Effect of sugar/osmotica levels on in vitro microtuberization of potato (Solanum tuberosum L.)

In order to evaluate of using microtubers for conservation of potato germplasm, the main effects of sucrose, mannitol and PEG on percentage of microtuber initiation and formation, size and fresh weight of microtuber were studied. PEG decreased production and weight of microtubers, whereas higher concentrations of sucrose promoted microtuber production, microtuber size as well as microtuber fresh weight. Increasing of sucrose concentrations were improved efficiently in vitro microtuber production without negative side effects. Addition of mannitol to all media was increased microtuberization than media containing PEG. So, alcoholic sugars such as mannitol increased microtuberization, but after 5 weeks, microtuberization in media supplied with sucrose was more than the mannitol. Such studies might help to reduce the cost of production of virus free potato seed from different cultivars.