The effects of abscisic acid, silver nitrate and cefotaxime on cucumber in vitro organogenesis and evaluation of regenerated clones by AFLP marker

In vitro organogenesis of cucumber (Cucumis sativus L.) was evaluated using the cotyledonary explants of “Beth Alpha” and “Dastgerdi” cultivars. Organogenesis was examined on the MS medium containing 2 mgl-1 Benzylaminopurine (BAP) along with eight combinations of abscisic acid (ABA) (0 and 1 mgl-1), silver nitrate (0 and 5 mgl-1), and cefotaxime (0 and 200 mgl-1). The results indicated the significant effect of ABA on increasing the percent of shoot induction and number of regenerated shoots. In the absence of ABA, silver nitrate had a significant effect on shoot induction and number of shoots. Not only the negative effects of cefotaxime was not observed, but also the number of shoots increased in one case. Root induction in the regenerated shoots was also studied using 5 different media including PGR-free MS medium and the media containing indolebutyric acid (IBA) (0.1 and 1 mgl-1) or naphthaleneacetic acid (NAA) (0.1 and 1 mgl-1). The highest number of roots per shoot in “Beth Alpha” (9.4) and “Dastgerdi” (8.6) were observed in the MS medium supplemented with 0.1 mgl-1 IBA. The genetic stability among 10 randomly selected clones of “Beth Alpha” cultivar was evaluated using AFLP markers. Besides that, cytogenetic assessment of 10 clones from each cultivar was implemented. In total 293 monomorphic bands were amplified using 9 primer combinations of AFLP marker, indicating the absence of somaclonal variation. The chromosome counting of root meristematic cells revealed the stability of ploidy level among regenerated clones.