10th Symposium on the Flora of Southeastern Serbia and ...

10 th <strong>Symposium</strong> on the Flora of Southeastern Serbia and Neighbouring regions,Vlasina 17 to 20 June 2010germination, but only 10 % embryos retained haploidity after 3 years subculturing,while 10.5 % were diploid, 73.5 % tetraploid and 6 % octaploid on hormone-freemedium. Unlike those from anther culture, after 3 years of subculturing on hormonefreemedium, there were no haploid regenerant from anther culture, while 8.5 %were diploid, 81 % tetraploid and 10.5 % octaploid. Since the zygotic embryocotyledons accumulate the highest amount of aescin, it is currently extracted fromthe seeds of horse on a large scale. As this material is available during only shortperiod of the year, we studied the possibility of using plant tissue culture to obtainaescin. For this purpose, the content of aescin in horse chestnut androgenic embryoswas studied. Aescin content was found to be dependent on the stage of androgenicembryo development and the type of the phytoregulator supplemented to thenutritive medium. In the absence of the phytoregulators, androgenic embryos at theglobular stage of development contained approximately four times less aescin thanthose at the cotyledonary stage. In conclusion, horse chestnut androgenic embryosproduce high amount of aescin, which can be manipulated by the addition ofphytoregulators. We find this approach promising for resolving the problemsassociated with commercial production of aescin. This method enables high biomassproduction, even availability of the phytohemical all the year round, simplificationof the extraction procedure and manipulation of the factors affecting secondarymetabolite biosynthesis.Chenopodium rubrum L. , a short-day plant, as a modelplant for physiological and biochemical investigations ofontogenesis in vitroMitrović, A., Živanović, B., Dučić, T., Bogdanović Pristov, J., Radotić, K.Institut za multidisciplinarna istraživanja, Beograd, Srbijamita@imsi.rsChenopodium rubrum L. belongs to the family Chenopodiaceae, genusChenopodium. This is a short-day weedy annual, distributed in Europe, Asia andNorthern America. Ecotypes of this species differ in their photoperiodiccharacteristics. Sel. 184 is a qualitative short day plant, with defined critical nightlength of 8h. As an early flowering species, it is a suitable model plant for studyingontogenesis in vitro. Culture of intact plants in vitro and antioxidative enzymesdetection were used. We showed sequential expression of antioxidative enzymesduring seed germination. Prior to radicle protrusion, catalase (CAT) and superoxidedismutase (SOD) showed maximal activity. Peroxidase (POD) activity appeared andincreased after radicle protrusion. Seed ageing affected changes in antioxidative77