تاثیر محلول‌پاشی آسکوربیک‌اسید بر عملکرد دانه و برخی صفات بیوشیمیایی گیاه کینوا (chenopodium quinoa wild) تحت شرایط تنش کم‌آبی

به منظور بررسی اثر آسکوربیک اسید بر عملکرد دانه و برخی خصوصیات بیوشیمیایی گیاه کینوا تحت شرایط تنش کم آبی آزمایشی به صورت کرت های خرد شده در قالب طرح بلوک های کامل تصادفی با سه تکرار در سال‌های 1399 و 1400 در ایستگاه مرکز تحقیقات و کشاورزی و منابع طبیعی کرمان اجرا شد. عامل اصلی شامل سه سطح تیمار آبیاری (آبیاری تا مرحله رسیدگی کامل (شاهد)، آبیاری تا شروع مرحله گلدهی و آبیاری تا شروع مرحله خمیری) و عامل فرعی شامل دو سطح محلول پاشی آسکوربیک اسید (صفر و 2 میلی مولار) بود. سال و اثرات متقابل آن با هر دو عامل روی کلیه صفات تاثیر معنی داری نداشت. اثر عامل آبیاری و آسکوربیک اسید و اثر متقابل آن ها بر کلیه صفات غیر از اثر عامل آبیاری بر محتوای کاروتنوئیدها و اثر متقابل بر عملکرد دانه و محتوای کربوهیدرات معنی دار بود. تنش کم‌آبی (آبیاری تا شروع مرحله گلدهی و آبیاری تا شروع مرحله خمیری) سبب کاهش عملکرد دانه، محتوای رنگیزه های فتوسنتزی، پروتئین برگ، محتوای نسبی آب و افزایش محتوای کربوهیدرات و پرولین شد. عملکرد دانه تحت شرایط آبیاری تا شروع مرحله گلدهی و آبیاری تا شروع مرحله خمیری نسبت به شرایط کنترل به ترتیب 40.5 و 18.7 درصد کاهش داشت. صرف نظر از عدم اختلاف معنی‌دار بین تیمارهای آبیاری و محلول‌پاشی آسکوربیک اسید در صفت عملکرد دانه، محلول پاشی با آسکوربیک اسید منجر به بهبود صفات بیوشیمیایی و عملکرد دانه در هر سه تیمار آبیاری شد. عملکرد دانه با محلول پاشی آسکوربیک اسید 22.7 درصد افزایش نشان داد. از آن جایی که محلول پاشی با آسکوربیک اسید سبب بهبود عملکرد دانه شده است، استفاده از این ماده برای جبران آسیب های وارده در نتیجه تنش خشکی به گیاه کینوا پیشنهاد می شود.

the effect of ascorbic acid foliar application on grain yield and some biochemical traits of quinoa (chenopodium quinoa wild) under water stress conditions

in order to investigate the effect of ascorbic acid on seed yield and some biochemical characteristics of quinoa plant under drought stress, the experiment was implemented in the form of split plots based on randomized complete blocks design with three replications in 2019 and 2019 at the station research, agriculture and natural resources center of kerman. the main factor included three levels of irrigation treatment (irrigation until the full ripening stage (control), irrigation until the beginning of the flowering stage, and irrigation until the beginning of the pulp stage) and the secondary factor included two levels of ascorbic acid foliar spraying (0 and 2 mm). year and its interactions with both factors had no significant effect on all traits. the effect of irrigation factor, ascorbic acid and their interaction on all traits were significant except for the effect of irrigation factor on carotenoids content and interaction effect on grain yield and carbohydrate content. drought stress (irrigation until the beginning of the flowering stage and irrigation until the beginning of the pulp stage) caused a decrease in grain yield, the content of photosynthetic pigments, leaf protein, relative water content and an increase in carbohydrate and proline content. the seed yield under the conditions of irrigation until the beginning of the flowering stage and irrigation until the beginning of the pulp stage was reduced by 40.5% and 18.7%, respectively, compared to the control conditions. regardless of the lack of significant difference between irrigation and ascorbic acid foliar treatments in trait of seed yield, foliar application with ascorbic acid led to the improvement of biochemical traits and seed yield in all three irrigation treatments. seed yield increased by 22.7% with ascorbic acid foliar spraying. since foliar spraying with ascorbic acid has improved grain yield, it is suggested to use this substance to compensate for the damage caused to quinoa plant as a result of drought stress.materials and methods: in order to evaluate ascorbic acid effect on grain yield and some biochemical traits (photosynthetic pigments content, relative water content and leaf protein, carbohydrate and proline contents, total phenol content and total flavonoid content) of quinoa plant under water deficit stress conditions, an experimental in the form of split plots based on the randomized complete block design with three replications in two years at research and agriculture and natural resources center kerman was performed. the main factor included three levels of irrigation treatments (irrigation to the full maturity stage (control), irrigation to the beginning of the flowering stage, and irrigation to the beginning of the dough development stage) and the secondary factor included two levels of ascorbic acid foliar spraying (0 and 2 mm).  results and discussion: ascorbic acid is one of the most important and well-known water-soluble antioxidants in plants. the effect of irrigation factor and ascorbic acid and their interaction on seed yield and most of the measured physiological traits were significant. water stress decreased grain yield, content of photosynthetic pigments, leaf protein content and relative water content and increased carbohydrate and proline content. the seed yield decreased by 40.5% and 18.7% under the conditions of irrigation to the beginning of the flowering stage and irrigation to the beginning of the dough development stage, respectively, compared to the control conditions. foliar spraying with ascorbic acid led to the improvement of physiological traits and grain yield in all three irrigation treatments. seed yield increased by 22.7% with ascorbic acid solution. since foliar spraying with ascorbic acid improved seed yield in three irrigation treatments, it is suggested to use this substance to compensate for the damage caused to quinoa plant as a result of drought stress. conclusions: water deficit stress caused damage to physiological traits and subsequently reduced grain yield in quinoa plant, which indicates oxidative damage in these conditions. foliar spraying with ascorbic acid led to the improvement of physiological traits such as photosynthetic pigments, relative water content and leaf protein, carbohydrate and proline contents in all three irrigation treatments, followed by quinoa seed yield, which shows the positive effect of this solution in reducing the harmful effects of oxidative stress.