scholarly journals ESTABLECIMIENTO DEL SISTEMA DE REGENERACION POR EMBRIOGÉNESIS SOMÁTICA DE Azadirachta indica A. Juss.

2014 ◽  
Vol 20 (2) ◽  
Author(s):  
Maria D. Artigas R ◽  
Rafael Fernandez Da Silva

<p><em>Azadirachta indica</em>, es una planta con múltiples aplicaciones tanto forestal como farmacológica. Por ende, el establecimiento del sistema de cultivo <em>in vitro</em> por embriogénesis somática ofrece diversas y variadas ventajas, tales como obtener plantas altamente productivas en metabolitos. En este estudio, se utilizaron secciones foliares y cotiledonares, inducidas en medios MS (1962) suplementados con: BAP sólo y combinado con ANA/2,4-D, TDZ sólo y con ABA. La regeneración fue con MS sólo o con K + AIA y BAP + AIA. Como resultado se estableció un sistema eficiente con secciones de cotiledones, observándose organogénesis a bajas concentraciones de BAP, mientras a altos niveles de BAP (2,5 mg.L<sup>-1</sup>), así como  con TDZ + ABA (0,02 + 1mg.L<sup>-1</sup>) respectivamente favorecieron la embriogénesis somática primaria y secundaria en un 96 % y 71 % respectivamente. La regeneración fue 71 % con MS, mientras que el enraizamiento fue de 86,67 % con MS½, obteniéndose plantas completas a corto plazo. </p><p><strong>ABSTRACT</strong></p><p><em>Azadirachta indica</em>, is a plant with multiple forest and pharmacological application. Therefore, the establishment of <em>in vitro</em> culture system for somatic embryogenesis offers several distinct advantages such as obtaining highly productive plant metabolites. In this study, were used sections cotyledon and leaf, induced on MS medium (1962) supplemented with: BAP alone and combined with NAA / 2,4-D, TDZ alone and ABA. Regeneration was with MS alone or with K + BAP + IAA and IAA. As a result was established an efficient system with cotyledon sections, being observed organogenesis at low concentrations of BAP, while high levels of BAP (2.5 mg.L<sup>-1</sup>) with 96 % and TDZ + ABA (0.02 + 1mg.L<sup>-1</sup>) with 71 %, favoring the primary and secondary somatic embryogenesis. Regeneration was 71 % with MS; rooting was 86.67 % with MS½, presenting whole plants obtained short term.</p><p><strong>RESUMO</strong></p><p><em>Azadirachta indica, </em>é uma planta com várias aplicaçãos florestas e farmacológicas. Por conseguinte, a criação de sistema de cultur<em>a in vitro </em>para a embriogénese somática apresenta várias vantagens, tais como a obtenção de plantas altamente produtivas de metabolitos. Neste estudo, as seções de cotilédones e folhas, induzidas em meios suplementado en MS (1962) con: BAP sozinho e combinado com ANA / 2,4-D, TDZ e ABA sozinho. A regeneração foi apenas com MS ou com K + BAP + IAA e IAA. Como resultado, foi eficiente con seções cotiledones, observados organogênese em baixas concentrações de BAP, en quanto altos níveis de BAP (2,5 mg L-1) e com TDZ + ABA (0,02 + 1mg.L-1) favoreceu a embriogênese somática primária e secundária até 96 % e 71%, respectivamente. Regeneração estava com MS 71 %, en quanto que o enraizamento foi de 86,67 %, com ½ MS produzindo plantas inteiras curto prazo.</p><p><strong><br /></strong></p><p> </p>

2018 ◽  
pp. 7-20
Author(s):  
Maria Daniela Artigas Ramirez ◽  
Rafael Fernandez Da Silva

Background and Aims: Meliaceae species are extremely recalcitrant during germination and in vitro processes. Therefore, this research focuses on characterization and optimization of a highly efficient system by secondary somatic embryogenesis in Azadirachta indica, which is an important step for enhancing secondary metabolite production and regeneration in recalcitrant species.Material and Methods: Leaf and cotyledon sections were induced in MS medium supplemented with benzylaminopurine (BAP) alone, or combined with 1-naphthaleneacetic acid (NAA) and, abscisic acid (BA) with thidiazuron (TDZ).Key results: Azadirachta indica developed primary somatic embryos with BAP. Shoot and root formation occurred at low concentrations of BAP, while somatic embryogenesis was favored under high levels of BAP or TDZ. Primary and secondary somatic embryos were evidenced continuously and asynchronously. The highest amount of somatic embryos was obtained with cytokinins. However, the concentration might be significant to differentiate between primary and secondary embryos. Moreover, the auxins are key for inducing histodifferentiation in embryos. Shoot induction occurred after transfer of the embryos to hormone-free MS medium. The shoots were rooted in MS1/2.Conclusions: The secondary somatic embryos were distinguished and characterized during the whole process and the efficient system was established with cotyledon sections at short term, which offers several advantages such as the production of metabolites.


