28 research outputs found
Plant regeneration from leaf explants in apple rootstock MM111: Effect of cytokinins and auxins
Get PDF370-378A reproducible protocol for adventitious shoot formation has been achieved in commercially important clonal apple rootstock Malling-Merton111 (MM111). The procedure consists of inducing leaves excised from micropropagated shoots, on Murashige and Skoog (MS) medium supplied with various concentrations and combinations of cytokinins benzyl adenine (BA), thidiazuran (TDZ) and auxins indole butyric acid (IBA), naphthalene acetic acid (NAA), indole acetic acid (IAA), and 2-4, diphenoxy acetic acid (2,4-D). Frequency of regeneration was influenced by the concentration and type of cytokinin and auxin, light and dark incubation and length of explant exposure to plant growth regulators. Shoots were regenerated either through callus or directly from leaves on regeneration medium incubated in light/dark. However, number of explants regenerated and number of shoots were highest in explants incubated in light. Among BA treatments, optimum shoot regeneration (34%) was obtained at 3 mg l-1 BA with 1 mg l-1 NAA, while TDZ treatments (0.6 mg l-1 TDZ with 0.5 mg l-1 NAA) resulted in higher regeneration rate (44%), and produced increased number with longer shoots. The potential of regeneration was further increased at 0.6 mg l-1 TDZ with 0.5 mg l-1 NAA by using a two stage procedure where leaves were incubated on regeneration medium for 10 days and then transferred to basal medium. Here, 49% shoots originated directly with maximum of six shoots per regenerating explant in comparatively less time period while BA supplemented medium did not promote shoot induction in this experiment. Regenerated shoots were rooted successfully and the resulting plantlets were hardened in the potting mixture
Elimination of viruses through thermotherapy and meristem culture in apple cultivar ‘Oregon Spur-II’
No full textDevelopment of high frequency in vitro shoot regeneration system from leaves of apple cultivar ‘Oregon Spur’ and optimization of antibiotics concentration
No full text463-472Optimization of efficient shoot regeneration protocol and selection of transformed plants at optimum level of antibiotics
are pre-requisite in genetic engineering. Here, we explored standardization of in vitro shoot regeneration protocol from leaf
explants of apple cv. Oregon Spur for the first time using different concentrations of plant growth regulators. Further, we
determined the effect of two antibiotics (kanamycin and cefotaxime) on shoot regeneration efficiency. About 95% of leaves
induced adventitious shoots on MS medium supplemented with 4 mg/L BA and 0.2 mg/L NAA. The frequency of shoot
regeneration increased to 100% when leaf explants were cultured on 2 mg/L TDZ along with 0.5 mg/L NAA. The number of
shoots regenerated per leaf was enhanced but abnormal and vitrified shoots were obtained in case of TDZ supplemented
medium. Dark incubation of initial one week decreased the shoot regeneration frequencies at all the combinations of plant
growth regulators. Leaf explants were found highly sensitive to kanamycin and inhibited shoot induction above 5 mg/L.
This concentration was found suitable for selection of transgenic shoots. Cefotaxime at 100-300 mg/L promoted
organogenesis, whereas 500 mg/L was found optimal to eliminate Agrobacterial overgrowth after co-cultivation with leaf
explants. Our results have demonstrated that the above protocol can successfully be applied for transgenic development in
‘Oregon Spur’ cultivar of apple in future trials
Distinguishing clonal apple rootstocks by isozymes banding patterns
No full text1149-1155<span style="font-size:14.0pt;line-height:
115%;font-family:" times="" new="" roman";mso-fareast-font-family:"times="" roman";="" color:black;mso-ansi-language:en-in;mso-fareast-language:en-in;mso-bidi-language:="" hi"="" lang="EN-IN">Molecular characterisation of clonal apple rootstocks using isozymes was
carried out to identify isozyme polymorphism in seven clonal apple rootstocks
and to identify the most characteristic and stable enzyme markers for each
individual rootstock. Five enzyme systems were studied out of which polyphenol
oxidase, malate dehydrogenase, acid phosphatase and peroxidase were useful in
discriminating among the rootstocks. The peroxidase enzyme system showed
maximum variation and esterase showed the least variation among the rootstocks.
Out of seven rootstocks, three were distinguished on the basis of one enzyme
system only (M.3 with MDH or PER, M.7 with PPO or PER and MM.111 with MDH).
