scholarly journals Genotype, Explant and Growth Regulator Effects in the Determination of Adventitious Regeneratin in Curcurbits, in Aid of Genetic Transformation

Author(s):  
Dennis Gray ◽  
Victor Gaba

The objective of this study was to gain an understanding of the in vitro regeneration process in watermelon and melon to enable the development of genetic transformation systems. The objectives were met and additional progress, unplanned during the original proposal, was made. Organogenic regeneration in vitro was studied in both melon and watermelon. Genotype played a significant role in regeneration. In melon, epidermal cells were responsible for most regeneration. Methods to obtain in vitro-derived watermelon tetraploids, needed for seedless varieties, were developed. The culture systems were refined so that they could be routinely used for transformation. Particle guns were constructed and Agrobacterium strains were obtained to study the effect of transformation procedures on culture system performance, allowing refinement of transformation protocols. The culture systems were shown to enable the stable transformation of both crops, allowing their future use for insertion of agriculturally-important genes. In addition, we showed that shoot apical meristems might be suitable target tissue for transformation and allow a wider range of genotypes to be used, which is needed for crops as diverse as cucurbits.

2012 ◽  
Vol 40 (2) ◽  
pp. 140 ◽  
Author(s):  
Hafiz Mamoon REHMAN ◽  
Iqrar Ahmad RANA ◽  
Siddra IJAZ ◽  
Ghulam MUSTAFA ◽  
Faiz Ahmad JOYIA ◽  
...  

Dalbergia sissoo Roxb. ex DC. (Sissoo) is a native forest tree species in Pakistan. Many ecological and economical uses are associated with this premier timber species, but dieback disease is of major concern. The objective of this study was to develop a protocol for in vitro regeneration of Sissoo that could serve as target material for genetic transformation, in order to improve this species. Callus formation and plantlet regeneration was achieved by culturing cotyledons, immature seeds, and mature embryos on a modified Murashige and Skoog (1962) (MS) medium supplemented with plant growth regulators. Callus induction medium containing 2.71 ?M 2, 4-dichlorophenoxyacetic acid (2,4-D) and 0.93 ?M kinetin produced better callus on all explants tested compared to other treatments, such as 8.88 ?M 6-benzylaminopurine (BA) and 2.69 ?M ?-naphthalene acetic acid (NAA), or 2.71 ?M 2, 4-D and 2.69 ?M NAA. Shoot regeneration was best on MS medium containing 1.4 ?M NAA and 8.88 ?M BA compared to other treatments, such as 1.4 ?M NAA and 9.9 ?M kinetin, or 2.86 ?M indole-3-acetic acid and 8.88 ?M BA. Murashige and Skoog medium containing 1.4 NAA ?M and 8.88 ?M BA was better in general for regeneration regardless of callus induction medium and the type of explant used. Rooting was best on half-strength MS medium with 7.35 ?M indole-3-butyric acid. Regenerated plantlets were acclimatized for plantation in the field. Preliminary genetic transformation potential of D. sissoo was evaluated by particle bombardment of callus explants with a pUbiGus vector. The bombarded tissue showed transient Gus activity 1week after bombardment. Transformation of this woody tree is possible provided excellent regeneration protocols. The best combination for regeneration explained in this study is one of such protocols.


1970 ◽  
Vol 20 (2) ◽  
pp. 145-155 ◽  
Author(s):  
Rita Sarah Borna ◽  
M. I. Hoque ◽  
R. H. Sarker

Genetic transformation using nodal and internodal segments from three economically important potato (Solanum tuberosum L.) varieties namely, Diamant, Cardinal and Granola was conducted using an Agrobacterium tumefaciens strain LBA4404 harbouring binary plasmid pBI12 containing the GUS and nptII genes. Node and internodal segments were used for direct regeneration as well as regeneration with the intervention of callus. best responses were  obtained for direct regeneration of shoots when the explants were cultured on MS supplemented with 4.0 mg/l BAP +1.0 mg/l IAA, 1.5 mg/l BAP  + 0.5 mg/l IAA and 5.0 mg/l BAP +1.0 mg/l IAA in Diamant, Cardinal  and  Granola, respectively. In Diamant spontaneous in vitro microtuberization was obtained from these proliferated shoots. Further culturing of these in vitro grown green microtubers regenerated a large number of shoots on MS containing 4.0 mg/l BAP +1.0 mg/l IAA. By combining the best treatments, this protocol yielded an average transformation rate of 87% of treared explants. Stable expression of GUS gene was visualized in the various parts of transformed shoots through histochemical assay. Genomic DNA was isolated from transformed shoots and stable integration of the GUS and nptII genes was confirmed by PCR analysis.   Key words:  Potato, in vitro regeneration, transformation   D.O.I. 10.3329/ptcb.v20i2.6894   Plant Tissue Cult. & Biotech. 20(2): 145-155, 2010 (December)


1970 ◽  
Vol 19 (1) ◽  
pp. 101-111 ◽  
Author(s):  
Rakha Hari Sarker ◽  
Khaleda Islam ◽  
M.I. Hoque

