Calli cultures from Abies equi-trojani (Aschers et Sinten) and changes in antioxidant defense system enzymes.

This study was conducted to explain difficulties of indirect regeneration of forest trees in tissue culture conditions. For this purpose, changes of antioxidant defense system enzymes; superoxide dismutase (SOD), peroxidase (POD) activities were determined during calli formation on young apical shoots of Abies equi-trojani (Aschers et Sinten). Young apical shoots were collected from naturally growing trees and cultured on two different media; Murashige and Skoog (MS) and McCown Woody plant medium (WPM) supplemented with growth regulators benzyl amino purine (BAP), 2,4-dichloro phenoxy acetic acid (2.4-D), kinetin (Kn) in various concentrations for callus induction. WPM media containing 1 mg ml(-1) BAP and 1 mg ml(-1) 2,4-D gave the best calli induction ratio (74%) between tested combinations. POD and SOD enzyme activities were measured both on young shoot explants and 10 day-old calli derived from these explants. POD and SOD enzyme activities were higher being 81.02% and 74.82%, respectively on calli when compared to shoots. The results showed that culture stress tolerated with increased antioxidant enzyme activities could be considered as protective physiological responses in calli cells.