In vitro regeneration in Dierama erectum Hilliard

Dormant buds from a mature tree of Populus tremula 'Erecta' were incubated on a Murashige and Skoog (MS) medium supplemented with 1.0 lM thidiazuron (TDZ). Induced shoots were then proliferated on medium of MS or Woody Plant Medium (WPM), or Driver and Kuniyuki Walnut (DKW) supplemented with varying levels of benzyladenine (BA). Overall, shoots grown on MS medium supplemented with 1.25-2.5 lM BA exhibited the highest frequency of shoot proliferation ([95%) and more than 60% of responding explants produced more than five shoots per explant. Shoot organogenesis was induced from both leaf and petiole explants incubated on WPM medium containing BA, or TDZ, or zeatin. Among the different cytokinins tested, zeatin induced the highest frequency (average 72.1%) of shoot organogenesis. None of explants survived on media containing no cytokinins within 6-8 weeks following culture. Overall, a higher frequency of shoot regeneration was obtained from petioles than from leaf explants. The highest frequency of regeneration was achieved when petioles were incubated on WPM containing 10-20 lM zeatin. Addition of naphthaleneacetic acid (NAA) did not have a significant effect on shoot regeneration in all treatments. Shoot organogenesis was directly induced from petiole explants without intervening callus. Regenerated shoots were easily rooted on all tested media supplemented with 0.5 lM NAA. Rooted plants were transferred to potting mix and grown in the greenhouse.

Section: Discussionsupporting

confidence: 80%

Direct regeneration from in vitro leaf and petiole tissues of Populus tremula ‘Erecta’

Huang

Dai

2011

“…This difference in regenerative capacity between the two ends may be the result of varying endogenous auxin concentrations in these regions (Lane 1978), which has also been reported more recently by Singh et al (2002). Shoot regeneration in L. frutescens hypocotyls was found to be successful with the application of a single cytokinin, kinetin, at a concentration of 1 mg l -1 , even though K is considered to be a relatively weak cytokinin (Koetle et al 2010). In comparison, optimal shoot regeneration in the cotyledons required relatively higher concentrations of K, both on its own and in combination with BA.…”

Section: Discussionsupporting

confidence: 61%

Cytokinin-induced organogenesis in Lessertia (Sutherlandia) frutescens L. using hypocotyl and cotyledon explants affects yields of l-canavanine in shoots

Shaik

Singh

Nicholas

2010

A simple protocol for direct shoot organogenesis and plant regeneration in Lessertia frutescens using hypocotyl and cotyledon segments is reported. L-canavanine content in the derived shoots is also quantified. Media containing different concentrations and combinations of the cytokinins kinetin (K) and benzyladenine (BA) were tested for shoot induction potential. The best shoot regeneration rate (83%) was obtained from hypocotyl segments cultured in Murashige and Skoog (MS) medium supplemented with 1 mg l -1 K; these hypocotyls also produced the largest number of shoots per explant (3.5) and the longest shoots per explant (13.3 mm). The best shoot regeneration rate (46%) using cotyledons as explant material was obtained in MS medium supplemented with 1 mg l -1 K and 1 mg l -1 BA or with 5 mg l -1 K and 0.5 mg l -1 BA. The highest number of cotyledon-derived shoots (1.5) was obtained in MS medium containing 2 mg l -1 K and 0.5 mg l -1 BA, and the longest cotyledon-derived shoots (6.1 mm) were obtained in MS medium containing 1 mg l -1 K and 0.5 mg l -1 BA. Shoots derived from hypocotyls cultured on media containing 1 mg l -1 K contained the highest quantity of L-canavanine (1.42 mg g -1 ) relative to the control (0.52 mg g -1 ). Shoots derived from cotyledons cultured on media containing 2 mg l -1 K contained the highest quantity of L-canavanine (2.07 mg g -1 ) compared to the control. Scanning electron microscopy revealed that shoots regenerated directly from the wounded epidermal tissue, although callus formation was observed in most cultures. Young shoot clusters proliferated into healthy adventitious shoots that were subsequently transferred directly onto rooting medium (MS medium containing 4 mg l -1 indole-3-butyric acid), eliminating the need for an additional multiplication or elongation phase. The in vitro plants were successfully acclimatized in a growth chamber, achieving an 85% survival rate.

“…These latter authors found that mT was nearly twice as effective as BA in the induction of shoot growth of cuttings. The effectiveness of mT in shoot bud differentiation has been widely reported (Kubalakova and Strnad 1992;Baroja-Fernandez et al 2002;Escalona et al 2003;Bairu et al 2008;Koetle et al 2010). Meta-topolin, which was first isolated from poplar leaves, differs from isoprenoid cytokinins with respect to its biochemistry, receptors and biological activity (Strnad et al 1997).…”

Section: Controlmentioning

confidence: 99%

Micropropagation and ex vitro rooting of pistachio (Pistacia vera L.)

Benmahioul

Dorion

Kaïd-Harche

et al. 2011

An effective pistachio (Pistacia vera L.) micropropagation system was developed involving rapid axillary bud proliferation and ex vitro rooting. The highest shoot proliferation frequency was obtained from nodal explants cultured on Murashige and Skoog (MS) basal salts containing Gamborg (B 5 ) vitamins and supplemented with 4 mg l -1 6-benzyladenine (BA). The addition of 2 mg l -1 meta-topolin (mT) generated an optimal number of shoots with suitable morphological features, while kinetin (KIN) was found to be unsuitable for pistachio shoot proliferation. Microcuttings were rooted ex vitro after being dipped in rooting powder. The peak ex vitro rooting response was achieved after shoot explants were treated with Rhizopon Ò 2% indole-3-butyric acid (IBA). Rooted plantlets were transplanted in plastic pots containing a peat-perlite-vermiculite (1:1:1) mixture and then transferred to the greenhouse. After 2 months, 81.5% survival of rooted microshoots was achieved.