scholarly journals A Laboratory Exercise to Demonstrate Direct and Indirect Shoot Organogenesis from Leaves of Torenia fournieri

1994 ◽  
Vol 4 (3) ◽  
pp. 320-322 ◽  
Author(s):  
Mark P. Bridgen ◽  
Masood Z. Hadi ◽  
Madeleine Spencer-Barreto

A laboratory exercise on direct and indirect organogenesis from leaf explants is presented for students of plant tissue culture or plant propagation. Torenia fournieri, the wishbone flower, is used for this laboratory exercise because the in vitro production of adventitious shoots from Torenia is easy to control, seeds are easy to obtain, and plants are easy to grow. Direct shoot organogenesis results from leaf explants without an intervening callus phase, and indirect shoot organogenesis is possible after 4 to 6 weeks of callus production from leaf explants. The basal medium for all forms of organogenesis contains Murashige and Skoog (MS) salts and vitamins, 30 g sucrose/liter, and 7 g agar/liter at pH 5.7. To obtain direct shoot organogenesis, leaf explants should be placed on the MS basal medium with 1.1 μM (0.25 mg·liter-1) 6-benzylaminopurine (BAP) and 0.25 μM (0.05 mg·liter-1) indole-3-butyric acid (IBA). If leaf explants are placed on MS medium with 2.3 μM (0.5 mg·liter-1) 2,4-dichlorophenoxyacetic acid (2,4-D), callus formation will occur. Callus can be subcultured onto a MS medium with 8.88 μM BAP (2.0 mg·liter-1) plus 2.5 μM IBA (0.5 mg·liter-1) for indirect shoot organogenesis to occur.

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
K. Varutharaju ◽  
C. Soundar Raju ◽  
C. Thilip ◽  
A. Aslam ◽  
A. Shajahan

An efficient protocol for direct shoot organogenesis has been developed for the medicinal plantAerva lanata(L.) Juss. ex Schult. Regeneration was achieved from leaf segments of 20 days oldin vitroplantlets raised on Murashige and Skoog (MS) medium containing 0.25–2.0 mg L−1thiadiazuron (TDZ), 3% sucrose, and 0.8% agar. After 21 days of culture incubation, maximum number of shoot organogenesis (23.6 ± 0.16) was obtained on medium containing 1.0 mg L−1TDZ. The shoots were able to producein vitroflowers on medium containing 1.0 mg L−1TDZ in combination with 0.25–0.5 mg L−1  α-naphthaleneacetic acid (NAA). Histological observation showed that the epidermal cells of the leaf explants exhibited continuous cell division led to formation of numerous dome shaped meristematic protrusions and subsequently developed into adventitious shoots. Upon transfer of shootlets to half strength MS medium containing 1.0 mg L−1indole-3-butyric acid (IBA), around 86% of the regenerated shoots formed roots and plantlets. Rooted plants were hardened and successfully established in the soil at the survival rate of 92%. The regeneration protocol developed in this study provides an important method of micropropagation of this plant. Furthermore, this protocol may be used for a large scale production of its medicinally active compounds and genetic transformations for further improvement.


HortScience ◽  
1990 ◽  
Vol 25 (11) ◽  
pp. 1353E-1354
Author(s):  
Sheila M. Colby ◽  
Adrian M. Juncosa ◽  
James A. Stamp ◽  
Carole P. Meredith

The developmental anatomy of direct shoot organogenesis from in vitro leaves of Vitis vinifera L. cv. French Colombard was studied by light microscopy. Regenerating petiole stubs of leaf explants were fixed at intervals and were sectioned longitudinally to determine the developmental sequence of direct shoot organogenesis. After 6 days, three distinct regions of meristematic activity were apparent within expanding petiole stub: the wound-response, organogenic, and vascularization regions. In the organogenic region, divisions of vacuolate outer cortical cells formed nodular bumps that sometimes became adventitious leaves. Promeristems, which had the potential to become adventitious shoot meristems, were also initiated asynchronously in the organogenic region. Promeristem initiation occurred by two or several synchronous cell divisions occurring in the epidermal and subepidermal cell layers. Adventitious shoots and leaves developed new vascular bundles that connected to the pre-existing vascular bundles of the explant.


HortScience ◽  
2005 ◽  
Vol 40 (4) ◽  
pp. 1062F-1063
Author(s):  
Khalid M. Ahmad ◽  
Syed M. A. Zobayed ◽  
Praveen K. Saxena ◽  
David M. Hunter

Dionaeamuscipula Ellis commonly known as Venus fly trap is an important carnivorous plant with medicinal importance. It contains certain secondary metabolites like naphthoquinones and is used in anti-aid and anti-cancer drugs and other medicines like Cornivora. Increasing interest and use as an ornamental and medicinal plant, and dietary supplement have put it in an endangered state. Development of in vitro techniques for the preservation of germplasm that is on the brink of extinction is highly demanded. A regeneration protocol for the multiplication and micropropagation of Dionaeamuscipla Ellis was established. In vitro regeneration potential of leaf explants in different concentrations and combinations of plant growth substances was investigated in this study. Seeds were grown and leaf disc explants were excised and cultured under aseptic conditions on nutritional medium containing half strength Murashige and Skoog (MS) mix with combinations of 1.0–20.0 μm BA, 2.5.0 μm IBA, 1.0–10.0 μm 2iP and 0.1–0.5μm TDZ. The cultures were kept in growth cabinet with cool white light (40–60 μmol·m-2·s-1) under 16-h photoperiod. Regeneration was recorded after 60 days with the intervals of 15 days based on the degree of shoot organogenesis and somatic embryogenesis. 1/2 MS + 0.1 TDZ appeared to be efficient for somatic embryogenesis and simple MS for direct shoot organogenesis. 1/2 MS combined with 2iP appeared to be efficient for regeneration either by direct shoot organogenesis or by somatic embryogenesis. Plants were rooted well in Cape Cundew medium. These investigations will aid in the development of a model system for clonal mass propagation and in vitro regeneration of Dionaeamuscipla Ellis.


HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 696b-696
Author(s):  
Richard L. Bell

Discs of cambial tissue were excised from actively growing shoots of `Bartlett' pear, and explanted directly on regeneration induction media. The basal medium was 1/2 strength MS macro-nutrients, MS micro-nutrients and organics, 8 g/l agar, and 30 g/l sucrose. Phytohormone treatments consisted of a factorial design of NAA (0 and 5μM) and TDZ (1, 2, 3, 4, and 5μM). After 4 weeks incubation in the dark, the explants were transferred to auxin-free media with identical concentrations of TDZ. There was an absolute requirement for auxin in the induction medium, as all discs on auxin-free initial media died without callusing. Maximum shoot regeneration 4 weeks after transfer to expression media was obtained with an initial medium containing 5μM NAA and 3μM TDZ, from which 30% of the explants produced one or more adventitious shoots. This rate of regeneration is similar to that obtained in some experiments with in vitro leaf explants, and provides an alternative system for regeneration of pear.


HortScience ◽  
2011 ◽  
Vol 46 (3) ◽  
pp. 466-469
Author(s):  
Jin Cui ◽  
Juanxu Liu ◽  
Jianjun Chen ◽  
Richard J. Henny

Chlorophytum amaniense Engl. ‘Fire Flash’ is a popular exotic ornamental foliage plant as a result of its unique coral-colored midribs and petioles and tolerance to interior low light levels. Currently, demand for propagative materials exceeds the availability of seeds. This study was intended to develop an in vitro culture method for rapid propagation of this cultivar. Leaf and sprouted seed explants were cultured on a Murashige and Skoog basal medium supplemented with different cytokinins with 1.1 μM α-naphthalene acetic acid (NAA) or 2.3 μM 2,4-dichlorophenoxyacetic acid (2,4-D). Leaf explants showed poor responses in callus production and no adventitious shoots were obtained. Callus formation frequencies from sprouted seeds were 71% and 85% when induced by 9.8 μM N6-(2-isopentyl) adenine (2iP) with 1.1 μM NAA and 9.1 μM N-phenyl-N′-1,2,3-thiadiazol-5-ylurea (TDZ) with 1.1 μM NAA, respectively. Adventitious shoots occurred after the induced calluses were subcultured on the same concentrations of TDZ or 2iP with NAA. Shoot formation frequencies from calluses cultured on TDZ with NAA and 2iP with NAA were 92% and 85%, and the corresponding mean shoot numbers were 37 and 31 per piece of callus (1 cm3), respectively. Adventitious shoots rooted at 100% after transferring to the basal medium containing 4.4 μM 6-benzylaminopurine (BA) with 2.7 μM NAA. Plantlets, after transplanting to a soilless substrate were easily acclimatized in a shaded greenhouse under a photosynthetic photon flux (PPF) density of 200 μmol·m−2·s−1. Regenerated plants grew vigorously without undesirable basal branching or distorted leaves. This newly established regeneration method can provide the foliage plant industry with a means for rapidly propagating ‘Fire Flash’ liners in a year-round fashion.


HortScience ◽  
2010 ◽  
Vol 45 (8) ◽  
pp. 1250-1254 ◽  
Author(s):  
Juanxu Liu ◽  
Min Deng ◽  
Richard J. Henny ◽  
Jianjun Chen ◽  
Jiahua Xie

This study established a method of regenerating Dracaena surculosa Lindl. ‘Florida Beauty’ through indirect shoot organogenesis. Bud, leaf, and stem explants were cultured on a Murashige and Skoog basal medium supplemented with N6-(2-isopentyl) adenine (2iP) at 12.3 and 24.6 μM with 3-indoleacetic acid (IAA) at 0, 1.1, and 2.3 μM, respectively, and 2iP at 36.9, 49.2, 61.5, and 73.8 μM with IAA at 1.1 and 2.3 μM, respectively. Calluses were induced from leaf explants but failed to produce adventitious shoots. Calluses were also induced from stem and bud explants cultured on the basal medium containing 12.3 μM 2iP and 2.3 μM IAA, 24.6 μM 2iP or higher with either 1.1 or 2.3 μM IAA. The highest callus induction frequency was 63.2% from stem explants and 69.6% from bud explants when they were cultured on the basal medium supplemented with 49.2 μM 2iP and 2.3 μM IAA. The highest shoot formation frequency was 65.7% from stem-derived callus cultured on the basal medium containing 61.5 μM 2iP and 1.1 μM IAA and 88% from bud-derived callus cultured with 49.2 μM 2iP and 1.1 μM IAA. The highest number of shoots per piece of stem- and bud-derived calluses was 3.8 and 6.7, respectively. Adventitious shoots developed better root systems in the basal medium supplemented with 2.0 μM IAA. Plantlets after transplantation into a soilless substrate grew vigorously in a shaded greenhouse under a maximum photosynthetic photon flux density of 300 μmol·m−2·s−1. Neither disease incidence nor somaclonal variants were observed in the regenerated population. This established method could be used for efficient micropropagation of D. surculosa, and the availability of tissue-cultured liners could reduce the dependency on imported cuttings, which often bring new or invasive pests into the United States.


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