Direct Regeneration of Plants Derived from in vitro Cultured Shoot Tips and Leaves of Poplar (Populus × euramericana ‘Neva’)

Abstract

Abstract:The purpose of the present study was to establish a regeneration procedure for Populus × euramericana 'Neva' by using in vitro shoots tips and leaves. For sterilization, 0.1% (w/v) mercuric chloride (HgCl 2 ) solution for 8 to 10 min was the optimal treatment for this poplar cultivation. The effects of benzyladenine (BA) and α-naphthaleneacetic acid (NAA) added to Murashige and Skoog (MS) medium were tested on organogenesis. The highest regeneration rate and numbers of shoots/explant from shoot tips (96.7%, 9.8) and leaves (90.0%, 8.7) were obtained on the half-strength MS medium supplemented with 0.5 mg/L BA and 0.1 mg/L NAA. The optimal medium for in vitro rooting of shoots was on a half-strength MS medium containing 1 mg/L indolebutyric acid (IBA) with the highest rooting frequency (93.3%) and numbers of roots/explant (8.2). For acclimatization, in vitro rooted plantlets were transferred to plastic cups containing vermiculite and peat (1: 1). After acclimatization, transplanted plantlets grew well in a shade house. Therefore, we believe that this efficient plant regeneration protocol especially by leaf explants is very important for in vitro clonal propagation of Populus × euramericana 'Neva'.

Differences in Environmental and Hormonal Regulation of Growth Responses in Two Highly Productive Hybrid Populus Genotypes

“…This may result in beneficial scientific findings and practical applications for the propagation of selected Populus genotypes, including micropropagation via in vitro cultures. Although, with respect to the use of plant hormones for Populus micropropagation, the application of different concentrations of cytokinins and auxins remains the most popular approach [28][29][30], positive developmental changes in shoot cultures were reported after GA-and ABA-related chemical regulations. For instance, in the case of aspen (P. tremula), the application of paclobutrazol (PBZ), a well-reviewed GA biosynthesis inhibitor [31], resulted in a higher number of ARs per explant, while ABA had a positive effect on AR elongation [32].…”