پديد آورندگان :
قرباني ساماني، شميم دانشگاه آزاد اسلامي واحد علوم و تحقيقات - دانشكده علوم پايه - گروه زيست‌شناس , سعادتمند، سارا دانشگاه آزاد اسلامي واحد علوم و تحقيقات - دانشكده علوم پايه - گروه زيست‌شناس , خاوري نژاد، رمضانعلي دانشگاه آزاد اسلامي واحد علوم و تحقيقات - دانشكده علوم پايه - گروه زيست‌شناس
كليدواژه :
آفتابگردان , پرتو فرابنفش , درصد جوانه‌زني , فعاليت آنزيمي
چكيده فارسي :
در اين پژوهش تأثير پرتو UV بر جوانه‌زني بذر، رشد اندام هوايي و ريشه، شاخص سطح برگ، خواص آنتي‌اكسيداني (آنزيم‌هاي كاتالاز، پراكسيداز و سوپراكسيد ديسموتاز) و ميزان كلروفيل گياه آفتابگردان (.Helianthus annuus L) مورد بررسي قرار گرفت. نتايج نشان داد كه تحت تأثير پرتوي UV، درصد جوانه‌زني افزايش يافت. طول اندام هوايي و ريشه، وزن خشك و وزن تر اندام هوايي و ريشه و همچنين شاخص سطح برگ كاهش نشان داد. در مورد فعاليت آنزيمي نيز براي آنزيم كاتالاز و سوپراكسيد ديسموتاز روند كاهشي و براي آنزيم پراكسيداز روند افزايشي مشاهده شد. به طور كلي نتايج اين تحقيق حاكي از تغيير در رشد و نمو گياهان تحت تأثير پرتوي فرابنفش است.
چكيده لاتين :
Ultraviolet radiation (UV) is a component of the solar light, depending on its wavelength; it can be divided in three different ranges: UVA, UV-B and UV-C. Among these, UV-C is the radiation with the lower wavelength and has an acute germicidal action on microorganisms in water, on surfaces and in air. Moreover, it can induce oxidative results and genetic mutations in plants that in turn have strong negative effects on plant morphology, flowering, pollination, transpiration and photosynthesis. Fortunately, UV-C is strongly affected by the ozone layer in the stratosphere, so that the amount of this radiation reaching the Earth's surface. Nevertheless, in the last decades, human activities have contributed to the depletion of ozone protective layer. In this research, the effect of UV radiation on the seed germination, shoot and root growth, leaf area index, antioxidative properties (catalase enzymes, peroxidase and superoxide dismutase) and chlorophyll content of sunflower (Helianthus annuus L.) were investigated. For this purpose, the plants were divided into two groups, two hours UV irradiation and four hours UV irradiation with a control sample that was not UV-treated. The results showed that under UV radiation, germination percentage increased. On the other hand, the length of shoot and root, dry weight and fresh weight of shoot and root, as well as leaf area index were decreased. In the case of enzyme activities, catalase and superoxide dismutase enzymes were decreased and for the enzyme peroxidase, a decreasing trend was observed. In general, the results of this study indicate a change in the growth of plants under the influence of ultraviolet radiation.
