Agar alternatives for micropropagation of African violet (<i>Saintpaulia ionantha</i>)

Abstract

Agar is one of the most popular solidifying agents in plant tissue culture. High price of pure grade agar and fear of over exploitation of its resources caused searching for low cost alternatives. In this study,
liquid medium with cotton substratum and different combinations of starch, semolina, potato powder and agar in two steps of micropropagation (shoot induction and proliferation) were investigated. The highest frequency of regeneration was found in media containing agar (0.8%), combination of starch: semolina: potato powder (2:1:1) in 9 and 12% and combination of starch (6%) plus agar (0.4%), but
maximum shoot numbers were produced in media containing agar (0.8%), combination of starch (6%) plus agar (0.4%) and liquid medium with cotton substratum. The best shoot proliferation take place in liquid medium with cotton substratum. The results show that the combination of starch: semolina: potato powder (2:1:1) in 9% and starch (6%) plus agar (0.4 %) can be suitable alternatives for agar in regeneration stage but the shoot number is lower than agar alone. These options are very cheaper than agar. The best shoot proliferation can be done in bioreactors or liquid medium with suitable substratum like cotton.

Keywords: Gelling agent, low cost, micropropagation, liquid culture