بررسی اثر سالیسیلیک‌اسید بر تعدیل تنش شوری در گوجه‌فرنگی

سالیسیلیک اسید یکی از ترکیبات مفید برای گیاهان محسوب می شود که نقش مهمی در مقاومت گیاهان به تنش های محیطی از جمله تنش شوری دارد. بدین منظور جهت بررسی تاثیر سالیسیلیک ‌اسید در تعدیل اثرات تنش شوری در گوجه‌فرنگی آزمایشی به صورت فاکتوریل در قالب طرح کاملاً تصادفی، با 12 تیمار، در 3 تکرار و با مجموع 36 واحد آزمایشی در گلخانه‌ی هیدروپونیک گروه باغبانی دانشکده کشاورزی دانشگاه تبریز در بهار و تابستان سال 1397 صورت گرفت. تیمارها شامل دو سطح سالیسیلیک ‌اسید (صفر و 1 میلی‌مولار) و سه سطح شوری (صفر ، 35 و 70 میلی‌مولار nacl) بر روی دو ژنوتیپ گوجه‌فرنگی توده محلی بانه و لاین نیمه پاکوتاه (semi dwarf) بود. نتایج نشان داد که با افزایش تنش شوری تا سطح 70 میلی مولار، شاخص‌های رویشی در هر دو ژنوتیپ کاهش یافت. درحالی که برهمکنش تیمار سالیسیلیک‌اسید در تنش شوری باعث افزایش شاخص‌های رویشی شد. بیشترین عملکرد مربوط به ژنوتیپ semi dwarf بدون تنش شوری (1373 گرم) است. با اعمال تنش شوری و سالیسیلیک اسید میزان اسیدیته قابل تیتراسیون و ویتامین ث در هر دو ژنوتیپ افزایش یافت. برهمکنش سطوح مختلف شوری در سالیسیلیک‌اسید باعث افزایش میزان پرولین شد، اما اثر متقابل تنش شوری × سالیسیلیک اسید باعث کاهش میزان کلروفیل شد. این نتایج نشان می دهد که تیمار با سالیسیلیک اسید می تواند تحمل گیاه را در برابر تنش شوری از طریق تجمع پرولین و در نتیجه حفظ فشار تورژسانس سلول ها افزایش دهد.

investigating the effect of salicylic acid on reduce salinity stress in tomatoes

introductionvarious methods of stress directly affected the growth and production yield of numerous plants. for example, environmental stress reduces the tomato manufacturing by the disrupting its natural metabolism, or, salinity stresses affect the it is growth and development from the germination stage to the fruit ripening stage. salinity in tomatoes by stimulating the biosynthesis of growth regulators such as ethylene and abscisic acid leads to the acceleration of the aging of the leaves. therefore, development of different methods to induce salinity stress tolerance in plants is necessary. some approaches were studied to develop the salinity tolerant plants such as genetic breeding, environmental improvements and usage of phytohormones and signal molecules. salicylic acid or orthohydroxybenzoic acid plays an important role in regulating the physiological and biochemical responses of plants to stress conditions, which improves the plant’s resistance to adverse environmental conditions. for instance, salicylic acid is a facile and effective way to increase plant productivity under salt stress conditions. considering the positive effects of salicylic acid in modulating the effects of salinity, this study was conducted with the aim of investigating the effects of salicylic acid’s usage in modulating the harmful effects of salinity on some vegetative, physiological, quantitative and qualitative characteristics of two tomato cultivars of baneh local mass and semi dwarf line.materials and methodsto investigate the effect of salicylic acid in modulating the effects of salinity stress in tomato, a factorial experiment was conducted in the form of a randomized complete block design, with 12 treatments, in 3 replications and with a total of 36 experimental units in the hydroponic greenhouse of the department of horticulture, faculty of agriculture, and university of tabriz. the treatments included two levels of salicylic acid (0 and 1 mm) and salinity levels (0, 35 and 70 mm nacl) on two tomato cultivars of baneh and semi dwarf.results and discussionthe results showed that in baneh and semi dwarf cultivars, the increase in salinity levels caused a decrease in vegetative indices, meanwhile the treatment of salicylic acid along with salt stress increased same indices. also, salt stress caused yield reduction in both baneh and semi dwarf cultivars. by examining the qualitative indicators, it was observed that titratable acidity and vitamin c increased with salt stress and salicylic acid treatment in both cultivars. in terms of physiological indicators, the amount of proline increased at different salinity levels with salicylic acid treatment, but the amount of leaf chlorophyll index decreased with the increase of same condition.conclusionthe results of testing the effect of salicylic acid and the effects of salinity stress on vegetative, quantitative, qualitative and physiological indicators in baneh and semi dwarf tomatoes showed a remarkable difference in terms of significance. in terms of vegetative traits; plant height, leaf area index, shoot wet in baneh and semi dwarf cultivars decreased with increasing salinity levels of vegetative indices, but salicylic acid treatment along with salinity stress increased same indices. indicators such as yield, fresh weight of fruit, and percentage of dry matter of fruit showed different responses to different levels of salinity and salicylic acid treatment. the fresh weight of fruit increased with the application of salicylic acid. also, salt stress caused an increase in the percentage of dry matter of the fruit. but salt stress caused yield reduction in both baneh and semi dwarf cultivars. in terms of quality indicators; the amount of titratable acidity and vitamin c increased with salt stress and salicylic acid treatment in both cultivars. in terms of physiological indicators, the level of proline increased across various salinity levels with salicylic acid treatment. however, the leaf chlorophyll index decreased with rising salinity levels, even in the presence of salicylic acid treatment. overall, salinity stress caused a decrease in most analyzed traits in the baneh and semi dwarf cultivars. nevertheless, it led to improvements in certain quality traits. additionally, salicylic acid treatment enhanced the mentioned indices in most of the examined traits in both cultivars. therefore, considering the positive effects of salicylic acid treatment on baneh and semi dwarf cultivars under salinity stress conditions, its use is recommended.