Rapid shoot regeneration from thin cell layer explants excised from petioles and hypocotyls in four cultivars of Brassica napus L.

Abstract

The present work describes a procedure that allows for the easy and rapid induction of caulogenesis in four cultivars of Brassica napus L. from transversal Thin Cell Layers (tTCLs). In order to investigate the regeneration ability of this crop, the effects of genotype, explant source and culture medium were examined on shoot regeneration. The tTCL explants were excised from hypocotyl and petiole of 2-week-old seedlings and cultured on a solid basal MS medium supplemented with a-naphthaleneacetic acid (NAA: 0.1-0.4 mg l -1 ), 6-benzylamino-purine (BAP: 1-4 mg l -1 ) and sucrose (20-40 g l -1 ). A significant genotypic effect was observed between the four cvs; Jumbo and Drakkar displayed higher capacities to produce shoots than Pactol and Cossair. Regeneration commenced earlier and the percentage of shoot-producing explants as well as the number of shoots per regenerating explant was greater. The comparison between the regeneration ability of different explants showed that the hypocotyls exhibited a high rate of shoot organogenesis when they were cultured on MS medium supplemented with 3 mg l -1 BAP, 0.3 mg l -1 NAA and 30 g l -1 sucrose. Adventitious shoot buds developed from 46% of the tTCLs, with a mean of 7.5 buds. Furthermore, the method was fast with shoot formation occurring by 7 days culture. Plantlets regenerated from all shoots and developed normally. The regenerated plants were fertile and identical to source plants.

A two-step protocol for shoot regeneration from hypocotyl explants of oilseed rape and its application for Agrobacterium-mediated transformation

“…A similar observation had been reported in different regeneration systems, e.g. with cotyledonary explants of B. campestris (Chi et al 1991), hypocotyl explants of B. juncea (Pua and Chi 1993), cotyledon, leaves and thin cell layer explants of B. napus (Tang et al 2003, Akasaka-Kennedy et al 2005, Ghnaya and Charles 2008. In consistence with the observation of Khan et al (2003), we observed that most of transformed shoots were necrotic on the medium not supplemented by STS (data not shown).…”

“…Generally, there are two strategies leading to shoot regeneration: one is via somatic embryogenesis and the other one is via organogenesis (Hanson andWright 1999, Dibax et al 2010). In case of oilseed rape, various explants can be used for shoot regeneration, including cotyledon (Narasimhulu andChopra 1988, Tang et al 2003), hypocotyl (Khehra and Mathias 1992, Tang et al 2003, Jonoubi et al 2005, flowering internodes (Klimaszewska andKeller 1985, Tang et al 2003), stem sections (O'Neill et al 1996), immature cotyledons (Turgut et al 1998), leaves (Akasaka-Kennedy et al 2005) and as well thin cell layer (Shu andLoh 1991, Ghnaya andCharles 2008).…”

Direct adventitious shoot induction and plant regeneration of Embelia ribes Burm F.

“…Direct organogenesis using hypocotyl segments as explants has been reported in many other species (Kim et al 1997;Rai 2002;Cui et al 2004;Başalma et al 2008;Makunga and van Staden 2008;Ghnaya et al 2008). The type of explants used in direct organogenesis is highly important in establishing an efficient regeneration system (Babaoglu and Yorgancilar 2000;Koroch et al 2002;Cui et al 2004;Uranbey et al 2005).…”

Influence of phenyl-urea and adenine-type cytokinins on direct adventitious shoot regeneration of cabbage (Brassica oleracea subsp. capitata) ^|^#8220;KY Cross^|^#8221;

“…Direct organogenesis has been achieved in a variety of Brassica species such as from the petioles (Ghnaya et al 2007) and hypocotyls of Brassica napus (Phogat et al 2000). Guang et al (2008) established an efficient procedure for direct regeneration of turnip (B. rapa L. ssp.…”