The morphology and anatomy of holdfasts and branching radicles of Arceuthobium pusillum cultured in vitro

1969 ◽  
Vol 47 (12) ◽  
pp. 1935-1938 ◽  
Author(s):  
J. M. Bonga

Seeds of the eastern dwarf mistletoe, Arceuthobium pusillum Peck, were cultured on White's medium supplemented with coconut milk, casein hydrolysate, and indoleacetic acid (IAA) or 2,4-dichlorophenoxyacetic acid (2,4-D). Large holdfasts were obtained with 2,4-D. At first, growth of these holdfasts arose from a centrally located meristem, but later from growth centers near the periphery of the holdfasts. Reticulate thickening of the cell walls was observed in the center area of the holdfasts. With IAA, flat structures with branches or papillae were obtained. If the seeds were cultured with 2,4-D for 3 months and then with IAA, a number of holdfasts formed branches. Centers of meristematic activity developed occasionally where radicles and branches were subjected to pressure.

HortScience ◽  
1999 ◽  
Vol 34 (3) ◽  
pp. 461D-461 ◽  
Author(s):  
Lurline Marsh

Four cowpea [Vigna unguiculata (L). Walp] genotypes; IT 82E-18, IT 82E-16, Pinkeye Purple Hull, and Coronet were tested for somatic embryo formation and embryogenesis. Explants were 3-week-old cotyledons from which the embryonic axes were removed. Cotyledons were cultured in eight media combinations representing modifications of two media, one containing Murashige and Skoog Basal salt with B5 vitamins (MSB), 500 mg/L casein-hydrolysate (CS), 500 mg/L sodium chloride, 3% sucrose, 0.7% agar, 2mg/L 2,4-dichlorophenoxyacetic acid (2,4-D) and 0.5 mg/L benzylamino purine, and the other containing (MSB), 3% sucrose, 40 mg/L 2-4-D and 0.2% gellan gum. After 1 month, 40% to 100% of explants produced calli and few produced shoots. Subcultured shoots in MS with 0.1 mg/L indole-3-butyric acid (IBA) or with IBA and 0.5mg/L kinetin (KT) failed to produced roots. The only green cotyledonary stage embryo was produced on this latter medium. Subculture of calli in MSB containing CS, mannitol, sucrose, agar, indoleacetic acid, and KT produced cream-colored globular embryos, roots, and a few leaves.


2006 ◽  
Vol 6 ◽  
pp. 169-175
Author(s):  
A.E. De Silva ◽  
M.A. Kadir ◽  
M.A. Aziz ◽  
S. Kadzimin

Differential effect of plant growth regulators and additives in proliferation of 18-month-old calli ofAnanas comosusL. cv. Moris were assessedin vitro. The proliferation of callus relied on the growth regulators and additives. Of the different auxins supplemented in the Murashige and Skoog (MS) media, 32.22 μM α-naphthaleneacetic acid (NAA) gave the highest mean fresh weight of callus (46.817 g). Medium supplemented with 2,4-dichlorophenoxyacetic acid (2,4-D) was inferior to NAA, while b-naphthoxy acetic acid (BNOA) and p-chlorophenoxy acetic acid (4-CPA) were not effective in proliferating 18-months old callus. Addition of casein hydrolysate and coconut water to NAA supplemented medium showed better proliferation and production of callus. However, in terms of callus production, NAA at 32.22 μM was economically better.


Plants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 761
Author(s):  
Arun Kumar Khajuria ◽  
Christophe Hano ◽  
Narendra Singh Bisht

Viola canescens Wall. ex. Roxb. is an important but threatened medicinal herb found at 1500–2400 m above mean sea level in the Himalayas. Overexploitation and habitat preference have put the plant under serious threat. Thus, the present study was undertaken to develop an efficient protocol for in vitro propagation via somatic embryogenesis. The results revealed that plant can be regenerated successfully through somatic embryogenesis using leaf derived calli. Regular subculturing of calli on Murashige and Skoog (MS) medium with 2,4-dichlorophenoxyacetic acid (2,4-D)/indole-3-butyric acid (IBA)/kinetin (Kn) and varying combinations of 2,4-D+Kn induced somatic embryogenesis. The maximum average number of somatic embryos (SE) (19.15 ± 2.66) was induced on the medium with 0.15 + 0.05 mg L−1 of 2,4-D and Kn, respectively, and this medium was used as a control. To enhance somatic embryo induction, the control MS medium was supplemented with l-glutamine (200–400 mg L−1) and casein hydrolysate (1–4%). The maximum average number of SE (27.66 ± 2.67) and average mature SE (13.16 ± 3.48) were recorded on the medium having 2 % l-glutamine and 50 mg L−1 casein hydrolysate. The induced SE were asynchronous, so, to foster their maturation, the culture medium (free from growth regulators) was supplemented with abscisic acid (ABA) and silver nitrate (AgNO3). The maximum average number (35.96 ± 3.68) of mature SE was noticed on MS medium supplemented with 1.5 mg L−1 ABA. Mature embryos had two well-developed cotyledons and an elongated hypocotyl root axis. The development of SE into plantlets was significant for embryos matured on the medium with AgNO3 and ABA, with 86.67% and 83.33% conversion on the medium with 0.20 mg L−1 6-benzylaminopurine (BAP). The plantlets thus produced acclimatized in a growth chamber before being transferred to the field, which showed 89.89% survival. The plants were morphologically similar to the mother plant with successful flowering.


