تاثیر برخی هورمون‌ها و غلظت‌های نانولوله کربنی در بهینه‌سازی کالوس‌زایی زعفران

به منظور بهینه‌سازی کالوس‌زایی زعفران در غلظت‌های مختلف هورمونی در شرایط حضور نانولوله‌های کربنی، آزمایشی در قالب روش‌شناسی سطح پاسخ در آزمایشگاه بیوتکنولوژی دانشگاه آزاد اسلامی واحد سبزوار انجام شد. صفات مورد بررسی شامل تعداد کالوس، قطر کالوس، وزن کالوس، درصد القا کالوس و فاکتورها شامل غلظت‌های هورمون 2-4-d (0.5 -2 میلی‌گرم در لیتر)،bap (0- 1.5 میلی‌گرم در لیتر) و غلظت‌های نانولوله کربنی چند جداره (0-50 میکروگرم در میلی‌لیتر) در این آزمایش بودند. نتایج برازش مدل رگرسیونی نشان داد که تابع درجه دو برازش مناسبی برای تعداد کالوس، قطر کالوس، وزن تر کالوس و درصد کالوس‌زایی بود. بیشترین درصد کالوس‌زایی در غلظت 0.5 میلی مولار2-4-d و 25میلی‌گرم نانولوله کربنی مشاهده شد. در غلظت‌های پایین 2-4-d، افزایش مقدار نانولوله کربنی سبب کاهش درصد القاء کالوس اما در غلظت‌های بالای 2-4-d سبب افزایش درصد القاء کالوس شد. تغیرات تعداد، وزن و قطر کالوس در برابر غلظت‌های مختلف 2-4-d و bap تقریبا مشابه بود، به نحوی که هم در غلظت‌های پایین و هم در غلظت‌های بالا افزایش غلظت bap سبب افزایش صفات مورد بررسی شد. تعداد، وزن و قطر کالوس با افزایش غلظت نانولوله‌های کربنی در حضورbap افزایش نشان داد. در مجموع نتایج بهینه‌سازی آزمایش نشان داد که بالاترین قطر کالوس( 18.81 میلی‌متر، وزن کالوس 0.26 میلی‌گرم و القاء (کالوس 91.92%) در شرایط مصرف 0.5 میلی‌مولار 2-4-d  ، 1.5 میلی‌مولار bap،28.94 میلی‌گرم نانولوله کربنی چند جداره مشاهده شد.

effect of some hormones and carbon nanotube concentrations on optimizing saffron callus formation

introduction: saffron, a member of the lily family, is highly valued for its low water requirements, potential for job creation, and medicinal properties. despite the high costs associated with traditional saffron cultivation, the use of tissue culture is recommended to enhance cultivation practices and produce disease-free seedlings. in vitro cultivation can significantly boost the production rate of new seedlings, with success largely dependent on the hormonal composition used. additionally, carbon nanotubes, which have various applications in biology, have demonstrated a positive impact on plant growth. this study employs the response surface methodology (rsm) to optimize the saffron culture medium with carbon nanotubes and to identify the appropriate hormonal composition. materials and methods: this research was conducted using in vitro culture techniques and a rsm design, comprising four replications. the factors investigated included concentrations of 2,4-d (0.2-0.5 mg/l), bap (1.5-6 mg/l), and multi-walled carbon nanotubes (30-70 μg/ml). the culture medium and equipment were sterilized in an autoclave at 120°c and 1.5 atmospheres. pedicel shells were removed, washed, and then immersed in vitex solution for 30 minutes. the explants were placed in culture dishes and maintained under controlled light and temperature conditions. after five weeks, callus induction characteristics, such as callus induction percentage, diameter, and fresh weight, were measured. the box-benken statistical design was utilized for data analysis, and necessary transformations were applied based on software recommendations. a quadratic function was generally selected for the fitted model, even in cases of non-significance, and response surface curves along with contour diagrams were used to interpret the interaction effects of the traits. tissue culture optimization aimed at maximizing callus formation, fresh weight, and diameter, with the highest model fitness identified as the optimal environmentresults and discussion: the study’s findings indicated that the concentrations of nanocarbon and 2,4-d significantly affected the number of calluses produced. at lower concentrations of 2,4-d, increasing bap resulted in a higher number of calluses, while at higher concentrations, this effect remained positive. the maximum number of calluses was achieved with specific combinations of 2,4-d and bap concentrations. high levels of bap and carbon nanotubes increased the callus production percentage to 174%, whereas at lower concentrations, it was below 85%. the ratios exhibited a saddle function, with the highest number of calluses observed at low concentrations of 2,4-d and nanocarbon. additionally, the linear effects of 2,4-d and carbon nanotube concentrations were significant at the 1% level, while the effect of bap was not significant. elevated concentrations of 2,4-d negatively impacted callus diameter, whereas increasing nanocarbon at high concentrations contributed to an increase in diameter. ultimately, raising the concentration of 2,4-d led to an increase in callus induction percentage from 79.68% to 92.185%, although high concentrations had a detrimental effect. the highest callus induction percentage was noted with a specific combination of 2,4-d and carbon nanotubes. conclusion: the experimental results demonstrated that carbon nanotubes and the hormones bap and 2,4-d significantly influenced saffron callus induction. high concentrations of 2,4-d exhibited the most substantial effect on the number of calluses produced. furthermore, the application of bap hormone up to a certain concentration increased callus number, but higher concentrations resulted in a decrease. finally, the percentage of callus induction was positively affected by carbon nanotubes, while other characteristics did not show significant effects