پاسخ مورفوفيزيولوژيكي ريحان رقم كشكني لولو به تغذيه با دياكسيدكربن و اتانول

Morphophysiological response of basil under carbon dioxide and ethanol nutrition

باهدف بررسي اثرسطوح مختلف دياكسيدكربن ومحلولپاشي اتانول بر خصوصيات مورفوفيزيولوژيكي ريحان رقم كشكني لولو درسال 1398 آزمايشي گلداني به‌صورت فاكتوريل در قالب طرح كاملاً تصادفي با سه سطح دياكسيدكربن (380، 700 و 1050 پيپيام) و چهار سطح محلول‌پاشي اتانول (0، 10، 20 و 30درصد حجمي) در سه تكرار انجام شد.صفات مورد مطالعه شامل خصوصيات رشدي (ارتفاع بوته، تعداد شاخه‌فرعي، طول ميانگره، قطر ساقه و وزن تر و خشك اندام هوايي)، رنگيزههاي فتوسنتزي (كلروفيل a، كلروفيلb، كارتنوئيد و كلروفيل كل)، فعاليت آنتياكسيداني، فنل كل و محتواي اسانس بودند. نتايج مقايسه ميانگين داده‌ها نشان داد كه با افزايش غلظت اتانول اكثر خصوصيات رشدي گياه افزايش يافت همچنين كاربرد دياكسيدكربن در سطح 700 پيپيام بيشترين تاثير را در افزايش خصوصيات رشدي برجاي گذاشت. كاربرد 700 پيپيام دياكسيدكربن و محلولپاشي 20 درصد حجمي اتانول بهترتيب موجب افزايش 18/72، 01/74 و 33/71 درصدي كلروفيل a، كلروفيل b و كلروفيل كل نسبت به سطح 380 پيپيام دياكسيدكربن و عدم محلولپاشي اتانول شد. همچنين نتايج نشان داد كه بيشترين فعاليت آنتياكسيداني (8/93 درصد) و فنل كل (28/5 ميليگرم در گرم وزن تر برگ) در سطح 700 پيپيام دياكسيدكربن و محلولپاشي 20 درصد اتانول مشاهده شد. بيشترين محتواي اسانس نيز در سطح 1050 پيپيام دياكسيدكربن و محلول‌پاشي 30 درصد حجمي اتانول حاصل شد. نتايج اين آزمايش نشان داد كه كاربرد دياكسيدكربن و اتانول با تاثير بر متابوليت گياهي و بهبود فتوسنتز ميتواند بر خصوصيات مورفوفيزيولوژيكي گياه ريحان تاثيرگذار باشد؛ بطوريكه براي رسيدن به بيشترين عملكرد كاربرد سطح 700 پيپيام دياكسيد كربن و 20 درصد حجمي اتانول پيشنهاد ميشود.

Introduction The side effects of chemical drugs have resulted in more attention from humans to use medicinal plants and their extract ingredients to treat many diseases. Basil (Ocimum basilicum) is a medicinal plant from the Lamiaceae family that is used in the food and cosmetic industries. Due to the serious problems in the past decades resulting in the excessive application of chemical inputs and plant growth regulators to enhance agricultural production, nowadays, the need for new technologies to produce safe food and protect the environment has been of great interest to the international community. In this regard, the application of alcohols, especially ethanol and methanol solutions, to improve the performance of plants in the agricultural systems is important. The use of foliar application of methanol and ethanol on the aerial parts of different plants propound as one of the newest strategies to increase growth and their yield. Short-term exposure to elevated CO2 for plants generally leads to an increase in the rates of leaf-level photosynthesis due to enhance the activity of ribulose-1.5-bisphosphate carboxylase/oxygenase (Rubisco). The response to elevated CO2 results in an increase in leaf area, biomass accumulation, or individual plant size. Materials and Methods To study the morphophysiological response of basil cv. keshkeni luvelou under CO2 and ethanol nutrition, a pot experiment was conducted at the research greenhouse of Ferdowsi University of Mashhad as factorial based on a completely randomized design with three levels of CO2 (380, 700, and 1050 mg/L) and four levels of ethanol foliar application (0, 10, 20 and 30 %v/v) in three replications in 2019. The studied traits were included growth characteristics (plant height, number of branches, stem diameter, internode distance, and fresh and dry weight of the aerial part) and photosynthetic pigments (chlorophyll a, chlorophyll b, carotenoid, and total chlorophyll), antioxidant activity, total phenol, and essential oil content. Statistical analysis was performed using Minitab 17 software. The mean comparison was done by the Bonferroni test at the 5% probability level. The figures drew by Microsoft excel software. Results and Discussion The results of the mean comparisons showed that, with increasing ethanol concentration, the growth characteristics of the plant increased, and also the application of 700 mg/L carbon dioxide was able to increase the growth characteristics of the plant. Application of 700 mg/L CO2 and foliar application of ethanol (20%v/v) increased chlorophyll a, chlorophyll b, and total chlorophyll by 72.18, 74.01, and 71.33%, respectively compared to 380 mg/L CO2 and no ethanol application. The results also showed that the highest antioxidant activity (87.38%) and total phenol (264 mg g fresh leaf weight) higher than control at 700 mg/L CO2 and 20 %v/v ethanol foliar application. The highest essential oil content was observed at 1050 mg/L CO2 and 30%v/v ethanol. The results of this experiment showed that the use of CO2 and ethanol by affecting plant metabolites and improving photosynthesis can affect the morphophysiological characteristics of the basil. Conclusions Based on the results of this experiment, the growth characteristics, photosynthetic pigments, antioxidant activity, total phenol, and essential oil content of O. basilicum cv. Keshkeni luvelu was influenced by CO2 and ethanol. At 700 mg/L CO2 and 20%v/v ethanol application due to the effect on these compounds in improving photosynthesis, the highest growth characteristics were observed. While the highest essential oil content was observed in the highest levels of carbon dioxide and ethanol foliar application. Therefore, according to the results of this study to achieve the highest yield of basil, 700 mg/L CO2 and 20%v/v ethanol application is recommended