پديد آورندگان :
محمدي، ميثم دانشگاه زنجان - دانشكده كشاورزي - گياهان زينتي، زنجان، ايران , اعلائي، ميترا دانشگاه زنجان - دانشكده كشاورزي - گروه علوم باغباني، زنجان، ايران , صيدي، مهدي دانشگاه ايلام - دانشكده كشاورزي - گروه علوم باغباني
چكيده فارسي :
تيمار محلول‌هاي نگهدارنده گل‌هايبريده با مواد باكتري‌كش يكي از راه‌هاي كاهش انسداد آوندي و افزايش عمرگلجايي مي‌باشد. در اين پژوهش عصاره آبي-الكلي گياه اسپند در غلظت‌هاي صفر، 25/0، 5/0، 75/0 و 1 درصد به مدت 3، 6 و 9 روز در دماي 1±22 درجه سلسيوس و رطوبت نسبي 70 درصد بر جمعيت باكتري‌هاي محلول نگهدارنده و برخي خصوصيات كيفي رقم‌هاي ‘Stanza’ و ‘Pink Elegance’ گل بريده ژربرا به‌صورت آزمايش فاكتوريل بر پايه طرح كاملاً تصادفي با چهار تكرار در بهار سال 1397 در دانشگاه ايلام مورد مطالعه قرار گرفت. نتايج نشان داد كه اثر بازدارندگي عصاره‌ها بر رشد باكتري‌هاي گرم مثبت بيشتر از باكتري‌هاي گرم منفي بود و با افزايش غلظت عصاره اسپند، اثر بازدارندگي نيز افزايش يافت. همچنين تحت تأثير تيمارها، رقم ‘Stanza’ نسبت به رقم‘Pink Elegance’از كيفيت بهتر و عمر گلجايي بيشتري برخوردار بود. با افزايش مدت زمان نگهداري گل‌ها، كيفيت آن‌ها كاهش يافت، ولي در مرتبه اول غلظت 25/0 و سپس 5/0 درصد عصاره اسپند علاوه بر كاهش جمعيت باكتري‌ها در محلول گلجايي و انتهاي ساقه، باعث كاهش نشت يوني ساقه و گلبرگ، حفظ كيفيت (تغيير رنگ محلول گلجايي، ساقه و گلبرگ)، وزن تر نسبي، قطر ساقه، مواد جامد محلول و حفظ آنزيم‌هاي كاتالاز و فنيل آلانين آمونيالياز نسبت به نمونه‌هاي شاهد شدند و عمر گلجايي گل‌هاي ژربرا را افزايش دادند. غلظت‌هاي 75/0 و يك درصد اگرچه جمعيت ميكروبي محلول گلجايي و انتهاي ساقه را كاهش دادند ولي در حفظ كيفيت و عمر گلجايي گل‌هاي ژربرا اثر قابل توجهي نداشتند كه مي‌تواند به دليل افزايش غلظت مواد آللوپاتيك در آن‌ها باشد.
چكيده لاتين :
Background and Objectives
Gerbera is one of the important cut flowers in the floriculture industry, but it is sensitive to early wilting and neck bending which reduce its postharvest vase life. In cut flowers, water deficits are created when transpiration is more than water absorption. Therefore, petal wilting and neck bending increase in these flowers. These conditions are mainly due to occlusion of the vascular bundle, which can occur in different ways, such as the activity of pathogenic bacteria and other microorganisms in vascular bundle. In recent years, due to the adverse effects of chemical antimicrobial compounds on human health and the environment, many studies have been conducted to find replacement materials to maintain the quality and vase life of cut flowers in postharvest. Therefore, in this study, the effect of different concentrations of harmel aqueous-alcoholic extract (Peganum harmala L.) on bacterial population and vas life of ‘Stanza’ and ‘Pink Elegance’ cultivars of Gerbera cut flower were studied.
Materials and Methods
The effect of concentrations 0, 0.25, 0.5, 0.75 and 1% of the aqueous-alcoholic extract of Harmel plant was studied in a factorial experiment based on completely randomized design with four replications. At harvest time, 3, 6 and 9 days after harvest (at 20 °C and 70% relative humidity), the effect of treatments on the bacterial population of the vase solution and end stem, vase life and some characteristics of ‘Stanza’and ‘Pink Elegance’ Gerbera cut flowers were studied.
Results
The results showed that the inhibitory effect of harmal extracts on gram-positive bacteria was higher than gram-negative bacteria. Also,‘Stanza’cultivar had better quality and longer vase life than ‘Pink Elegance’ cultivar. By increasing the vase life of flowers, the quality of these flowers decreased. In the first place, however, concentrations of 0.25% and then 0.5% of the harmal extract performed better than other treatments in various aspects: first, they reduced the bacterial solution, stem end, and electrolyte leakagein stem and petals; second, they preserved quality (discolored of vase solution, discolored of petals and stem), relative fresh weight, stem diameter, totalsolublesolids, catalase activity and phenylalanine ammonia lyase activity; and finally, they increased vase life of gerbera flowers in both cultivars. Concentrations of 0.75% and 1% increased allelopathic substances in cut flower. While these treatments decreased the bacterial population in vase solution and stem end, they did not have a significant effect on the quality and vase life of gerbera cut flowers.
Discussion
The results of this study showed that the different concentrations of harmal extract significantly reduced the growth of microbial agents, including the bacterial population, but by increasing the concentration of the harmal extract, the allelopathic effects of this plant extract on gerbera cut flowers were harmful and did not affect their vase life and quality. Therefore, the concentration of 0.25% then 0.5% reduced the bacterial populations in vase solution and stem end of cut flowers and preserved the quality and vase life of ‘Stanza’ and ‘Pink Elegance’ cultivars. Therefore, the use of low concentrations of the harmel aqueous-alcoholic extract is recommended to reduce the microbial population of the vase solution and maintain the quality and vase life of the gerbera cut flowers
