پاسخ‌ های رشدی، فیزیولوژیکی و کارآیی مصرف آب گیاه بادمجان به محلول‌پاشی ال - سیستئین و لاکتات کلسیم تحت شرایط کم آبیاری

به‌ منظور بررسی اثر تنش کم‌ آبیاری بر رشد و شاخص ‌های فیزیولوژیکی بادمجان (solanum melongena cv. greta rz) آزمایشی به صورت کرت‌‌‌های خرد شده در قالب طرح بلوک‌ها‌ی کامل تصادفی در سه تکرار در دانشگاه زنجان در طی سال 1400 انجام شد. تیمارهای آزمایش شامل آبیاری در سه سطح 60، 80 و 100 درصد نیاز آبی گیاه و تیمار محلول‌پاشی در پنج سطح شامل دو سطح لاکتات‌کلسیم (1 و 2 گرم در لیتر)، دو سطح ال-سیستئین (0/15 و 0/5 درصد) و آب مقطر به عنوان شاهد بود. نتایج نشان داد که تنش کم‌آبیاری به طور معنی‌داری رشد، شاخص های فیزیولوژیکی و کارایی مصرف آب را تحت تاثیر قرار داد. کاربرد لاکتات کلسیم و اسید‌آمینه سیستئین به طور فزاینده ای رشد بوته، شاخص های فیزیولوژیکی و کارایی مصرف آب را در شرایط آبیاری بهینه و کم‌آبیاری بهبود بخشید. بیشترین ارتفاع بوته، سطح برگ، هدایت روزنه ای، محتوای نسبی آب برگ و عملکرد میوه در بوته در گیاهان تیمار شده با لاکتات کلسیم 2 گرم در لیتر تحت آبیاری 100 درصد حاصل شد که با تیمارسیستئین 0/5 درصد تفاوت معنی داری نداشت. بیشترین مقدار پرولین و کارایی مصرف آب به ترتیب در بوته‌های تیمار شده با لاکتات کلسیم 2 گرم در لیتر و سیستئین 0/5درصد تحت آبیاری 60 درصد حاصل شد. با توجه به نتایج حاضر، کاربرد لاکتات کلسیم 2 گرم در لیتر و یا سیستئین 0/5 درصد به صورت جداگانه جهت بهبود شاخص های رشدی و فیزیولوژیکی و کارایی مصرف آب گیاه بادمجان در شرایط آبیاری بهینه و کم آ‌بیاری پیشنهاد می‌شود.

growth, physiological responses and water use efficiency of eggplant to foliar spray of l-cysteine and calcium lactate under deficit irrigation condition

water stress is the most prominent abiotic stress limiting agricultural crop growth and productivity. deficit irrigation stress as a consequence of the progressive decrease in water availability has been a hot topic regarding food security during the last two decades. growth and development of plants are influenced by reduction in turgor that results in decreased nutrient acquisition from dry soil. due to the threat of climate change, there is a need to limit the use of water resources in arid and semi-arid climates. it is therefore important to find new approaches to avoid crop productivity losses in ‘limited fresh-water’ areas. eggplant (solanum melongena) is an important non-climacteric fruit grown in tropical and subtropical regions. the estimated total world production for eggplants in 2019 was 51287210 tons. foliar application of agro-chemicals has widely been used in agriculture as a rapid, low-cost and effective way for enhancing growth and productivity of many vegetable crops under water deficit conditions. ca is an essential macronutrient for plant growth and development, and is considered as an important intracellular messenger, mediating responses to hormones, stress signals and a variety of developmental processes. amino acids are important bio-regulators which have promotive effects on plant growth and productivity. cysteine is the precursor molecule of glutathione, the predominant non-protein thiol, which plays an important role in plant stress responses.2.materials and methods: the field experiment was carried out at the research farm of agriculture faculty, university of zanjan, iran, during 2021. the experiment was performed using a split plot based on a randomized complete blocks design with three irrigation regimes (60, 80 and 100 %etc) as the main plot and foliar spray of two levels of calcium lactate (cal) (1 and 2 g l-1) and l-cystein (cys) (0.15 and 0.5 %) as the sub-plot in three replicates. distilled water was used as a control. eggplant (cv. greta rz) seedlings were transplanted at the 4-5 leaf stage with 35 cm spacing within row and 100 cm spacing between rows. after plant establishment, eggplants were sprayed with different concentrations of cal and cys at 6-7 leaf stage. second and third times of foliar application were performed at 10 and 20 days after the first spraying. irrigation treatments were applied one week after the first spraying. number of branch per plant, plant height and leaf area were measured as growth parameters in harvest stage. total chlorophyll and carotenoid contents, proline, leaf relative water content, stomatal conductance and electrolyte leakage were measured as physiological characteristics. also plant fruit yield and water use efficiency (wue) were evaluated.3.results and discussion: as the results showed, plant growth, physiological indices and wue significantly affected by deficit irrigation. water deficit stress significantly reduced plant length, leaf area and chlorophyll content, and increased carotenoid content. decreased plant growth may be due to limited cell division, cell enlargement due to turgor loss, and inhibition of various growth metabolites. foliar spray of cal and cys improved plant growth, fruit yield and physiological indices. leaf relative water content (lrwc) is among the main physiological criteria affecting plant water relations and have been used for assessing drought tolerance. based on the findings, deficit irrigation caused a significant reduction in lrwc and stomatal conductance, which is due to the reduction of leaf water potential and the decrease of root water absorption rate under drought conditions.