اثر شدت نور و تنش سرما بر روند تغییرات مؤلفه‌های فلورسانس کلروفیل در سویا (Glycine max L.)

The aim of this parameters study was to evaluate the effect of cold stress on the changes of fluorescence chlorophyll efficiency in soybean (cv. 032) and in different light intensities in controlled condition in 2013. Treatment were arranged in a factorial experiment based on completely randomized design with three replications soybean seedlings after 20 days, for 12 days were exposured to two temperature treatments (5 and 28 °C) and two light intensities (2000 and 8000 lux) and chlorophyll fluorescence parameters were measured once every two days. The process of reducing the amount of variable fluorescence (Fv), Maximum photochemical quantum yield of photosystem II (Fv/Fm) and Effective photochemical quantum yield of photosystem II [Y(II)] immediately after cold treatments, especially at the beginning and end of high intensity testing to continue found. Cold stress also leads to an increased non-photochemical quenching (NPQ), quantum yield of regulated non-photochemical [Y(NPQ)] and quantum yield of non-regulated non-photochemical [Y(NO)] in both light treatments, where as increasing stress increased these parameters as compared to the controls. In conclusion, the results showed that chilling stress causes increased sensitivity to soybean leaf parameters chlorophyll fluorescence, especially in both higher light intensity and stress duration.