Agrobacterium-mediated genetic transformation system has been developed for two tomato (Lycopersicon esculentum Mill.) varieties, namely Pusa Ruby (PR) and BARI Tomato-3 (BT-3). Prior to the establishment of transformation protocol cotyledonary leaf explants from the two varieties were cultured to obtain genotype independent in vitro regeneration. Healthy multiple shoot regeneration was obtained from the cut ends of cotyledonary leaf segments for both the varieties on MS containing 1.0 mg/l BAP and 0.1 mg/l IAA. The maximum root induction from the regenerated shoots was achieved on half the strength of MS medium supplemented with 0.2 mg/l IAA. The in vitro grown plantlets were successfully transplanted into soil where they flowered and produced fruits identical to those developed by control plants. Transformation ability of cotyledonary leaf explants was tested with Agrobacterium tumefaciens strain LBA4404 harboring binary plasmid pBI121, containing GUS and npt II genes. Transformed cotyledonary leaf explants were found to produce multiple shoots on MS containing 1.0 mg/l BAP and 0.1 mg/l IAA. Selection of the transformed shoots was carried out by gradually increasing the concentration of kanamycin to 200 mg/l since kanamycin resistant gene was used for transformation experiments. Shoots that survived under selection pressure were subjected to rooting. Transformed rooted plantlets were transferred to soil. Stable expression of GUS gene was detected in the various tissues from putatively transformed plantlets using GUS histochemical assay.  Key words: In vitro regeneration, transformation, tomato D.O.I. 10.3329/ptcb.v19i1.5004 Plant Tissue Cult. & Biotech. 19(1): 101-111, 2009 (June)


2020 ◽  
Vol 1 (1) ◽  
pp. 9-14
Author(s):  
Tina Oana Cristea ◽  
Alin Gabriel Iosob ◽  
Creola Brezeanu ◽  
Petre Marian Brezeanu ◽  
Dan Avasiloaiei ◽  
...  

The aim of the present research work was the screening of the effect of the main cytokinin (BAP, kinetin or zeatin) in different concentrations and combinations with the auxin NAA on androgenesis of white cabbage anthers cultivated in vitro. The results obtained are regarded as an intermediary stage for the development of a reproducible protocol for in vitro regeneration of plant from anther culture. Thus, for the determination of the influence of plant growth regulators formula over the callus induction and plant regeneration from anthers cultivated in vitro in the present study the authors undergo a screening of the three most frequently utilized cytokinins (BAP, kinetin and zeatin) in different concentration and combination with the auxin NAA. The results obtained, indicated that the best morphogenetic reaction is obtained on variant with BAP as the main growth regulator.


2014 ◽  
Vol 70 (1) ◽  
pp. 5-10 ◽  
Author(s):  
Ewa Hanus-Fajerska

Plant regeneration in vitro from virus-infected somatic tomato (<em>Lycopersicon</em> sp.) tissue was performed. Regeneration experiments were started after the determination of virus presence, using enzyme-linked immunosorbent assay, in leaves used as a source of explants. Leaf explants infected with selected strains of tomato mosaic <em>Tobamovirus</em> or cucumber mosaic <em>Cucumovirus</em> respectively, were cultured on a standarised MS agar medium to induce adventitious shoots, which were afterwards excised, rooted in vitro and cultured to plants. Explants were also screened for their ability to produce callus. Diverse effects of viral infection, ranging from stimulation to inhibition of callus formation and of morphogenesis rate, were observed. The health condition of the tissue proved to affect regeneration potential of <em>Lycopersicon esculentum</em>, whereas wild accesions did not react in that case so distinctly. In cultivated tomato was encountered the decline in competence to reproduce shoots adventitiously in infected tissue. There was also relationship between donor plant health condition and adventitious root formation in regenerated shoots. Experiments with short-term cultures of <em>L. esculenum</em> reveled also that a certain number of shoots regenerated from diseased tissue can be virus-free.


2019 ◽  
Vol 29 (2) ◽  
pp. 245-255
Author(s):  
Mohammad Mahmood Hasan ◽  
Sujay Kumar Bhajan ◽  
M. Imdadul Hoque ◽  
R.H. Sarker ◽  
Mohammad Nurul Islam

In genetic improvement of mungbean much success has not been achieved due to its recalcitrant nature towards in vitro regeneration. An attempt was made to develop an Agrobacterium-mediated in planta genetic transformation protocol for a locally grown mungbean variety BARI Mung-3 using a screenable marker gene. Two minutes of vacuum infiltration followed by 60 minutes of incubation period in Agrobacterium suspension of Winans’ AB medium containing wounded tobacco leaf extract was found most suitable towards genetic transformation in pricked de-coated half seed explants. An optical density (OD600) of 0.7 was found most effective for transient gus gene expression. Chimeric GUS expression was observed in the root and leaf tissues from the successfully transformed plantlets obtained through in planta transformation. This methodology of genetic transformation was found more suitable, easier and less time consuming than tissue culture based genetic transformation, which may be used for the genetic improvement of mungbean.


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