2011 ◽  
Vol 108 (8) ◽  
pp. 1463-1475 ◽  
Author(s):  
D. A. Steinmacher ◽  
M. P. Guerra ◽  
K. Saare-Surminski ◽  
R. Lieberei

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Jingli Yang ◽  
Songquan Wu ◽  
Chenghao Li

Embryogenic callus was obtained from mature seed explants on medium supplemented with 2,4-dichlorophenoxyacetic acid. Primary somatic embryos (SEs) can only develop into abnormal plants. Well-developed SEs could be obtained through secondary somatic embryogenesis both in solid and liquid cultures. Temperature strongly affected induction frequency of secondary embryogenesis. Relatively high temperature (30∘C) and germinated SEs explants were effective for induction of secondary somatic embryos, and low temperature (20∘C) was more suitable for further embryo development, plantlet conversion, and transplant survival. Somatic embryos formed on agar medium had larger cotyledons than those of embryos formed in liquid medium. Supplementing 0.1 mg L−16-benzyladenine (BA) was effective for plant conversion; the rate of plant conversion was 43.3% in somatic embryos from solid culture and 36.5% in embryos from liquid culture.In vitroplants were successfully acclimatized in the greenhouse. The protocol established in this study will be helpful for large-scale vegetative propagation of this medicinal tree.


1976 ◽  
Vol 231 (1) ◽  
pp. 52-55 ◽  
Author(s):  
R Batt ◽  
JM McKenzie

With the use of microelectrodes, membrane potential (MP) was measured in mouse thyroid glands in vitro. A basal resting MP of about -39 mV was confirmed. The initial effect of feeding a low-iodine diet (6-12 days) was hyperpolarization, up to -47 m V; chronic low-iodine diet led to depolarization. Low concentrations of thyrotropin (less than 3 mU/ml superfusate) caused hyperpolarization and high ones (greater than 10 mU/ml) led to depolarization. Cyclic AMP (10(-3) M), dibutyryl cyclic AMP (1.2 X 10(-4) M or 1.2 X 10(-3) M) and theophylline (10(-2) or 10(-3) M) caused similar hyperpolarization: D- and DL-propranolol (5 X 10(-5) -5 X 10(-4) M) produced depolarization and inhibited hyperpolarization by thyrotropin. Conclusions are that hyperpolarization is a consequence of short-term increased secretion of thyrotropin in vivo or of low (near physiological) concentrations in vitro; these effects are probably mediated by cyclic AMP. The relationship to and mechanism of depolarization resulting from chronic enhanced endogenous secretion or high in vitro concentrations of thyrotropin are unknown.


2015 ◽  
Vol 27 (1) ◽  
pp. 116
Author(s):  
K. L. Beck ◽  
J. Singh ◽  
M. Anzar

Successful cryopreservation of bovine ovarian tissue holds enormous potential for long-term maintenance of female gametes to preserve genetic diversity by tissue banking. Traditionally, in vitro culture followed by histopathological examination has been used to assess the post-thaw viability of cryopreserved tissues. Recently, in ovo transplantation of mammalian tissues on the chorio-allantoic membrane (CAM) of a growing chicken embryo has emerged as an alternative method for short-term culture. The purpose of this experiment was to compare CAM culture of bovine ovarian tissue over a 5-day period with the in vitro culture system. Fertilized White Leghorn eggs were incubated at 37°C and 62% relative humidity. A window (1 × 2 cm) was cut into the eggshell on Day 3 of incubation. Ovaries were retrieved from a local abattoir and brought to the laboratory within 6 h. Ovarian cortex pieces (1–2 mm3) were randomly assigned to control, CAM-culture, or in vitro-culture groups. Control-group tissues were fixed immediately in 4% paraformaldehyde. The CAM was traumatized on Day 10 of incubation to expose the underlying blood vessels, and tissue pieces were grafted at the site (one graft per egg). For in vitro culture, the ovarian cortex pieces were placed on tissue culture inserts within 6-well plates containing TCM199 with 1% insulin-transferrin-selenium, 100 mIU mL–1 of FSH, 100 IU mL–1 of penicillin, and 50 μg mL–1 of streptomycin and incubated at 38°C in 5% CO2. Ovarian tissues from the CAM and in vitro culture group were removed on Day 1, 3, and 5 of grafting/culture, fixed, embedded in paraffin, sectioned at 5 μm, stained with hematoxylin-eosin, and analysed under a light microscope. The numbers of normal and degenerated follicles (indicating follicle survival) and number of blood vessels containing bovine and avian red blood cells (indicating angiogenesis) were counted using standard stereological procedures. All ovarian cortex grafts from surviving chick embryos showed adhesion with the CAM and a marked neo-vascularization in the graft areas. Gross and histological examination revealed the circulation of avian blood cells in ovarian stromal vessels with a concomitant decrease in the number of bovine blood vessels over the incubation period. Total follicle densities (mean ± s.e.m.) on Day 1, 3, and 5 were 13.3 ± 5.9, 27.9 ± 6.7, and 36.9 ± 7.3 in the in vitro-cultured group and 36.7 ± 13.0, 73.6 ± 24.0, and 44.02 ± 12.67 per millimeter cubed in the CAM-cultured group, respectively. Overall, total follicle density was higher in the CAM-cultured group (P < 0.05). Likewise, the normal follicle densities on Day 1, 3, and 5 were 10.4 ± 4.9, 15.5 ± 3.6, and 20.7 ± 6.3 in the in vitro-cultured group and 30.5 ± 8.5, 45.7 ± 18.4, and 22.7 ± 7.3 per millimeter cubed in the CAM-cultured group (P > 0.05). In conclusion, in ovo CAM grafting system was as successful as the in vitro-culture system and may be considered an acceptable alternative to the traditional in vitro-culture system for bovine ovarian tissue.


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