تاثیر نوع محیط کشت بر زیست‌توده، غلظت عناصر غذایی و محتوی پروتئین آزولا، و کاربرد عصاره آن در تغذیه فلفل دلمه‌ای

عصاره آزولا ترکیبی تجزیه‌پذیر و غنی از عناصر غذایی و ترکیب شیمیایی و بدون ترکیبات آلوده‌کننده محیط زیست است، بنابراین در سال‌های اخیر تبدیل آزولا به کود آلی محرک رشد گیاه مورد توجه قرار گرفته است. در این پژوهش تاثیر ترکیب شیمیایی محیط کشت بر عملکرد و ترکیب شیمیایی آزولا فیلیکلوئیدس و آزولا کارولینیانا و کاربرد عصاره آزولا به‌عنوان کود آلی در محیط کشت فلفل دلمه‌ای مورد بررسی قرار گرفته است. این پژوهش در مرکز پژوهشی روابط خاک و گیاه دانشگاه صنعتی اصفهان انجام گرفت. نتایج نشان داد تیمارهای محیط کشت آزولا تاثیر معنی‌داری (p<0.05) بر غلظت آهن و روی دو گونه آزولا داشته‌اند. همچنین تیمار افزایش 20% گوگرد و فسفر به محیط کشت آزولا غلظت آمینواسیدهای آلیفاتیک و آروماتیک دو گونه آزولا را به‌طور معنی‌داری نسبت به شاهد افزایش داده است. از سوی دیگر نتایج مطالعه دوم نشان داد تیمارهای کاربرد 5 و 10 درصد عصاره آزولا در محیط کشت جانسون و نیم‌جانسون بیش‌ترین عملکرد میوه و غلظت آهن، روی و پروتئین را در میوه، شاخصاره و ریشه فلفل دلمه‌ای نشان داده‌اند اگر چه تنها در برخی موارد این افزایش از لحاظ آماری معنی‌دار (p<0.05) بود. به‌طور کلی، ترکیب محیط کشت آزولا ممکن است بر کمّیت و کیفیت آزولا تاثیرگذار باشد و کاربرد عصاره غنی آزولا می‌‌تواند موجب غنی‌سازی زیستی در فلفل دلمه‌ای شود.

effect of azolla culture medium on biomass, nutrient and protein concentrations of azolla and its application as a nutrient supply for bell pepper

abstractazolla extracts are biodegradable and non-polluting to the environment, and because of its unique composition, it was subjected to integrated bio­­refineries for organic fertilizer and plant growth stimulants production. here we investigated the effect of media culture on productivity and chemical composition of azolla filiculoides and azolla caroliniana and then application of azolla extract as an organic fertilizer. this research was conducted in the two studies at the soil-plant interaction research center of isfahan university of technology. the azolla culture media treatments showed significant effect (p < 0.05) on azolla iron and zinc concentration. in the both azolla species, addition of 20% of sulfur and phosphorus to the culture media significantly increased concentrations of nitrogen and acidic, alkaline, polar, aromatic and aliphatic amino acids. in the second study, johnson and half johnson media contained 5% and 10% azolla extract showed highest fruit yield (i.e., fresh and dry weights) and concentrations of iron, zinc and nitrogen in the fruit, shoot and root of bell pepper, in which some of them were significant (p < 0.05). in total, our results showed that azolla culture media composition may change quality and quantity of the azolla extract and application of the extract may led to biofortification of bell pepper significantly.background and objective: micronutrient malnutrition or hidden hunger remains a major global challenge for human health and wellness. being free floating aquatic plants, azolla can be produced independently of arable lands. the aquatic fern azolla is a special case among free-floating aquatic plants because it has evolved a symbiosis with the cyanobacterium nostoc azollae, which fixes atmospheric nitrogen (n2). azolla ferns occur across many continents and across various climates. using azolla extract as a biofertilizer to replace artificial nitrogen fertilizer reduces pollution by nitrogen losses of various cultivation and provides added value to farmers (brouwer, 2017; brouwer et al., 2018). here, we investigated the effect of media culture on productivity and chemical composition of azolla filiculoides and azolla caroliniana and then application of azolla extract as an organic fertilizer.methods: we tested two hypotheses: 1) azolla culture medium could affect biomass, nutrient and protein concentrations of azolla, and 2) azolla extract application may improve fruit quality and cover some required nutrients of plant. the treatments of first study included a) irri2 culture media (the standard azolla medium) (control), b) irri2 culture media + 10% extra sulfur concentration, c) irri2 culture media + extra 20% sulfur concentration, d) irri2 culture media + 10% extra phosphorus concentration, e) irri culture medium + 20% extra phosphorus concentration, f) irri2 + 10% sulfur + 20% phosphorus concentration, and g) irri2 + 20% extra sulfur + 20% extra phosphorus concentrations. the second study treatments were a) johnson media (control), b) johnson media + 5% azolla extrat, c) johnson media + 10% azolla extrat, d) half johnson media + 5% azolla extract, and e) half johnson media + 10% azolla extract. analysis of variance, comparison of the azolla culture media and application of the extract in bell pepper growing media were done by completely randomized design with a one-way treatment structure using sas 9.0 software.results: the results of the first study showed that the highest concentrations of iron and zinc in the third generation of azolla filiculoides were detected in the irri2 + 10% sulfur + 20% phosphorus culture media and the highest concentrations of zinc in the first and third generation of azolla caroliniana and the first generation of azolla filiculoides were detected in the irri2 + 20% sulfur culture media. the irri2 + 20% sulfur + 20% phosphorus culture media treatment increased concentrations of nitrogen and acidic, alkaline, polar, aromatic and aliphatic amino acids in the both azolla species. although, the highest dry weight yield of the both azolla species was observed in the irri2 + 10% phosphorus treatment. in the second study, johnson and half johnson media contained 5% and 10% azolla extract showed highest fruit yield (i.e., fresh and dry weights) and concentrations of iron, zinc and nitrogen in the fruit, shoot and root of bell pepper, in which some of them were significant (p < 0.05).conclusions: the fast-growing, nitrogen fixing, aquatic fern azolla could be a promising novel crop for the production of organic and eco-friendly fertilizer, due to its high protein content, favorable amino acid profile and micronutrient contents. references:1. brouwer, p., 2017. turning the aquatic weed azolla into a sustainable crop. phd thesis, utrecht university, the netherlands.2. brouwer, p., schluepmann, h., nierop, k.g.j., elderson, j., bijl, p.k., van der meer, i., de visser, w., reichart, g.j., smeekens, s., van der werf, a., 2018. growing azolla to produce sustainable protein feed: the effect of differing species and co2 concentrations on biomass productivity and chemical composition. j. sci. food agric. 98, 4759–4768. https://doi.org/10.1002/jsfa.9016.