تاثیر سطوح مختلف نیترات در محلول‌غذایی برخصوصیات مورفولوژیک و فیزیولوژیک سجافی (chlorophytum comosum)

جهت ارزیابی تاثیر سطوح مختلف نیترات بر شاخص‌های رشدی و فیزیولوژیکی گیاه سجافی (chlorophytum comosum) آزمایشی بر پایه طرح بلوک‌های کامل تصادفی با 4 تیمار و 3 تکرار به اجرا درآمد. تیمارها شامل چهار سطح مختلف نیترات 2/5 (به‌ عنوان شاهد)، 5، 7/5 و10 میلی‌‎مولار بود که از نیترات آمونیوم، نیترات کلسیم و نیترات پتاسیم به منظور تامین منبع نیترات در محلول‌غذایی استفاده گردید. محلول‌دهی دو بار در هفته انجام شد. صفات مورد بررسی شامل ویژگی های مورفولوژیک (ارتفاع، تعداد برگ، وزن‌ گلدان، وزن ‌تر ‌اندام ‌هوایی، وزن‌ خشک ‌اندام ‌هوایی، وزن ‌تر ‌ریشه، وزن‌ خشک‌ ریشه، عمق ‌ریشه، حجم ‌ریشه، طول ریشه، سطح‌ برگ) و ویژگی های فیزیولوژیک (کلروفیل کل، مقدار ‌پروتئین موجود در بافت، مقدار نیترات موجود در بافت و میزان پرولین) اندازه‌گیری شد و همچنین آنالیز بسترکشت پیش از شروع آزمایش انجام شد. بیشترین میزان ارتفاع، تعداد برگ، وزن ‌‌تر ‌اندام ‌هوایی، وزن‌ خشک ‌اندام ‌هوایی، وزن‌ خشک‌ ریشه، سطح‌ برگ‌ و حجم‌ ریشه در غلظت 7/5 میلی‌مولار نیترات مشاهده گردید. با افزایش سطوح نیترات مقدار پروتئین موجود در بافت، نیترات موجود در بافت، نیترات موجود در زهاب، کلروفیل کل و پرولین افزایش یافت. با توجه به نتایج بدست آمده تیمار 7/5 میلی‌مولار نیترات، موجب افزایش شاخص‌های رشد، عملکرد و افزایش جنبه زینتی گیاه سجافی به عنوان یک گیاه برگ زینتی گردید.

influence of different nitrate levels of nutrient solution on morphological and physiological characteristics of spider plant (chlorophytum comosum)

introduction: the spider plant (chlorophytum comosum) is cultivated mainly as an ornamental plant for its variegated leaves. this is a perennial rhizomatous plant with often short and indistinct rhizomes, while having thicker or slightly fleshy roots. the roots of these species are one of the important phytochemical components. the use of chlorophytum comosum as a contaminant accumulator has also been previously documented in the literature. this plant is a soil softener that can absorb lead, cadmium, selenium and arsenic while its leaves accumulate mercury. it is also able to absorb toxic organic pollutants such as formaldehyde and benzene and is also able to retain co2. leaf surface morphology has been shown to affect the ability of a particular plant to retain contaminants. chlorophytum comosum was introduced as a plant requiring high nitrogen. nitrogen is an essential macro element for plant growth that is involved in many physiological reactions and is one of the elements that the plant needs in all its activities. the effect of nitrogen form on plant growth depends on plant species and soil nitrogen levels. plants absorb both ammonium (nh4 +) and nitrate (no3-) from the soil solution, and these two minerals are their most important sources of nitrogen. most plants seem to have the best performance in a certain ratio of nitrate to ammonium.  this ratio seems to regulate the distribution of absorbed nitrogen between the branches and roots. it may also vary between species. the optimal ratio may also depend on environmental conditions such as ph, light intensity and root zone temperature. this study was conducted to determine the effect of different levels of nitrate on growth and yield factors and the ornamental aspect of the spider plant as an ornamental product. the use of nitrate increases the yield and quality of these plants. however, despite the importance of the nitrogen in the performance of this ornamental plant (chlorophytum comosum), the desired amount of nitrogen for its growth and quality has not yet been reported. therefore, the present study was conducted to investigate the effect of different levels of nitrate on the growth and physiological characteristics of spider plant to find the best level of application of nitrate fertilizer as an easily available source to increase the growth and visual quality of this plant.material and methods: in order to evaluate, the effect of different levels of nitrate in nutrient solution on the morphological and phytochemical characteristics of spider plant (chlorophytum comosum), an experiment was conducted based on randomized complete block design (rcbd) with four treatments and three replications. treatments including four levels of nitrate of 2.5 (control), 5, 7.5, 10 mm were considered in nutrient solution by the source of ammonium nitrate, calcium nitrate and potassium nitrate. nutrient solutions were applied in the form of fertigation twice a week. desired factors such as morphological characteristics (plant height, leaf number, pot weight, fresh weight, dry weight, root fresh weight, root dry weight, root depth, root volume, root length, leaf area) and physiological characteristics (total chlorophyll, total protein, shoot nitrate and proline) were measured. soil analysis was performed before starting of the experiment.results and discussion: the results indicated that the application of nitrate fertilizer significantly improved most of the studied traits. supplying nitrate fertilizer at desired level meet the nitrogen demand of spider plant during the growth and improved production of further biomass. maximum height, leaf number, shoot fresh and dry weight, root fresh and dry weight, root volume, root length and leaf area observed in 7.5 mm of nitrate level. the amount of protein, shoot nitrate, nitrate drainage water, total chlorophyll and proline were increased by increasing nitrate level of the supplied solution.