In vitro morphogenesis in zygotic embryo cultures of neem (Azadirachta indica A. Juss.)

Plant Regeneration via Adventitious Shoot Formation from Immature Zygotic Embryo Explants of Camelina

Camelina is an oil seed crop that is enjoying increasing interest because it has a particularly valuable fatty acid profile, is modest regarding its water and nutrient requirements, and is comparatively resilient to abiotic and biotic stress factors. The regeneration of plants from cells accessible to genetic manipulation is an essential prerequisite for the generation of genetically engineered plants, be it by transgenesis or genome editing. Here, immature embryos were used on the assumption that their incomplete differentiation was associated with totipotency. In culture, regenerative structures appeared adventitiously at the embryos' hypocotyls. For this, the application of auxin- or cytokinin-type growth regulators was essential. The formation of regenerative structures was most efficient when indole-3-acetic acid was added to the induction medium at 1 mg/L, zygotic embryos of the medium walking stick stage were used, and their hypocotyls were stimulated by pricking to a wound response. Histological examinations revealed that the formation of adventitious shoots was initiated by locally activated cell division and proliferation in the epidermis and the outer cortex of the hypocotyl. While the regeneration of plants was established in principle using the experimental line Cam139, the method proved to be similarly applicable to the current cultivar Ligena, and hence it constitutes a vital basis for future genetic engineering approaches.

Evaluación de un sistema de regeneración por embriogénesis somática de Neem (Azadirachta indica)

Azadirachta indica, también conocida como neem, es una especie arbórea leñosa perteneciente a la familia Meliaceae, de gran importancia en diversas disciplinas científicas, tales como la forestal y la médico-farmacéutica. Se estableció un método para la propagación in vitro de esta planta, evaluándose como explantes, secciones foliares de vitro-plantas, cotiledones y esquejes. Se emplearon medios semisólidos con combinaciones variables de la citocinina 6-benzylaminopurina (BAP) y las auxinas ácido 2,4-diclorofenoxiacético (2,4-D) y ácido indolacético (AIA). Se observó la formación de callo regenerativo, a partir del cual se generó embriogénesis somática primaria y secundaria, mediante los reguladores de crecimiento BAP (1,0 mg.L-1) y  2,4-D (0,2 mg.L-1), mientras que la formación de callo no regenerativo fue promovida por concentraciones mayores a 0,3 mg.L-1 de 2,4-D. De los explantes evaluados, la mayor frecuencia de regeneración de plantas (~67%) se presentó con secciones cotiledonares.

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

<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^-1), así como  con TDZ + ABA (0,02 + 1mg.L^-1) 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^-1) with 96 % and TDZ + ABA (0.02 + 1mg.L^-1) 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>

Effect of Growth Regulators on In Vitro Morphogenic Response of Boscia senegalensis (Pers.) Lam. Poir. Using Mature Zygotic Embryos Explants

The percent study describes the in vitro responses of mature zygotic embryos of Boscia senegalensis to different concentrations (0.0–5.0 mg/L) of 6-benzyladnine (BA), Thidiazuron (TDZ), α-Naphthalene acetic acid (NAA), and 2, 4-Dichlorophenoxyacetic acid (2, 4-D) supplemented on Murashige and Skoog medium (MS). The plant growth regulators (PGRs) were considerably affected the morphogenetic responses. BA produced adventitious shoots through two ways: direct organogenesis and auxiliary shoot formation. Both 2, 4-D and TDZ tend to produce callus, whereas NAA improve the development of embryos to seedlings. Maximum number of shoots/explant (14.8 ± 0.6) was obtained on MS medium supplemented with 3.0 mg/L BA. 67.0% of excised shoots were rooted either on 1/2 MS medium augmented with or without 0.25 mg/L IBA. The highest number of roots (1.2 ± 0.4) and root length (0.5 ± 0.2 cm) was produced on 0.25 mg/L IBA-containing medium. Regenerated plants were successfully acclimatized and transferred to the green house with 70% survival rate. All the plants appeared morphologically uniform with normal growth pattern. A rapid (30 days), efficient and without subculturing protocol for in vitro regeneration of B. senegalensis was developed.

Establishment of an in vitro micropropagation protocol for Boscia senegalensis (Pers.) Lam. ex Poir

This report describes in vitro micropropagation of Boscia senegalensis, so-called famine foods, that helped the people in Darfur and Kordofan, Sudan survive during the 1984-1985 famine. Four types of explants prepared from green mature zygotic embryos were cultured on Murashige and Skoog (MS) medium augmented with 1-5 mg/L 6-benzyladenine (BA). The highest number of shoots per explant (14.3±0.9) was achieved on MS medium supplemented with 3 mg/L BA, while the highest shoot length [(3.5±0.4) cm] was obtained with 1 mg/L BA. The shoot cluster, when subcultured to its same medium, significantly increased the rate of shoot multiplication by the end of the third subculture. The maximum mean number of shoots per explant (86.5±3.6) was produced after three multiplication cycles on 3 mg/L BA-supplemented medium. In vitro induced shoots were excised and rooted on half strength MS medium fortified with 0.25 mg/L indole-3-butyric acid (IBA) to obtain complete plantlets. B. senegalensis-regenerated plantlets obtained in vitro for the first time, were hardened and 95% survived under greenhouse conditions.