1982 ◽  
Vol 60 (6) ◽  
pp. 917-921 ◽  
Author(s):  
Leonor Fernandez ◽  
Estela Sanchez de Jimenez

Callus cultures were induced from radicle and leaf tissues of Bouvardia ternifolia (trompetilla). Optimum growth regulator concentrations for radicle callus cultures were 1 mg/L 2,4-dichlorophenoxyacetic acid and 0.005 mg/L kinetin; for leaf callus they were either 2 mg/L naphthaleneacetic acid and 0.002 mg/L benzylaminopurine or 5 mg/L of idoleacetic acid and 0.01 mg/L kinetin. Callus has been maintained in culture for nearly 3 years with a very rapid growth rate.A generation time of approximately 24 to 28 h was obtained for batch cell suspension cultures. Production of protoplasts from suspension cultures was optimized with a yield of 70 to 90%. Protoplast culture was achieved in droplets of fresh medium with 2 mg/L napthaleneacetic acid, 0.01 mg/L benzylaminopurine, and0.5 M mannitol. After 2 years, callus in culture still retained its organogenetic capacity. An average of 18 complete plantlets from approximately 2 g of callus can be obtained after transfer to medium with 0.1 mg/L indoleacetic acid and 0.1 mg/L benzylaminopurine.


HortScience ◽  
1994 ◽  
Vol 29 (10) ◽  
pp. 1186-1188 ◽  
Author(s):  
S.A. Merkle ◽  
B.A. Watson-Pauley

Low conversion rates of somatic embryos and poor early growth of somatic embryo-derived plantlets of some forest trees may be related as much to prolonged maintenance in vitro as to basic developmental problems with the embryos. We tested ex vitro conversion as an alternative method for producing the rare North American pyramid magnolia (Magnolia pyramidata Bartram) plantlets from somatic embryos. Tissue cultures were initiated from immature seed explants of pyramid magnolia. Immature seeds collected from each of three trees formed proembryogenic masses (PEMs) following 7 to 10 weeks of continuous culture on semisolid medium containing 9.0 μm 2,4-D, 1.1 μm BA, and 1 g casein hydrolysate/liter. PEMs transferred to semisolid medium without plant growth regulators produced somatic embryos that germinated following transfer to the same medium without casein hydrolysate. Conversion frequency to plantlets was higher and plantlets were more vigorous when germinants were transferred directly to potting mix and grown in a humidifying chamber instead of being maintained in plantlet development medium in test tubes. Chemical names used: 2,4-dichlorophenoxyacetic acid (2,4-D); N-(phenylmethyl)-1H-purine-6-amine (BA).


1972 ◽  
Vol 50 (12) ◽  
pp. 2471-2477 ◽  
Author(s):  
T. T. Lee

Peroxidase in tobacco callus tissue (Nicotiana tabacum, cv. White Gold) was resolved into three groups of isoenzymes by polyacrylamide gel electrophoresis, and a combined action of cytokinin, auxin, and gibberellin in their formation was clearly demonstrated. The most significant change was in a group of fast-migrating isoperoxidases, the development of which required both kinetin and indoleacetic acid. Kinetin was most stimulatory at 0.2 μM but became inhibitory with increasing concentrations. Indole acetic acid was effective at concentrations from 0.1 to 100 μM with an optimum at 10 μM. With both kinetin and indoleacetic acid at optimal concentrations, addition of gibberellic acid further increased the contents of the fast migrating isoperoxidases, but it was inactive in the absence of indoleacetic acid or in the presence of kinetin in 5 μM or higher concentrations. Cycloheximide, actinomycin D, and abscisic acid inhibited the formation of the fast-migrating peroxidases. Formation of the fast-migrating isoperoxidase in the tissue was associated with tumor-type growth.2,4-Dichlorophenoxyacetic acid had a dual effect on peroxidase; at low concentrations (0.1 to 1 μM) it promoted a fast-migrating isoperoxidase; at high concentrations (10 to 100 μM) it inhibited the fast-migrating isoperoxidase but caused a significant increase in other isoperoxidases of lower electrophoretic mobilities.


HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 460e-460 ◽  
Author(s):  
Marisa F. de Oliveira ◽  
Gerson R. de L. Fortes ◽  
João B. da Silva

The aim of this work was to evaluate the organogenesis of Marubakaido apple rootstock under different aluminium concentratons. The explants were calli derived from apple internodes treated with either 2,4-dichlorophenoxyacetic acid or pichloram at 0.5 and 1.0 μM and under five different aluminium concentrations (0, 5, 10, 15, 20 mg/L). These calli were then treated with aluminium at 0, 5, 10, 15, and 20 mg/L. It was observed shoot regeneration only for those calli previously treated with pichloram. There were no significant difference among the aluminium concentrations.


HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 483a-483
Author(s):  
Roy N. Keys ◽  
Dennis T. Ray ◽  
David A. Dierig

Guayule (Parthenium argentatum Gray, Asteraceae) is a latex-producing perennial desert shrub that is potentially of economic importance as an industrial crop for the desert Southwest. It is known to possess complex reproductive modes. Diploids are predominantly sexual and self-incompatible, while polyploids show a range of apomictic potential and self-compatibility. This paper describes the development of a relatively rapid and simple technique for characterizing reproductive modes of breeding lines of P. argentatum. Initial field experiments were based on an auxin test used successfully to characterize reproductive mode in the Poaceae. The application of 2,4-dichlorophenoxyacetic acid inhibited embryo formation in P. argentatum, but this was not the case with other auxins tested. Results of field experiments were ambiguous because: 1) the floral structure of P. argentatum is such that auxins might not have penetrated to the ovules, and 2) there was potential self-fertilization by pollen released within isolation bags. Therefore, in vitro culture of flower heads was tested because it provided much better control of environmental conditions, growth regulator application, and pollen release. Auxin alone, or in combination with gibberellic acid or kinetin, inhibited parthenogenesis in vitro. Embryo production did not vary using two substantially different nutrient media. In vitro flower head culture using a (Nitsch and Nitsch) liquid nutrient medium without growth regulators, enabled characterization of the reproductive mode of seven breeding lines, ranging from predominantly sexual to predominantly apomictic. The results of this technique were substantiated using RAPD analyzes of progeny arrays from controlled crosses.


1984 ◽  
Vol 62 (7) ◽  
pp. 1393-1397 ◽  
Author(s):  
M. D. Zhou ◽  
T. T. Lee

The callus-promoting activity of most commonly known as well as some rarely tested auxins was compared with that of 2,4-dichlorophenoxyacetic acid (2,4-D) for in vitro culture of the excised embryo of spring and winter wheat (Triticum aestivum L.), cv. Chinese Spring and cv. Fredrick. Different auxins in a concentration range from 1 to 50 μM showed widely different activities. Also the two wheat cultivars responded differently to the auxins. When rapid callus formation with limited root growth was used as the basis for comparison, 2-(2-methyl-4-chlorophenoxy)propionic acid (2-MCPP), α-naphthaleneacetic acid, 3,6-dichloro-2-methoxybenzoic acid (dicamba), 4-amino-3,5,6,trichloropicolinic acid (picloram), γ-(2,4-dichlorophenoxy)butyric acid, 2,4,5-trichlorophenoxyacetic acid, and 2,4,5-trichlorophenoxypropionic acid, in the order of effectiveness, were superior to 2,4,-D for callus induction from the embryo of 'Chinese Spring,' although the concentration required was higher than that of 2,4-D. For the winter wheat 'Fredrick,' however, only picloram, dicamba, and 2-MCPP performed as well as 2,4-D. All auxins tested promoted shoot growth; 2-methyl-4-chlorophenoxypropionic acid was most effective for 'Chinese Spring,' whereas picloram was most effective for 'Fredrick.'


Agronomy ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 839
Author(s):  
Dorota Weigt ◽  
Idzi Siatkowski ◽  
Magdalena Magaj ◽  
Agnieszka Tomkowiak ◽  
Jerzy Nawracała

Ionic liquids are novel compounds with unique chemical and physical properties. They can be received based on synthetic auxins like 2,4-dichlorophenoxyacetic acid or dicamba, which are commonly used hormones in microspore embryogenesis. Nevertheless, ionic liquids have not been adapted in plant in vitro culture thus far. Therefore, we studied the impact of ionic liquids on the ability to undergo microspore embryogenesis in anther cultures of wheat. Two embryogenic and two recalcitrant genotypes were used for this study. Ten combinations of ionic liquids and 2,4-dichlorophenoxyacetic acid were added to the induction medium. In most cases, they stimulated induction of microspore embryogenesis and green plant regeneration more than a control medium supplemented with only 2,4-dichlorophenoxyacetic acid. Two treatments were the most favorable, resulting in over two times greater efficiency of microspore embryogenesis induction in comparison to the control. The effect of breaking down the genotype recalcitrance (manifested by green plant formation) was observed under the influence of 5 ionic liquids treatments. Summing up, ionic liquids had a positive impact on microspore embryogenesis induction and green plant regeneration, increasing the efficiency of these phenomena in both embryogenic and recalcitrant genotypes. Herbicidal ionic liquids can be successfully used in in vitro cultures.


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