Somatic embryogenesis and plant regeneration from leaves of Ulmus minor Mill.

Abstract

Somatic embryogenesis from mature elm ( Ulmus minor Mill.) in vitro-cloned material is possible. Embryogenic callus was obtained from leaves inoculated on two different MS-based media-one supplemented with 2.3 microM 2,4-dichlorophenoxyacetic acid (I2) and the other supplemented with 1.1 microM kinetin (I6). However, only leaves cultured on medium I6 produced somatic embryos, at the globular stage, when embryogenic callus was maintained in induction media. When embryogenic callus from medium I6 was transferred to basal medium, somatic embryos with green cotyledons were obtained. An average of 35.9% of these embryos converted easily into normal plants in conversion medium with 1% sucrose. Acclimatisation reached 39.7%, and this was not significantly different from a control group consisting of plants propagated by axillary buds. No morphological differences were observed between plants derived from somatic embryos and control plants. Also, no differences in ploidy were detected between the somatic embryo-derived plants and the mother plants.

POTENCIAL DE LA ORGANOGÉNESIS COMO ESTRATEGIA PARA LA MASIFICACIÓN in vitro DE Fitzroya cupressoides EN SUDAMÉRICA AUSTRAL

“…En las coníferas los mayores éxitos en la inducción de callo se han logrado empleando como explante embriones cigóticos maduros e inmaduros, debido a que poseen un alto potencial embriogénico en relación con cualquier otra parte de la planta (Tang et al, 1998;Tang y Newton, 2004). No obstante, se ha demostrado la posibilidad de formar y obtener callo a partir de hojas jóvenes como explante inicial (Conde et al, 2004).…”

“…In conifers, the greatest successes in callus formation have been achieved using mature and immature zygotic embryos as explants, as they have a high embryogenic potential in relation to any other part of the plant (Tang et al, 1998;. However, the ability to form and obtain callus from young leaves as initial explants has been demonstrated (Conde et al, 2004).…”

Somatic embryogenesis as a main tool in forest biotechnology

“…Recientemente se ha confirmado dicha posibilidad, clonando diferentes alcornoques seleccionados (Hernández et al, 2003). Asimismo la posibilidad de lograr embriones somáticos a partir de hojas de árboles adultos se está empezando a extender a otras especies como olmo (Conde et al, 2004) y roble , confirmando las posibilidades que abría un antiguo trabajo en encina (Féraud-Keller y Espagnac, 1989). También se puede lograr embriogénesis a partir de elementos florales (Merkle y Battle, 2000;Toribio et al, 2000), pero en este caso hay que confirmar si se trata de embriogénesis somática o gamética.…”

Indirect somatic embryogenesis from transgenic immature leaf of safflower Carthamus tinctorius (Mohler, Roth, Schmidt & Boudreaux, 1967) (Asterales: Asteraceae)

“…There have been several reports that somatic embryogenesis is a multi-step regeneration process starting with formation of proembryogenic masses, followed by somatic embryo formation, maturation, desiccation and plant regeneration (Von Arnold et al, 2002). Two different pathways of somatic embryogenesis generally occur namely, directly without forming the callus phase (Chen et al, 2004;Zhang et al, 2005) and indirectly following callus formation from explants (Griga, 2002;Kim et al, 2003;Conde et al, 2004 ). Callus formation from direct embryogenesis, without the callus phase, is likely to be more suitable for mass propagation because genetic rearrangement is limited compared with the embryogenesis via calli, which often showed aberrant chromosome numbers during culture (Tanaka et al, 2000).…”