scholarly journals In Vitro Shoot Regeneration and Polyploid Induction from Leaves of Hypericum Species

HortScience ◽  
2009 ◽  
Vol 44 (7) ◽  
pp. 1957-1961 ◽  
Author(s):  
Elisabeth M. Meyer ◽  
Darren H. Touchell ◽  
Thomas G. Ranney

Hypericum L. H2003-004-016 is a complex hybrid among Hypericum frondosum Michx., Hypericum galioides Lam., and Hypericum kalmianum L. and exhibits valuable ornamental characteristics, including compact habit, bluish green foliage, and showy flowers. Inducing polyploidy may further enhance the ornamental traits of this hybrid and provide new opportunities for hybridizing with other naturally occurring polyploid Hypericum sp. In this study, in vitro shoot regeneration and treatment of regenerative callus with the dinitroaniline herbicide oryzalin (3,5-dinitro-N4,N4-dipropylsufanilamide) were investigated as a means of inducing allopolyploidy. First, in vitro regeneration was optimized for callus and shoot induction by culture of leaf explants on medium supplemented with benzylamino purine (BA) or meta-topolin (mT) at 5, 10, or 15 μM in combination with indoleacetic acid (IAA) at 0, 1.25, 2.5, or 5 μM. Both BA and mT treatments successfully induced regenerative callus and shoots. Multiple regression analysis estimated maximum regenerative callus (94%) and shoot induction (18 shoots per explant) in medium supplemented with 5 μM BA and 3.75 μM IAA. In the second part of the study, exposure of regenerative callus to oryzalin at 0, 7.5, 15, 30, 60, or 90 μM for durations of 3, 6, or 9 d was investigated for polyploid induction. There was no survival for any of the calli in the 60- or 90-μM oryzalin treatments, but calli subjected to the other treatments exhibited some survival and polyploid induction. Duration had no effect on callus survival or ploidy level, but oryzalin concentration was a significant factor in both. The greatest percentage (44%) of polyploids was induced with 30 μM oryzalin. Spontaneous chromosome doubling was observed in 8% of control explants receiving no oryzalin treatment.

HortScience ◽  
2010 ◽  
Vol 45 (5) ◽  
pp. 801-804 ◽  
Author(s):  
Cary J. Hebert ◽  
Darren H. Touchell ◽  
Thomas G. Ranney ◽  
Anthony V. LeBude

Rhododendron L.‘Fragrantissimum Improved’ is an attractive cultivar with showy, fragrant flowers but has limited potential for breeding because it is a sterile wide hybrid. Protocols for in vitro regeneration and polyploid induction were developed for this cultivar as a means to potentially restore fertility and enhance ornamental traits. Combinations of thidiazuron (TDZ) at 0, 5, 10, 15, or 20 μM and 1-naphthaleneacetic acid (NAA) at 0, 2.5, 5, or 10 μM were used to induce shoot regeneration from leaves. Shoot regeneration was optimized (68% of leaf segments produced shoots) using 8.8 μM TDZ and 10 μM NAA. To induce polyploidy, regenerative callus was treated with 7.5, 15, 30, 60, or 90 μM of the mitotic inhibitor oryzalin for 1, 3, 5, 7, or 14 d in various combinations. Oryzalin significantly affected survival and shoot regenerative capacity. A percentage of homogenous, tetraploid shoots was recovered from treatments of 30 μM oryzalin for 1 (13%) or 3 (13%) days and 7.5 μM oryzalin for 7 (20%) or 14 (7%) days.


2010 ◽  
Vol 40 (10) ◽  
pp. 2210-2213
Author(s):  
Monalize Salete Mota ◽  
Juliana de Magalhães Bandeira ◽  
Eugenia Jacira Bolacel Braga ◽  
Valmor João Bianchi ◽  
José Antonio Peters

A shoot regeneration system for Plectranthus neochilus was studied from leaf explants. Leaves developed under in vitro conditions were cultured on Wood Plant Medium supplemented with 0.2mg dm-3 α-naphthaleneacetic acid (NAA) and different 6-benzilaminopurine (BAP) or thidiazuron (TDZ) concentrations (0, 1.5, 3.0, 4.5 and 6.0mg dm-3). An increase in percentage of responsive explants (85.3%) and in the number of shoots developed per explant (3.2) was observed when the explants were treated with 5.3 and 4.7mg dm-3 BAP, respectively. The leaf explants cultured on media supplemented with TDZ became vitreous and did not form buds. The regeneration system used is efficient for boldo bud induction and shoot development, showing high potential for advanced cellular and molecular studies.


