The study of weight changes in two varieties of rap eseed under the influence of different dosages of gamma ray and PEG at early seedling stage

In order to develop nuclear energy uses in improvem ent of plants to dry condition and to investigate t he effect of Gamma ray (800, 1000, 1200 gry and control) and PEG (-3, -6, -9 bar and control) on the length of root and shoot in two varieties of rapeseed (Sarigol and RGS003), an experiment was conducted in CRD design in factor ial way at laboratory condition with 3 replication in 2011. Th e obtained results indicated that gamma ray had a s effect on total fresh weight and turgescence weight (p<0.01). Drought stress affected significantly al l 4 investigated traits (TFW, TW, TDW and RWC) with (p<0.01). The mu tual effect of variety and PEG on total fresh weigh t and turgescence weight was significant (p<0.05) and thi s effect on RWC was significant, too (p<0.01). The obtained results revealed that the mutual effect of gamma ra y with drought stress and variety on RWC was signif icant (p<0.05). The comparison of data mean showed that g amma ray on both traits namely TFW and TW led to we ight loss and the highest weight is referred to the cond ition without application of gamma ray. The differe nce in TFW in 800, 1000, and 1200 gry dosages didn't prove to be significant. 800 gry dosage of gamma ray compared t o other dosages indicated higher turgescence weight. The ne gative effect of drought stress on TFW was in a way that the highest TFW was observed in no stress condition and the least TFW was observed in -9 bar osmotic press ure. The drought stress had no effect on total dry weight of Sarigol, but increased the TDW of RGS003 so that t he highest dry weight was observed in -3 bar osmotic pressure. The comparison of data mean indicated that the increas e in negative osmotic pressure reduces the TW so that bo th varieties experience the highest weight in no st ress condition and the least weight in -9 bar osmotic pressure. Th e application of ray had positive effect on increas e of TDW in 800 and 1200 gry dosages.