Out of the sixteen loci studied seven were found to be polymorphic. Genetic
variation among the rootstocks was explained on the basis of various
parameters. The percentage of polymorphic loci varied from 13.33 to 35.71 per
cent.</span
Successful propagation <i>in vitro </i>of apple rootstock MM106 and influence of phloroglucinol
No full text1236-1240Successful in vitro propagation
of clonal apple rootstock MM 106 was achieved by culturing axillary buds on MS
basal medium with BAP (1 mg/L) , GA3 (0.5 mg/L) and IBA (0.1
mg/L). Use of liquid medium (LM) in initial cultures reduced phenol exudation to
a greater extent and gave maximum sprouting percentage when transferred to solid
MS medium. Phloroglucinol (PG) did not enhance sprouting of buds but increased the
rate of multiplication when added in the medium. Maximum number of shoots were obtained
when MS medium was supplemented with BAP (0.5 mg/L), GA3 (1
mg/L), IBA (0.1 mg/L) and PG (100 mg/L). For rooting, in
vitro regenerated shoots were placed in IBA (30 mg/L) for 3 hr
and transferred to solidified auxin free medium. Rooting was recorded in about
80% of shoots. Inclusion of PG in rooting medium was not beneficial but shoot cultures
grown in its presence gave higher rooting percentage. Rooted plantlets showed about
70% survival rate in palling mixture of sand : soil: perlite (1:1:1)
<i>In vitro</i> multiplication of Merton I. 793–An apple rootstock suitable for replantation
No full text362-368In vitro shoot multiplication of Merton I. 793, a clonal apple rootstock,
was achieved through terminal/axillary bud culture using Murashige and Skoog
(MS) basal medium supplemented with 0.5-1.0 mg/L 6-benzyl amino purine (BA) and
0.1 mg/L indole-3-butyric acid (IBA). Time of collection of explants, duration
of surface sterilents and growth regulators added in the medium influenced the
survival of explants and their bud break. Although, the shoots were multiplied
on different concentrations of cytokinins and auxins, improved multiplication
was achieved with 0.5 mg/L BA and 0.01 mg/L IBA. Of the three types of explants
evaluated for shoot multiplication, shoot tips on elongation were found suitable
for rooting whereas, nodal cuttings and cluster of small shoots for further
multiplication. Low concentrations of α-naphthyl acetic acid (NAA) was proved
to be more effective for rooting as compared to IBA and indole-3-acetic acid
(IAA). To overcome profuse callus formation during rooting, activated charcoal
was added. In another experiment, auxin was discontinued from the rooting
medium after few days, thus, resulting in better rooting frequency (72%).
Thirty plantlets of Merton I. 793 were successfully hardened after 7 wks, with
around 80% survival rate
Comparison of various RNA extraction methods, cDNA preparation and isolation of calmodulin gene from a highly melanized isolate of apple leaf blotch fungus Marssonina coronaria
No full textIN VITRO REGENERATION AND TRANSFORMATION OF APPLE (Malus domestica Borkh.) ROOTSTOCK MALLING 7 USING RICE CHITINASE GENE
No full textData underlying the publication: Development of high frequency in vitro shoot regeneration system from leaves of apple cultivar Oregon Spur and optimization of antibiotics concentration
No full textthe present study is carried out optimize the high efficiency shoot regeneration protocol from the leaf explant of the Oregon Spur cultivar. The different concentration of the Cytokinin (BAP, TDZ) and auxin (NAA, IBA) were tested to identify the optimium ratio and quantity required to generate shoots. 4mg/l BA alongwith 0.2mg/l NAA was found more effective cytokinin than TDZ for high quality shoot induction. Effect of dark treatment was also tested on the shoot regeneration and inhbitory effect was observed. During optimization of the antibiotics concentration, Leaf explant were found highly sensitive to Kanamycin and inhibited shoot induction above 5mg/l, whereas cefotaxime at 100-300mg/l promoted organogenesis. 500mg/l cefotaxime was found optimal to eliminate bacterial overgrowth after co-cultivation and 5 mg/l of kanamycin was found best for selection of plant.</p
Has Covid-19 accelerated opportunities for digital entrepreneurship? An Indian perspective
Get PDFCovid-19 has challenged many businesses to orient themselves towards digital solutions for their survival. Due to the rising digital wave during Covid-19, there has been a plethora of opportunities for aspiring entrepreneurs to enter the market. Hence, this study focuses on understanding emerging areas and technologies for digital entrepreneurship. This study adopted a qualitative approach with semi-structured interviews through the lens of the diffusion of innovations theory. A total of 23 entrepreneurs responded and presented their views on Covid-19-induced opportunities for digital entrepreneurship. A structured process of open, axial, and selective coding was adopted for the thematic analysis. The study presents a framework based on four promising propositions. Results of the thematic analysis indicate the emergence of digital entrepreneurship opportunities in technology (EdTech, FinTech, cybersecurity), healthcare (diagnostics, virtual care, fitness), entertainment (over the top, gaming, social media), and e-commerce (contactless delivery, payment methods, augmented reality). In this study, entrepreneurs presented their views based on their experience with the platform or technology they operated. To this end, the present study offers implications both for scholars and entrepreneurs working in and aspiring to digital entrepreneurship along with future scope of research
