Induction of somatic embryogenesis and evaluation of genetic stability in regenerated plants of Magnolia dealbata

Abstract

The utility of plant tissue culture for the mass propagation of trees is well known, but continuous in vitro multiplication of plant material may increase the possibility of somaclonal variation; therefore, it is essential to evaluate the genetic integrity of regenerants from species-specific in vitro protocols prior to mass production and implementation. The objectives of this study were: 1) to determine the effect of 2,4-dichlorophenoxyacetic acid (2,4-D) concentration over two cycles of secondary somatic embryogenesis in Magnolia dealbata; and 2) to verify the genetic stability of the regenerants obtained. The embryogenic response was not significantly affected by the concentration of 2,4-D but did vary across cycles of induction. The addition of 4.52 μM 2,4-D induced the highest total number of embryos (100.5), the mean number of somatic embryos (25.1) and somatic embryos per explant (80.6). In both 2,4-D concentration (2.26 or 4.52 μM), genetic integrity between the donor and the propagated clones was 0.90, and the low genetic instability (≤ 0.10 in both PGR treatments) might be due to effect of cyclic somatic embryogenesis or the different response of the explants at stress in in vitro culture conditions. However, it is necessary to examine more cell lines and somatic embryogenesis cycles.

Secondary Somatic Embryogenesis in Centaurium erythraea Rafn

“…Our results showed that the secondary embryo formation occurred at low efficiency on hormone-free medium or medium containing only 2,4-D. In Tetrapleura tetraptera [ 58 ] and M. dealbata [ 49 ], secondary se were formed on the media supplemented with 2,4-D only.…”

“…Namely, 2,4-D and CPPU successfully induced both primary [ 13 ] and secondary SE in C. erythraea ( Figure 2 , Figure 3 , Figure 4 and Figure 5 ). Similarly, 2,4-D induced both primary and secondary SE in peanut [ 48 ] and Magnolia dealbata [ 49 ], while in some species, hormone-free medium was suitable for efficient induction of both primary and secondary SE [ 33 ]. However, there are cases where primary SE is induced by PGRs, but the induction of the secondary SE requires a medium without PGRs for its completion.…”

“…The embryogenic potential and the mean number of embryos per explant displayed a gradual reduction with subculturing in A. trifoliata [ 35 ]. Similarly, the percentage of explants with se decreased with each cycle of SE induction in M. dealbata [ 49 ] and in two Brassica oleracea varieties [ 55 ]. In C. persicum, embryogenic competence of calli was affected by number of subculture cycles, since calli from the first cycle showed the highest competence for SE, which decreased during second subculture [ 32 ].…”

Potential of In Vitro Culture of Scutellaria baicalensis in the Formation of Genetic Variation Confirmed by ScoT Markers

“…The mean similarity among the analyzed genotypes was 0.90, which indicated rather minor changes within the studied group of regenerants. The level of polymorphism in the range of 10–15% indicates low genetic variability for the SSR, RAPD and ISSR markers [ 35 , 36 , 38 ]. Etminan et al [ 39 ] and Shahlaei et al [ 40 ] reported that the verification of the results with SCoT markers could lead to different conclusions due to the higher informativeness of this marker compared to other marker systems.…”