In vitro control of de novo flower differentiation from tobacco thin cell layers cultured on a liquid medium

1981 ◽  
Vol 51 (1) ◽  
pp. 77-84 ◽  
Author(s):  
A. Cousson ◽  
K. Tran Thanh Van
1987 ◽  
Vol 70 (3) ◽  
pp. 453-460 ◽  
Author(s):  
Patrizia Torrigiani ◽  
Maria Maddalena Altamura ◽  
Gabriella Pasqua ◽  
Barbara Monacelli ◽  
Donatella Serafini-Fracassini ◽  
...  

1989 ◽  
Vol 67 (3) ◽  
pp. 650-654 ◽  
Author(s):  
A. Cousson ◽  
P. Toubart ◽  
K. Tran Thanh Van

Thin cell layer explants of tobacco were floated in vitro on the surface of liquid culture media. The initial exogenous concentrations of indolyl-3-butyric acid, and kinetin, the initial medium pH, and the explant density were varied. Various patterns of de novo and direct differentiation without any intermediate callus (flower, vegetative bud, root) as well as the absence of morphogenesis and callus formation without any subsequent organogenesis were separately controlled on 100% of the explants. On the same exogenous combination of glucose, indolyl-3-butyric acid, and kinetin, changes in initial medium pH changed the pattern of morphogenesis. For a given initial exogenous indolyl-3-butyric acid concentration, vegetative buds were obtained at either pH 6.1 or 7.8, whereas a mixture of flowers and vegetative buds was obtained at pH 6.8. Furthermore, changes in explant density changed the morphogenetic response. It is suggested that the effects of the initial medium pH and explant density on morphogenesis may be related partially to modifications of the physicochemical properties of the cell wall and (or) plasmalemma.


2007 ◽  
Vol 330 (10) ◽  
pp. 728-734 ◽  
Author(s):  
Asma Ben Ghnaya ◽  
Gilbert Charles ◽  
Annick Hourmant ◽  
Jeannette Ben Hamida ◽  
Michel Branchard

1993 ◽  
Vol 71 (3) ◽  
pp. 506-511 ◽  
Author(s):  
Alain Cousson ◽  
Kiem Tran Thanh Van

Floral and vegetative organogenesis in thin cell layers of Nicotiana tabacum cv. Samsun was studied in relation to the ionic composition of the medium. The control liquid medium was buffered to pH 5.5. NH4+, NO3−, K+, and Ca2+ were separately varied between 0 or 0.1 times and 2, 3 or 4 times their initial control concentration. Increasing the concentrations of NO3−, and Ca2+ above their control concentration promoted the formation of vegetative buds instead of flowers. When K+ at 80.0 mM, Na+ at 78.9 mM, and NH4+ as the sole nitrogen source used, neither flower formation nor morphogenesis were observed in 70, 100, and 100% of the explants, respectively. NH4+ as the sole nitrogen source acidified the medium to pH 4.2, whereas the other ionic conditions did not change the external pH. NO3− at 7.9 mM prevented this acidification and allowed flower formation in 75% of the explants. This acidification could increase the K+ and Na+ influxes via a possible lowering of the intracellular pH. This hypothesis corroborates the morphogenic effect of K+ and Na+. Key words: absence of morphogenesis, acidification of medium, floral and vegetative organogenesis, ionic composition of the medium, thin cell layers, Nicotiana tabacum cv. Samsun.


2015 ◽  
Vol 20 (3) ◽  
pp. 181-192 ◽  
Author(s):  
Catalina BOTERO GIRALDO ◽  
Aura Inés RREA TRUJILLO ◽  
Esther Julia NARANJO GÓMEZ

<p>Conociendo las propiedades medicinales de la especie vegetal <em>Psychotria</em> <em>ipecacuanha</em> (Brot.) Stokes, su crítico estado de conservación, así como las dificultades que presenta para la propagación efectiva, el presente estudio tuvo como objetivo evaluar su potencial de propagación por los sistemas de regeneración <em>in vitro</em>, organogénesis y embriogénesis somática. Para este propósito, capas delgadas de células (CDCs) de tallos y de hojas, así como segmentos foliares fueron sometidos a diferentes tratamientos con reguladores de crecimiento y condiciones de luz. Además se estableció el efecto de diferentes longitudes de onda vía diodos emisores de luz (LEDs), sobre la regeneración en estos explantes y nudos provenientes de plantas <em>in vitro</em>. Los resultados obtenidos mostraron que los segmentos de hoja y las CDCs de tallo sembrados en el medio de cultivo MS suplementado con las combinaciones de los reguladores de crecimiento IBA + BAP e IBA + TDZ formaron embriones somáticos y brotes. Los cortes histológicos realizados corroboraron estos dos tipos de origen. Se encontró que bajo la condición lumínica 16/8, se alcanzaron los mejores resultados de inducción de brotes y embriones. En cuanto al efecto de las diferentes longitudes de onda de luz, se encontró que las correspondientes al rojo, verde y blanca, favorecieron el crecimiento y desarrollo de brotes y la inducción de embriones somáticos. El desarrollo de los brotes a partir de los nudos no presentó diferencias estadísticas entre los tratamientos con LEDs, por lo que se recomienda el uso de la luz blanca continua y con fotoperiodo durante el proceso de multiplicación y desarrollo de estos.</p><p><strong>Regeneration Potential of <em>Psychotria Ipecacuanha</em> (Rubiaceae) from Thin Cell Layers </strong></p><p>Knowing the medicinal properties of the plant specie <em>Psychotria ipecacuanha</em> (Brot.) Stokes, its critical condition and the difficulties for its effective propagation, the present study aimed to assess the potential of propagation of <em>P. ipecacuanha</em> by <em>in vitro</em> systems of regeneration, organogenesis and somatic embryogenesis. For this purpose, thin cell layers (TCL) of stems and leaves, as well as leaf segments were subjected to different treatments of plant growth regulators and light conditions. Furthermore, the effect of different wavelengths via light emitting diodes (LED’s), was established for the regeneration in these explants and nodal explants from <em>in vitro</em> plants. The results showed that leaf segments and stem TCL, cultured in MS medium supplemented with the combinations of growth regulators IBA + BAP and IBA + TDZ, formed somatic embryos and shoots. The histological sections supported the two types of source. It was found that the best results in shoot induction and embryos were achieved under the light condition 16/8-h light/dark. Regarding the effect of different wavelengths, it was found that those corresponding to red, green, and white supported the growth and shoot development as well as somatic embryos induction. The shoots development from the nodal explants did not show statistical differences between LEDs treatments, so the use of a continuous white light and photoperiod is recommended during their multiplication and development.</p>


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