Somatic embryogenesis induction system for cloning an adult Cyphomandra betacea (Cav.) Sendt. (tamarillo)

Abstract

Somatic embryogenesis is a valuable tool for plant breeding. In recent years, different aspects related to somatic embryogenesis (SE) induction in tamarillo have been studied at our laboratory. In this work, results concerning the establishment of a protocol for cloning an adult tamarillo tree through SE are presented. Attempts to induce SE in tamarillo from various explants directly taken from an adult tree were unsuccessful and only calli with no embryogenic potential were initiated. To overcome the lack of potential of adult tissues for SE, an indirect approach was attempted in which shoots from an adult tree were first established in vitro and then wounded leaves were used for SE induction. A low rate of embryogenic tissue formation was obtained (19.4%), but it was in the range of initiation rates from leaf explants of in vitro cloned plantlets of different tamarillo cultivars (red, orange and yellow) that originated from a single seedling (13.3-54.4%). High variation in SE initiation among juvenile controls could not be explained by different organogenetic potential, as no significant differences in shoot proliferation or rooting ability during micropropagation could be detected. Subcultures of embryogenic lines from the adult tree allowed us to obtain a large amount of embryogenic tissue that, after 8 weeks on a PGR-free medium, gave an average of 111 plants per gram of fresh mass of embryogenic tissue. A RAPD comparative analysis of somatic embryo-derived plantlets and the donor tree confirmed that the plantlets had no variation in the DNA regions amplified by 12 primers. These results open the way for large-scale cloning of elite tamarillo trees through SE.

Protective Role of Putrescine against Picloram Induced Genomic Instability and DNA Methylation in Phaseolus vulgaris

“…Our conclusions are consistent with the previously demonstrated genotoxic effect of picloram with various mutagenens tests in plants (Mohammed and Ma, 1999;Salvi et al, 2001;Correia et al, 2011). Sawamura and Jackson, (1968) have reported that picloram decreased the rate of cytoplasm streaming in stamen hairs of Tradescantia, while Brownian movement increased and numerous and size of chloroplasts affected in Vicia leaf.…”

Induction of somatic embryogenesis from different explants of shoot cultures derived from young Quercus alba trees

“…robur (San-José et al 2010), as well as other fruit trees (Correia et al 2011). In the present study, the approach was applied to Q. alba, in which initiation of SE was effective with explants obtained from cultures during active shoot growth.…”

Ploidy stability in embryogenic cultures and regenerated plantlets of tamarillo

“…Somatic embryogenesis induction followed the protocols of Canhoto et al (2005) and Correia et al (2011). Briefly, wounded leaves were placed abaxial side down on the induction medium (MS basal medium supplemented with 20 lM Picloram and 0.26 M sucrose, P medium).…”

“…betacea can be propagated by seeds or through conventional macropropagation techniques such as grafting or cuttings (Slack 1976;. In vitro protocols have also been applied, including axillary shoot proliferation (Obando and Jordan 2001), organogenesis (Atkinson and Gardner 1993) and somatic embryogenesis (Guimarães et al 1988;Lopes et al 2000;Canhoto et al 2005;Correia et al 2011. Somatic embryogenesis has proved to be particularly interesting since high rates of somatic embryo induction and plant conversion can be achieved both from juvenile and adult selected trees .…”