TDZ, auxin and genotype effects on leaf organogenesis in Fragaria

Abstract

The different types of organogenic (roots and adventitious shoots) and callus formation responses of leaves from 30-day-old proliferating shoots of different Fragaria spp. genotypes were studied in response to MS medium supplemented with 4.54 microM 1-phenyl-3-(1,2,3-thiadiazol-5-yl) urea (thidiazuron; TDZ) alone and in combination with 0.98 microM indole-3-butyric acid (IBA), 0.84 microM 3-benzo[b]selenienyl acetic acid (BSAA) or 0.90 microM 2,4-dichlorophenoxy acetic acid (2,4-D). The study included: nine octoploid Fragaria x ananassa cultivars and breeding selections; two octoploid breeding selections from F. virginiana glauca inter-species crosses; two diploid F. vesca cultivars; and one diploid clone of F. nubicola Lindl. TDZ plus IBA promoted the highest shoot regeneration efficiencies from leaves of nearly all of the genotypes, while the TDZ/BSAA and TDZ/2,4-D combinations promoted high regeneration efficiencies for only some of the genotypes (Alpina W.O., Sveva, AN 91.371.53, Onda, Paros and FO93.143.5). For the more efficient regenerating genotypes, IBA induced the highest frequency of regenerating leaves, while BSAA induced the highest number of regenerated shoots from leaves and more callus production for most of the genotypes.

In vitro REGENERATION OF Fragraria PLANTS

“…One of disadvantages of TDZ is possibility of inhibitory effect occurring on shoot elongation [Debnath 2009] which is associated with their cytokinin activity [Huetteman and Preece 1993] which occured also in strawberries [Jones et al 2003]. Consequently, a combination of TDZ and IBA (indole-3-butyric acid) activity induced the higher regeneration frequency on the same genotypes, which confirms positive effects of this auxin in strawberry leaf tissue callogenesis [Yonghua et al 2004, Husaini and Srivastava 2006, Landi and Mezzetti 2006, Yildirim and Turker 2014. For 'Camarosa', optimal concentration of TDZ and IBA was respectively 1,5 mg·dm -3 and 1,0 mg·dm -3 [Adak et al 2010].…”

“…Using TDZ at concentra-tion of 1,0 mg·dm -3 in combination with NAA or 2,4-D at concentration of 0,2 mg·dm -3 allowed also to obtain satisfactory results of shoot regeneration [Passey et al 2003]. Impact of other auxins, such as 2,4-D and BSAA on shoot regeneration was more dependent on plant genotypes [Landi and Mezzetti 2006]. By Yonghua et al [2004], 2,4-D is increasingly used to strawberry shoot induction.…”

“…In this method there is no intermediate stage of callus and it avoids the risk of the occurrence of the phenomenon of genetic instability [Nehra et al 1994]. Leaf explants are particularly useful to shoot regeneration and genetic transformation of Fragaria plants due to the fact that in the most of cases they have the highest regeneration frequency [Landi and Mezzetti 2006]. For Fragaria vesca, shoot regeneration rate from petioles was merely about 10%, wherein lamina utilizing could achieve more than 80% regeneration rate on MS media with addition of IBA and BA [Alsheikh et al 2002].…”

Organogenesis and plant selection by kanamycin of strawberry in vitro aiming at genetic transformation

“…Marker genes that induce resistance to substances such as antibiotics assist in transformed plant selection by inhibiting untransformed shoot growth (ABDAL-AZIZ et al, 2006;KARAMI et al, 2009;QIN et al, 2011). Many transformation methods use the nptII gene, which confers resistance to the aminoglycoside group of antibiotics (neomycin, kanamycin, and gentamicin), to transform cells (MARCELLINO et al, 2007;QIN et al, 2011;PANTAZIS et al, 2013). However, the selective agents can have a negative effect on callus induction and regeneration capacity and vary according to the concentration, species, cultivar and explant type (KARAMI et al, 2009).…”

“…Among citokinins frequently used in strawberry regeneration, 6-benzilamino-purine (BA) and tidiazuron (TDZ) have been recently used. These may be used alone or in combination with an auxin such as indolebutyric acid (IBA) (LANDI; MEZZETTI, 2006) to improve the regeneration rate and number of shoots per explant (MURTIL et al, 2012).…”