Physiological and Phytochemical Responses of Rosemary (Rosmarinus officinalis L.) Plant on in vitro Callus Formation

Abstract

Two experiments were carried out to determine the physiological and phytochemical responses in Rosmarinus officinalis on in vitro callus formation/induction using natural and synthetic auxin, different cytokinin types and concentrations, different phenylalanine concentrations and varying incubation periods. The first one was conducted to study the effect of different auxin types; IAA or NAA combined with cytokinins; BAP or TDZ. Second was done to examine the interaction between phenylalanine and incubation period. The results indicated that callus induction was completely inhibited in the absence of both auxin and cytokinin. Different ratios of auxin to cytokinin significantly affected the physiological callus responses. The treatment of NAA0.125 + BAP1.0 gave the highest callus induction and growth. Rosmarinic acid was slightly influenced growth regulators. Maximum callus fresh and dry weight and rosmarinic acid biosynthesis was recorded in (Phe150 + D42) treatment. Phe0.0 + D42 achieved the highest value of callus growth index (CGI), while the lowest CGI was found in the treatment of (Phe150 + D28). The minimum value of relative growth rate (RGR) was resulted with (Phe150 + D56), while (Phe0.0 + D28) achieved the best RGR.