[Extracellular polymers in callus cultures of Fagopyrum tataricum (L.) Gaertn. with different morphogenic activities: time courses during the culture cycle].

Time courses of the content of extracellular polymers (ECPs) in culture media of morphogenic and non-morphogenic calluses (MCs and NCs, respectively) of Tartar buckwheat Fagopyrum tataricum (L.) Gaertn. were studied during the culture cycle. It was demonstrated that MCs secreted into the medium much more ECPs compared with NCs. During the passage of MCs, two ECPs "blowouts" were observed, which preceded formation of proembryonic cell complexes (PECCs). It is supposed that the molecules secreted might be involved in PECC recycling in MCs. The maximal content of ECPs in NCs was observed by the end of stationary growth phase of the culture, which is presumably related to changes in the cell walls during callus aging.