.2 MPa, respectively. Following bombardment at 6.2 MPa, 75% of the explants produced more than 20 regenerants per explant. With a 20-day dark period, average shoot production per explant ranged from 8.9 to 19 following bombardment at 13.8 MPa and following no bombardment, respectively. Shoot production per explant was significantly less than the controls following bombardments ranging from 6.2 to 13.8 MPa. Shoot production was highest per explant with particle bombardment at 6.2 MPa followed by incubation in darkness for 10 days. Chemical name used: thidiazuron (TDZ).

Shoot Regeneration from Rhododendron Leaf Explants and Callus

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 478a-478
Author(s):  
Sarah S. Crist ◽  
John E. Preece
Keyword(s):  
Somaclonal Variation ◽  
Shoot Regeneration ◽  
Adventitious Shoots ◽  
Leaf Explants ◽  
Shoot Cultures ◽  
Indolebutyric Acid ◽  
Tissue Proliferation ◽  
Shoot Number ◽  
All Treatment

Shoots were regenerated adventitiously from leaf explants and from callus to determine if there is any effect on somaclonal variation and tissue proliferation of the three rhododendron cultivars, Arctic Pearl, P.J.M. Elite, and Purple Gem. The focus of this paper is regeneration. Leaves from shoot cultures were placed on a pre-conditioning medium for 2 weeks containing 10 μM indolebutyric acid (IBA) and 50 μM isopentenyladenine (2iP) and then transferred to treatment media. The six media tested were 0.1, 1.0, or 10.0 μM thidiazuron (TDZ) or 25.0, 50.0, or 75.0 μM 2iP. All treatment media contained 10 μM IBA. Data were collected on shoot regeneration after 24 weeks. Shoot number increased with increasing levels of TDZ for `P.J.M. Elite', but decreased with increasing concentrations of TDZ for `Arctic Pearl'. Shoot number for `Purple Gem' leaf explants was greatest when there was 1.0 μM TDZ in the medium. In another experiment, leaf explants were placed on the same preconditioning medium for 2 weeks as above and then transferred to three treatment media containing 0.1, 1.0, or 10.0 μM TDZ and 100 μM IBA. Callus was produced on leaf explants after 4 weeks, regardless of cultivar or level of TDZ. After 11 weeks, adventitious shoots regenerated from `Purple Gem' callus regardless of level of TDZ and from `Arctic Pearl' callus when the medium contained 0.1 or 10.0 μM TDZ. After 11 weeks, there were no visible shoots on `P.J.M. Elite' callus.

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