In recent years, due to the phenomenon of climate change, the cultivation of ornamental plants outdoors and even in the greenhouse environment has been associated with many challenges, and at present, the best solution to manage environmental damages and stresses will be the use of resistant cultivars and anti-stress nutritional supplements. Zinnia elegans, a plant that tolerates intense light, moderate soils in terms of nutrients and low moisture requirements, is suitable for outdoor cultivation. The present study was conducted in two studies in the presence of genotype and nano-silica agents. In the first study, 11 genotypes of Ahar were sprayed with nano-silica at a concentration of 2%. Morphological and physiological traits and postharvest indices were measured 1 week after the end of treatment. The results showed that genotype had a direct effect on increasing morphological traits such as number of flowering stems, number of leaves per flowering stem, and number of nodes per flowering stem, and traits such as inflorescence diameter, flowering stem diameter, flowering stem length, fresh and dry weight of flowering stem, and bud quality were improved under the influence of both genotype and nano-silica treatments. In relation to physiological traits, the application of nano-silica treatment improved the yield of traits such as total chlorophyll by 39.9%, carotenoid by 2-fold, anthocyanin by 8.18%, carbohydrate by 38.39%, sising index by 31.6% and relative water content by 48.7%. Postharvest indices such as flower lifespan, relative water content of flowers, and spectroscopy indices also increased, while the amount of ion leakage decreased in the nano-silica treatment, and along with other mentioned factors, increased the shelf life of cut flowers. The second study was performed on 5 superior genotypes from the previous cultivation under the influence of two factors. In this study, biomechanical traits were eva‎luated. Nano-silica treatment increased leaf area, fluff length, stomata area and cell wall thickness, cell wall thickness increased by 1.8 times due to the application of nano-silica and among biomechanical traits, it was more affected by this treatment. It should be noted that genotype 2 studies showed high performance due to the application of nano-silica and it can be said that this genotype is the best option for the production of cut flowers in the open space among the genotypes of Ahar plant in this study.

علي نيك بخت

نعمت اله اعتمادي شلمزاري , محمدحسين اهتمام

محمدرضا سبزعليان دستجردي , مريم حقيقي