فعالیت کاتالاز

In order to investigate the effect of sowing date and nitrogen and phosphorus fertilizer on the seed flavonoid content, qualitative and germination characteristics of lady’s mantle (Lallemantia royleana Benth.), a factorial experiment based on randomized complete block design with three replications was conducted in 2013-2014 crop year. Experimental factors included sowing date at two levels (autumn and spring) and chemical fertilizer at three levels (without fertilizer, half application of required fertilizer (23 kg ha-1 pure N+ 50.6 kg ha-1 P2O5) and full application of required fertilizer (46 kg ha-1 pure N+ 101.2 kg ha-1 P2O5). Flavonoid measurement of the seeds was performed weekly from flowering to seed ripening. The results of the mean comparison showed that the highest seed germination percentage was obtained at autumn sowing (74.8%) with an increase of 11.6% compared to spring sowing and at the full application of required fertilizer (88.6%) with an increase of 73.4% compared to without fertilizer. The application of chemical fertilizer and autumn cultivation of lallemantia significantly increased the percentage of seed mucilage compared to control. Seven days after flowering, the highest flavonoid content was obtained at spring sowing (0.264 mg quercetin per g sample) with an increase of 63.97% compared to autumn sowing, and at no fertilizer treatment (0.282 mg quercetin per g sample) with an increase of 90.54% compared to the full application of required fertilizer (0.148 mg quercetin per g sample). Twenty-eight days after flowering, the highest flavonoid content was obtained at spring sowing (0.554 mg quercetin per g sample) and no fertilizer treatment (0.629 mg quercetin per g sample). In general, the results showed that the autumn sowing date and full application of required chemical fertilizer increased the seed quality in terms of mucilage percentage and germination, but the spring sowing date and no fertilizer treatment increased the flavonoid content of lallemantia seeds.

To evaluate changes in proline, soluble sugars and chlorophyll accumulation, catalase (CAT) and ascorbate peroxidase (APX) activity under different irrigation regimes at two growth stages on potato (Solanum tuberosum L.), a factorial experiment was carried out based on complete randomized design (CRD) with three replications in greenhouse condition. Experimental factors were irrigation regimes at four levels of field capacity (I0=100%, I1=80%, I2=60% and I3=40% FC) and growth stages at two levels (GS1=50% emergence to 50% flowering, GS2= 50% flowering to physiological maturity). The results showed that irrigation regimes highly affect proline content, soluble sugars and catalase activity at 1% level. Studied traits were not affected by growth stages. Interaction between irrigation regimes and growth stages was not significant for any studied traits. Mean comparison of treatments showed that maximum content of proline(4.94µmol g 1 - dw) , soluble sugars(55.99 mg g 1 - dw) and catalase activity(12.75µmolH2O2min) were related to 40% FC (I3) irrigation regime. The highest significant correlation observed between total chlorophyll with chlorophyll a (0.86) and catalase activity with soluble sugars (0.81). It was concluded that studied physiological characteristics of potato severely affected by irrigation regimes, and 40% FC treatment had the highest effect on studied traits.