The effects of benzyladenine and meta-topolin on in vitro shoot regeneration of a citrus citrandarin rootstock

Authors: Niedz, Randall; Evens, Terence

Submitted to: Research Journal of Agricultural & Biological Sciences
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/15/2010
Publication Date: 2/15/2010
Citation: Niedz, R.P., Evens, T.J. 2010. The effects of benzyladenine and meta-topolin on in vitro shoot regeneration of a citrus citrandarin rootstock. Research Journal of Agricultural & Biological Sciences. 6:45-53.

Interpretive Summary: Plant tissue culture is essential for applying certain techniques to enhance plant variety development. One type of tissue culture is the regeneration of shoots from stem pieces, an important method required to genetically engineer a plant. In this study, we compared the effects of the two plant growth regulators benzyladenine purine (BA) and meta-topelin (mT) on shoot regeneration from stem pieces of US-812, an important rootstock used in commercial citrus production. BA is the standard plant growth regulator used in citrus tissue culture. mT is a closely related molecule isolated from poplar. Because small alterations in chemical structures can sometimes have large effects, we compared the ability of these two growth regulators to produce shoots from isolated stem pieces. We found out three things about how these two compounds affect shoot regeneration in citrus; first, they have similar effects; second, the two compounds act independently and do not interact; and, three, it takes about 25 times more mT to achieve an effect similar to BA.

Technical Abstract: The effect of 6-benzyladeninepurine (BA) and meta-topolin (mT) on the three responses shoot quality, numbers of epicotyl explants producing shoots, and the number of shoots greater than 2 mm from citrus rootstock US-812 (Citrus reticulata x Poncirus trifoliata) epicotyl explants was determined. The experiment was designed as a mixture-amount. The two mixture components, BA and mT were varied proportionally from 0 BA:1 mT to 1 BA:0 mT and the amount of total cytokinin varied from 1 to 50 µM. Highly significant models were developed for each of the three measured responses. Results were as follows: first, the three responses were similar over the design space; second, no synergistic or antagonistic interactions were detected; and, third, BA and mT resulted in similar responses, but at substantially different amounts – BA at 1 µM was essentially equivalent to mT at 25 µM.