| چکیده انگلیسی مقاله |
In the present study, the effect of ammonium nitrogen rates on bioactive compounds of Cichorium spinosum L. was examined. For this purpose, five fertilizer treatments were applied with different percentages of ammonium nitrogen in relation to total nitrogen, namely (1) 14%, (2) 24%, (3) 34%, (4) 43%, and (5) 53% of total nitrogen applied in the form of ammonium nitrogen, while total nitrogen was the same for all treatments. C. spinosum were grown from seeds after putting them in seed trays containing peat. Young seedlings were transplanted in 2L pots containing peat and perlite in a ratio 1:1. Plants were harvested at the stage of flower stalk elongation and when plants started to form spiny bushes, while samples of both leaves and flower stalks were collected for fatty acids and phenolic compounds composition and content analysis. The results showed significant differences in chemical composition between the ammonium nitrogen rates, as well as between plant parts. In particular, the main fatty acids in all treatments and plant parts were α-linolenic, linoleic and palmitic acid; however, linoleic acid was higher in flower stems comparing to leaves harvested at the same time, whereas α-linolenic acid was the most abundant fatty acid, being higher in leaves, ranging from 52.02 to 59.67%. Palmitic acid was detected in similar amounts in both flower stems and leaves, except for treatment 3 where leaves content was higher than that in flower stems. Moreover, α-linolenic and linoleic acids were higher in treatment 1 and 5, respectively, while palmitic acid was higher in treatment 3. The main detected phenolic compounds were chicoric and 5-O-caffeoylquinic acid, followed by two kaempferol-O-glucuronide, 3,5-O-dicaffeoylquinic acid and quercetin-3-O-glucuronide, which were detected in lower amounts. Moreover, p-coumaroylquinic and 5-O-feruolyquinic acids were detected in flower stems of treatment 1 in significantly higher amounts in comparison to the other treatments, while significant differences were also observed between plant parts and fertilizer treatments for the other main phenolic compounds with no specific trends being observed. In conclusion, ammonium nitrogen rates and plant parts have a significant effect on chemical composition of C. spinosum at the flowering stage, while the high content of flower stems in phenolic compounds and fatty acids could be further exploited with alternative uses of these plant parts, such as pickled products and decoctions. |
