Regeneration of Aeschynanthus radicans via direct somatic embryogenesis and analysis of regenerants with flow cytometry

Flow cytometry was used for analyzing DNA contents of nuclei isolated from in vitro grown somatic embryos, shoots and calli, as well as mammillae of in vivo grown shoots of cactus, Copiapoa tenuissima Ritt. forma monstruosa. Endoreduplication was detected in both in vitro grown somatic embryos, shoots and calli and in mammillae derived from in vivo grown shoots. However, the lowest ploidy levels ranged from 2C to 4C in somatic embryos, and reaching up to 32C for in vitro grown shoots and calli from mammillae. Whereas, ploidy levels of in vivo-derived mammillae ranged from 2C to 16C. The presence of 2,4-dichlorophenoxyacetic acid (2,4-D) in the culture medium had no influence on levels of ploidy of regenerated tissues. The mean genome size of cactus was calculated as 2C = 2.87 ± 0.05 picogram (pg).

Section: Analysis With Flow Cytometrymentioning

confidence: 81%

Flow cytometric analysis of somatic embryos, shoots, and calli of the cactus Copiapoa tenuissima Ritt. forma monstruosa

Lema-Rumińska

2011

“…In this study, TDZ was more effective for callus proliferation of S. alfredii than BA. TDZ, first introduced as a cotton defoliant and later demonstrated to possess cytokinin-like activity (Mok et al 1979;Thomas and Katterman 1986), has long been reported to exhibit stronger activity in inducing cellular differentiation in a wide range of plant species (Amutha et al 2006;Yookongkaew et al 2007;Cui et al 2009). In this study, callus fresh weight gradually increased when explants were grown in the presence of combinations of 2,4-D and BA (data not shown).…”

Section: Discussionmentioning

confidence: 99%

Plant regeneration of the mining ecotype Sedum alfredii and cadmium hyperaccumulation in regenerated plants

Zhao

Zhang

Gao

et al. 2009

An efficient micropropagation system for mining ecotype Sedum alfredii Hance, a newly identified Zn/Cd hyperaccumulator, was developed. Frequency of callus induction reached up to 70% from leaves incubated on Murashige and Skoog (MS) medium supplemented with 1.0 mg l -1 2,4-dichlorophenoxy acetic acid (2,4-D) and 0.5 mg l -1 6-benzyladenine (BA), and 83% from internodal stem segments grown on MS medium with 0.1 mg l -1 2,4-D and 0.1 mg l -1 BA. Callus proliferated rapidly on MS medium containing 0.2 mg l -1 2,4-D and 0.05 mg l -1 thidiazuron. The highest number of adventitious buds per callus (17.3) and frequency of shoot regeneration (93%) were obtained when calli were grown on MS medium supplemented with 2.0 mg l -1 BA and 0.3 mg l -1 a-naphthalene acetic acid (NAA). Elongation of shoots was achieved when these were incubated on MS medium containing 3.0 mg l -1 gibberellic acid. Induction of roots was highest (21.4 roots per shoot) when shoots were transferred to MS medium containing 2.0 mg l -1 indole 3-butyric acid rather than either indole 3-acetic acid or NAA. When these in vitro plants were acclimatized and transferred to the greenhouse, and grown in hydroponic solutions containing 200 lM cadmium (Cd), they exhibited high efficiency of Cd transport, from roots to shoots, and hyperaccumulation of Cd.

“…However, recent evidence suggests that somatic embryogenesis has a multicellular origin that may result in chromosomal alterations or ploidy changes (Endemann et al 2001;Tremblay et al 1999). Therefore, detection of such variation early in the life of a plant would be required to avoid economic disaster for commercial regeneration of broccoli plants (Cui et al 2009;Qin et al 2007). …”

Section: Introductionmentioning

confidence: 99%

Direct somatic embryogenesis from pericycle cells of broccoli (Brassica oleracea L. var. italica) root explants

Yang

Seong

Kim

et al. 2009

Cotyledon, hypocotyl or root explants of 7-dayold broccoli seedlings were cultured on Murashige and Skoog (MS) agar or liquid medium supplemented with 1.0 mg l -1 2,4-dichlorophenoxyacetic acid (2,4-D). The frequency of direct somatic embryo formation was 100% when root explants were cultured in liquid medium. Histological analysis indicated that somatic embryos were initiated directly from the pericycle cell layers of root explants as early as 1 day after liquid culture. Genotype did not affect the frequency of somatic embryo formation or the number of somatic embryos per explant. All broccoli genotypes examined had 100% somatic embryo induction efficiency, and the number of somatic embryos per 0.8 mm root segment ranged from 22.9 in 'Luhui' to 26.0 in 'Haizi'.The number of normally developed somatic embryos in culture increased with increasing 2,4-D concentration. Plantlet regeneration frequency was the highest (73.3%) when germinated plantlets were transferred to 1/2 strength MS agar medium containing 1.0 mg l -1 6-benzyladenine (BA). When regenerated plantlets were transferred to a greenhouse, approximately 75% survived and there were no morphological differences between regenerated plants and seed-derived controls. The protocols established in this study will benefit large-scale vegetative propagation and transformation-based genetic improvement of broccoli.