Physiological and Anatomical Studies on the Bending in Rose and Gerbera Cut Flowers Treated With Silver Nanoparticles and Thyme Oil

Abstract

Bent neck or stem bending is the most essential problem of some cultivars of rose and gerbera cut flowers in the postharvest stage, as it decreases vase life as well as its commercial value. This research was conducted to evaluate the effectiveness of silver nanoparticles (SNPs) at 9 mg/l, 0.2 ml/l thyme oil and 200 mg/l 8-hydroxyquinoline sulfate (8-HQS) as holding solutions and 20 mg/l silver nanoparticles as a pulsing solution compared to distilled water (control) in delaying bent neck in Rosa hybrida cv. Avalanche and stem bending in Gerbera jamesonii cv. Julia cut flowers (these are more cultivars sensitive to bending). Our results indicated a positive effect of SNPs and thyme oil on delaying the bent neck and decreasing bacterial counts. The flowers placed in 9 mg/l SNPs significantly delayed the bending, reduced the number of bacteria, improved water relations, maintained a higher lignin percentage, and extended longevity in both flowers compared to control and other treatments. The results of scanning microscopy pictures of the bending area indicated that 9 mg/l SNPs prevented vessel blockage and maintain anatomical structures such as epidermis cells, parenchyma cells, and vascular bundles in both cut rose and gerbera flowers. The results indicated that SNPs are superior to thyme oil in improving the quality, prolonging vase life, and delaying the bending of rose and gerbera cut flowers.