Behavior of Some Triazoles Derivatives as Synthysised Cytokinins in the Presence of New Growth Regulator (PDA) in the Initiation Growth and Differentiation of Lettuce callus (Lactuca sativa L.)


The addition of PDA compound (10-6, 10-7, 10-8 M) with (10-6 M) triazoles compounds stimulates callus formation from stem segments depending on the types of derivative and PDA concentration used. Moreover, the addition of most triazoles compounds (10-6 M) with PDA (10-8 M) induced the shoots regeneration in greater numbers as compared with the presence of NAA. Most compounds added enhanced growth of the callus similar to that grown on the standard medium or more especially in the case of G, H and D compounds. The fresh weights of callus grown on medium containing G and PDA were 27.5 g as compared with other compounds used.Interestingly, protein content of callus increased with the lapses of growth period in the same pattern as the changes in fresh weight.The conclusion is that triazoles compounds behave in the same way as cytokinins in the culture medium.These compounds were more effective than the standard growth regulators in growth and differentiation of lettuce plant.However, the use of PDA instead of standard auxins enables to exclude the use of imported growth regulators, which has great economic importance. This study is regarded for the first time an attempt to use locally prepared auxins and cytokinins in Lettuce tissue culture system.