Thidiazuron-induced high-frequency plant regeneration from leaf explants of Paulownia tomentosa mature trees

Abstract

Attempts were made to study the effect of thidiazuron (TDZ) on adventitious shoot induction and plant development in Paulownia tomentosa explants derived from mature trees. Media with different concentrations of TDZ in combination with an auxin were used to induce adventitious shoot-buds in two explant types: basal leaf halves with the petiole attached (leaf explant) and intact petioles. Optimal shoot regeneration was obtained in leaf explants cultured on induction medium containing TDZ (22.7 or 27.3 lM) in combination with 2.9 lM indole-3-acetic acid (IAA) for 2 weeks, and subsequent culture in TDZ-free shoot development medium including 0.44 lM BA for a further 4-week period. The addition of IAA to the TDZ induction medium enhanced the shoot-forming capacity of explants. The caulogenic response varied significantly with the position of the explant along the shoot axis. The highest regeneration potential (85-87%) and shoot number (up to 17.6 shoots/explant) were obtained in leaf explants harvested from the most apical node exhibiting unfolded leaves (node 1). An analogous trend was also observed in intact petiole explants, although shoot regeneration ability was considerably lower, with values ranging from 15% for petioles isolated from node 1 to 5% for those of nodes 2 and 3. Shoot formation capacity was influenced by the genotype, with regeneration frequencies ranging from 50% to 70%. It was possible to root elongated shoots (20 mm) in basal medium without growth regulators; however, rooting frequency was significantly increased up to 90% by a 7-day treatment with 0.5 lM indole-3-butyric acid, regardless of the previous culture period in shoot development medium (4 or 8 weeks). Shoot quality of rooted plantlets was improved not only by IBA treatment but also by using material derived from the 4-week culture period. Regenerated plantlets were successfully acclimatized in the greenhouse 8 weeks after transplanting.

An Efficient Method for Direct Shoot Regeneration from Leaf Explants of Solanum nigrum Induced by Thidiazuron

“…Aggarwal et al (2012) reported maximum percent of shoot regeneration from leaf explants of Populus on MS medium supplemented with TDZ. Similar results of regeneration from leaf explants using TDZ has been reported in primrose (Gyves et al, 2001), mulberry (Chitra and Padmaja, 2005), Paulownia tomentosa (Corredoira et al, 2008) and Jatropha curcus (KhuranaKaul et al, 2010), which are in agreement with our results. Similarly, In vitro shoot regeneration has also been reported in plants of family Solanaceae (Magioli et al, 1998;Mallaya and Ravishankar, 2013;Rathore et al, 2016).…”

Effect of Explant, Genotype and Plant Growth Regulators on Regeneration and Agrobacterium-Mediated Transformation of Potato

“…Agron., 14 (4): 227-233, 2015 such as thidiazuron (TDZ) and 6-benzyladenine (BAP), is critical for initiation of shoot primordia from cultured explants. TDZ, a phenylurea-type cytokinin, has been used as a plant growth regulator to induce organogenesis, including adventitious regeneration of transformed plants in many plant species that were thought to be recalcitrant to regeneration (Cuenca et al, 2000;Corredoira et al, 2008;Sriskandarajah and Lundquist, 2009).…”

Protuberance-mediated high frequency of adventitious shoot regeneration from sweetpotato leaf explants [ Ipomoea batatas (L.) Lam.]

“…Leaf explants did not show any response on an MMS medium alone, or an MMS containing 0.5 or 1.0 μM TDZ, while a callus was induced from explants on a medium containing 20.0 μM TDZ (data not shown). The largest number of shoots was induced from leaf explants either on a medium containing TDZ alone or in combination with other growth regulators in Saintpaulia ionantha (Mithila et al, 2003), Arachis correntina (Mroginski et al, 2004), Hydrangea quercifolia (Ledbetter and Preece, 2004), Vaccinium vitis-idaea (Debnath, 2005), Pautownia tomentosa (Corredoira et al, 2008), Vaccinum corymbosum (Liu et al, 2010), Phyllanthus amarus (Nitnaware et al, 2011), Viburnum dentatum (Dai et al, 2011) and Ziziphus jujube (Ma et al, 2012). Plant regeneration in vitro was dependent on the concentration of plant growth regulators in the culture medium.…”