2017 ◽  
Vol 14 (2) ◽  
pp. 24-31 ◽  
Author(s):  
S S Riva ◽  
A Islam ◽  
M E Hoque

An experiment was conducted on in vitro regeneration and multiplication of Dendrobium bensoniae. Different concentrations of BA and IBA alone or combination of both hormones were used as treatment for regeneration.  It was revealed that shoot regeneration from node was the best at 2.0 mg/l BA supplemented to MS medium. It gave better responses than all other concentrations and combinations of BA and BA+IBA, used in the present study. The highest number of shoots and leaves were found when 1.0 mg/l BA with 1.5 mg/l IBA was supplemented into MS medium.  For rooting, 0.5 mg/l BA with 1.0 mg/l IBA was found to be the most effective. The well-rooted plantlets were successfully acclimatized under 70-80% humidity and planted in pots and transferred to the shade house for establishment. Around 85% of plantlets survived in the field. From the present result, it may be recommended that MS medium supplemented with 2.0 mg/l BA may be used for rapid shoot induction and regeneration of D. bensoniae.The Agriculturists 2016; 14(2) 24-31


HortScience ◽  
1999 ◽  
Vol 34 (3) ◽  
pp. 461E-461
Author(s):  
Winthrop B. Phippen ◽  
James E. Simon

A plant regeneration protocol was successfully developed for basil (O. basilicum L.). Explants from 1-month-old seedlings yielded the highest frequency of regeneration of shoots (37%) with an average number of 3.6 shoots per explant. Calli and shoot induction were initiated on Murashige and Skoog (MS) basal medium supplemented with thidiazuron (TDZ) (4 mg/L) for ≈30 days. Shoot induction and development was achieved by refreshing the induction medium once after 14 days. The most morphogenetically responsive explants were basal leaf explants from the first fully expanded true leafs of greenhouse-grown basil seedlings. Developing shoots were then rooted on MS media in the dark without TDZ. Within 20 days, rooted plantlets were transferred and acclimatized under greenhouse conditions where they developed normal morphological characteristics. This is the first report of a successful in vitro regeneration system for basil through primary callus. The establishment of a reliable regeneration procedure is critical when developing a transformation protocol for enhancing the production of basil for insect and disease resistance and improved essential oil constituents.


Author(s):  
Shikha Sharma ◽  
Geetika Gambhir ◽  
D. K. Srivastava

In vitro regeneration of pea explants (Pisum sativum L. var. ‘Lincon’) was done in 49 different combinations and concentrations of BAP, BAP and NAA, BAP and IBA, TDZ, TDZ and Adenine for shoot regeneration from hypocotyl, root, leaf and cotyledonary node. High frequency shoot regeneration was obtained in hypocotyl (81.43%), root(83.53%) and cotyledonary node(72.76%) on MS medium supplemented with 4.50 mg/l BAP and 1.86mg/l NAA, 2.00mg/l TDZ and4.50 mg/l BAP and 1.86mg/l NAA respectively. No shoot regeneration was obtained from leaf explants on any of the combination used. Shoot elongation was observed on the same medium used for shoot regeneration respectively.MS medium supplemented with 0.20 mg/l IBA was found best for root regeneration from in vitro raised shoots. The plantlets were able to regenerate within 6-7 weeks. The regenerated plantlets were acclimatized in pre-sterilized cocopeat.


2020 ◽  
Vol 10 (15) ◽  
pp. 5370 ◽  
Author(s):  
Mohsen Hesami ◽  
Jorge A. Condori-Apfata ◽  
Maria Valderrama Valencia ◽  
Mohsen Mohammadi

Optimizing in vitro shoot regeneration conditions in wheat is one of the important steps in successful micropropagation and gene transformation. Various factors such as genotypes, explants, and phytohormones affect in vitro regeneration of wheat, hindering the ability to tailor genotype-independent protocols. Novel computational approaches such as artificial neural networks (ANNs) can facilitate modeling and predicting outcomes of tissue culture experiments and thereby reduce large experimental treatments and combinations. In this study, generalized regression neural network (GRNN) were used to model and forecast in vitro shoot regeneration outcomes of wheat on the basis of 10 factors including genotypes, explants, and different concentrations of 6-benzylaminopurine (BAP), kinetin (Kin), 2,4-dichlorophenoxyacetic acid (2,4-D), indole-3-acetic acid (IAA), indole-3-butyric acid (IBA), 1-naphthaleneacetic acid (NAA), zeatin, and CuSO4. In addition, GRNN was linked to a genetic algorithm (GA) to identify an optimized solution for maximum shoot regeneration. Results indicated that GRNN could accurately predict the shoot regeneration frequency in the validation set with a coefficient determination of 0.78. Sensitivity analysis demonstrated that shoot regeneration frequency was more sensitive to variables in the order of 2,4-D > explant > genotype < zeatin < NAA. Results of this study suggest that GRNN-GA can be used as a tool, besides experimental approaches, to develop and optimize in vitro genotype-independent regeneration protocols.


2009 ◽  
Vol 100 (2) ◽  
pp. 235-239 ◽  
Author(s):  
Poornananda Madhava Naik ◽  
Shirugumbi Hanamanthagouda Manohar ◽  
Nagella Praveen ◽  
Hosakatte Niranjana Murthy

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